Objective Smokers have lower short-term mortality after acute myocardial infarction (AMI) than non-smokers; 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 long-term 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.