Treatment of acute coronary syndrome at the prehospital stage. Treatment of Ox at the prehospital stage, modern presentation of Prof. Ox, diagnosis and treatment at the prehospital stage

According to modern concepts, the course of the atherosclerotic process is characterized by periods of exacerbation with destabilization of the atherosclerotic plaque, disruption of the integrity of its covering, inflammation and the formation of a parietal or obstructive plaque.

V. I. Tseluiko, Doctor of Medical Sciences, Professor, Head of the Department of Cardiology and Functional Diagnostics KhMAPO, Kharkov

According to modern concepts, the course of the atherosclerotic process is characterized by periods of exacerbation with destabilization of the atherosclerotic plaque, disruption of the integrity of its covering, inflammation and the formation of a parietal or occlusive thrombus. The clinical manifestation of atherothrombosis is acute coronary syndrome (ACS), including acute myocardial infarction with or without ST segment elevation and unstable angina. In other words, the term acute coronary syndrome refers to a period of illness in which there is a high risk of developing or the presence of myocardial damage. The introduction of the term acute coronary syndrome is necessary, since these patients require not only more careful monitoring, but also a rapid determination of treatment tactics.

The course and prognosis of the disease largely depend on several factors: the volume of the lesion, the presence of aggravating factors such as diabetes mellitus, arterial hypertension, heart failure, old age, and to a large extent on the speed and completeness of medical care. Therefore, if ACS is suspected, treatment should begin at the prehospital stage.

Treatment for ACS includes:

• general measures (urgent hospitalization in the ICU, ECG monitoring, monitoring of diuresis and water balance, bed rest with its subsequent extension after 1-3 days). In the first 1-2 days, food should be liquid or semi-liquid, then easily digestible, low in calories, limiting salt and foods containing cholesterol;
• anti-ischemic therapy;
• restoration of coronary blood flow;
• secondary prevention.

To eliminate pain, nitroglycerin should be used. Its positive effect is associated both with the vasodilating effect of the drug on the coronary vessels and with positive hemodynamic and antiplatelet effects. Nitroglycerin can have a dilating effect on both atherosclerotic and intact coronary arteries, which helps improve blood circulation in ischemic areas.

According to the ACC/AHA recommendations (2002) for the treatment of patients with ACS, it is advisable to use nitroglycerin in patients with a SBP of at least 90 mm Hg. Art. and in the absence of bradycardia (heart rate less than 50 beats per minute) in the following cases:

• during the first 24-48 hours from the onset of MI in patients with heart failure, extensive anterior MI, transient myocardial ischemia and high blood pressure;
• after the first 48 hours in patients with repeated anginal attacks and/or pulmonary congestion.

Nitroglycerin is used sublingually or as a spray. If pain relief does not occur or there are other indications for prescribing nitroglycerin (for example, extensive anterior myocardial infarction), proceed to intravenous drip administration of the drug.

Isosorbide dinitrate can be used instead of nitroglycerin. The drug is administered intravenously under blood pressure control at an initial dose of 1-4 drops per minute. If well tolerated, the rate of administration of the drug is increased by 2-3 drops every 5-15 minutes.

Prescription of molsidomine, according to the results of a large placebo-controlled study ESPRIM (Eurohean Study of Prevention of Infarct with Molsidomine Group, 1994) conducted in Europe, does not improve the course and prognosis of AMI.

Despite the undeniable positive clinical effect of nitrates, unfortunately, there is no data on the beneficial effect of this group of drugs on the prognosis.

The use of β-blockers in the treatment of AMI is extremely important, since this group of drugs not only has an anti-ischemic effect, but is also the main one in terms of limiting the area of ​​necrosis. The area of ​​myocardial infarction largely depends on the caliber of the occluded vessel, the size of the thrombus in the coronary artery, thrombolytic therapy and its effectiveness, and the presence of collateral circulation. There are two main ways to limit the size of the MI and preserve left ventricular function: restoring the patency of the occluded artery and reducing the myocardial oxygen demand, which is achieved through the use of β-blockers. Early use of β-blockers makes it possible to limit the area of ​​necrosis, the risk of developing ventricular fibrillation, early cardiac rupture, and reduce patient mortality. The use of β-blockers in parallel with thrombolysis helps reduce the incidence of a severe complication of thrombolysis - cerebral hemorrhage.

β-Blockers should be prescribed as early as possible if there are no contraindications. Preferable is intravenous administration of the drug, which allows you to more quickly achieve the desired positive effect and, if side effects develop, to stop the supply of the drug. If the patient has not previously taken β-blockers and the response to their administration is unknown, it is better to administer short-acting cardioselective drugs in a small dose, for example metoprolol. The initial dose of the drug can be 2.5 mg intravenously or 12.5 mg orally. With satisfactory tolerability, the dose of the drug should be increased by 5 mg after 5 minutes. The target dose for intravenous administration is 15 mg.

Subsequently, they switch to oral administration of the drug. The first dose of tableted metoprolol is given 15 minutes after intravenous administration. Such pronounced variability in the dose of the drug is associated with the individual sensitivity of the patient and the form of the drug (retarded or not).

Maintenance doses of β-blockers in the treatment of coronary artery disease:

• Propranolol 20-80 mg 2 times a day;
• Metoprolol 50-200 mg 2 times a day;
• Atenolol 50-200 mg per day;
• Betaxolol 10-20 mg per day;
• Bisoprolol 10 mg per day;
• Esmolol 50-300 mcg/kg/min;
• Labetalol 200-600 mg 3 times a day.

If there are contraindications to the use of β-blockers in the treatment of AMI, it is advisable to prescribe calcium antagonists of the diltiazem series. The drug is prescribed at a dose of 60 mg 3 times a day, increasing it if well tolerated to 270-360 mg per day. If there are contraindications to β-blockers, diltiazem is the drug of choice for the treatment of patients with ACS, especially without Q waves.

The use of calcium antagonists of the dihydroperidine series in acute coronary syndrome is justified only in the presence of anginal attacks that are not prevented by therapy with β-blockers (drugs are prescribed in addition to β-blockers) or if the vasospastic nature of ischemia is suspected, for example, in case of “cocaine” myocardial infarction. It should be recalled that we are talking only about long-acting calcium antagonists, since the use of short-acting drugs in this group worsens the prognosis of patients with myocardial infarction.

The next direction of therapy for AMI is the restoration of coronary blood flow, which makes it possible to partially or completely prevent the development of irreversible myocardial ischemia, reduce the degree of hemodynamic impairment, and improve the prognosis and survival of the patient.

It is possible to restore coronary circulation in several ways:

• carrying out thrombolytic and antiplatelet therapy;
• balloon angioplasty or stenting;
• urgent coronary artery bypass grafting.

The results of studies conducted on 100 thousand patients indicate that effective thrombolytic therapy can reduce the risk of death by 10-50%. The positive effect of thrombolytic therapy is associated with the restoration of the patency of the affected artery due to lysis of the thrombus in it, limiting the area of ​​necrosis, reducing the risk of developing heart failure by maintaining the pumping function of the left ventricle, improving repair processes, reducing the incidence of aneurysm formation, reducing the incidence of thrombus formation in the left ventricle and increasing the electrical stability of the myocardium.

Indications for thrombolysis are:

• all cases of probable AMI in the presence of anginal syndrome lasting 30 minutes or more in combination with ST segment elevation (more than 0.1 mV) in two or more leads in the first 12 hours from the onset of pain;
• acute complete blockade of the left bundle branch in the first 12 hours from the onset of pain;
• no contraindications.

It should be noted that, despite the fact that the time interval is outlined at 12 hours, it is more effective to carry out thrombolysis at an earlier time, preferably up to 6 hours, in the absence of ST segment elevation; the effectiveness of thrombolytic therapy has not been proven.

There are absolute and relative contraindications to thrombolytic therapy.

Absolute contraindications to thrombolysis are the following.

1. Active or recent (up to 2 weeks) internal bleeding.
2. High arterial hypertension (BP more than 200/120 mm Hg).
3. Recent (less than 2 weeks) surgery or trauma, especially traumatic brain injury, including cardiopulmonary resuscitation.
4. Active peptic ulcer of the stomach.
5. Suspicion of dissecting aortic aneurysm or pericarditis.
6. Allergy to streptokinase or APSAP (urokinase or tissue plasminogen activator can be used).

Given the high risk of reocclusion after thrombolysis, antithrombin and antiplatelet therapy must be carried out after the introduction of reperfusion.

In Ukraine, due to the low availability of invasive intervention, this therapy is the main one in restoring coronary blood flow in patients with ACS without ST segment elevation.

The next stage is anticoagulant and antiplatelet therapy. The standard antiplatelet therapy is aspirin.

Aspirin should be taken at the very beginning of the pain syndrome in a dose of 165-325 mg, it is better to chew the tablet. In the future - 80-160 mg of aspirin in the evening after meals.

If the patient is allergic to aspirin, it is advisable to prescribe inhibitors of ADP-induced platelet aggregation - clopidogrel (Plavix) or ticlopidine (Ticlid). Ticlopidine - 250 mg 2 times a day with meals.

In the recommendations of the European Society of Cardiology (2003) and the AHA/AAC (2002), a fundamentally new feature is the inclusion of the inhibitor of ADP-induced platelet aggregation - clopidogrel - in the range of mandatory antithrombotic therapy.

The basis for this recommendation was the results of the CURE study (2001), which examined 12,562 patients who received, along with aspirin, clopidogrel (first loading dose of 300 mg, then 75 mg per day) or placebo. Additional administration of clopidogrel contributed to a significant reduction in the incidence of heart attack, stroke, sudden death, and the need for revascularization.

Clopidogrel is the standard treatment for acute myocardial infarction, especially if it develops while taking aspirin, which indirectly indicates the inadequacy of prophylactic antiplatelet therapy. The drug should be prescribed as early as possible in a loading dose of 300 mg, the maintenance dose of the drug is 75 mg per day.

The second study, PCI-CURE, assessed the effectiveness of clopidogrel in 2658 patients scheduled for percutaneous angioplasty. The study results indicate that the administration of clopidogrel helps reduce the incidence of the end point (cardiovascular death, myocardial infarction, or urgent revascularization within a month after angioplasty) by 31%. According to the AHA/AAC recommendations (2002), patients with unstable angina and non-ST segment elevation myocardial infarction who are undergoing revascularization should receive clopidogrel one month before surgery and continue to take it for as long as possible after the intervention. The prescription of the drug must be mandatory.

IIb/IIIa platelet receptor blockers are a relatively new group of drugs that bind platelet glycoprotein receptors and thereby prevent the formation of a platelet thrombus. The effectiveness of glycoprotein receptors has been proven after surgery on the coronary arteries (stenting), as well as in the treatment of high-risk patients. Representatives of this group are: abciximab, eptifibrate and tirofiban.

