Effect of selective cyclooxygenase 2 inhibitors and naproxen on short-term risk of acute myocardial infarction in the elderly

Background: Recent debate has emerged regarding the cardiovascular safety of selective cyclooxygenase 2 inhibitors and the possible cardioprotective effect of naproxen sodium. We compared the rates of acute myocardial infarction (AMI) among elderly patients dispensed selective cyclooxygenase 2 inhibitors, naproxen, and nonselective nonnaproxen nonsteroidal antiinflammatory drugs (NSAIDs). Methods: We conducted a population-based retrospective cohort study using administrative health care data from Ontario, Canada, from April 1, 1998, to March 31, 2001. We identified NSAID-naive cohorts of subjects aged 66 years and older in whom treatment was initiated with celecoxib (n = 15 27 1), rofecoxib (n = 12 156), naproxen (n=5669), and nonnaproxen nonselective NSAIDs (n = 33 868), along with a randomly selected control cohort not exposed to NSAIDs (n =100 000). Multivariate Cox proportional hazards models were used to compare AMI rates between study drug groups while controlling for potential confounders. Results: Relative to control subjects, the multivariate model showed no significant differences in AMI risk for new users of celecoxib (adjusted rate ratio [aRR], 0.9; 95% confidence interval [CI], 0.7-1.2), rofecoxib (aRR, 1.0; 95% Cl, 0.8-1.4), naproxen (aRR, 1.0; 95% Cl, 0.6-1.7), or normaproxen nonselective NSAIDs (aRR, 1.2; 95% Cl, 0.9-1.4). Conclusions: The findings of this observational study suggest no increase in the short-term risk of AMI among users of selective cyclooxygenase 2 inhibitors as commonly used in clinical practice. Furthermore, the findings do not support a short-term reduced risk of AMI with naproxen.