Risk of acute first myocardial infarction and use of nicotine patches in a general population.

ABSTRACT

OBJECTIVES: To determine if nicotine patches, both as prescribed and used over-the-counter, increase the risk of first myocardial infarction (MI). BACKGROUND: Although nicotine patches improve smoking cessation rates, case reports have raised the hypothesis that they may increase the risk of MI. METHODS: A population-based case-control study among 68 hospitals in an eight-county region surrounding Philadelphia was performed to determine if nicotine patches increase the risk of first MI. Cases were smokers (current or within the prior year) admitted to all hospitals in the region with a first MI. Controls were smokers (current or within the prior year) without prior MI selected from the same region using random-digit dialing. Data were collected by telephone interviews and chart reviews. The study had 80% power to detect an odds ratio (OR) of 2.5. RESULTS: A total of 653 cases and 2,990 controls were interviewed. There was no association between nicotine patches and MI (OR 0.46; 95% CI 0.09, 1.47), and the confidence interval (CI) excluded an effect from nicotine patches equal to that from cigarette smoking itself (OR < 2.5). Among those who abstained from smoking, the OR for use of nicotine patches was 0.25 (95% CI 0.01, 1.67); among those who smoked concomitantly, the OR for patch use was 0.83 (95% CI 0.09, 3.81). Adjustment for confounding did not alter the study's findings (OR adjusted for confounders that could mask a harmful effect of patches 0.70; 95% CI 0.20, 2.46). CONCLUSIONS: Nicotine patches, as used in actual practice, do not appear to be associated with an increased risk of MI.