Investigating the Smoker's Paradox: Acute Myocardial Infarction Outcomes in Smokers

Abstract

BackgroundNon-adherence is a barrier to the control of hypertension. This study Background.Smoking is known to negatively impact cardiovascular health and reduce life expectancy. However, the smoker's paradox suggests that current smokers with acute myocardial infarction (AMI) experience lower short-term mortality rates than non-smokers. This study investigates the effect of smoking on in-hospital outcomes for AMI patients in the United States, aiming to understand the presence of this paradox within this population. MethodsIn this study, we utilized the National Inpatient Sample (NIS) for the year of 2020 to identify all patients who were admitted for a principal diagnosis of AMI. Subsequently, we isolated those patients with an ICD-10 code indicating smoking or tobacco use. To examine associations, both logistic and linear regression analyses were employed while adjusting for potential confounding factors. Our findings were considered significant if the 2-tailed p-value was 0.05 or lower. ResultsIn 2020, there were 446,834 hospitalizations for AMI. Of these cases, 230,120 (51.5%) involved patients with a secondary diagnosis of smoking history or use. After accounting for various factors such as age, race, gender, hospital bed size, location, teaching status, insurance coverage, income level, and Elixhauser comorbidities, patients admitted for AMI with a secondary diagnosis of smoking use exhibited a lower rate of in-hospital mortality (aOR 0.58, 95% CI 0.55-0.63), mechanical ventilation (aOR 0.74, 95% CI 0.66-0.74), vasopressor initiation (aOR 0.69, 95% CI 0.64-0.76), mechanical circulatory support (aOR 0.52, 95% CI 0.46-0.57), and hemodialysis initiation (aOR 0.52, 95% CI 0.48-0.56). Notably, these patients also had higher odds of receiving percutaneous coronary intervention (PCI) (aOR 1.18, 95% CI 1.37-1.98) compared to non-smoking patients with AMI (Figure 1). ConclusionOur study showed that AMI patients with a smoking history had lower odds of in-hospital mortality, mechanical ventilation, vasopressor use, circulatory support, and hemodialysis initiation, but higher odds of PCI compared to non-smokers. To fully understand the smoker's paradox, larger, robust investigations are needed to reveal underlying mechanisms, and ultimately, inform more effective patient care strategies.