According to treatment standards, unfractionated heparin or low molecular weight heparins can be used as anticoagulant therapy.

Despite the fact that heparin has been used in clinical practice for decades, the regimen of heparin therapy for AMI is not generally accepted, and the results of assessing its effectiveness are contradictory. There are studies showing that the administration of heparin leads to a 20% reduction in the likelihood of death, along with which the results of a meta-analysis of 20 studies indicate no effect. This contradiction in research results is largely due to the different form of drug administration: subcutaneous or intravenous drip. To date, it has been proven that only with intravenous drip administration of the drug is a positive effect of therapy actually observed. The use of subcutaneous administration, and this method of drug administration, unfortunately, is the most common in Ukraine, does not have a significant effect on the course and prognosis of the disease. That is, we supposedly partially follow treatment recommendations, but without providing the correct treatment regimen, we cannot count on its effectiveness.

The drug should be used as follows: bolus 60-70 units/kg (maximum 5000 units), then intravenous drip 12-15 units/kg/hour (maximum 1000 units/hour).

The dosage of heparin depends on the partially activated thromboplastin time (aPTT), which must be extended by 1.5-2 times to ensure the full hypocoagulative effect. But APTT, unfortunately, in Ukraine is determined only in a few medical institutions. A simpler, but less informative method, which is often used in medical institutions to monitor the adequacy of the heparin dose, is to determine the blood clotting time. However, this indicator cannot be recommended for monitoring the effectiveness of therapy due to the incorrectness of its use. In addition, the administration of heparin is fraught with the development of various complications:

• bleeding, including hemorrhagic stroke, especially in the elderly (from 0.5 to 2.8%);
• hemorrhages at injection sites;
• thrombocytopenia;
• allergic reactions;
• osteoporosis (rarely, only with long-term use).

If complications develop, it is necessary to administer a heparin antidote - protamine sulfate, which neutralizes the anti-IIa activity of unfractionated heparin at a dose of 1 mg of the drug per 100 units of heparin. At the same time, discontinuation of heparin and use of protamine sulfate increase the risk of thrombosis.

The development of complications when using heparin is largely associated with the characteristics of its pharmacokinetics. Heparin is eliminated from the body in two phases: a rapid elimination phase, as a result of the drug binding to membrane receptors of blood cells, endothelium and macrophages, and a slow elimination phase, mainly through the kidneys. The unpredictability of receptor uptake activity, and therefore the binding of heparin to proteins and the rate of its depolymerization, determines the second “side of the coin” - the impossibility of predicting therapeutic (antithrombotic) and side (hemorrhagic) effects. Therefore, if it is not possible to control the aPTT, it is impossible to talk about the required dose of the drug, and therefore about the usefulness and safety of heparin therapy. Even if the aPTT is determined, the dose of heparin can only be controlled with intravenous administration, since with subcutaneous administration there is too much variability in the bioavailability of the drug.

In addition, it should be noted that bleeding caused by the administration of heparin is associated not only with the effect of the drug on the blood coagulation system, but also on platelets. Thrombocytopenia is a fairly common complication of heparin administration.

The limited therapeutic window of unfractionated heparin, the difficulty of selecting a therapeutic dose, the need for laboratory monitoring and the high risk of complications were the basis for the search for drugs that have the same positive properties, but are safer. As a result, so-called low molecular weight heparins (LMWH) were developed and put into practice. They have a predominantly normalizing effect on activated coagulation factors, and the likelihood of developing hemorrhagic complications with their use is much lower. LMWHs have a greater antithrombotic than hemorrhagic effect. Therefore, the undoubted advantage of LMWH is the absence of the need for constant monitoring of the blood coagulation system during treatment with heparin.

LMWHs are a heterogeneous group with respect to molecular weight and biological activity. Currently, 3 representatives of LMWHs are registered in Ukraine: nadroparin (Fraxiparin), enoxaparin, dalteparin.

Fraxiparine is prescribed at a dose of 0.1 ml per 10 kg of patient weight 2 times a day for 6 days. Longer use of the drug does not increase the effectiveness of therapy and is associated with a greater risk of side effects.

The results of multicenter studies studying nadroparin indicate that the drug has the same clinical effect as heparin administered intravenously under APTT control, but the number of complications is significantly lower.

Thrombin inhibitors (hirudin), according to the results of several multicenter studies GUSTO Iib, TIMI 9b, OASIS, in medium doses are no different in effectiveness from UFH, but in large doses they increase the number of hemorrhagic complications. Therefore, in accordance with the recommendations of the AHA/AAC (2002), the use of hirudins in the treatment of patients with ACS is advisable only in the presence of heparin-induced thrombocytopenia.

Unfortunately, drug treatment for ACS does not always stabilize the condition and prevent the development of complications. Therefore, it is extremely important if the treatment of this group of patients is insufficiently effective (the persistence of anginal syndrome, episodes of ischemia during Holter monitoring or other complications) to ask the following questions: are the most effective drugs used in the treatment of patients, are the optimal forms of administration and doses of drugs used, and is it time to admit the feasibility of invasive or surgical treatment.

If the treatment result is positive and the patient’s condition has stabilized, it is necessary to conduct a stress test (while stopping β-blockers) to determine further treatment tactics. The inability to perform stress testing or discontinue β-blockers based on clinical signs automatically makes the prognosis unfavorable. Low exercise tolerance is also evidence of high risk and determines the advisability of coronary angiography.

The following preventive measures are mandatory:

• lifestyle modification;
• prescribing maintenance antiplatelet therapy (aspirin 75-150 mg, clopidogrel 75 mg or a combination of these drugs);
• use of statins (simvastatin, atorvastatin, lovastatin);
• the use of ACE inhibitors, especially in patients with signs of heart failure.

And finally, another aspect that should be addressed is the feasibility of using metabolic therapy for ACS. According to the recommendations of the AHA/AAC and the European Society of Cardiology (2002), metabolic therapy is not the standard treatment for ACS, since there is no convincing data from large studies confirming the effectiveness of this therapy. Therefore, those funds that can be spent on drugs with metabolic effects are more wisely used on truly effective drugs, the use of which is the standard of treatment and can improve the prognosis and sometimes even save the patient’s life.

Acute coronary syndrome (for simplicity it is abbreviated as ACS) is a working diagnosis used by emergency and ambulance doctors. In fact, it combines two diseases - unstable angina and true myocardial infarction.

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Causes of acute coronary syndrome

The main cause of ACS was and remains atherosclerosis. Deposits in the form of plaques on the walls of the coronary arteries lead to a narrowing of the effective lumen of the vessels. Partial destruction of the plaque capsule provokes parietal thrombus formation, which further impedes blood flow to the heart muscle. A decrease in the capacity of the coronary artery by more than 75% leads to the appearance of symptoms of myocardial ischemia. According to this mechanism, unstable angina more often develops - a more favorable form of ACS.

The second mechanism is the complete detachment of the plaque and its blockage of the coronary arteries. In this case, the blood flow completely stops and the phenomena of ischemia and, later, necrosis rapidly increase in the heart muscle. Myocardial infarction develops.

The third mechanism is the occurrence of a powerful spasm of the coronary arteries under the influence of catecholamines released in response to stress. The process that occurs as a result of taking certain medications with a vasoconstrictor effect is also similar.

Symptoms of the disease

The main clinical symptom of ACS is chest pain, varying in both intensity and sensation. It can be squeezing, pressing, burning - these are the most typical forms of pain. An attack of ischemia is provoked by stress, physical activity, emotional stress, and taking certain medications and drugs (amphetamines, cocaine).

Often it is not localized only behind the sternum, but radiates to various regions of the body - neck, left arm, shoulder blade, back, lower jaw. Situations are possible when pain is felt exclusively in the upper abdomen, simulating the clinical picture, for example, of acute pancreatitis. In this case, the diagnosis is facilitated by instrumental and laboratory studies. However, the abdominal form of myocardial ischemia still remains the most difficult to diagnose.

The second most common symptom is shortness of breath. Its occurrence is associated with a decrease in the functions of the heart in pumping blood. The appearance of this clinical sign indicates a high probability of life-threatening acute heart failure with pulmonary edema.

The third symptom is the occurrence of various arrhythmias. Sometimes heart rhythm disturbances are the only sign of an impending myocardial infarction, which can occur in a painless form. In this case, there is also a high risk of developing fatal complications in the form of cardiac arrest or cardiogenic shock, followed by the death of the patient.

How is ACS detected?

Prehospital doctors are extremely limited in the means of diagnosing acute coronary syndrome. Therefore, they are not required to make an accurate diagnosis. The main thing is to correctly interpret the data available at the time of examination and transport the patient to the nearest medical center for final identification of the disease, observation and treatment.

An emergency physician or therapist suspects ACS based on:

• medical history data (what could have provoked the attack, whether it was the first, when the pain occurred and how it developed, whether the pain was accompanied by shortness of breath, arrhythmia and other signs of ACS, what medications the patient took before the attack);
• data from listening to heart sounds, blood pressure numbers;
• electrocardiographic study data.

However, the main diagnostic criterion is the duration of chest pain. If the pain lasts more than 20 minutes, the patient is given a preliminary diagnosis of ACS. Depending on the ECG signs, it can be supplemented with information about the presence or absence of ST segment elevation.

Emergency care for acute coronary syndrome

The patient's chances of survival are higher the faster he receives emergency care for acute coronary syndrome. Even if ACS subsequently develops into myocardial infarction, timely medical intervention will limit the area of ​​necrosis and reduce the consequences of the disease.

WHO proposes the following algorithm for carrying out emergency measures:

• The patient is placed on his back, the clothes on his chest are unbuttoned;
• the most important element of treatment is oxygen therapy, which promotes the saturation of myocardial cells with oxygen under conditions of tissue hypoxia;
• administration of nitroglycerin under the tongue at intervals of 5 minutes, three doses, taking into account contraindications;
• give aspirin in a dose of 160-325 mg once;
• anticoagulants are administered subcutaneously - heparin, fondaparinux, fraxiparin, etc.;
• analgesia with morphine in a dose of 10 mg is required with a single repetition of the same amount of the drug after 5-15 minutes if necessary;
• oral administration of one of the drugs from the beta-blocker group is prescribed, taking into account contraindications (low blood pressure, bradyarrhythmia).

In addition to these measures, actions are taken to eliminate complications, such as arrhythmias, impending or existing pulmonary edema, cardiogenic shock, etc.

