Impact of smoking on outcomes in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Abstract

Introduction:  Smoking is a well-established risk factor for cardiovascular diseases. However, in ST-segment elevation myocardial infarction (STEMI) patients, smoking has been associated with better clinical outcomes, a phenomenon termed the “smoker’s paradox.”

Objectives: The aim of this study was to evaluate the association between smoking and clinical outcomes in STEMI patients treated with primary percutaneous coronary intervention (PCI), using a large national registry.

Patients and methods: We retrospectively analyzed the data of 82235 hospitalized patients with STEMI, treated with primary PCI. Among analyzed population 30966 patients (37.96%) were smokers and 51269 (62.36%) patients were non-smokers. We evaluated baseline characteristics, medication management, clinical outcomes, and readmission causes in 36-month follow-up.

Results: Smokers were significantly younger (58 [52-64] vs. 68 [59-77] years, P<0.001) and more frequently male when compared to nonsmokers. Patients from smokers group were less likely to have traditional risk factors when compared to nonsmokers. In unadjusted analysis in-hospital and 36-month mortality and rehospitalization rate were lower in the smokers group. However, after adjustment for baseline characteristics for which smokers and non-smokers were found to be different, the multivariable analysis has shown that tobacco use was one of independent risk factors of 36-month mortality (HR=1.11;CI:1.06-1.18; P<0.001).

Conclusions: In the present large-scale registry-based analysis, the observed lower 36 months crude rates of adverse events among smokers compared with non-smokers might be partially explained by significantly lower burden of traditional risk factors and younger age in smokers. After accounting for age and other baseline differences smoking was found to be one of independent risk factors of 36 months mortality.