Clarifying the Obesity Paradox in Transcatheter Aortic Valve Replacement: Findings From the STS/ACC TVT Registry

Higher body mass index (BMI) has been associated with better outcomes after transcatheter aortic valve replacement (TAVR), but whether this "obesity paradox" varies by age is unclear.

The objective of the study was to determine whether age modifies the association between BMI and 1-year outcomes after TAVR.

The authors performed a retrospective analysis of the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry, including patients who underwent TAVR between January 2021 and February 2023. Patients were categorized by age (<65 or ≥65 years) and BMI (<25 or ≥25 kg/m²). The primary outcome was 1-year all-cause mortality. Secondary outcomes included major adverse cardiovascular and cerebrovascular events: stroke, cardiac mortality, myocardial infarction, and readmission. Inverse probability of treatment weighting regression models were used to assess outcomes.

Among the 6,639 patients (mean age 76.7 ± 11.6 years; mean BMI 29.7 ± 9.9 kg/m²), 1-year all-cause mortality occurred in 427 (6.4%). Among patients <65 years, outcomes did not differ between BMI groups (P > 0.05). Among patients ≥65 years, BMI <25 kg/m² was associated with a higher risk of all-cause mortality (adjusted HR [aHR]: 1.29; 95% CI: 1.05 to 1.57; P = 0.013) and major adverse cardiovascular and cerebrovascular events (aHR: 1.20; 95% CI: 1.08-1.34; P = 0.001) vs those with BMI ≥25 kg/m². The association between higher BMI and lower mortality strengthened with advancing age and was significant in patients 75 to 84 years (aHR: 0.60; 95% CI: 0.44-0.82; P = 0.001) and ≥85 years (aHR: 0.36; 95% CI: 0.25-0.51; P < 0.001), but not in younger strata.

Higher BMI was not uniformly protective. Among older adults, lower BMI was associated with a higher-risk phenotype and worse 1-year outcomes.