After stabilizing the patient’s condition, he is urgently hospitalized in a hospital where there are conditions for thrombolysis (destruction of a blood clot), and if there is no such medical institution within reach, in any hospital with an intensive care unit or intensive care unit.

It should be remembered that the patient’s life depends on timely emergency care provided at the prehospital stage. World practice shows that most deaths from myocardial infarction occur before the arrival of specialized medical teams. For this reason, any patient with coronary heart disease should be trained in both recognizing the first signs of acute coronary syndrome and self-help tactics when an attack begins.

For quotation: Vertkin A.L., Morozov S.N., Maykova N.Yu., Nikishov I.V., Morozova E.A., Donskaya A.A., Fedorov A.I. Thrombolysis at the prehospital stage: study “Register of patients with acute coronary syndrome in the Far Eastern Federal District (ROKS-VOSTOK): treatment before hospitalization” // RMZh. 2014. No. 12. S. 900

Acute coronary syndrome (ACS) is any group of clinical signs or symptoms that suggest acute myocardial infarction (AMI) or unstable angina (UA). This term includes ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI); myocardial infarction, diagnosed by changes in enzymes, biomarkers, late ECG signs of iNS. It appeared due to the need to choose treatment tactics for the final diagnosis of the listed conditions and is used at the first contact with patients, mainly at the pre-hospital stage. The diagnosis of ACS is made based on the clinical symptoms of coronary heart disease (CHD): the appearance, frequency and/or worsening of anginal attacks. The morphological basis of ACS is damage to the atherosclerotic plaque by the formation of a thrombus in the coronary artery (Fig. 1).

In this case, a large coronary artery can be occluded (Fig. 2), and then extensive transmural necrosis of the myocardium develops, which is reflected on the ECG in the form of ST segment elevation. With incomplete occlusion of the artery, there may be ECG changes in the form of ST segment depression, the formation of negative T waves, or there may be no ECG changes.

ACS with or without ST segment elevation is a diagnosis made by a doctor upon first contact with a patient. Further, based on the results, including a repeated blood test for the content of markers of myocardial necrosis, ECG dynamics, it is clarified whether the development of STEMI or MIB/STI is occurring, or whether the patient does not have necrosis of myocardial cells, and we are talking about NS.

The current standard of care for patients with STEMI includes emergency percutaneous coronary intervention (PCI) with stenting of the infarct-related artery within the first 120 minutes from the onset of an anginal attack. This allows you to restore coronary blood flow in more than 90% of patients.

At the same time, current recommendations stipulate that in patients whose hospitalization in a specialized center is postponed for any reason, it is possible to use a pharmacological method of myocardial revascularization - thrombolytic therapy (TLT) (Fig. 3).

As a result of systemic thrombolysis (intravenous administration of a thrombolytic drug), the thrombus is lysed and the patency of the occluded coronary artery is restored. Restoration of coronary blood flow leads to preservation of the viability and electrical stability of cardiomyocytes, limitation of the necrosis zone, normalization of myocardial function, and reduction of mortality in patients with STEMI. Thrombolysis is considered effective if after 90 minutes there is a significant decrease in intensity or disappearance of pain, a decrease in the ST segment by more than 50%, and the appearance of reperfusion arrhythmias.

The effectiveness of thrombolysis is limited by time parameters and sharply decreases with increasing time from the onset of a painful attack (i.e., from the beginning of the formation of a coronary thrombus). Thrombolysis is most effective in the first 2 hours from the onset of symptoms, and after 12 hours the risk of complications outweighs the possible benefit (Fig. 4). Thrombolysis increases the risk of hemorrhagic complications. Risk factors for the development of hemorrhagic complications in patients with ACS are: older age, female gender, a history of bleeding, renal failure, ongoing intracoronary interventions, recent pharmacological reperfusion, as well as therapy with inotropes, diuretics and blockers of glycoprotein ΙΙ, B/ΙΙΙ α-receptors . One of the most severe hemorrhagic complications is intracerebral hemorrhage. In patients with risk factors for hemorrhagic complications and a high risk of bleeding, TLT is contraindicated.

To carry out thrombolysis, fibrinolytic agents (plasminogen activators) are used, under the influence of which the inactive plasminogen protein circulating in the blood is converted into the active fragment plasmin, causing fibrin lysis and destruction of the blood clot. There are three generations of thrombolytics (Table 1):

Ι - streptokinase - a highly purified protein preparation of plasminogen activator, produced by β-hemolytic streptococcus of group C. Streptokinase forms a complex with plasminogen, converting plasminogen into plasmin. Does not have fibrin specificity.

ΙΙ - alteplase (drug Actilyse®) is a recombinant preparation of human tissue plasminogen activator created by genetic engineering. When administered intravenously, it selectively activates plasminogen adsorbed on fibrin. It has a fibrin-specific effect without significantly reducing the fibrinogen content in the blood plasma. Compared to streptokinase, alteplase has a faster and more pronounced fibrinolytic effect and is resistant to plasminogen activator inhibitor. Due to fibrin specificity, hemorrhagic complications occur less often with its use. Hypersensitivity reactions are rare.

ΙΙΙ - tenecteplase (Metalise® drug). As a result of modification of the alteplase molecule, a new fibrinolytic was created, which has even more pronounced fibrin specificity and high resistance to endogenous plasminogen activator inhibitor Ι (PIA). The half-life of the drug has been increased to 20 minutes, allowing it to be administered as a single bolus.

Thus, direct plasminogen activators have high fibrin specificity, which significantly reduces the time of effective thrombolysis, and a high level of safety due to a very low systemic effect, which reduces the risk of hemorrhagic complications and hypotension. Since these drugs are not allergenic, they can, unlike streptokinase, be used repeatedly.

An additional advantage of tenecteplase is that it is most resistant to PAI 1, making thrombolysis possible via a single bolus injection. Unlike alteplase, tenecteplase potentiates collagen-sensitized platelet aggregation to a very small extent, which reduces the risk of re-occlusion of the coronary artery after effective thrombolysis.

The multicenter clinical trial ASSENT-II, which included almost 16,949 patients with STEMI, assessed the effectiveness and safety of TLT in two groups of patients. One used alteplase at a dose of ≤100 mg administered intravenously over 90 minutes, and the other used tenecteplase 30-50 mg (depending on the patient’s body weight) intravenously as a single bolus over 5-10 s. It was found that 30-day mortality rates did not differ between patients in both groups (6.15% in the alteplase group and 6.18% in the tenecteplase group), while the incidence of unwanted side effects was significantly lower when using tenecteplase.

The transfer of TLT to the prehospital stage ensured not only a reduction in hospital mortality in patients with ACS by 17%, but also increased life expectancy by an average of 2.5-3 years.

The ASSENT-III PLUS trial examined the efficacy and safety of prehospital thrombolysis with tenecteplase. It was shown that the time from the first onset of symptoms to treatment was reduced by 47 minutes compared to patients treated in hospital. 53% of patients had a positive clinical picture of the disease, which was expressed in a decrease in the duration and nature of the anginal attack and positive dynamics of the ST segment on the ECG, which as a result contributed to a decrease in 30-day mortality in the group of patients who received TLT. This indicator increased with a decrease in the time of thrombolysis from the moment the clinical picture of the disease appeared.

Mortality within 12 months in patients with interrupted myocardial infarction as a result of thrombolysis performed at the prehospital stage is 5.3 times lower compared to the group of patients with established myocardial infarction.

Emergency medical care (EMS) is the first medical authority where patients with ACS go. Every year in Russia, EMS performs about 50 million visits, including more than 25 thousand daily for ACS. The emergency medical team, regardless of the profile, must carry out the full range of treatment measures, and in patients with STEMI, if prompt hospitalization to a specialized vascular center is not possible, conduct reperfusion therapy with thrombolytics. TLT is currently the most accessible reperfusion strategy for patients living in large areas, remote from specialized centers providing high-tech care.

Prehospital thrombolysis using tenecteplase by an emergency physician may be preferable due to ease of use and a higher level of safety.

The objectives of the prospective cohort multicenter clinical trial ROKS-VOSTOK were to determine the safety of prehospital TLT for STEMI, as well as the dependence of mortality on time intervals, assessing its effect on 30-day mortality and the incidence of major complications when using recombinant preparations of human tissue plasminogen activator.

Materials and methods. The study was conducted in large cities of the Far Eastern Federal District (FEFD): Yakutsk, Blagoveshchensk, Komsomolsk-on-Amur, Yuzhno-Sakhalinsk, Petropavlovsk-Kamchatsky from 2009 to 2012. We studied two groups of patients with STEMI, which were comparable by gender and age , clinical and anamnestic indicators. Group 1 consisted of 460 patients with STEMI who received TLT at the prehospital stage; Group 2 included 553 patients with STEMI who did not undergo TLT due to contraindications. For thrombolysis, alteplase was used (15 mg IV bolus, then IV infusion of 0.75 mg/kg, but not more than 50 mg over 30 minutes, then infusion of 0.5 mg/kg, maximum 35 mg over 60 min) and tenecteplase (iv bolus over 5-10 s 30 mg per body weight< 60 кг, 35 мг — при массе тела 60-69 кг, 40 мг — 70-79 кг, 45 мг — 80-89 кг и 50 мг — 90 и более кг). Пациенты включались в исследование при установлении диагноза ОКС с подъемом сегмента ST, при этом выбор препарата был обусловлен наличием последнего в укладке врача СМП. Проведение ТЛТ, согласно протоколу системного тромболизиса, включало применение ацетилсалициловой кислоты — 75 мг, клопидогрела — 300 мг, внутривенное введение гепарина 5 тыс. ед.

At the prehospital stage, all patients with ACS, in addition to a standard clinical examination and ECG recording in 12 standard leads, were assessed for biomarkers of myocardial necrosis (blood troponin T I) in capillary blood using the ACON express panel (China, Medilink).

To assess the effectiveness of reperfusion, we used non-invasive ECG criteria. A repeat recording of a standard ECG was performed 90 and 180 minutes from the start of thrombolytic administration. The dynamics of the ST segment was assessed by the degree of its total displacement in the informative ECG leads. In this case, a decrease in ST by 50% or more compared to the initial level was regarded as a sign of successful TLT (presence of reperfusion); the absence of ST segment dynamics, its decrease by less than 50%, or an increase in its elevation is a sign of the ineffectiveness of TLT.

Temporal parameters characterizing the work of the EMS were assessed and recorded: symptom-needle time (SI) - the time from the debut of an anginal attack until the start of first aid, transportation time (TT) - the time from the start of transportation to the transfer of the patient to the emergency room doctor, total service time call (OC) - the sum of time intervals from the moment the ambulance team leaves until the patient is transferred to the emergency room doctor (Table 2).

Statistical data processing was carried out using the IBM SPSS Statistics 19 application package.

