Effect of smoking relapse on outcome after acute coronary syndromes

Abstract

The aim of the present study was to evaluate the smoking relapse rate among smokers who had become abstinent during admission for acute coronary syndromes. The association between smoking relapse and mortality was also analyzed. A cohort of 1,294 consecutive active smokers who had interrupted smoking after admission for acute coronary syndromes (1,018 men and 276 women, mean age 59.7 ± 12.3 years) was followed up for 12 months after the index admission. All patients received a brief in-hospital smoking cessation intervention consisting of repeated counseling sessions. During follow-up, 813 patients (62.8%) resumed regular smoking (median interval to relapse 19 days, interquartile range 9 to 76). Increasing age (hazard ratio [HR] 1.034 per year, 95% confidence interval [CI] 1.028 to 1.039, p = 0.001) and female gender (HR 1.23, 95% CI 1.09 to 1.42, p = 0.03) were independent predictors of smoking relapse. Patients enrolled in a cardiac rehabilitation program (HR 0.74, 95% CI 0.51 to 0.91, p = 0.02) and those with diabetes (HR 0.79, 95% CI 0.68 to 0.94, p = 0.03) were more likely to remain abstinent. During follow-up, 97 patients died (1-year probability of death 0.075, 95% CI 0.061 to 0.090). Multivariate analysis with the Cox proportional hazard regression method, including smoking relapse as a time-dependent covariate, demonstrated that, after adjustment for patient demographics, the clinical history features and variables related to the index event, the resumption of smoking was an independent predictor of total mortality (HR 3.1, 95% CI 1.3 to 5.7, p = 0.004). In conclusion, smoking relapse after acute coronary syndromes is associated with increased mortality, and counseling interventions should be integrated into the postdischarge support to reduce the negative effects of smoking resumption.