The smoker's paradox in acute coronary syndrome: Is it real?

Introduction Smoking is associated with atherosclerotic disease, but there is controversy about its protective nature after acute coronary syndrome (ACS). Objective To determine the impact of smoking on the presentation, treatment and outcome of ACS. Methods We analyzed all consecutive patients with ACS in a single center between 2005 and 2014. Current smokers and never-smokers were compared. Independent predictors of in-hospital mortality and of a composite of all-cause mortality, rehospitalization for cardiovascular causes, angiography, percutaneous coronary intervention and coronary artery bypass grafting were assessed by multivariate logistic regression. Results A total of 2727 patients were included, 41.7% current smokers and 58.3% never-smokers. Current smokers were younger, more often male, had fewer comorbidities, a typical clinical presentation, lower heart rate, systolic blood pressure, Killip class, BNP/NT-pro-BNP and creatinine, better left ventricular systolic function and less severe coronary anatomy. ST-segment elevation myocardial infarction was more common in current smokers. Current smokers received more evidence-based treatments and had less in-hospital complications, in-hospital mortality and adverse outcomes at one year. More frequent percutaneous coronary intervention at one year was noted in current smokers. Smoking was not an independent predictor of outcome when the multivariate model was fully adjusted for baseline characteristics. Conclusion The smoker's paradox was not observed in this population, since all differences in outcome were explained by smokers’ more benign baseline characteristics.