Intravenous thrombolytic therapy in unstable angina

One hundred consecutive age and sex-matched patients of 3 different subsets of unstable angina (recent onset angina -65, crescendo angina -20, post-infarct angina-15) were randomized 1:1 after coronary angiography to receive I.V., either 1.5 x 10(6) units of streptokinase (SK) in 200 ml of normal saline or 200 ml of normal saline alone (control) in 1 hour. Repeat angiography was done in those patients having intra-coronary thrombi (37.3%) during the initial angiography. Both groups received optimal doses of heparin followed by warfarin, aspirin and other standard drugs and were followed up for 6 months. Anginal pain subsided significantly in the SK group-41 (82%) vs 25 (50%) (P < 0.005), especially in patients with recent onset angina (92.5% vs 60%, P < 0.005). Incidence of acute myocardial infarction (AMI) was much less in the SKgp (4(8%) vs 17 (34%) (p < 0.05). Four cases of fatal MI and four cases of sudden cardiac death (SCD) occurred in the control group against none in the SKgp. Requirements of mechanical revascularization was significantly less (P < 0.05) in the SK gp. Angiographic evidence of partial or complete clot lysis was noted in 90% of SK gp. vs 4.8% of control (P < 0.01). Echocardiographically assessed LV function improved significantly with SK-therapy in recent onset (P < 0.05) and crescendo angina (P < 0.001) subsets--however, the improvements in post infarct angina subset were not statistically significant. The beneficial outcome with SK therapy was observed in patients irrespective of angiographic evidence of thrombi.(ABSTRACT TRUNCATED AT 250 WORDS)