Recurrent ischemia after thrombolysis for acute myocardial infarction

Abstract

Background: Reliable predictors have yet to be found for recurrent ischemia after thrombolysis for acute myocardial infarction (AMI), nor do we know whether early angiography can herald recurrent ischemia. This study sought to investigate the relationship between recurrent ischemia and cardiac procedures after thrombolysis for AMI.

Methods: The Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial prospectively studied recurrent ischemia, which was defined as the presence of angina and changes in hemodynamics or the electrocardiogram. Cox regression analysis was used to identify predictors of recurrent ischemia. Other variables examined included time to coronary angiography and revascularization.

Results: Of 21,772 US GUSTO-I patients, 6313 (29%) had recurrent ischemia before discharge. Women (hazard ratio [HR] 1.25, 95% confidence interval [CI] 1.17-1.33) and patients with hypercholesterolemia (HR 1.14, 95% CI 1.07-1.22) or prior angina (HR 1.40, 95% CI 1.32-1.49) had a higher likelihood of recurrent ischemia. Current smoking and hours to thrombolysis were inversely related to recurrent ischemia (HR 0.86, 95% CI 0.81-0.92, HR 0.97, 95% CI 0.95- 0.99, respectively). Patients who underwent angiography before recurrent ischemia had a marginally increased risk of ischemia within 12 hours after angiography (HR 1.2, 95% CI 1.1-1.4); ultimately, they had a considerably lower risk 1 week after angiography than did patients without angiography (HR 0.57, 95% CI 0.45-0.72).

Conclusions: Female sex, hypercholesterolemia, prior angina, and nonsmoking status weakly predict recurrent ischemia. Early coronary angiography reduces recurrent ischemia, probably because high-risk patients are identified and revascularized.