Current use of nonsteroidal antiinflammatory drugs and the risk of acute myocardial infarction

Study Objective. To evaluate the risk of acute myocardial infarction during current exposure to nonsteroidal antiinflammatory drugs (NSAIDs). Design. Retrospective case-control analysis. Setting. General practice offices. Subjects. A total of 8688 case patients, aged 89 years or younger, with a first-time acute myocardial infarction and 33,923 control subjects matched on age, sex, calendar time, and general practice attended. Intervention. The United Kingdom General Practice Research Database was searched for potential cases of first-time acute myocardial infarction between January 1995 and April 2001. Control subjects without acute myocardial infarction were identified at random. Measurements and Main Results. Exposure to NSAIDs was assessed, and 650 case patients and 2339 control subjects were found to be currently taking NSAIDs. After adjusting for various risk factors for acute myocardial infarction (e.g., hypertension, hyperlipidemia, diabetes mellitus, ischemic heart disease, body mass index, smoking), the relative risk (expressed as odds ratio [OR]) of acute myocardial infarction was 1.07 (95% confidence interval [CI] 0.96-1.19) for subjects with current NSAID exposure compared with those not taking NSAIDs. The adjusted OR for current diclofenac use was 1.23 (95% Cl 1.00-1.51), for current ibuprofen use 1.16 (95% CI 0.92-1.46), and for current naproxen use 0.96 (95% CI 0.66-1.38) compared with those not taking NSAIDs. Current aspirin use combined with current NSAID use was associated with a statistically significant risk reduction (adjusted OR 0.74, 95% CI 0.57-0.97), compared with nonuse of NSAIDs and aspirin. Current use of aspirin together with current use of ibuprofen yielded an adjusted OR of 0.69 (95% CI 0.42-1.15). Conclusions. Our results provide additional evidence that the risk of first-time acute myocardial infarction during current use of NSAIDs is not materially altered. We found no evidence for a reduced cardioprotective effect of aspirin with concomitant NSAID use.