Impact of body mass index on the outcome of elderly patients treated with transcatheter aortic valve implantation

Abstract

Underweight or overweight patients with cardiovascular diseases are associated with different outcomes. However, the data on the relation between body mass index (BMI) and outcomes after transcatheter aortic valve implantation (TAVI) are not homogeneous. The aim of this study was to assess the role of low BMI on short and long-term mortality in real-world patients undergoing TAVI. We retrospectively included patients undergoing TAVI for severe aortic valve stenosis. Patients were classified into three BMI categories: underweight (< 20 kg/m²), normal weight (20-24.9 kg/m²) and overweight/obese (≥ 25 kg/m²). Our primary endpoint was long-term all-cause mortality. The secondary endpoint was 30-day all-cause mortality. A total of 794 patients were included [mean age 82.3 ± 5.3, 53% females]. After a median follow-up of 2.2 years, all-cause mortality was 18.1%. Patients in the lowest BMI group showed a higher mortality rate as compared to those with higher BMI values. At the multivariate Cox regression analysis, as compared to the normal BMI group, BMI < 20 kg/m² was associated with long-term mortality independently of baseline risk factors and postprocedural adverse events (hazard ratio [HR] 2.29, 95% confidence interval [CI] 1.30-4.03] and HR 2.61, 95% CI 1.48-4.60, respectively). The highest BMI values were found to be protective for both short- and long-term mortality as compared to lower BMI values even after applying the same adjustments. In our cohort, BMI values under 20 kg/m² were independent predictors of increased long-term mortality. Conversely, the highest BMI values were associated with lower mortality rates both at short- and long-term follow-up.

Keywords: Aortic valve stenosis; Body mass index; Cardiovascular disease; Obesity paradox; TAVI.