Gradients after transcatheter aortic valve replacements are impacted by both body mass index and valve size: a...

Obesity is a common comorbidity among patients undergoing transcatheter aortic valve replacement (TAVR) and may influence valve hemodynamics. The impact of body mass index (BMI) and valve size on post-TAVR echo-derived gradients is not fully understood; however, it is clinically important for optimizing outcomes, particularly in high-BMI populations, where procedural success may be affected. This study aims to determine the relationship between BMI and post-procedural gradients.

This retrospective cohort study was conducted at a single large academic medical center to study patients who underwent balloon-expandable TAVR between 2021 and 2023. Patients had pre-procedural computed tomography (CT) and echocardiographic data and completed a 30-day follow-up echocardiogram. Patients were stratified based on BMI (<30 vs. ≥30 kg/m²) and valve size (20/23 vs. 26/29 mm). Mean 30-day echocardiogram gradients, measured with Doppler echocardiography, were compared across groups. A total of 180 patients were identified and stratified into 4 groups: high-BMI small valve (n=26); high-BMI large valve (n=33); low-BMI small valve (n=47); and low-BMI large valve (n=74). Both univariate analysis and multivariate analysis compared different groups and the impacts of individual variables on mean 30-day echocardiogram gradients.

The groups were similar in demographics and clinical characteristics, except for age, which was significantly lower in the high BMI group (P<0.001). Low-BMI patients with large valves had significantly lower gradients than high-BMI patients with small valves (P=0.002). Among high-BMI patients, small valves were associated with significantly higher gradients than large valves (P=0.009). In low-BMI patients, gradients were similar regardless of valve size (P=0.16). In small valve patients, there was a trend for higher gradients in high versus low BMI (P=0.056).

Both BMI and valve size impact 30-day echo-derived gradients after balloon-expandable TAVR. High BMI and small valves are associated with higher gradients. With larger valves, the impact of BMI on valve gradient is attenuated. Additionally, for low-BMI patients, valve size has less impact on gradients. This study suggests that BMI is a crucial factor impacting gradients, and suggests that future research into the role of weight loss in TAVR treatment should be conducted.