THROMBOLYSIS AND ACUTE MYOCARDIAL INFARCTION (AMI)

AMI is a major cause of morbidity and mortality in modern society Conventional treatment has no benefic effect on the size of infarct, alteration of left ventricular (LV) function and mortality. Intravenous (IV) thrombolysis reduces in hospital mortality by 23 % if infused within 3 hours of ischemia, 47 % if within 1 hour. It reduces the size of infarct by 51 % if reperfusion occurs within 1 hour of ischemia, 31 % if between 1 and 2 hours and 13 % if between 2 and 4 hours. The preservation of LV function is of 28 to 42%. These benefic effects, thanks to IV thrombolysis, can be obtained only if reperfusion occurs within 3 or 4 hours of ischemia. Unfortunately, a french prospective study “ENIM 84” estimates that the mean delay between onset of chest pain and arrival at hospital is 10,3 hours.Goals of the study were to show that “at home” thrombolysis: 1) is a feasible and a safe technique, 2) is responsible of a significant saving of time, 3) preserves LV function according to the precocity of treatment.Two groups of patients (pts) are compared : group A : 62 pts had “at home” thrombolysis by a trained medical staff aboard a mobile emergency care unit. Group B : 53 pts had thrombolysis at arrival at CCU. Protocol is simular in both groups : An IV infusion of 1 5 M iu of streptokinase over 45 to 60 min after an IV bolus of 100 mg Hydrocortisone. Criteriae and contra-indications are those usually used for thrombolysis. Radionuclide angiography was performed 4 days and 1 month after AMI to evaluate global and regional ejection fraction (EF). Only 1 hemorrhagic complication (a mild melaena) and 2 reversible ventricular fibrillations were reported. Reperfusion arrythmias were frequent (55 %) but do not need treatment. The number of candidates for thrombolysis is then increased. The saving of time is 73 min. Difference between the 4 days and 1 month EF is not significant in pts with conventional treatment or if reperfusion occurs after 4 hours of ischemia 48 ± 11 % vs 51 ± 13 %.But it is significant if before 4 hours 49 ± 11 % vs 56 ± 12 % and highly significant if before 2 hours 48 ± 12 % vs 59 ± 10 %.