Background: Trials report a 2% to 6% incidence of reinfarction after fibrinolysis for acute myocardial infarction (MI). We combined the Global Utilization of Streptokinase and Tissue plasminogen activator (alteplase) for Occluded coronary arteries (GUSTO I) and Global Use of Strategies To Open occluded coronary arteries (GUSTO III) populations to better define frequency, timing, and clinical predictors of in-hospital reinfarction.
Methods and results: In 55 911 patients with ST-segment elevation myocardial infarction (MI) who were receiving fibrinolysis, we compared baseline characteristics and mortality rate by reinfarction incidence and developed multivariable logistic regression models to predict in-hospital reinfarction and composite of death or reinfarction. Reinfarction occurred in 2258 patients (4.3%) a median of 3.8 days after fibrinolysis; rates did not differ between GUSTO I (4.0%) and GUSTO III (4.2%) or by fibrinolytic assignment (streptokinase, 4.1%; alteplase, 4.3%; reteplase, 4.5%; combined streptokinase and alteplase, 4.4%; P=0.55). Advanced age, shorter time to fibrinolysis, non-US enrollment, nonsmoking status, prior MI or angina, female sex, anterior MI, and lower systolic blood pressure were associated significantly with reinfarction. Patients with reinfarction had higher mortality at 30 days (11.3% versus 3.5% without reinfarction; odds ratio, 3.5; P<0.001) and from 30 days to 1 year (4.7% versus 3.2%; hazard ratio, 1.5; P<0.001). Significant multivariate predictors of in-hospital death or reinfarction included age, Killip class, systolic and diastolic blood pressures, heart rate, anterior MI, smoking status, prior MI, sex, and country of enrollment (all P<0.001).
Conclusions: Reinfarction occurs infrequently after fibrinolysis but confers increased risk of 30-day and 1-year mortality. Some predictors of reinfarction differ from known predictors of death after MI. Improved treatment and prevention strategies for reinfarction deserve study.