Three life-years gained from smoking cessation after coronary artery bypass surgery: a 30-year follow-up study

Abstract

Background: Previous studies have shown that smoking cessation after a cardiac event reduces the risk of subsequent mortality in patients, but the effect of smoking cessation in terms of prolonged life-years is not yet known.

Methods: We analyzed the 30-year clinical outcome of the first 1,041 consecutive patients (age at operation 51 years, 92% male) who successfully underwent isolated venous coronary artery bypass surgery between 1971 and 1980. All 551 smokers (53%) were included in this study. Of these, 43% stopped smoking throughout the first year whereas 57% persisted smoking.

Results: The median follow-up was 29 years (range 26-36 years). The cumulative 10-, 20-, and 30-year survival rates were 88%, 49%, and 19%, respectively, in the group of patients who quit smoking, and only 77%, 36%, and 11%, respectively, in the persistent smokers (P < .0001). After adjusting for all baseline characteristics, smoking cessation remained an independent predictor of lower mortality (hazard ratio 0.60, 95% CI 0.48-0.72). We were able to assess the exact life expectancy by calculating the area under the Kaplan-Meier curves. Life expectancy in the quitters was 20.0 years and 17.0 years in the persistent smokers (P < .0001).

Conclusions: Using 30-year follow-up data, we estimated that self-reported smoking cessation after coronary artery bypass surgery was associated with a life expectancy gain of 3 years. Smoking cessation turned out to have a greater effect on reducing the risk of mortality than the effect of any other intervention or treatment.