Abstract 15980: Smoking, Smoking Cessation and Risk of Sudden Cardiac Death in Women
Background: Smoking is a strong and modifiable risk factor for sudden cardiac death (SCD). However, few prospective studies have examined the impact of quantitative cigarette consumption and smoking cessation on SCD risk among individuals without pre-existing cardiovascular disease (CVD) over a long term follow-up.
Methods: A total of 101,018 women participating in the Nurses' Health Study, free of CVD, stroke and cancer were prospectively followed from 1980 to 2008. SCD was defined as death within 1 hour of symptom onset. Time-varying Cox models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for SCD adjusted for CVD risk factors across categories of smoking status, cigarettes smoked daily, and years since quitting smoking updated at 2 year intervals.
Results: At baseline, 29.1%, 26.4%, and 49.5% of women were current, past, and never smokers, respectively. During follow-up, 19.7 % of current smokers quit smoking and 333 SCDs were confirmed. As compared to never smokers, current smokers had a 2.51-fold (95% CI, 1.83-3.04) increased SCD risk, and quantity of cigarettes smoked daily was linearly associated with SCD risk; 1-14: HR 1.89 (95% CI, 1.18-3.04), 15-24: HR 2.65 (95% CI, 1.74-4.03), and > 25: HR 3.43 (95% CI, 2.11-5.56, p for trend <.0001) in multivariable analysis. As compared to current smokers, past smokers had a lower risk of SCD (HR=1.41; 95% CI, 1.09-1.80). SCD risk reduction linearly increased with length of time since quitting (Figure, p trend <0.0001), and reached significance, decreasing to the level of a never smoker after 15 years.
Conclusions: In this large prospective cohort of women without CVD, even small-to-moderate quantities of cigarettes smoked daily are associated with an elevated SCD risk. Smoking cessation reduced and eventually eliminated excess risk after 15 years of cessation. Thus, efforts to prevent SCD among women should include aggressive strategies for smoking cessation.
- © 2011 by American Heart Association, Inc.