Results obtained. Reducing mortality from cardiovascular diseases in Russia currently depends on three main factors: public awareness, training of primary care doctors and correct patient routing.

In large cities of the Far Eastern Federal District, the time from the onset of ACS symptoms to the start of medical care ranges from 25 minutes to 3 hours. In large cities of the Far Eastern Federal District, patients with STEMI at the prehospital stage are served by both specialized cardiology and intensive care, as well as general line medical and paramedic teams. Despite this, the one-stage scheme for providing medical care to patients with STEMI, when medical care is provided by one EMS team, amounted to 76%, while exclusively all patients with a one-stage scheme were served by specialized EMS teams. The two-stage scheme for servicing patients with STEMI, according to our data, accounted for 24% of cases. When analyzing the two-stage scheme, it was found that the first team providing medical care in 87% of cases was a line medical team, in 13% - a paramedic team. The transfer of a call to a specialized team is associated with the need to conduct TLT or the need to correct unstable clinical or hemodynamic parameters of the patient.

Specialized and general medical EMS teams work within the recommended 90 minutes to carry out effective thrombolysis, but due to untimely or late calls to the EMS by patients, this time increases by 86 minutes.

SI and OS are the main time indicators and predictors of disease outcome in the group of patients with ST-segment elevation ACS with TLT (Table 3).

The probability of death increases with increasing time from the onset of the disease in the group of patients with ACS with ST segment elevation and TLT over 88 minutes.

For OB, the cut-off points were distributed as follows (Fig. 6):

The probability of death significantly increases when the OS time in the STEMI + TLT group exceeds 85 minutes.

Patients with ACS included in the study suffered from arterial hypertension (AH), angina pectoris, 10% had type 2 diabetes mellitus (DM), 81% were obese. Concomitant somatic diseases were noted in more than half of the patients, with the most common patients having chronic obstructive pulmonary disease (COPD) (Table 4). The main factors in the development of the clinical picture of the disease in the groups were physical and/or emotional stress, and anginal pain also appeared during sleep. In 7.5% of patients with ST-segment elevation ACS with TLT and in 21.5% of patients with ST-segment elevation ACS without TLT, alcohol was the precipitating factor (Table 5).

The levels of systolic (SBP) and diastolic (DBP) blood pressure in the group of patients with ST-segment elevation ACS with TLT were significantly lower compared to the group of ST-segment elevation ACS patients without TLT. In patients of both groups, ECG signs of widespread damage to the anterior wall of the left ventricle predominated, while in the group of patients who underwent TLT, cases with ST segment elevation of 5 mm or more were more common.

A positive result of a qualitative test for the content of troponin T and/or I was obtained in patients in the group with TLT in 92.4%, without TLT in 93.0% of cases.

In the ST-segment elevation ACS group with TLT, patients initially reported discomfort in 16.5%, moderate pain in 25.2%, and severe pain in 58.3% of cases. At 90 minutes, pain was relieved in 27.6% of patients, severe pain remained in 4.7%, pain of moderate intensity remained in 11%, and discomfort remained in 56.7% of patients. In patients with ACS with ST segment elevation without TLT, severe pain was indicated in 45%, discomfort in 22%, moderate pain intensity in 33%, at 90 minutes from the start of treatment pain was relieved in 13.2% of patients, severe pain remained in 23%, 17.6% had pain of moderate intensity and 46.2% had a feeling of discomfort.

At the prehospital stage, positive dynamics according to ECG signs were observed in 63% of patients in the ST-segment elevation ACS group with TLT and 38% of patients in the ST-segment elevation ACS group without TLT (p<0,01). На 30-й день с момента заболевания прерванный ИМ зафиксирован у больных с ТЛТ в 12,9%, без ТЛТ — в 5,2% случаев (р<0,01), развитие Q-образующего ИМ в группе с ТЛТ — в 75,6%, в группе без ТЛТ — в 94,5% (р<0,01), рецидив нефатального ИМ в группе с ТЛТ нами отмечен в 1,5%, а в группе без ТЛТ — в 15,4% случаев (р<0,01).

Uncomplicated clinical course of MI (without deaths, relapses, progression of circulatory failure, complex rhythm and conduction disturbances): in the group with TLT - in 51.2%, in the group without TLT - in 19.8% of patients (p<0,01). У 25,2% пациентов с ТЛТ зафиксированы реперфузионные аритмии, а у больных без ТЛТ они отмечены в 5,5% случаев (р<0,01).

In the group of patients without TLT, the 30-day mortality rate was 85.4%, versus 50% in patients with TLT(p<0,001). Общая летальность в группе больных с ТЛТ составила 13,5%, а в группе без ТЛТ — 27,4% (р=0,000). Это составляет 15 спасенных жизней на 100 пациентов, при этом шанс выжить при использовании ТЛТ повышается в 2,4 раза.

In conclusion, it should be noted that our study confirmed the dependence of the survival of patients with ACS on the time of seeking medical help. Conducting thrombolysis by EMS physicians within the first 90-120 minutes from the onset of symptoms with recombinant preparations of human tissue plasminogen activator is safe and can reduce mortality from ST-segment elevation ACS: 13.5% in the group with TLT compared to 27.4% in the group group without TLT.

Literature

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Treatment of ACS at the prehospital stage: modern view Prof. Tereshchenko S. N. Institute of Clinical Cardiology named after. A. L. Myasnikova. RKNPK Russian Cardiology Research and Production Complex

Acute coronary syndrome Single cause of disease but different clinical manifestations and other treatment strategies Substernal pain Acute coronary syndrome No ST elevation No troponin Unstable angina ST elevation Positive troponin MV CK MI without ST elevation MI with ST elevation

Pathogenesis of acute coronary syndrome Rupture of a vulnerable atherosclerotic plaque intracoronary thrombosis change in plaque geometry distal embolization local spasm Spasm of the coronary artery at the site of stenosis without visible stenosis myocardial oxygen demand with significant stenoses of oxygen delivery to the myocardium with significant stenoses Appearance/worsening of myocardial ischemia Symptoms of exacerbation of CAD (spicy coronary syndrome)

Goals of treatment of acute coronary syndrome Improve the prognosis of mortality rate of MI complications Eliminate symptoms and pain syndromes HF arrhythmia ...

The main tasks during the first examination are §Providing emergency care §Assessing the probable cause of chest pain (ischemic or non-ischemic) §Assessing the immediate risk of developing life-threatening conditions §Determining the indication and place of hospitalization.

Physician tactics for ACS at the prehospital stage §Initial assessment of patients with chest pain. Differential diagnosis.

Differential diagnosis of chest pain is not only a clinical, but also an organizational problem solved in diagnostic departments for patients with chest pain

DOCTOR'S TACTICS IN ACS AT THE PREHOSPITAL STAGE §Initial assessment of patients with chest pain. Differential diagnosis. §Indications for hospitalization and transportation.

The slightest suspicion (probable ACS) regarding the ischemic origin of chest pain, even in the absence of characteristic electrocardiographic changes, should be a reason for immediate transportation of the patient to the hospital.

DOCTOR'S TACTICS IN ACS AT THE PREHOSPITAL STAGE §Initial assessment of patients with chest pain. Differential diagnosis. §Indications for hospitalization and transportation. §Prehospital assessment of the level of risk of death and development of AMI in patients with ACS without ST segment elevation.

Risk stratification in non-ST ACS Acute risk of adverse outcomes in non-ST ACS (assessed during observation) High recurrent angina dynamic ST segment displacements (the more widespread, the worse the prognosis) Low during observation ischemia does not recur no ST segment depression early post-infarction angina not markers myocardial necrosis cardiac troponins (the higher, the worse the prognosis) normal cardiac troponin levels when determined twice with an interval of at least 6 hours diabetes mellitus hemodynamic instability serious arrhythmias Eur Heart J 2002; 23: 1809 -40

DOCTOR'S TACTICS IN ACS AT THE PREHOSPITAL STAGE §Initial assessment of patients with chest pain. Differential diagnosis. §Indications for hospitalization and transportation. §Prehospital assessment of the risk level of death and MI in patients with ACS. §Treatment of OSK at the prehospital stage.

Providing emergency care Pain relief Nitroglycerin 0.4 mg p.i. or spray for p. Blood pressure >90 If ineffective, after 5 minutes Nitroglycerin 0.4 mg p.i. or spray at s. Blood pressure >90 If “03” is ineffective Morphine (especially in cases of agitation, acute heart failure) IV 2 -4 mg + 2 -8 mg every 5 -15 minutes or 4 -8 mg + 2 mg every 5 minutes or 3 - 5 mg until pain relief IV nitroglycerin for blood pressure >90 mm Hg, if there is pain, acute pulmonary congestion, high blood pressure

Basic principles of treatment of patients with non-ST segment elevation ACS at the prehospital stage §Adequate pain relief §Antithrombotic therapy.

The effect of aspirin and heparin on the sum of cases of death and MI in ACS without ST Meta-analysis of studies % p=0.0005 12.5 6.4 5.3 2.0 n=2488 No treatment www. acc. org n=2629 Aspirin 5 days-2 years Heparin 1 week

Factors influencing the choice of antithrombotic treatment for ACS without persistent ST Nature of myocardial ischemia and time of the last episode Risk of adverse outcome (MI, death) in the near future Approach to patient management is invasive conservative Risk of bleeding Renal function Clinical judgment of the presence of ongoing intracoronary thrombosis

Aspirin for ACS without ST. Current recommendations Initial dose European Society of Cardiology, ACS without ST (2002) Long-term use 75 -150 ≤ 100 with clopidogrel Class I (A) American College of Cardiology and Heart Association, ACS without ST (2002) 162 -325 75 - 160 I (A) Russian recommendations, ACS without ST (2004) 250 -500 75 -325, then 75 -160 (150) - European Society of Cardiology, antiplatelet agents (2004) 160 -300 75 -100 I (A ) American College of Chest Physicians (2004) 160 -325 75 -162 I (A) Eur Heart J 2002; 23: 809 -40. Circulation 2002; 106: 893 -1900. Chest 2004; 126: 513 S-548 S. Eur Heart J 2004; 25: 166 -81. Cardiology 2004, supplement.

