Current cigarette smoking is associated with a significantly increased risk of sudden cardiac death in people with coronary artery disease, according to an article in the October 27th issue of The Archives of Internal Medicine.

Sudden cardiac death accounts for roughly one quarter of all major events related to coronary artery disease and accounts for more than half of all related deaths, according to the authors. Ventricular arrhythmia is believed to be the most common direct cause of sudden cardiac death. Nicotine can provoke arrhythmias, and smoking cessation is recommended for all patients with coronary artery disease. However, few studies have looked at the effects of smoking status on sudden cardiac death in patients with coronary artery disease.

Ilan Goldenberg, M.D., and his Israeli colleagues evaluated the effect of cigarette smoking on risk for sudden cardiac death in a subset of 3,122 participants in the Bezafibrate Infarction Prevention Trial (BIP Trial). The Trial was initiated in 1990 and was designed to determine whether bezafibrate would reduce coronary artery disease-related deaths and nonfatal myocardial infarctions in patients with established coronary artery disease and moderately elevated cholesterol levels.

The researchers prospectively followed the 3,122 participants (aged 45 to 74 years) for an average of about 8 years. All participants had a previous myocardial infarction or had stable angina. Smoking status was determined at the beginning of the Trial and each of the 4-month follow-up visits. Never smokers were people who had not smoked more than 100 cigarettes in their lifetime; past smokers were people who had smoked more than 100 cigarettes, but quit before the baseline trial examination or before the first 4-month follow-up visit; and current smokers were people who continued to smoke after the first 4-month follow up visit.

The researchers found that among the 370 participants who were current smokers, 30 (8.1 percent) experienced sudden cardiac death; 83 (4.6 percent) of the 1,821 participants who had quit smoking and 43 (4.6 percent) of the 931 participants who had never smoked experienced sudden cardiac death. Current smoking was associated with an increased risk (almost two and one half times) of death.

Participants who stopped smoking had no significant increase in the risk of sudden cardiac death compared with participants who had never smoked. Current smokers also had a substantially greater cardiac-related and all-cause death rate compared with never smokers and past smokers.

The researchers also found that there was no correlation between the risk of sudden cardiac death and the number of years without smoking in patients who had quit smoking before the beginning of the trial.

The authors wrote "The findings of this long-term prospective follow-up of 3,122 patients with preexisting coronary artery disease suggest the following: (1) continued cigarette smoking is associated with a significantly increased risk of sudden cardiac death; (2) in patients who quit smoking, the risk of sudden cardiac death is significantly lower and comparable to the risk of patients who had never smoked; and (3) the decline in the risk of sudden cardiac death with smoking cessation is immediate and not time dependent."

They concluded "Thus, efforts to reduce mortality from sudden cardiac death in patients with coronary artery disease should include vigorous smoking cessation strategies."