Aspirin as Primary Prevention of Acute Coronary Heart Disease Events

Background/Objective: Aspirin for primary prophylaxis is controversial. This study evaluated associations between prophylactic aspirin use and incident acute coronary heart disease (CHD) events.
Methods and Results: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study was accessed for aspirin use examining black and white hazards for incident CHD, for men and women, each adjusting incrementally for sampling, socio-demographics, and CHD risk factors. Stratified models examined risks across strata of the Framingham risk score, and all-cause mortality. 23,949 participants (mean 64 yo), had 503 incident events over a 3.5 year follow-up. Prophylactic aspirin use was not associated with incident acute CHD, HR 1.05 (95% CI 0.86, 1.29). Modeling had little impact on the HR (1.09 {95% CI 0.89, 1.33) nor did the addition of risk factors (HR 1.00 {95% CI 0.81, 1.23). Aspirin use was not associated with incident CHD for any Framingham risk level. Findings were similar when including all aspirin users (not just those taking aspirin prophylactically), and when examining associations with all-cause mortality. There was no excess hospitalized bleeding in the aspirin users.
Conclusion: Aspirin was not associated with lower risk for incident acute CHD overall, or within race, gender, or Framingham Risk Score.