Prehospital Thrombolysis in Acute Myocardial Infarction

Abstract

AbstractIntroduction:The effectiveness and safety of thrombolytic treatment (TT) for acute myocardial infarction (AMI) in the prehospital setting have not been defined. Therefore, its use on a mobile coronary care unit (MCCU) was studied.Methods:A MCCU was provided with the equipment and supplies necessary for the administration TT and its personnel were trained in the indications for TT and in its administration. When an emergency medical team physician suspected the diagnosis from the presence of chest pain typical of an AMI, the patient's ECG was transmitted to the Cardiological Consulting Center. If the S-T segments were elevated and the patient met all of the screening criteria, the cardiologist ordered the MCCU personnel to carry out TT. Streptokinase (Avelyzin, Germed, GDR) was administered intravenously at a dose of 500,000 UE.Results:Sixty-seven patients with AMI were included in the trial. The mean interval between the onset of the symptoms and the beginning of the TT was 156±77 minutes; it was less than 3 hours for 54 patients. Thirty-four patients (50.7%) had non-invasive markers of successful reperfusion, while 33 (49.3%) did not. Three patients had non-fatal ventricular fibrillation (VF), ventricular tachycardia (VT) and/or ventricular premature beats of high grades (Lown classes 3–5) developed in six and 22 patients respectively. Five patients had conduction disturbances, and 40 had symptomatic hypotension. None of the patients died before arrival at the hospital. Four suffered reinfarction, and one died of VF during the in-hospital phase of care. Post-discharge follow-up (17.5±5.0 months) demonstrated a positive exercise test in 23 (43%), and a left ventricular ejection fraction >80% in 29 (85.2%) and <40% in five (14.8%) of the patients. The in-hospital and post-discharge mortalities were 1.5 and 4.8% respectively. There was not a single case of bleeding sufficient to require a transfusion.Conclusions:The study indicates that the administration of TT for AMI in the prehospital setting is both safe and effective.