Heparin for ACS without persistent ST on ECG 48 -72 hours for pain IV infusion of UFH SC injection of LMWH Observation 6 -12 hours High risk of thrombotic complications No signs of high risk of thrombotic complications ST troponin ... no ST normal troponin (twice at intervals >6 hours) Administration from 2 to 8 days (according to the doctor’s decision) Cancellation of heparin

Addition of clopidogrel for ACS without ST CURE study (n=12,562) Death, MI, stroke, severe ischemia risk 34% p=0.003 11.4% 0.14 Event risk 0.12 Heparin 92% of which LMWH 54% Aspirin 0.10 9.3% 0.08 Aspirin + clopidogrel 0.06 0.04 Hours after randomization 0.02 0.00 0 Circulation 2003; 107: 966– 72 3 6 9 12 Months

Manifestations of myocardial ischemia Severe pain behind the sternum, squeezing, pressing Perspiration, sticky cold sweat Nausea, vomiting Shortness of breath Weakness, collapse

Clinical variants of MI % 65.6 status anginosus 89 status asthmaticus 7 10.5 status gastralgicus 1 6.7 arrhythmic 2 14.3 cerebral 1 - asymptomatic - 2.9 616 people 105 people Syrkin A.L.

Necessary and sufficient signs for the diagnosis of AMI One of the following criteria is sufficient for the diagnosis of AMI: - clinical picture of ACS; - the appearance of pathological Q waves on the ECG; - ECG changes indicating the appearance of myocardial ischemia: the occurrence of ST segment elevation or depression, LBP blockade;

50% of deaths are from UTIs. ST occurs in the first 1.5-2 hours from the onset of an anginal attack and most of these patients die before the arrival of the ambulance team. Therefore, the greatest efforts must be made to ensure that first medical aid is provided to the patient as early as possible, and that the volume of this assistance is optimal

Organization of EMS work for AMI Treatment of a patient with UTI. ST is a single process that begins in the prehospital stage and continues in the hospital. To do this, EMS teams and hospitals where patients with ACS are admitted must work according to a single algorithm based on common principles of diagnosis, treatment and a common understanding of tactical issues. which actually begins treatment and transports the patient to the hospital, leads to an unjustified loss of time §Each ambulance team (including paramedics) must be prepared to carry out active treatment of a patient with UTI. ST

Organization of EMS work in case of AMI §Any EMS team, having made a diagnosis of ACS and determined the indications and contraindications for appropriate treatment, must stop the pain attack, begin antithrombotic treatment, including the administration of thrombolytics (if invasive restoration of the patency of the coronary artery is not planned), and if complications develop - heart rhythm disturbances or acute heart failure - necessary therapy, including cardiopulmonary resuscitation measures §EMS teams in each locality must have clear instructions to which hospitals it is necessary to transport patients with UTI. ST or suspected UTI. ST §Doctors of these hospitals, if necessary, provide emergency medical assistance with appropriate advisory assistance

It is necessary to transport the patient as quickly as possible to the nearest specialized institution, where the diagnosis will be clarified and treatment will be continued.

The line EMS team must be equipped with the necessary equipment: 1. Portable ECG with self-powered power supply; 2. Portable device for EIT with autonomous power supply and monitoring of heart rhythm; 3. Cardiopulmonary resuscitation kit, including a device for manual ventilation; 4. Equipment for infusion therapy, including infusion pumps and perfusors; 5. Kit for installing an IV catheter; 6. Cardioscope; 7. Pacemaker; 8. System for remote transmission of ECG; 9. Mobile communication system; 10. Suction; 11. Medicines required for basic treatment of AMI

Treatment of uncomplicated UTI. ST at the prehospital stage Each ambulance team (including paramedics) must be prepared to actively treat a patient with UTI. ST Basic therapy. 1. Eliminate pain syndrome. 2. Chew a tablet containing 250 mg of ASA. 3. Take 300 mg of clopidogrel orally. 4. Start IV infusion of NG, primarily for persistent angina, hypertension, AHF. 5. Start treatment with b-blockers. Initial IV administration is preferable, especially for ischemia that persists after IV administration of narcotic analgesics or recurs, hypertension, tachycardia or tachyarrhythmia, without HF. It is expected that a primary TBA will be performed. The loading dose of clopidogrel is 600 mg.

Oxygen therapy In all cases, 2 l/min through nasal catheters in the first 6 hours § When arterial blood is saturated with O § preservation of myocardial ischemia § pulmonary congestion 2 -4 (4 -8) l/min through nasal catheters 2

Nitrates in acute myocardial infarction Indications for the use of nitrates § myocardial ischemia § acute pulmonary congestion § need to control blood pressure No contraindications § p. BP 30 mm Hg below baseline § Heart rate 100 § suspicion of right ventricular MI §

Prehospital triple antiplatelet therapy Data from the On-TIME 2 trial Prehospital IG IIb/IIIa tirofiban (25 mcg/kg bolus followed by 0.15 mcg/kg/min infusion over 18 hours) or placebo in addition to aspirin (500 mg intravenously), clopidogrel (600 mg orally) and intravenous bolus (5000 IU) UFH p=0.043 p=0.051 p=0.581

Restoration of coronary perfusion The basis of treatment of acute MI is the restoration of coronary blood flow - coronary reperfusion. Destruction of the thrombus and restoration of myocardial perfusion lead to limiting the extent of its damage and, ultimately, to improving the short-term and long-term prognosis. Therefore, all patients with UTI. ST should be immediately examined to clarify the indications and contraindications for restoration of coronary blood flow. Russian recommendations. Diagnosis and treatment of patients with acute myocardial infarction with ST segment elevation ECG. 2007 VNOK

Thrombolytic therapy in patients with AMI in 2008 according to data from 12 regions, 2008

Prehospital thrombolysis: gain in time = saving the myocardium Decision to call an ambulance Arrival of an ambulance Arrival at the hospital Occurrence of pain Diagnosis Formation in the emergency room Actilyse SK today PTCA Metalyse in the ICU tomorrow Occurrence of pain Decision to call an ambulance Metalyse in Metalyse at Arrival Diagnosis in the emergency room at the prehospital emergency stage “Early Thrombolysis” Strategy

Prehospital thrombolysis for MI with ST

USIC registry 2000: reduction in mortality with prehospital thrombolysis Mortality (%) 15 12. 2 10 5 8. 0 6. 7 3. 3 0 Prehosp. TL TL in hospital Without PCI reperfusion therapy Danchin et al. Circulation 2004; 110: 1909–1915.

VIENNA STEMI REGISTRY: Change in reperfusion strategy Thrombolysis Without reperfusion PCI 60 60 50 50 Patients (%) 40 34 26. 7 30 20 16 13. 4 10 0 VIENNA 2002 VIENNA 2003/2004 Kalla et al. Circulation 2006; 113: 2398–2405.

VIENNA STEMI REGISTRY: Time from onset of disease to treatment for different strategies 0 -2 hours 100 90 19. 5 6 -12 hours 2 -6 hours 5. 1 80 44. 4 Patients (%) 70 60 50 65. 9 40 30 20 10 50. 5 14. 6 0 PCI THROMBOLYSIS Kalla et al. Circulation 2006; 113: 2398–2405.

GRACE REGISTRY Reperfusion therapy Without reperfusion PCI only 50 48 Patients (%) 43 40 40 41 36 32 30 35 33 33 31 30 25 20 10 TLT only 35 32 26 19 13 15 0 1999 2000 2001 2002 Years 2003 2004 Eagle et al. 2007, Submitted

Treatment of uncomplicated UTI. ST at the prehospital stage Thrombolytic therapy at the prehospital stage. It is carried out if there are indications and no contraindications. When using streptokinase, at the discretion of the physician, direct-acting anticoagulants can be used as concomitant therapy. If anticoagulant use is preferred, UFH, enoxaparin, or fondaparinux may be chosen. When using fibrin-specific thrombolytics, enoxaparin or UFH should be used. Reperfusion therapy is not expected. The decision about the advisability of using direct anticoagulants may be postponed until admission to the hospital. Russian recommendations. Diagnosis and treatment of patients with acute myocardial infarction with ST segment elevation ECG. 2007 VNOK

Indications for TLT If the time from the onset of an anginal attack does not exceed 12 hours, and the ECG shows ST segment elevation ≥ 0.1 m. V, in at least 2 consecutive chest leads or 2 limb leads, or LBP block appears. The administration of thrombolytics is justified at the same time with ECG signs of true posterior MI (high R waves in the right precordial leads and ST segment depression in leads V 1 -V 4 ​​with an upward T wave). Russian recommendations. Diagnosis and treatment of patients with acute myocardial infarction with ST segment elevation ECG. 2007 VNOK

Contraindications for TLT Absolute contraindications for TLT § previous hemorrhagic stroke or stroke of unknown etiology; § ischemic stroke suffered during the last 3 months; § brain tumor, primary and metastatic; § suspicion of aortic dissection; § presence of signs of bleeding or hemorrhagic diathesis (except for menstruation); § significant closed head injuries in the last 3 months; §changes in the structure of cerebral vessels, for example, arteriovenous malformation, arterial aneurysms Russian recommendations. Diagnosis and treatment of patients with acute myocardial infarction with ST segment elevation ECG. 2007 VNOK

Checklist for making a decision by the EMS medical and paramedic team to conduct TLT for a patient with acute coronary syndrome (ACS) Check and mark each of the indicators given in the table. If all the boxes in the “Yes” column and none in the “No” column are checked, then thrombolytic therapy is indicated for the patient. If there is even one unchecked box in the “Yes” column, TLT therapy should not be carried out and filling out the checklist can be stopped. “Yes” The patient is oriented, can communicate. Pain syndrome characteristic of ACS and/or its equivalents lasting at least 15-20 minutes. , but no more than 12 hours After the disappearance of the pain syndrome characteristic of ACS and/or its equivalents, no more than 3 hours have passed. A high-quality ECG recording in 12 leads has been performed. The EMS doctor/paramedic has experience in assessing changes in the ST segment and bundle branch block on an ECG (test only in the absence of a remote assessment of the ECG by a specialist) There is ST segment elevation of 1 mm or more in two or more adjacent ECG leads or a left bundle branch block is registered, which the patient did not have before. The EMS doctor/paramedic has experience in performing TLT. Transporting the patient to the hospital will take more than 30 minutes. It is possible to receive medical recommendations from the hospital’s cardiac resuscitator in real time. During the patient’s transportation, it is possible to constantly monitor the ECG (at least in one lead), intravenous infusions (in “No”

