SMOKING CESSATION AND ARRHYTHMIC DEATH - THE CAST EXPERIENCE

Objectives. This study was performed to assess the effect of cigarette smoking cessation on overall mortality and the incidence of arrhythmic death in the population of the Cardiac Arrhythmia Suppression Trial (CAST). Background. Cigarette smoking is a known risk factor for sudden cardiac death. Some of the adverse effects of smoking have been shown to dissipate with smoking cessation, but the time frame over which these changes occur and the population that stands to benefit have not been web delineated. CAST was a multicenter double-blind placebo-controlled study to determine whether suppression of ventricular ectopic activity by means of antiarrhythmic drugs in patients with left ventricular dysfunction after acute myocardial infarction would reduce the incidence of arrhythmic death. Methods. Of 2,752 patients randomized to blinded therapy, 1,026 were smoking at the time of their baseline examination and completed a 4-month follow-up visit, Of these, 517 stopped smoking by the time of this visit (''quitters'') and 509 continued to smoke (''smokers''). Results. Over a mean follow-np period of slightly < 16 months, there were 17 arrhythmic deaths and 32 total deaths among the quitters versus 30 and 45, respectively, among the smokers; these differences were of marginal statistical significance. Most of the fatal events occurred in a group at high risk of ongoing ischemia: the 558 patients who did not have thrombolysis or undergo revascularization after their qualifying myocardial infarction. In this high risk cohort, smoking cessation greatly reduced the incidence of arrhythmic death and was associated with a statistically significant benefit in survival, Conclusions. Smoking cessation was accompanied by a marked reduction in arrhythmic death and overall mortality that achieved statistical significance in a high risk cohort, These data imply that smoking cessation is important in risk factor reduction in patients with advanced ischemic heart disease.