Long-term follow-up of gender-specific outcomes after thrombolytic therapy for acute myocardial infarction from the GUSTO-I trial. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

Abstract

Our objective was to assess gender differences in mortality 1 year after acute myocardial infarction (MI). The Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial database of 41,021 patients with suspected acute MI was used to generate 1-year Kaplan-Meier survival plots. Risk quartiles and mortality of women and men were compared. The unadjusted 1-year mortality rate for the initial GUSTO-I population and 30-day survivors demonstrates a large gender gap [odds ratio for all patients = 2.2, 95% confidence interval (CI), 2.0-2.3, p < 0.001]. For the initial population, when adjusted for age, the gender gap is still apparent (odds ratio = 1.4, 95%, CI = 1.3-1.5, p < 0.001) although no longer significant when adjusted using the 30-day survival model (odds ratio = 1.06, 95% CI = 0.97-1.15, p < 0.001). For the 30-day survivors, adjustment based on age alone explained the 1-year mortality difference (risk ratio = 0.96, 95% CI 0.85-1.07, p = 0.441). When the population was divided into expected risk quartiles, women were more likely to fall into the higher expected risk quartiles, even after adjusting for age. A gender gap after acute MI is apparent, nearly all of which occurs within the first 30 days. A substantial portion of the gender gap is explained by the increased age of women, and the rest of the gap may be attributed to differences in variables predictive of 30-day mortality. During 1-year follow-up, the late mortality of women is no greater than that of age-matched men.