Lower BMI in older patients undergoing TAVR was associated with higher risk of all-cause mortality and major cardiovascular and cerebrovascular events at one year; however, outcomes did not differ between BMI groups among patients younger than 65 years old, according to a study published July 10 in JACC: Advances.

Using data from the STS/ACC TVT Registry, Sant Kumar, MD; Hursh Naik, MD; and Nezar Falluji, MD, included 6,639 patients (mean age 77 years, mean BMI 29.7 kg/m²) who underwent TAVR between January 2021 and February 2023. Patients were stratified by age (<65 or ≥65 years) as well as BMI (<25 or ≥25 kg/m²), and the primary outcome was all-cause mortality at one year.

Overall, all-cause mortality at one year was observed in 6.4% of patients. Younger patients did not see a difference in outcomes by BMI (p>0.05). Meanwhile, older patients with lower BMI had a higher risk of all-cause mortality (adjusted hazard ratio [aHR], 1.29; p=0.013) as well as major adverse cardiovascular and cerebrovascular events (aHR:,1.20; p=0.001) when compared to those with higher BMI.

The association between higher BMI and lower mortality was significant in patients aged 75 to 84 years (aHR, 0.60; p=0.001) and ≥85 years (aHR, 0.36; p<0.001), strengthening with advancing age.

"These findings suggest that the TAVR obesity paradox is predominantly an age-dependent phenomenon, most evident in older adults rather than across all patients undergoing TAVR," write the authors. "In clinical terms, higher BMI should not be viewed as uniformly protective; rather, lower BMI in elderly TAVR patients may identify a more vulnerable phenotype with reduced physiologic reserve."