Association of Body Mass Index With Procedural Success and Outcomes in Patients undergoing Transcatheter Aortic Valve Implantation

Abstract

Obesity is a major public health concern linked to adverse cardiovascular outcomes. Recent studies suggest an obesity paradox, showing lower mortality in obese patients after transcatheter aortic valve implantation (TAVI). This study investigates the impact of body mass index (BMI) on procedural and long-term clinical outcomes in patients undergoing TAVI. Patients undergoing TAVI at two high-volume centers were analyzed and categorized into four BMI groups: underweight (BMI <18.5 kg/m²), normal (BMI 18.5-24.9 kg/m²), overweight (BMI 25.0-29.9 kg/m²), and obese (BMI ≥30.0 kg/m²). To relax the proportional hazards assumption, restricted cubic splines were constructed. The primary outcome was procedural success and safety, including 30-day all-cause-mortality, stroke, and overall bleeding. Secondary outcomes included all-cause mortality at one and five years. In total, 6,156 patients were included: 114 (1.8%) were underweight, 2,393 (38.8%) normal weight, 2,380 (38.6%) overweight, and 1,269 (20.6%) obese. No significant differences between BMI groups were found in 30-day mortality, stroke, or bleeding. However, underweight patients had higher mortality compared to normal-weight patients at one year (23.7 vs 13.2%, p = 0.001) and five years (53.2% vs. 44.0%, p = 0.048). Obese patients had similar mortality to normal-weight patients at one year (11.4 vs 13.2%, p = 0.120) and five years (41.0 vs 44.0%, p = 0.200). Obesity showed no outcome advantage over normal weight, while underweight was an independent predictor of higher all-cause mortality after TAVI. These findings challenge the obesity paradox in the context of TAVI.

Keywords: Aortic stenosis; Body Mass Index; Obesity; Obesity paradox; Transcatheter aortic valve implantation; Underweight.