Survival 12 years after randomization to streptokinase: The influence of thrombolysis in myocardial infarction flow at three to four weeks

OBJECTIVES The purpose of this study was to determine whether the mortality benefit of intravenous streptokinase administered within 4 h of the onset of acute myocardial infarction is maintained at 12 years, and whether Throm bolysis in Myocardial Infarction (TIMI) flow grades independently influence late survival. BACKGROUND Treatment with reperfusion therapies and achievement of TIMI 3 f low are associated with increased short- and medium-term survival after inf arction. Whether infarct artery flow independently influences survival more than five years after infarction is unknown. METHODS The late survival of patients randomized to receive either streptok inase (1,500,000 IU over 30 to 60 min) or a matching placebo within 4 h of symptom onset in 1984-1986 was determined. Angiography was performed in sur viving patients at three to four weeks, and TIMI flow grades were assessed blind to randomization and outcomes. The late vital status was determined i n 99% of patients. RESULTS Patients randomized to receive streptokinase (n = 107) had improved survival compared with those randomized to placebo (n = 112) at five years (84% vs. 70%;; p = 0.023) and 12 years (66% vs. 51%; p = 0.022). At five y ears 94% of patients with TIMI grade 3 flow, 81% of those with TIMI grade 2 flow and 72% of those: with TIMI grade 0-1 flow survived (p = 0.005). At 1 2 years 72% of patients with TIMI 3, 67% of those with TIMI 2 and 54%, of t hose with TIMI 0-1 flow survived (p = 0.023). Multivariate analysis identif ied tie ejection fraction (p = 0.014), exercise duration (p = 0.013) and TI MI 3 flow (p = 0.04 compared with TIMI 0-2 flow) as important factors for f ive-year survival. At 12 years multivariate predictors of late survival wer e the ejection fraction (p = 0.006), exercise duration (p = 0.003) and myoc ardial score (p = 0.013). The end-systolic volume index was similar to the ejection fraction as a predictor of survival at five and 12 years. CONCLUSIONS The survival benefits of streptokinase persist for 12 years aft er infarction. TIMI flow at three to four weeks is an independent predictor of five-year survival. (C) 1999 by the American College of Cardiology.