Age over 35 years for men and over 40 years for women Systolic blood pressure does not exceed 180 mm Hg. Art. Diastolic blood pressure does not exceed 110 mmHg. Art. The difference in systolic blood pressure levels measured on the right and left arms does not exceed 15 mmHg. Art. There are no indications in the medical history of a stroke or the presence of other organic (structural) pathology of the brain. There are no clinical signs of bleeding of any location (including gastrointestinal and urogenital) or manifestations of hemorrhagic syndrome. The submitted medical documents do not contain data on the patient undergoing long-term (more than 10 minutes) ) cardiopulmonary resuscitation or the presence of internal bleeding in the last 2 weeks; the patient and his relatives confirm this. The presented medical documents do not contain data on the past 3 months. surgical operation (including on the eyes using a laser) or serious injury with hematomas and/or bleeding, the patient confirms this. The submitted medical documents do not contain data on the presence of pregnancy or the terminal stage of any disease, and survey and examination data confirm this The presented medical documents do not contain data on the presence of jaundice, hepatitis, renal failure in the patient and data from the survey and examination of the patient. CONCLUSION: TLT for the patient is CONTRAINDICATED confirm this _______________ (full name) SHOWN (circle as necessary, cross out as necessary) The sheet was completed by: Doctor / paramedic (circle as necessary ) _____________ (full name) Date ______ Time _____ Signature_______ The check sheet is sent with the patient to the hospital and filed in the medical history

Thrombolytic drugs Intravenous 1 mg/kg body weight (but not more than 100 mg): bolus 15 mg; subsequent infusion of 0.75 mg/kg body weight over 30 minutes (but not more than 50 mg), then 0.5 mg/kg (but not more than 35 mg) over 60 minutes (total infusion duration 1.5 hours). Intravenously: bolus of 2,000,000 IU and Purolaza followed by infusion of 4,000,000 IU over 30 -60 minutes. Streptokinase Intravenous infusion 1,500,000 IU over 30-60 minutes.). Tenecteplase Intravenous bolus: 30 mg for a weight of 90 kg. ST segment of the ECG. 2007 VNOK Alyeplaza

Evolution of thrombolysis First generation Streptokinase allergenic not selective for fibrin Second generation Third generation Metalyse Equivalent to Alteplase Actilyse High “gold standard” fibrin selectivity fibrin specificity not allergenic Continuous intravenous infusion Single bolus 5-10 seconds

Relative risk reduction Meta-analysis of studies with early IV beta-blockers for MI (n=52,411) 0 -5 -10 -15 -20 -13%

BETA BLOCKERS: USE IN PATIENTS WITH ACS IN 59 RUSSIAN CENTERS Data from the GRACE register (2000 -1) 100% N=2806 C ST – 50.3% Without ST – 49.7% 1 Prev. 7 days 3 During hospitalization 2 First 24 hours. 4 Recomm. at discharge 100% Without ST C ST 55. 6 54. 3 50. 7 50% 54 50% 20. 2 0% 4. 3% 2. 9 IV 60. 3 54. 5 12. 2 0% 1 2 3 4 I/O 1 2 3 4 www. cardiosite. ru

IV administration of beta-blockers for acute myocardial infarction From the first hours/day To eliminate symptoms § persistence of ischemia § tachycardia without HF § tachyarrhythmia § BP For everyone without contraindications § the feasibility of IV is discussed § if there are no contraindications

Beta blockers for UTIs. ST Drug Dose Treatment on the 1st day of the disease Metoprolol IV 5 mg 2-3 times with an interval of at least 2 minutes; The first oral dose is 15 minutes after intravenous administration. Propronolol IV 0.1 mg/kg in 2-3 doses at intervals of at least 2-3 minutes; The first oral dose is 4 hours after intravenous administration. Esmolol IV infusion at an initial dose of 0.05 -0.1 mg/kg/min, followed by a gradual increase in dose by 0.05 mg/kg/min every 10–15 minutes until the effect or dose of 0.3 mg/kg is achieved /min; for a faster onset of effect, an initial administration of 0.5 mg/kg over 2–5 minutes is possible. Emolol is usually discontinued after the second dose of an oral β-blocker if proper heart rate and blood pressure have been maintained during their combined use.

ACS P ST Data upon admission to hospital Odds ratio (confidence interval) City Clinical Hospital No. 29 (n=58) Other centers (n=1917) Time from the onset of symptoms to hospitalization (hours) 5, 48 2, 83 ST elevations on the initial ECG (%) 86.2 93.8 2.45 (1.13 ->5) Negative T on the initial ECG (%) 3.45 1.73 0.49 (0.12 -2.11) GRACE scale: proportion patients with risk of death =10% 10.3 19.4 2.08 (0.89 -4.88) Killip class I-II (%) 93.1 93.1 0.99 (0.35 -2.78 ) III (%) 5. 17 3. 86 0. 74 (0. 23 -2. 41) IV (%) 0 2. 74 1. 81 (0. 25 -13. 3) RUSSIAN REGISTRY OF ACUTE CORONARY SYNDROMES (RECORD )

ACS P ST Primary reperfusion therapy and anticoagulant treatment Odds ratio (confidence interval) City Clinical Hospital No. 29 (n=58) Other centers (n=1917) 27, 6 75, 7 0 47, 9 Streptokinase (%) 24, 1 5, 0 0. 17 (0. 09 -0. 31) T-PA (%) 3.5 22. 8 >5 81. 0 94. 0 3. 69 (1. 86 ->5) LMWH (%) 0 62 , 4 UFH (%) 100 50.5 Fondaparinux (%) 0 0.1 Bivalirudin (%) 0 0.1 Primary reperfusion (%) Primary PCI (%) TLT: Anticoagulants (%) RUSSIAN REGISTRY OF ACUTE CORONARY SYNDROMES (RECORD)

Practical approaches to the treatment of AMI Within 10 - 15 minutes Emergency treatment § morphine 2-4 mg IV until effect § RR, heart rate, blood pressure, O2 saturation ECG monitoring Preparedness for defibrillation and CPR Providing IV access ECG at 12 -ti leads Short targeted history, physical examination §O 2 4 -8 l/min for O 2 saturation >90% § § § aspirin (if not given earlier): § § clopidogrel 300 mg, chew 250 mg, suppositories 300 mg or IV 500 mg age 90, if there is pain, acute congestion in the lungs, high blood pressure § solution to the issue of TLT!!!

POINT OF VIEW

TREATMENT OF ACUTE CORONARY SYNDROME WITH ST SEGMENT ELEVATION AT THE PREHOSPITAL STAGE OF PROVIDING MEDICAL CARE

S.N.Tereshchenko*, I.V.Zhirov

Russian cardiological research and production complex.

121552 Moscow, 3rd Cherepkovskaya st., 15a

Treatment of acute coronary syndrome with B7 segment elevation at the prehospital stage of medical care

S.N.Tereshchenko*, I.V.Zhirov

Russian Cardiology Research and Production Complex. 121552 Moscow, 3rd Cherepkovskaya St., 15a

The issues of organizing medical care at the prehospital stage in patients with acute coronary syndrome (ACS) and elevation of the BT segment are discussed. An algorithm for diagnosing and providing emergency care to a patient with ACS and elevation of the BT segment at the prehospital stage is presented. The necessary examination methods, medications and their doses are indicated. The importance of reperfusion therapy as a key aspect of the treatment of patients in this group is emphasized. The advantages and disadvantages of each reperfusion therapy method and the algorithm for their selection are discussed.

Key words: acute coronary syndrome, myocardial infarction, prehospital stage, thrombolytic therapy.

RFK 2010;6(3):363-369

Treatment of the acute coronary syndrome with ST segment elevation at the pre-hospital care

S.N. Tereshchenko*, I.V Zhirov

Russian Cardiology Research and Production Complex. Tretya Cherepkovskaya st. 15a, Moscow, 121552 Russia

Details of pre-hospital medical care organization in patients with acute coronary syndrome (ACS) with ST segment elevation are discussed. The algorithm of pre-hospital diagnostics and emergency cardiac care to these patients is presented. The necessary methods of examination, drugs and their dosages are specified. The importance of reperfusion as a key approach to ACS patients treatment is emphasized. Advantages and disadvantages of reperfusion therapeutic methods and algorithm of their choice are presented.

Key words: acute coronary syndrome, myocardial infarction, pre-hospital cardiac care, thrombolytic therapy.

Rational Pharmacother. Card. 2010;6(3):363-369

Introduction

The term acute coronary syndrome (ACS) with persistent elevation of the 5T segment on the ECG refers to any group of clinical signs against the background of existing elevations of the BT segment with an amplitude of > 1 mm on the ECG for at least 20 minutes, allowing one to suspect a coronary catastrophe.

It should immediately be noted that the term ACS is not a diagnosis. Establishing an ACS allows a specialist to recognize the presence of a coronary catastrophe, requires a clear set of treatment and diagnostic techniques and dictates the need for hospitalization of the patient in a specialized hospital.

Tereshchenko Sergey Nikolaevich, MD, professor, head of the department of myocardial diseases and heart failure of the RKNPK, head. Department of Emergency Medical Care, Moscow State Medical and Dental University, Chairman of the Emergency Cardiology Section of VNOK Zhirov Igor Vitalievich, Doctor of Medical Sciences, Art. n. With. of the same department, scientific secretary of the section of emergency cardiology of the All-Russian Scientific Committee

Along with damage to the atherosclerotic plaque with subsequent intracoronary thrombosis, the causes of ACS can be a sharply increased myocardial oxygen demand (cocaine intoxication, thyroid pathology, anemia), coronary vasospasm and more rare causes (for example, dissection of the coronary arteries in pregnant women). At the same time, more than 95% of ACS with persistent elevation of the BT segment are associated precisely with the processes of violation of the integrity of the plaque shell.

Issues of organizing medical care at the prehospital stage in patients with ACS and ST segment elevation

It is known that almost 50% of adverse outcomes in various forms of ACS occur in the first hours of the disease. Thus, a competent scheme of examination and treatment of the patient in the early stages of ACS is the cornerstone of the success of therapy. Treatment of a patient is a single process that begins at the prehospital stage and continues

huddled in hospital. To do this, emergency medical teams and hospitals where patients with ACS are admitted must work according to a single algorithm based on common principles of diagnosis and treatment, and a common understanding of tactical issues. In this regard, the previously used two-stage system of medical care (line team - specialized team) led to an unjustified delay in the provision of appropriate medical care. Any team, having made this diagnosis and determined the indications and contraindications for appropriate treatment, must stop the pain attack, begin antithrombotic treatment, including the administration of thrombolytics (if primary angioplasty is not planned), and if complications develop - cardiac arrhythmias or acute heart failure - the necessary therapy , including cardiopulmonary resuscitation measures.

At the prehospital stage, a specialist needs to solve several practical problems at once - providing emergency care, assessing the risk of complications and preventing them, and hospitalizing the patient in a target hospital. All this is carried out in conditions of shortage of time and labor, under stressful conditions. Accordingly, clear treatment and diagnostic algorithms are required, as well as appropriate equipment for the team (Table 1).

It must be remembered that even a suspicion of ACS is an absolute indication for hospitalization of the patient in a hospital.

