Body Mass Index and Outcomes After Transcatheter Aortic Valve Replacement: Insights From the Transpacific-TAVR Registry.

Background: Whereas some studies suggest an "obesity paradox" with improved outcomes in obese patients following transcatheter aortic valve replacement (TAVR), the impact of pre-TAVR body mass index (BMI) and post-TAVR BMI changes on clinical and echocardiographic outcomes remains unclear.

Objectives: This study sought to evaluate the influence of BMI at the time of TAVR and subsequent BMI changes on clinical and echocardiographic outcomes in patients undergoing TAVR.

Methods: We included 1,339 patients with severe, native aortic stenosis from 2015 to 2019, stratified by BMI according to World Health Organization classifications, from an international registry. The primary outcome was overall survival, with secondary outcomes including short- and long-term survival, bleeding, vascular injury, stroke, and acute kidney injury. Descriptive statistics and time-to-event analyses were performed.

Results: Underweight patients were older (n = 45; age 83.8 ± 6.6 years) compared to normal weight (n = 576; 81.5 ± 7.0 years), overweight (n = 438; age 81.0 ± 7.4 years), and obese (n = 280; age 77.4 ± 8.3 years; P < 0.001) patients. Underweight patients had the highest rates of chronic kidney disease (66.7%) and moderate or greater aortic regurgitation (28.9%). Obese patients had the highest rates of atherosclerotic cardiovascular disease risk factors. Over a median follow-up of 1.1 (Q1-Q3: 0.6-2.7) years, there were no significant differences between BMI groups (P = 0.69). At 1-year follow-up, underweight patients showed improved left ventricular remodeling and favorable TAVR hemodynamics.

Conclusions: Pre-TAVR BMI did not significantly affect clinical outcomes in this diverse cohort, challenging the obesity paradox. However, underweight patients exhibited subtle improvements in left ventricular remodeling and valve hemodynamics post-TAVR, highlighting a nuanced role for BMI in recovery.