Reduction in the incidence of acute myocardial infarction associated with a citywide smoking ordinance

Background-Secondhand smoke exposure increases the risk of acute myocardial infarction (AMI). One study (Helena, Mont) examined the issue and found a decrease in AMI associated with a smoke-free ordinance. We sought to determine the impact of a smoke-free ordinance on AMI admission rates in another geographically isolated community (Pueblo, Colo). Methods and Results-We assessed AMI hospitalizations in Pueblo during a 3-year period, 1.5 years before and 1.5 years after implementation of a smoke-free ordinance. We compared the AMI hospitalization rates among individuals residing within city limits, the area where the ordinance applied, versus those outside city limits. We also compared AMI rates during this time period with another geographically isolated but proximal community, El Paso County, Colo, that did not have an ordinance. A total of 855 patients were hospitalized with a diagnosis of primary AMI in Pueblo between January 1, 2002, and December 31, 2004. A reduction in AMI hospitalizations was observed in the period after the ordinance among Pueblo city limit residents (relative risk [RR]=0.73, 95% confidence interval [CI] 0.63 to 0.85). No significant changes in AMI rates were observed among residents outside city limits (RR=0.85, 95% CI 0.63 to 1.16) or in El Paso County during the same period (RR=0.97, 95% CI 0.89 to 1.06). The reduction in AMI rate within Pueblo differed significantly from changes in the external control group (El Paso County) even after adjustment for seasonal trends (P < 0.001). Conclusions-A public ordinance reducing exposure to secondhand smoke was associated with a decrease in AMI hospitalizations in Pueblo, Colo, which supports previous data from a smaller study.