Intravenous streptokinase in acute myocardial infarction: Experience of community hospitals served by paramedics

Abstract

We studied 58 consecutive patients, ages 37 to 78, who were given intravenous streptokinase (IV STK) early in the course of acute myocardial infarction (AMI) in three community hospitals served by the same mobile intensive care system. Forty-four patients (76%) received IV STK within 3 hours and 53 patients (92%) received it within 4 hours of onset of chest pain. Half the patients were brought to the hospital by paramedics. The average time from pain to administration of IV STK for paramedic patients was 100 minutes vs 198 minutes for those brought by other modes. Fifty of 58 patients (86%) showed clinical evidence of reperfusion. Forty-six of 54 patients (85%) studied with coronary angiography an average of 6 days post infarction had patent vessels subtending the infarcted region of the myocardium. The average angiographic ejection fraction was 47% for patients with reperfused vessels vs 34% for those with occluded vessels. The in-hospital mortality was 2 of 58 patients (3.4%). There was one late death at 8 months (total 5.2%). Twenty-one patients eventually had coronary bypass surgery and 5 patients had angioplasty. The remaining 29 patients had conventional therapy including 6 months of warfarin sodium. Fifty-four of 55 surviving patients (98%) are in functional class I or II and none have angina at 2 to 18 months of follow-up. Fifty-one of 55 patients are back at work. Conclusions: (1) IV STK is effective in coronary thrombolysis in a high percentage of AMI patients. (2) IV STK is safely administered in community hospitals. (3) Paramedics act as an early warning system and allow for earlier treatment of patients than do patients presenting without paramedic involvement. (4) Successful coronary reperfusion with IV STK results in low mortality rates for AMI patients and minimizes functional disability.