EFFICACY OF 100 MG OF DOUBLE-BOLUS ALTEPLASE IN ACHIEVING COMPLETE PERFUSION IN THE TREATMENT OF ACUTE MYOCARDIAL-INFARCTION

Objectives. The purpose of this study was to assess the efficacy of 15 0 mg of aspirin plus 100 mg of alteplase, administered as two intraven ous bolus injections of 50 mg each given 30 min apart, and followed by intravenous heparin, on infarct-related coronary artery patency (Thro mbolysis in Myocardial Infarction [TIMI] flow grade 3). Background. Pr evious workers have shown in animals that reducing the duration of an infusion of recombinant tissue-type plasminogen activator increases th e initial rate of thrombolysis, resulting in high early infarct-relate d coronary artery patency rates. The logical progression of this idea is bolus administration. Methods. Consecutive patients presenting up t o 6 h from the onset of symptoms were recruited for the study. Angiogr aphy was performed at 60 and 90 min after the first bolus and between 19 to 48 h after study entry. Patients were followed up for 1 month. R esults. At 60 min, angiography revealed infarct-related coronary arter y patency of TIMI flow grade 3 in 55 (86%) of 64 patients (95% confide nce interval [CI] 75% to 93%) and TIMI flow grade 2 or 3 in 58 (91%) o f 64 patients (95% CI 81% to 97%). At 90 min, infarct-related artery p atency of TIMI flow grade 3 was achieved in 74 (88%) of 84 patients (9 5% CI 79% to 94%) and TIMI How grade 2 or 3 in 78 (93%) of 84 patients (95% CI 85% to 97%). Two patients (2.4%) had early angiographic reocc lusion whereas 10 (11.9%) had late reinfarction. Bleeding episodes wer e mostly minor, and there was no cerebrovascular bleeding. Five patien ts (6.0%) died within 1 month of the acute myocardial infarction. Conc lusions. In 84 patients with acute myocardial infarction, administrati on of 100 mg of double-bolus (2 x 50 mg) alteplase, aspirin and hepari n is associated with remarkably high early infarct-related coronary ar tery patency rates (TIMI flow grade 3) of 86% and 88%, respectively, a t 60 and 90 min.