Smoking status and life expectancy after acute myocardial infarction in the elderly

Abstract

Objective: Smokers have lower short-term mortality after acute myocardial infarction (AMI) than nonsmokers; however, little is known about the long-term effects of smoking on life expectancy after AMI. This study aimed to quantify the burden of smoking after AMI using life expectancy and years of life lost. Methods: We analysed data from the Cooperative Cardiovascular Project, a medical record study of 158 349 elderly Medicare patients with AMI and over 17 years of follow-up, to evaluate the age-specific association of smoking with life expectancy and years of life lost after AMI. Results: Our sample included 23 447 (14.8%) current smokers. Current smokers had lower crude mortality up to 5 years, which was largely explained by their younger age at AMI. After adjustment other patient characteristics, smoking was associated with lower 30- day (HR 0.91, 95% CI 0.87 to 0.94) but higher longterm mortality (17-year HR 1.19, 95% CI 1.17 to 1.20) after AMI. Overall, crude life expectancy estimates were lower for current smokers than non-smokers at all ages, which translated into sizeable numbers of life-years lost attributable to smoking. As age at AMI increased, the magnitude of life-years lost due to smoking decreased. After full risk adjustment, the differences in life expectancy between current smokers and non-smokers persisted at all ages. Conclusions: Current smoking is associated with lower life expectancy and large numbers of life-years lost after AMI. Our findings lend additional support to smoking cessation efforts after AMI.