Baseline, procedural and outcome features of patients undergoing transcatheter aortic valve implantation according to different body mass index categories

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has become first-line treatment for severe aortic valve stenosis in patients with moderate, high or prohibitive surgical risk. However, access site complications may occur more frequently in extreme body mass index (BMI) categories. The aim of this study was to describe the features and outcomes of patients undergoing TAVI in a comprehensive Italian prospective clinical registry, focusing on BMI classes. METHODS: A national prospective database was queried for baseline, procedural, and outcome details of patients undergoing TAVI according to established BMI categories: underweight (BMI <18.5 kg/m2), normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), and obese (BMI≥30 kg/m2). Short- and long-term outcomes, including major adverse events (MAE), i.e. the composite of death, stroke, myocardial infarction, major vascular complication, major bleeding, or renal failure, were appraised with bivariate and multivariable analyses. RESULTS: A total of 3075 subjects were included, 64 (2.1%) were underweight, 1319 (42.9%) were normal weight, 1152 (37.4%) were overweight, and 540 (17.6%) were obese. Several baseline differences were evident, including gender, diabetes mellitus, renal function, chronic obstructive pulmonary disease, surgical scores, and left ventricular ejection fraction (LVEF) (all P<0.05). Several procedural differences were also evident, including percutaneous approach, predilation, prosthesis type and size (all P<0.05), with postprocedural aortic regurgitation >2+ significantly more common in underweight patients (P<0.05). Nonetheless, unadjusted analysis for one-month outcomes showed similar rates for fatal and non-fatal outcomes, including MAE (all P>0.05), with the notable exception of permanent pacemaker implantation, which was more common in higher BMI classes (P=0.010) Unadjusted analysis for long-term events showed an increased rate of death in underweight patients (P=0.024). Multivariable adjusted analysis confirmed the increased risk of permanent pacemaker implantation in obese patients (P=0.015 when comparing obese vs. normal weight subjects), but disproved differences in long-term mortality and other outcomes (P>0.05 for all comparisons). CONCLUSIONS: Irrespective of BMI class, TAVI is associated with favorable outcomes in surgical high-risk risk patients, with the notable exclusion of permanent pacemaker implantation, which is significantly more common in obese subjects.