Prehospital examination of a patient with ACS and ST segment elevation

There is no doubt that conducting a full examination of a patient with this diagnosis at the prehospital stage is difficult for objective reasons. At the same time, the proposed algorithm is practically feasible; it is necessary for developing the correct treatment tactics, as well as for preparing the patient for therapy at the hospital stage (Table 2).

Treatment of ACS with ST segment elevation in the prehospital stage

We consider it appropriate to reflect the treatment algorithm in the sequence that occurs most often at the prehospital stage.

Anesthesia

Pain relief is an integral part of the complex therapy of ACS, not only for ethical reasons, but also due to excessive sympathetic activation during nociceptive

Table 1. Example of equipment for an emergency medical team to provide care to patients with ST-segment elevation ACS

1. Portable electrocardiograph with autonomous power supply

2. Portable device for electropulse therapy with self-powered power and the ability to monitor cardiac activity

3. Cardiopulmonary resuscitation (CPR) kit, including a device for manual artificial ventilation of the lungs

4. Equipment for infusion therapy including infusion pumps and perfusors

5. Set for installing an intravenous catheter

6. Cardioscope

7. Pacemaker

8. System for remote transmission of ECG

9. Mobile communication system

11. Medicines required for basic treatment of acute myocardial infarction

Table 2. Preliminary algorithm

diagnostic manipulations at the prehospital stage in a patient with ACS and elevation of the BT segment

1. Determination of respiratory rate, heart rate, blood pressure, blood saturation 02

2. Registration of ECG in 12 leads

3. ECG monitoring at the entire stage of treatment and transportation of the patient

4. Prepare for possible defibrillation and CPR

5. Providing intravenous access

6. Short targeted history, physical examination

RR - respiratory rate,

HR - heart rate

fighting. This leads to increased vasoconstriction, increased myocardial oxygen demand, and increased load on the heart. If the use of aerosol forms of nitrates is ineffective, immediate intravenous administration of morphine hydrochloride 2-4 mg + 2-8 mg every 5-15 minutes or 4-8 mg + 2 mg every 5 minutes or 3-5 mg until pain relief is recommended. When systolic blood pressure (BP) is above 90 mm Hg. an intravenous infusion of nitroglycerin should be started at a dose of 20-200 mcg/minute. In cases of severe anxiety, European authors consider intravenous administration of small doses of benzodiazepines to be indicated, but in most cases the use of opioid analgesics can achieve satisfactory results.

Respiratory support

Along with pain relief, all patients with ACS require respiratory support. Inhalation of humidified oxygen at a rate of 2-4 l/min is associated with a decrease in myocardial oxygen demand and the severity of clinical symptoms. In some cases, non-invasive mask ventilation is recommended, especially in the positive end-expiratory pressure (PEEP) mode. This mode of ventilation is especially indicated in the presence of heart failure; it is associated with hemodynamic unloading of the pulmonary circulation and correction of hypoxemia. Noninvasive mask ventilation also reduces the need for tracheal intubation and mechanical ventilation, which is important because mechanical ventilation itself can adversely alter hemodynamic parameters in a patient with ACS.

Acetylsalicylic acid, non-steroidal anti-inflammatory drugs, COX-2 inhibitors

Absolutely all patients with ACS should take a loading dose of acetylsalicylic acid (ASA) as early as possible - 160-325 mg of non-enteric soluble forms under the tongue. An acceptable alternative is the use of an intravenous form of ASA (250-500 mg) and ASA in the form of rectal suppositories. Contraindications to the use of a loading dose are active gastrointestinal bleeding, known hypersensitivity to ASA, thrombocytopenia, severe liver failure. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors leads to an increased risk of death, recurrent ACS, myocardial rupture and other complications. If ACS occurs, all drugs from the NSAIDs and COX-2 inhibitors groups should be discontinued.

All patients should then receive low doses of ASA (75-160 mg) every day indefinitely.

Clopidogrel

The addition of clopidogrel to ASA at the prehospital stage significantly improves clinical outcomes and reduces morbidity and mortality in patients with ACS. The dosage of clopidogrel varies depending on the type of ACS and the type of treatment provided (Table 3).

Subsequently, the dosage of clopidogrel is 75 mg. The duration of dual antiplatelet therapy (ASA plus clopidogrel) also varies depending on the type of ACS and treatment approach (invasive/non-invasive) and ranges from 4-52 weeks (at least 4 weeks, ideally 1 year).

Table 3. Loading doses of clopidogrel (according to, with modifications)

Various clinical scenarios Loading dose

Primary PCI is definitely possible At least 300 mg, preferably 600 mg

Carrying out thrombolytic therapy

Up to 75 years old

75 years and older (unless primary TBA is planned)

No reperfusion therapy

Up to 75 years 300 mg

75 years and older 75 mg

Reperfusion therapy for ST-segment elevation ACS

The importance of reperfusion therapy in the case of BT segment elevation in a patient with ACS is difficult to overestimate. The Russian recommendations for the diagnosis and treatment of patients with acute myocardial infarction with elevation of the BT segment (STEMI) on the ECG indicate that the basis for the treatment of acute MI is the restoration of coronary blood flow - coronary reperfusion. Destruction of the thrombus and restoration of myocardial perfusion lead to limiting the extent of its damage and ultimately to improving the short-term and long-term prognosis. Therefore, all patients with STEMI should be immediately examined to clarify the indications and contraindications for restoration of coronary blood flow.

To assess the significance of the early start of reperfusion therapy, the concept of the “golden hour” was introduced: its implementation in the first 2-4 hours can completely restore blood flow in the ischemic zone and lead to the development of the so-called “interrupted” or “aborted” myocardial infarction.

Until now, there are two ways to carry out reperfusion therapy - interventional intervention (PCI) or thrombolytic therapy (TLT).

It should be noted that these two reperfusion methods can be effectively combined with each other, which has led to the coining of the term “pharmacoinvasive reperfusion strategy” (Figure).

Thus, the most relevant at the prehospital stage is the choice of the initial reperfusion method. Below are the criteria for its selection (according to, with modifications):

An invasive strategy is preferable if:

There is a 24-hour angiography laboratory and an experienced investigator who performs at least 75 primary PCIs per year, and the time from first contact with medical personnel to inflation of the balloon in the coronary artery does not exceed 90 minutes; the patient has severe complications of myocardial infarction: cardiogenic

300 mg 75 mg

Invasive coronary artery recanalization

Primary PCI Rescue PCI Facilitated PCI

1 1 Fibrinolytic Fibrinolytic

No non-invasive signs of myocardial reperfusion

Transport to an “experienced” interventional center

Drawing. Options for reperfusion therapy (adapted from Tereshchenko S.N.)

shock, acute heart failure, life-threatening arrhythmias;

There are contraindications to thrombolytic therapy (TLT): high risk of bleeding and hemorrhagic stroke;

Late hospitalization of the patient: duration of STEMI symptoms >3 hours;

There are doubts about the diagnosis of MI or a mechanism of cessation of blood flow through the coronary artery is assumed to be different from thrombotic occlusion.

Accordingly, the choice in favor of TLT occurs if:

The duration of myocardial infarction is no more than 3 hours;

PCI is impossible (there is no available angiographic laboratory or the laboratory is busy, there are problems with vascular access, there is no possibility of transporting the patient to the angiographic laboratory or there is insufficient skill to use

Table 4. Contraindications to TLT

investigator);

PCI cannot be performed within 90 minutes after the first contact with medical personnel, and also when the expected delay between the first inflation of the balloon in the coronary artery and the start of TLT exceeds 60 minutes.

According to numerous studies, starting reperfusion therapy in the early stages of treatment can significantly improve clinical outcomes of the disease. In this regard, the cornerstone of successful therapy is the ability to perform prehospital TLT.

Carrying out TLT at the prehospital stage entails a significant improvement in the prognosis and clinical outcomes for the patient. Indications for TLT are:

The time from the onset of an anginal attack does not exceed 1–2 hours;

Absolute contraindications

Previous hemorrhagic stroke or stroke of unknown etiology

Ischemic stroke suffered within the last 3 months

Brain tumor, primary and metastatic

Suspicion of aortic dissection

Presence of signs of bleeding or bleeding diathesis (except menstruation)

Significant closed head injuries in the last 3 months

Changes in the structure of cerebral vessels, for example arteriovenous malformation, arterial aneurysms

Relative contraindications

History of persistent, high, poorly controlled hypertension

AH - at the time of hospitalization - BP sys. >180 mmHg, dia. >110 mmHg)

Ischemic stroke more than 3 months old

Dementia or intracranial pathology not listed in the “Absolute Contraindications”

Traumatic or prolonged (more than 10 minutes) cardiopulmonary resuscitation or surgery within the last 3 weeks

Recent (within the previous 2-4 weeks) internal bleeding

Puncture of a vessel that cannot be pressed

For streptokinase - administration of streptokinase more than 5 days ago or a known allergy to it

Pregnancy

Exacerbation of peptic ulcer

Taking indirect anticoagulants (the higher the INR, the higher the risk of bleeding)

Table 5. Scheme of use of various thrombolytic agents

Alteplase Intravenously 1 mg/kg body weight (but not more than 100 mg): bolus 15 mg; subsequent infusion of 0.75 mg/kg body weight over 30 minutes (but not more than 50 mg), then 0.5 mg/kg (but not more than 35 mg) over 60 minutes (total infusion duration 1.5 hours)

Prourokinase Intravenous: bolus of 2,000,000 IU followed by infusion of 4,000,000 IU over 30-60 minutes

Streptokinase Intravenous infusion 1,500,000 IU over 30-60 minutes)

Tenecteplase Intravenous bolus: 30 mg for weight<60 кг, 35 мг при 60-70 кг, 40 мг при 70-80 кг; 45 мг при 80-90 кг и 50 мг при массе тела >90 kg

Table 6. Characteristics of the “ideal” drug for thrombolytic therapy (with additions and corrections by the authors)

The ECG shows an elevation of the BT segment >0.1 tM in at least 2 consecutive chest leads or 2 leads from the extremities, or LBP block appears;

The administration of thrombolytics is justified at the same time when there are ECG signs of true posterior MI (high R waves in the right precordial leads and depression of the BT segment in leads V1-V4 with the T wave directed upward).

Contraindications to TLT are presented in Table 4.

The issue of possible modification of the TLT algorithm at the prehospital stage is quite relevant. This topic is the subject of quite heated discussions. The most generally accepted point of view is that prehospital TLT should be limited to the first 6 hours from the onset of clinical symptoms, and the existing relative contraindications should be considered absolute.

Carrying out TLT at the prehospital stage is facilitated by the creation of special questionnaires, the completion of which allows the specialist to more accurately decide the question of the possibility/impossibility of TLT in each specific case. The developed questionnaires are based on indications and contraindications for TLT, with any doubt or negative answer in favor of refusing prehospital TLT.

