Cyclooxygenase-2 selectivity of non-steroidal anti-inflammatory drugs and the risk of myocardial infarction and cerebrovascular accident

Aim To assess degree of cyclooxygenase-2 (COX-2) selectivity of a non-steroidal anti-inflammatory drug (NSAID) and risk of myocardial infarction (MI) or cerebrovascular accident (CVA). Methods Prescription fill data were linked to medical records of a merged VA-Medicare dataset. NSAIDs were categorized by Cox-2 selectivity. Incidence of CVA and MI within 180 days of index prescription was assessed using Cox-proportional hazards models adjusted for gender, race, cardiovascular and pharmacological risk factors and propensity for prescription of highly COX-2 selective NSAIDs. Results Of 384 322 patients (97.5% men and 85.4% white), 79.4% were prescribed a poorly selective, 16.4% a moderately selective and 4.2% a highly selective NSAID. There were 985 incident cases of MI and 586 cases of CVA in > 145 870 person-years. Highly selective agents had the highest rate of MI (12.3 per 1000 person-years; [95% CI: 12.2-12.3]) and CVA (8.1 per 1000 person-years; [95% CI: 8.0-8.2]). Periods without NSAID exposure were associated with lowest risk. In adjusted models, highly selective COX-2 selective NSAIDs were associated with a 61% increase in CVA and a 47% increase in MI, when compared with poorly selective NSAIDs. Conclusions The risk of MI and CVA increases with any NSAID. Highly COX-2 selective NSAIDs confer the greatest risk.