Intravenous streptokinase in acute evolving myocardial infarction--six to thirty-six months follow up.

ABSTRACT

270 consecutive patients who presented within six hours of the onset of acute myocardial infarction (AMI) and had no contraindication to thrombolytic therapy received intravenous infusion of 750,000 units of streptokinase (STK) in thirty minutes followed by heparin and oral anticoagulants. Treatment was instituted within 210 +/- 64 minutes after the onset of symptoms and reperfusion was achieved in 44 +/- 21 minutes. Reperfusion was recognised by indirect criteria in 249 patients, (92.2%) in the 0-6 hours group and 100% in the 0-3 hours group in all 72 patients. 2D echo LV ejection fraction (LVEF) improved from 51.6% +/- 9.4% at 0 hours to 60.61 +/- 8.4% at first week. In 40 patients (14.8%) there was early reocclusion in mean time of 36 +/- 13 hours of treatment. The incidence of reocclusion was higher in patients with anterior wall AMI than with inferior wall AMI. Reocclusion was also more frequent in patients who were administered adjuvant Dipyridamole therapy. In 36 of these patients reperfusion was achieved with an additional dose of streptokinase. During the last thirty-six months follow up, treadmill stress test was positive in 15 out of 80 (18.8%) streptokinase group subjected to it as compared to 42.2% conventionally managed patients. No LV thrombus, aneurysm or papillary muscle dysfunction was seen. 25 patients (9.2%) underwent coronary angiography six weeks later. CABG was undertaken in only 18 patients (6.6%) along with endarterectomy in one (.37%). None of the patients required additional aneurysmectomy or valve replacement. Elderly patients (above 75 years) suffered major haemorrhagic complications (.37%) and 17% of patients had minor bleeds. In-hospital mortality was 4.8% as compared to 10.2% in the control group (P less than .05). A long-term follow-up (6-36 months) revealed 11 patients that (4.07%) had reinfarction at mean time of 18 +/- 11 months (P less than .05). The late mortality rate in 6-36 months follow up was was 1.8% (P less than .05). It was concluded that intravenous streptokinase in acute myocardial infarction along with long-term anticoagulants is safe and effective. It reduces early and late mortality and morbidity significantly. A conservative strategy of subjecting patients to CABG after effective thrombolysis was found satisfactory during six to thirty-six months follow-up.