Current smoking, smoking cessation, and the risk of sudden cardiac death in patients with coronary artery disease

Background: Cigarette smoking is a known risk factor for sudden cardiac death (SCD). However, the effect of continued cigarette smoking and smoking cessation on SCD risk in patients with established coronary artery disease (CAD) is subject to controversy. We, therefore, evaluated the effect of cigarette smoking on SCD risk in a large cohort of patients with established CAD. Methods: The study population was composed of 3122 patients with a previous myocardial infarction or stable angina who participated in the Bezafibrate Infarction Prevention Trial. Patients were prospectively followed up for a mean of 8.2 years. The primary end point was the incidence of SCD according to smoking status. Results: Among the 370 patients who were current smokers, 30 (8.1%) experienced SCD; 83 (4.6%) of the 1821 patients who had quit smoking and 43 (4.6%) of the 931 patients who had never smoked experienced SCD (P=.01). In multivariate analyses, current smoking was associated with a significant increase in the risk of SCD (hazard ratio, 2.47; 95% confidence interval, 1.46-4.19). Patients who had stopped smoking had no significant increase in the risk of SCD compared with patients who had never smoked (hazard ratio, 1.06; 95% confidence interval, 0.70-1.62). Conclusions: Current cigarette smoking is a powerful independent predictor of SCD risk in patients with CAD. Patients who quit smoking experienced a significant reduction in SCD risk. Thus, efforts to reduce mortality from SCD in patients with CAD should include vigorous smoking cessation strategies.