EDMONTON, Alberta — New data from the Nurses' Health Study shed further light on the association between cigarette smoking and sudden cardiac death (SCD) and demonstrate that smoking is an important modifiable risk factor for SCD [1]. Dr Roopinder K Sandhu (Mazankowski Alberta Heart Institute, Edmonton) and colleagues report their findings online December 11, 2012 in Circulation: Arrhythmia and Electrophysiology.
Sandhu told heartwire that it is already known that smoking status--whether people are current, past, or never smokers--is a well-established risk factor for SCD, "but there have been limited data on the dose-response relationship. That is, the association between the quantity of cigarettes smoked, smoking duration, and the impact of smoking cessation on SCD risk, particularly among individuals without documented heart disease--who comprise the majority of SCDs in the population--and in particular among women." The new study helps plug these gaps, she says.
"We found there was a dose-response relationship between quantity of cigarettes smoked daily and smoking duration. Even small to moderate amounts of cigarette consumption, one to 14 per day, was associated with a significant, almost twofold increased risk of SCD." And with respect to the total number of years smoking, Sandhu notes that "every five years of continued smoking was associated with an almost 10% increase in SCD."
But "importantly, SCD risk reduced over time with smoking cessation, equaling that of a never smoker after 20 years," she points out.
The researchers also showed that in women who smoked and developed coronary heart disease, their SCD risk reduction took longer after quitting than someone who had never developed heart disease but who had smoked and quit.
"These are data supporting the fact that smoking cessation is an important modifiable risk factor and that women shouldn't wait until they develop heart disease to quit," Sandhu observes.
Link Between Smoking, Smoking Cessation, and SCD in 100,000 Women
Sandhu and colleagues prospectively examined the association between cigarette smoking and smoking cessation on the risk of SCD among 101 018 women participating in the Nurses' Health Study without known CHD, stroke, or cancer at baseline, in 1980.
During 30 years of follow-up, they identified 351 cases of sudden cardiac death. Compared with never smokers, current smokers had a 2.44 fold increased risk of SCD after researchers controlled for coronary risk factors. In multivariable analyses, quantity of cigarettes smoked daily (p for trend <0.0001) and smoking duration (p for trend <0.0001) were linearly associated with SCD risk among current smokers.
Low to moderate smoking, one to 14 cigarettes per day, was associated with a significant 1.84-fold increase in SCD risk, and each five years of continued smoking was associated with an 8% increase in SCD risk (p<0.0001).
But on the plus side, the SCD risk decreased linearly over time after quitting and was the same as that of a never smoker two decades after cessation (p for trend <0.0001).
Important for Physicians to Take a Smoking History to Try to Reduce SCD
The findings suggest that "efforts to prevent SCD among women should include aggressive strategies for smoking cessation," say Sandhu and colleagues.
"These data are in keeping with benefits that have been demonstrated for reductions in all-cause mortality for heart disease and cancer from stopping smoking," Sandhu observes.
"It's important that physicians take a smoking history and advise their patients on the adverse effects of continued smoking and that there are important implications, including SCD. They should work out an individual smoking-cessation strategy tailored to a particular patient," she recommends.
The authors report no conflicts of interest.
Heartwire from Medscape © 2012 Medscape, LLC
Cite this: Aggressive Smoking-Cessation Strategies Will Help Reduce SCD - Medscape - Dec 12, 2012.
