Intravenous versus intracoronary streptokinase in acute myocardial infarction

Abstract

One hundred sixty-four consecutive patients with acute myocardial infarction were enrolled in a prospective trial of coronary thrombolysis with streptokinase (STK). The first 98 patients received intracoronary(i.c.) STK after coronary angiography and the next 66 received a high-dose rapid infusion of STK (900,000 IU) intravenously (i.v.) before angiography. First-pass radionuclide ejection fraction (EF) was performed early (within 24 hours of admission and late (10 to 14 days after admission) to evaluate left ventricular function. In the i.v. group, 42 of 66 (64%) of infarct-related arteries were patent at the initial angiogram and 6 (9%) opened with subsequent i.c. STK. In the i.c. group, 13 of 98 (13%) of infarct-related arteries were patent at the initial angiogram and 50 of 85 (59%) opened with the i.c. STK. The i.v. and i.c. groups did not differ in time from onset of chest pain to presentation, type of infarct or underlying severity of coronary artery disease. In the i.v. group, STK was begun 67 minutes earlier than in the i.c. group. In 62 patients in whom reperfusion was successful, mean EF increased from 39 ± 11% early to 48 ± 13% late. In 30 in whom it was not, the mean EF increased from 36 ±10% to 40 ± 12%. The increase in EF was significantly greater in patients in the reperfused group (p < 0.03). In 18 patients who underwent reperfusion by i.v. STK, the mean EF increased 11 ± 12%, whereas in 44 patients who had reperfusion by i.c. STK, the mean EF increased 9 ± 10% (difference not significant). Complications of the lysis procedure were similar in the i.v. and i.c. groups. Thus, i.v. and i.c. STK are of comparable efficacy and safety in establishing reperfusion of the infarct-related artery in patients with acute myocardial infarction.