Gender and Smoking-Related Survival Differences in Patients with ST-Elevation Myocardial Infarction

Background: Smoking is the leading cause of preventable death. Female smokers bear a greater risk of experiencing an ST-segment elevation myocardial elevation (STEMI) than male smokers.

Objectives: This study aimed to investigate gender and smoking-related survival differences one-year post-STEMI.

Methods: This registry-based cohort study included all STEMI patients of Imam Ali Hospital, Kermanshah, Iran. All eligible adult patients with STEMI were enrolled. Baseline data and one-year post-STEMI data were collected. Cox proportional models were used to estimate crude and full-adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs). All analyses were performed using Stata.


Results: During 2080.9 person-years, 22 patients were lost to follow-up (success rate = 99%). There were 2,279 STEMI patients (22.99% women) during the study period. Men were younger than women (58.50 ± 12.22 vs. 65.26 ± 11.56 years, P ˂ 0.001). In men, smoking was a protective factor against in-hospital mortality in the unadjusted model (HR = 0.49, 95% CI: 0.31 – 0.78, P = 0.002), but was not a protective factor after adjusting for age, hypertension, dyslipidemia, diabetes, creatine kinase-MB, body-mass index, LDL-cholesterol, HDL-cholesterol, glomerular filtration rate, anterior wall MI/LBBB, left ventricular ejection fraction and reperfusion therapy (HR = 0.66, 95% CI: 0.34 – 1.25, P = 0.198).


Conclusions: Although male smokers with STEMI had a lower in-hospital mortality rate, this difference did not persist in the adjusted model. Thus, the smokers’ paradox phenomenon was not proven. The better outcomes of men with STEMI compared to women are probably related to their younger age and fewer risk factors at the time of presentation.