Potential confounders of the obesity paradox in older patients following transcatheter aortic valve replacement.

Key Summary Points: Aim: The present study aimed to investigate potential confounders of the obesity paradox in older patients following transcatheter aortic valve replacement (TAVR) for severe aortic stenosis. Findings: The obesity paradox was observed in older patients following TAVR. Cachexia may reflect higher mortality in patients with lower BMI and higher subcutaneous fat accumulation (SFA) may represent lower mortality in those with higher BMI. Message: Considering higher mortality in lower BMI with cachexia, prevention or treatment of the comorbidity would be important in older patients following TAVR. Purpose: A higher body mass index (BMI) is associated with lower mortality in older patients following transcatheter aortic valve replacement (TAVR) for severe aortic valve stenosis. The current study aimed to investigate potential confounders of association between BMI and prognosis. Methods: The retrospective single-center study included consecutive patients following TAVR and excluded those in whom subcutaneous fat accumulation (SFA), visceral fat accumulation (VFA), and major psoas muscle (MPM) volume were not assessed by computed tomography. Cachexia was defined as a combination of BMI < 20 kg/m² and any biochemical abnormalities. Results: After 2 patients were excluded, 234 (age, 86 ± 5 years; male, 77 [33%]; BMI, 22.4 ± 3.8 kg/m²; SFA, 109 (54–156) cm²; VFA, 71 (35–115) cm²; MPM, 202 (161–267) cm³; cachexia, 49 [21%]) were evaluated. SFA and VFA were strongly correlated with BMI (ρ = 0.734 and ρ = 0.712, respectively), whereas MPM was weakly correlated (ρ = 0.346). Two-year all-cause mortality was observed in 31 patients (13%). Higher BMI was associated with lower mortality (adjusted hazard ratio [aHR], 0.86; 95% confidence interval [CI], 0.77–0.95). A similar result was observed in the multivariate model including SFA (aHR in an increase of 20 cm², 0.87; 95% CI, 0.77–0.98) instead of BMI, whereas VFA was not significant. Cachexia was a worse predictor (aHR, 2.51; 95% CI 1.11–5.65). Conclusions: Association of higher BMI with lower mortality may be confounded by SFA in older patients following TAVR. Cachexia might reflect higher mortality in patients with lower BMI. [ABSTRACT FROM AUTHOR]