Table 7. Comparative effectiveness and

safety of tenecteplase and alteplase (based on the results of the ASSENT-2 study with additions and corrections by the authors)

Alteplase, n = 8488 Tenecteplase, p n = 8461

Death for 30 days 6.18% 6.165 ND

In-hospital ICH 0.94% D N % t.9 0,

In-hospital massive bleeding 5.94% 4.66% 0.0002

Blood transfusions 5.49% 4.25% 0.0002

nutritional stage of medical care and developed at the Federal State Institution RKNPK Rosmedtekhnologii, is presented in Appendix 1.

Currently, four drugs are registered in the Russian Federation for TLT in ACS with elevation of the BT segment. Table 5 provides information on the doses and methods of administration of various thrombolytics.

The requirements for an “ideal” thrombolytic drug are given in Table 6.

In our opinion, the most significant factors for TLT at the prehospital stage are the effectiveness, safety and ease of use of the drug. In this regard, the most promising is the use of tenecteplase, a genetically modified form of human tissue plasminogen activator, at the prehospital stage.

Tenecteplase is not inferior in its effectiveness to tissue plasminogen activator (alteplase), and in its safety it is superior (Table 7).

At the same time, in the highest risk group (women, elderly, body weight less than 60 kg) with the introduction of tenecteplase, a reduction in the risk of stroke by 57% was observed.

Extremely simple dose selection based on body weight, simplicity of TLT with tenecteplase - intravenous bolus administration of 6-10 ml of the drug - are an additional clinical advantage in conditions of shortage of time, manpower and increased

Fast onset of action

High efficiency within 60-90 minutes with improved blood flow (grade 3 on the T1M1 scale)

Low incidence of side effects (especially bleeding and stroke)

Low re-occlusion rate

Ease of administration (bolus versus continuous infusion)

Simple dosing regimen

Good prognosis in the long term

Saving resources (financial, labor, budget)

Table 8. Indications and contraindications for the use of intravenous beta-blockers in patients with ACS in the prehospital stage

Indications Contraindications

Tachycardia - heart failure

Recurrent ischemia - AV conduction disorders

Tachyarrhythmias - severe broncho-obstructive pulmonary diseases

Arterial hypertension - increased risk of developing cardiogenic shock

high stress characteristic of providing care at the prehospital stage.

A mandatory point before performing TLT is the ability to monitor the patient’s condition and the ability to timely identify and correct possible complications.

Antithrombotic therapy

Heparins

They are a standard part of anticoagulant therapy in patients with ACS. It is recommended to start the administration of unfractionated heparin with an intravenous bolus (no more than 5000 units for ACS without BT segment elevation and 4000 units for ACS with BT segment elevation) with a further transition to intravenous infusion at a rate of 1000 units/hour and monitoring of activated partial thromboplasty. stine time every 3-4 hours.

The use of low molecular weight heparins allows one to avoid laboratory control and facilitates the heparin therapy regimen. Among the representatives of the group, enoxaparin is the most studied. It has been shown that the combined use of enoxaparin and thrombolytic therapy is associated with additional clinical benefits for the patient. In addition, if anticoagulant therapy is expected to last more than 48 hours, then the use of unfractionated heparin is associated with a high risk of thrombocytopenia.

Enoxaparin in a non-invasive treatment strategy for ACS is used according to the following regimen: intravenous bolus 30 mg, then subcutaneously at a dose of 1 mg/kg 2 times a day.

ki until the 8th day of illness. The first 2 doses for subcutaneous administration should not exceed 100 mg. In persons over 75 years of age, the initial intravenous dose is not administered, and the maintenance dose is reduced to 0.75 mg/kg (the first 2 doses should not exceed 75 mg). When creatinine clearance is less than 30 ml/min, the drug is administered subcutaneously at a dose of 1 mg/kg once a day.

When using an invasive approach to the treatment of ACS, the following must be remembered to administer enoxaparin: if no more than 8 hours have passed since the subcutaneous injection of 1 mg/kg, no additional administration is required. If this period is 8-12 hours, then immediately before the procedure enoxaparin should be administered intravenously at a dose of 0.3 mg/kg.

Fondaparinux

The Scottish national guidelines for the treatment of ACS recommend immediate administration of fondaparinux once electrocardiological signs of ACS are established: patients with elevation of the ACS who will not undergo reperfusion therapy should immediately receive fondaparinux.

These recommendations, however, do not directly speak about the need for administration at the prehospital stage, but only paraphrase the words of the instructions, which indicate: the recommended dose is 2.5 mg once a day. The first dose is administered intravenously, all subsequent doses are administered subcutaneously. Treatment should begin as soon as possible after diagnosis and continue for 8 days or until the patient is discharged.

Table 9. Doses of beta blockers when used in patients with ACS in the prehospital stage

Drug Dose

Metoprolol succinate IV 5 mg 2-3 times with an interval of at least 2 minutes; first oral administration 15 minutes after intravenous administration

Propranolol IV 0.1 mg/kg in 2-3 doses at intervals of at least 2-3 minutes; first oral administration 4 hours after intravenous administration

Esmolol IV infusion at an initial dose of 0.05-0.1 mg/kg/min, followed by a gradual increase in dose by 0.05

mg/kg/min every 10-15 minutes until the effect or dose of 0.3 mg/kg/min is achieved; for a faster onset of effect, an initial administration of 0.5 mg/kg over 2-5 minutes is possible. Esmolol is usually discontinued after the second dose of an oral β-blocker if proper heart rate and blood pressure have been maintained during their combined use.

Application. Decision Checklist

by the medical and paramedic team of the EMS to conduct TLT for a patient with acute coronary syndrome (ACS)

Check and mark each of the indicators given in the table. If all the boxes in the “Yes” column and none in the “No” column are checked, then thrombolytic therapy is indicated for the patient.

If there is even one unchecked box in the “Yes” column, TLT therapy should not be carried out and filling out the checklist can be stopped

"Not really"

The patient is oriented and can communicate. The pain syndrome characteristic of ACS and/or its equivalents lasts for at least 15-20 minutes, but no more than 12 hours. After the disappearance of the pain syndrome characteristic of ACS and/or its equivalents, no more than 3 hours have passed. A qualitative assessment has been performed. registration of an ECG in 12 leads. The EMS doctor/paramedic has experience in assessing changes in the BT segment and bundle branch block on an ECG (test only in the absence of a remote ECG assessment by a specialist)

There is a rise in the BT segment by 1 mm or more in two or more adjacent ECG leads or a left bundle branch block is registered, which the patient did not have before. The EMS doctor/paramedic has experience in performing TLT. Transporting the patient to the hospital will take more than 30 minutes. It is possible to receive medical recommendations from a hospital cardioreanimatologist in real time

During the transportation of the patient, there is the possibility of constant ECG monitoring (at least in one lead), intravenous infusions (a catheter is installed in the cubital vein) and urgent use of a defibrillator Age over 35 years for men and over 40 years for women Systolic blood pressure does not exceed 180 mm Hg

Diastolic blood pressure does not exceed 110 mm Hg.

The difference in systolic blood pressure levels measured on the right and left arms does not exceed 15 mmHg. Art.

There are no indications in the medical history of a stroke or the presence of other organic (structural) pathology of the brain. There are no clinical signs of bleeding of any location (including gastrointestinal and urogenital) or manifestations of hemorrhagic syndrome. The submitted medical documents do not contain data on the patient undergoing long-term (more than 10 minutes) ) cardiopulmonary resuscitation or the presence of internal bleeding in the last 2 weeks; the patient and his relatives confirm this

The submitted medical documents do not contain data on the past 3 months. surgical operation (including on the eyes using a laser) or serious injury with hematomas and/or bleeding, the patient confirms this. The submitted medical documents do not contain data on the presence of pregnancy or the terminal stage of any disease, and survey and examination data confirm this The presented medical documents do not contain data on the presence of jaundice, hepatitis, renal failure in the patient, and the data from the survey and examination of the patient confirm this

: TLT for the patient__________________________________________________________ (full name)

SHOWN CONTRAINDICATED (circle what is necessary, cross out what is unnecessary)

The sheet was filled out by: Doctor / paramedic (circle as necessary)__________________________ (full name)

Date_________________Time___________ Signature___

The check sheet is sent with the patient to the hospital and filed in the medical history.

Time to start antithrombotic therapy in a patient with ACS

It should be especially emphasized that the earlier antithrombotic treatment of a patient with ACS is started, the greater the likelihood of a successful clinical outcome. That is why the use of antiplatelet agents (aspirin, clopidogrel) and anticoagulants must begin at the prehospital stage.

Other medicines

Beta blockers

In order to reduce the myocardial oxygen demand in ACS, it is necessary to prescribe beta-blockers. At the prehospital stage, it is advisable to use intravenous forms of beta blockers both for the speed of onset of the clinical effect and for the possibility of quickly reducing the effect with the possible occurrence of side effects (Tables 8,9).

ACE inhibitors

During the first 24 hours from the development of ACS, it is advisable to use drugs from the group of blockers of the activity of the renin-angiotensin system - ACE inhibitors or angiotensin receptor antagonists. However, the initiation of such therapy is recommended after the patient is hospitalized in a hospital.

Conclusion

The prehospital stage of providing medical care to patients with ACS and elevation of the 5T segment is the foundation for successful treatment and a favorable prognosis for the patient. Training specialists in treatment and diagnostic algorithms will help reduce cardiovascular morbidity and mortality in the Russian Federation.

Literature

1. Diagnosis and treatment of patients with acute myocardial infarction with ST segment elevation of the ECG. In Oganov R.G., Mamedov M.N., editors. National clinical guidelines. M.: MEDI Expo; 2009.

2. Van de Werf F, Bax J, Betriu A et al. Management of acute myocardial infarction in patients presenting with persistent ST-segment elevation: the Task Force on the Management of ST-Segment Elevation Acute Myocardial Infarction of the European Society of Cardiology. Eur Heart J 2008;29(23):2909-45.

3. Dudek D., Rakowski T., Dziewierz A. et al. PCI after lytic therapy: when and how? Eur Heart J Suppl 2008; 10(suppl J): J15-J20.

4. Scottish Intercollegiate Guidelines Network. Acute coronary syndromes. A national clinical guideline. Available on http://www.sign.ac.uk/pdf/sign93.pdf.

5. Chazov E.I., Boytsov S.A., Ipatov P.V. A task of large scale. Improving the technology for treating ACS as the most important mechanism for reducing cardiovascular mortality in the Russian Federation. Modern Medical Technologies 2008;(1):35-8.