Smoking in acute myocardial infarction patients: Observations from a registry heart hospital, Qatar

Introduction: Studies from the US and Europe showed a decline in smoking among patients with acute myocardial infarction (AMI), but limited data are available from the Middle East. In this study, we describe the temporal trend in the prevalence, associated risk factors, and outcomes of smoking among patients with AMI in Qatar.Materials and Methods: A total of 27,648 AMI patients were analyzed from the cardiology registry at Heart Hospital, Doha, Qatar. This spans from January 1991 to May 2022.Results: Of the total, 13,562 patients (49.1%, 95% confidence interval [CI]: 48%–50%) were smokers, with a clear majority of males (98.5%). Smoking habit was found to decrease in AMI patients with increasing age (age 51–60 years, adjusted odds ratio [OR]: 0.71, 95% CI: 0.67–0.76, P = 0.001, and age ≥61 years, adjusted OR: 0.45, 95% CI: 0.42–0.48, P = 0.001, in comparison to age ≤50 years). Smoking was associated with a lower risk of inhospital mortality (adjusted OR: 0.61, 95% CI: 0.54–0.70, P = 0.001), but triglyceride, obesity, and old myocardial infarction risk factors were associated with a higher risk. A decreasing trend in current smoking habits in each quantile of the 1996–2000 year (adjusted OR: 0.82, 95% CI: 0.71–0.93, P = 0.001), 2001–2005 year (adjusted OR: 0.70, 95% CI: 0.62–0.80, P = 0.001), 2006–2010 year (adjusted OR: 0.75, 95% CI: 0.67–0.84, P = 0.001), 2011–2015 year (adjusted OR: 0.48, 95% CI: 0.42–0.54, P = 0.001), 2016–2020 year (adjusted OR: 0.48, 95% CI: 0.43–0.54, P = 0.001), and ≥2021 year (adjusted OR: 0.46, 95% CI: 0.40–0.53, P = 0.001) was observed in comparison to the quantile 1991–1995 year. Similar results were also observed in the young population (age ≤50 years) including the non-Qataris, who had 25% more smokers in comparison to Qatari nationals.Conclusion: Smoking trended down significantly; however, it remained prevalent in 50% of patients among AMI patients. Smokers were younger, with fewer traditional risk factors, and had lower inhospital mortality.