Thrombolysis for Acute Myocardial Infarction

Indlvldual studies of patency rates and left ventricular (LV) function after thrombolysis have generally been limited by small numbers of observations, wide confidence intervals, and limRed numbers of time points. To obtain a more reliable estimate of patterns of patency and LV ejection fraction, a systematic overview of anglographic studies was performed after itira= venous thrombolytic therapy. A total of 14,124 anglo@aphic observations from 58 studies evaluating patency after no thrombolytic agent, strep toklnase, standard dose tissuetype plasmhmgen activator (WA), accelerated dose t-PA, or anlstreplase (anisoylated plasminogen streptoldnase activator complex [APSAC]) were included. At 60 and SO minutes, stmptokinase had the lowest patency rates of 48% and 51%, respectively, standard dose t-PA and APSAC had similar Intermediate rates of approximately 80% and 70%, and accelerated t9A had the highest patency rates of 74% and 84%. By 2 to 3 hours and longer, the patency rates were similar for the various reghnens. Reocclusion rates in studles Including 1,172 patlents randomized to t-PA versus TV nonflbrhrspeciflc agent were higher after &PA (13.4% vs S.O%, p q 0.002). Ten studies enrolling 4,088 patients treated with thrombolytlc therapy versus control demonstrated a modest improvement in mean LV ejection fraction in the thrombolytic group at each of the times after thrombolytlc therapy: hour 4, day 1, day 4, day 7 to 10, and day 10 to 28 after thromboiysis. By 4 days, mean ejection fraction was 53% versus 47% (thrombolytic vs control therapy, p eO.01); by 10 to 28 days it was 54.1% and 51.5%, respectlvely. In conclusion, this pooled analysis shows that accelerated t-PA resulted in higher minute coronary arterial patency rates than other standard regimens, but that by 2 to 3 hours the rates were similar, and that reocclusion rates were higher after t-PA than nonflbriu