EFFICACY OF INTRAVENOUS STREPTOKINASE IN ACUTE MYOCARDIAL INFARCTION: ACUTE AND FOLLOW UP STUDY

Abstract

The efficacy of intravenous streptokinase on recanalization of the 'infarct vessel' and its effect on left ventricular function was assessed in two groups of patients. Group I consisted of 90 consecutive patients (age 32-75 years, mean 56 years) received 500,000 units of intravenous streptokinase (STK) over 30 minutes within 6 hours of onset of acute myocardial infarction (MI). Forty-eight patients had anterior MI and forty-two had inferior MI. The control group consisted of forty survivors of acute MI comparable in age and site of infarction. In Group I, ten patients were administered STK after baseline coronary angiogram demonstrated total occlusion of infarct related coronary artery. In these patients, serial coronary angiogram were done at intervals of 30 minutes after STK infusion upto a period of 3 hours. Recanalization was seen in all cases within 75-135 minutes (average 120 minutes). Seventy-nine of STK group and all of the control group underwent selective coronary arteriography and contrast left ventriculography within 48 to 72 hours of acute MI. Recanalization of infarct related artery was demonstrated in 72 out of 79 patients (91%) in STK group while 8 (20%) in control group had spontaneous recanalization. Left ventricular ejection fraction (LVEF) was higher in STK group (58%) as compared to control group (49%). Among patients with anterior MI, LVEF was significantly better in STK compared to control group (59% Vs. 44%, p > 0.01)while in inferior MI the difference was not significant (63% Vs. 59.4%, p > 0.05) in the two groups. Follow up study in 20 STK patients at 6 months revealed a decrease in residual stenosis from 75 ± 8% to 60 ± 6% and improvement in LVEF from 59 ± 8% to 68 ± 12% (p > 0.01). In conclusion, intravenous STK in acute MI results in high rate of infarct vessel patency and improved global left ventricular function during both early and late follow up period.