Smoker's paradox in transcatheter aortic valve replacement: A National Inpatient Sample analysis from 2015 to 2020

Background: While smoking is recognized as a risk factor for multiple cardiovascular conditions, prior research has identified a smoker paradox, wherein smokers had better post-procedural outcomes following transcatheter aortic valve replacement (TAVR) in the initial years of its introduction among high-risk patients only. In recent years, TAVR has expanded to significant larger groups of low-risk patients and became the dominate approach for aortic valve replacement. Consequently, the study cohort from the previous research can no longer represent the current patient populations undergoing TAVR. This study aimed to examine the impact of smoking on TAVR outcomes in the later post-TAVR era. Methods: Patients who underwent TAVR were identified in the National Inpatient Sample (NIS) database from the last quarter of 2015–2020 by ICD-10-PCS. Patients were stratified into two cohorts based on smoker status. Multivariable analysis was performed comparing in-hospital post-TAVR outcomes. Adjusted pre-procedural variables included sex, age, race, socioeconomic status, comorbidities, and hospital characteristics. Results: A total number of 58,934 patients who underwent TAVR were identified including 23,683 smokers and 35,251 non-smokers. Compared to non-smokers, smokers had lower in-hospital mortality (aOR 0.589, p < 0.01), MACE (aOR 0.678, p < 0.01), MI (aOR 0.719, p < 0.01), stroke (aOR 0.599, p < 0.01), neurological complications (aOR 0.653, p < 0.01), pacemaker implantation (aOR 0.911, p < 0.01), cardiogenic shock (aOR 0.762, p < 0.01), respiratory complications (aOR 0.822, p < 0.01), mechanical ventilation (aOR 0.669, p < 0.01), AKI (aOR 0.745, p < 0.01), VTE (aOR 0.578, p < 0.01), hemorrhage/hematoma (aOR 0.921, p < 0.01), infection (aOR 0.625, p < 0.01), vascular complications (aOR 0.802, p < 0.01), reopen surgery (aOR 0.453), and transfer out to another facility (aOR 0.79, p < 0.01). In addition, cigarette smokers had shorter LOS (p < 0.01), and less hospital charge (p < 0.01). Conclusion: This study identified the smoker paradox in the later post-TAVR era with remarkably broad protection from many complications and lower mortality. The reasons underlying this apparent smoker paradox merit deeper investigation.