Effect of body mass index on clinical outcome and all-cause mortality in patients undergoing transcatheter aortic valve implantation

OBJECTIVES To assess the effect of body mass index (BMI) on outcome among patients with severe aortic stenosis (AS) admitted for transcatheter aortic valve implantation (TAVI). BACKGROUND Being overweight or obese is associated with improved outcome following certain medical treatments, suggesting the existence of a BMI paradox. However, the relationship between BMI and mortality after TAVI remains controversial. METHODS Patients were classified according to World Health Organisation criteria such as normal weight, overweight, or obesity according to their BMI (18.5 to 24.9 kg/m2, 25.0 to 29.9 kg/m2, and ≥30.0 kg/m2, respectively). RESULTS A total of 549 consecutive patients (age: 80.2 ± 7.5 years; logistic European system for cardiac operative risk evaluation [EuroSCORE]: 17.3 ± 9.9%) who underwent TAVI for AS were included. Of these patients, 43% (n = 237) had normal weight, 36% (n = 200) were overweight, and 20% (n = 112) were obese. There were no differences in peri-operative bleeding or vascular complication rates between the groups. All-cause mortality after 30 days, and 1 year, were higher in normal weight patients compared with overweight and obese patients (7% vs. 5 and 4%, p = 0.383, and 19% vs. 9 and 10%, p = 0.006, respectively). After adjustment for several confounding factors, overweight was associated with a decreased 30-day and 1‑year all-cause mortality outcome (hazard ratio [HR] 0.69; 95% confidence interval [CI] 0.47-0.99, and HR 0.65; 95% CI 0.45-0.94, respectively). CONCLUSIONS Despite the well-documented adverse effects of increased body weight on health, being overweight is associated with improved survival following TAVI when compared with normal weight.