METHODS AND RESULTS: Using combined data from the Global Utilization of
Streptokinase and
Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO I) and Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO III) trials (n=48 422
ST-elevation myocardial infarction patients), we compared the association between initial
aspirin dose of 162 versus 325 mg and 24-hour and 7-day mortality, as well as rates of in-hospital moderate/severe
bleeding. Results were adjusted for previously identified mortality and
bleeding risk factors. Overall, 24.4% of patients (n=11 828) received an initial
aspirin dose of 325 mg, and 75.6% (n=36 594) received 162 mg. The 24-hour mortality rates were 2.9% versus 2.8% (P=0.894) for those receiving an initial
aspirin dose of 325 versus 162 mg. Mortality rates at 7 and 30 days were 5.2% versus 4.9% (P=0.118) and 7.1% versus 6.5% (P=0.017) among patients receiving the 325 versus 162 mg
aspirin. After adjustment,
aspirin dose was not associated with 24-hour (odds ratio [OR], 1.01; 95% CI, 0.82 to 1.25), 7-day (OR, 1.00; 95% CI, 0.87 to 1.17), or 30-day (OR, 0.99; 95% CI, 0.87 to 1.12) mortality rates. No significant difference was noted for
myocardial infarction or the composite of death or
myocardial infarction between groups. In-hospital moderate/severe
bleeding occurred in 9.3% of those treated with 325 mg versus 12.2% among those receiving 162 mg (P<0.001). After adjustment, 325 mg was associated with a significant increase in moderate/severe
bleeding (OR, 1.14; 95% CI, 1.05 to 1.24; P=0.003).
CONCLUSIONS: