Non-aspirin, non-steroidal anti-inflammatory drugs (NANSAIDs) have complex effects that could either prevent or promote coronary heart disease. Comparison of the NANSAID rofexocib with naproxen showed a substantial difference in acute myocardial infarction risk, which has been interpreted as a protective effect of naproxen. We did an observational study to measure the effects of NANSAIDs, including naproxen, on risk of serious coronary heart disease.

We used data from the Tennessee Medicaid programme obtained between Jan 1, 1987, and Dec 31, 1998, to identify a cohort of new NANSAID users (n=181 441) and an equal number of non-users, matched for age, sex, and date NANSAID use began. Both groups were 50–84 years of age, were not resident in a nursing home, and did not have life-threatening illness. The study endpoint was hospital admission for acute myocardial infarction or death from coronary heart disease.

During 532634 person-years of follow-up, 6362 cases of serious coronary heart disease occurred, or 11·9 per 1000 person-years. Multivariate-adjusted rate ratios for current and former use of NANSAIDs were 1·05 (95% CI 0·97–1·14) and 1·02 (0·97–1·08), respectively. Rate ratios for naproxen, ibuprofen, and other NANSAIDs were 0·95 (0·82–1·09), 1·15 (1·02–1·28), and 1·03 (0·92–1·16), respectively. There was no protection among long-term NANSAID users with uninterrupted use; the rate ratio among current users with more than 60 days of continuous use was 1·05 (0·91–1·21). When naproxen was directly compared with ibuprofen, the current-use rate ratio was 0·83 (0·69–0·98).

Absence of a protective effect of naproxen or other NANSAIDs on risk of coronary heart disease suggests that these drugs should not be used for cardioprotection.