Comparison of Body Mass Index (Four Categories) to In-Hospital Outcomes in Patients Who Underwent Transcatheter Aortic Valve Implantation

Abstract

Although obesity is often associated with adverse outcomes in cardiovascular diseases, studies have demonstrated a beneficial effect on patients who underwent transcatheter aortic valve implantation (TAVI), coining the term "obesity paradox." We sought to determine if the obesity paradox is valid when patients are studied in body mass index (BMI) groups versus simplified classification of obese and nonobese. We examined the National Inpatient Sample database from 2016 to 2019 for all patients who underwent TAVI >18 years of age using the International Classification of Diseases, 10th edition procedure codes. Patients were grouped by BMI categories of underweight, overweight, obese, and morbidly obese. They were compared with normal-weight patients to assess the relative risk of in-hospital mortality, cardiogenic shock, ST-elevation myocardial infarction, bleeding complications requiring transfusions, and complete heart blocks requiring permanent pacemaker. A logistic regression model was constructed to account for potential confounders. Of the 221,000 patients who underwent TAVI, 42,315 patients with appropriate BMI designation were stratified into BMI groups. Compared to the normal-weight group, overweight, obese, and morbid-obese TAVI patients were associated with a lower risk of in-hospital mortality (relative risk [RR] 0.48, confidence interval [CI] 0.29 to 0.77, p <0.001), (RR 0.42, CI 0.28 to 0.63, p <0.001), (RR 0.49, CI 0.33 to 0.71, p <0.001 respectively), cardiogenic shock (RR 0.27, CI 0.20 to 0.38, p <0.001), (RR 0.21, CI 0.16 to 0.27, p <0.001), (RR 0.21, CI 0.16 to 0.26, p <0.001), and blood transfusions (RR 0.63, CI 0.50 to 0.79, p <0.001), (RR 0.47, CI 0.39 to 0.58, p <0.001), (RR 0.61, CI 0.51 to 0.74, p <0.001). This study indicated that obese patients were at a significantly lower risk of in-hospital mortality, cardiogenic shock, and bleeding complications requiring transfusions. In conclusion, our study supported the existence of the obesity paradox in TAVI patients.