Reduction in acute myocardial infarction hospitalization after implementation of a smoking ordinance

Background: Smoking ordinances have been associated with reduced acute myocardial infarction rates, but nearly all studies lack patient-level data.

Objective: We determined whether a smoking ordinance was associated with a reduction in hospitalizations for acute myocardial infarction, irrespective of smoking status and infarct presentation (ST elevation vs. non-ST elevation).

Methods: Detailed chart abstraction of biomarkers to confirm first acute myocardial infarction events was performed from the single community hospital serving Greeley, Colorado and adjacent zip codes, 17 months before and 31 months after implementing a public smoking ordinance. Poisson regression analysis, adjusted for population growth, was used to assess changes in mean incidence rates.

Results: A total of 706 hospitalizations were identified from July 2002 through June 2006: 482 among Greeley city residents and 224 within adjacent zip code areas. A postordinance reduction in hospitalizations was observed in Greeley (relative risk [RR] 0.73; 95% confidence interval [CI], 0.59-0.90). A smaller, nonsignificant decrease was noted in the area immediately surrounding Greeley (RR 0.83; 95% CI, 0.61-1.14). However, the comparison of relative risk reductions between Greeley and the surrounding area was not significant (P=.48). The reduction in Greeley was more pronounced among smokers (RR 0.44; 95% CI, 0.29-0.65) than nonsmokers (RR 0.86; 95% CI, 0.67-1.09) and did not differ by acute myocardial infarction presentation (P=.38).

Conclusions: A smoking ordinance was associated with a decrease in acute myocardial infarction hospitalizations of a magnitude similar to previous reports, but could not be distinguished from the adjacent geographic area. Reductions were greatest among smokers, despite previous studies suggesting that benefits accrue primarily among nonsmokers. Smoke-free policy may therefore exert a beneficial effect among smokers, who are disproportionately exposed to direct and sidestream smoke.