Background: Cessation of smoking after a cardiovascular event has been shown in Western countries to have a beneficial effect on clinical events during long-term follow-up. However, knowledge of the effect of smoking status after acute myocardial infarction (AMI) on the long-term mortality based on a large-scale sample is still limited in Japan.
Methods and results: In the present study 2,579 AMI patients were enrolled in the Osaka Acute Coronary Insufficiency Study (OACIS) between April 1998 and March 2003. Smoking status was assessed at baseline and 3 months after hospital discharge by mailed questionnaire. Patients were divided into nonsmokers (n=823), former smokers (those who had stopped smoking before AMI onset, n=332), quitters (those who stopped smoking after AMI onset, n=1,056), and persistent smokers (those who smoked before and after AMI, n=368). Quitters had lower long-term mortality rates than persistent smokers (3.0% vs 5.2%; log rank, p=0.032). Multivariate Cox regression analysis revealed that smoking cessation was independently associated with a reduction in risk of long-term mortality (hazard ratio, 0.39; 95% confidence interval, 0.20-0.77).
Conclusions: Patients who continue to smoke after AMI are at greater risk for death than patients who quit smoking. Cessation of smoking benefits the long-term prognosis in patients with AMI.