Purpose: To examine the association between cyclooxygenase-2 (COX-2) selective and traditional nonsteroidal anti-inflammatory drugs (NSAIDs) and incident acute myocardial infarction (AMI), and to address unanswered questions regarding the contour of risk over time.
Methods: A cohort of new NSAID users aged 40-84 years was followed for the occurrence of first AMI. Data were collected within the General Practice Research Database (GPRD) from 1 January 1997 to 31 December 2004.
Results: The study population included 1185 AMI events (889 probable and 296 possible) from a cohort of 283 136 patients. After adjustment for demographic and cardiovascular risk factors, the hazard ratio (HR) for AMI was significantly increased for both coxib (2.11, 95% confidence interval (CI) 1.04-4.26) and non-coxib (2.24, 95%CI 1.13-4.42) COX-2 selective NSAIDs when compared to remote exposure to NSAIDs, but was not increased for traditional NSAIDs. Stratifying exposure into the first month of use versus use beyond 1 month, the risk of AMI was increased during the first month of COX-2 selective NSAIDs use, but not later (3.43, 95%CI 1.66-7.07 and 1.88, 95%CI 0.82-4.31, respectively p-value for interaction = 0.6).
Conclusions: The results suggest that the use of coxib and non-coxib COX-2 selective NSAIDs was associated with an elevated risk of AMI within the first month of exposure. Recent past exposure to NSAID was not associated with a similar increase in risk.