The obesity paradox in patients undergoing transcatheter aortic valve implantation: is there any effect of body mass index on survival?

BACKGROUND: Conflicting results have been presented regarding influence of body mass index (BMI) on outcomes among patients undergoing transcatheter aortic valve implantation (TAVI).

AIMS: To investigate impact of the BMI on the clinical results after TAVI.

METHODS: A total of 148 consecutive patients were categorized using baseline BMI according to World Health Organization criteria. The baseline patient characteristics, frailty, procedural and clinical outcomes with 30 days and 12-month all-cause mortality were compared between BMI categories. Patients were followed-up for a median of 460.0 (182.0-1042.0) days.

RESULTS: Obesity was diagnosed in 37 (25.2%) patients, 73 were overweight (49.7%), and 37 (25.2%) had normal weight. Lower frailty prevalence as assessed with 5-meter walking test was confirmed in obese patients as compared to other groups. A trend towards a lower rate of in-hospital bleeding complications [18 (48.6%) vs. 21 (28.8%) vs. 9 (24.3%); p = 0.06] and less frequent blood transfusions in overweight and obese was observed [18 (48.6%) vs. 17 [23.3%) vs. 8 (21.6%); p = 0.016]. The rate of grade 3 acute kidney injury was the lowest in the overweight group [4 (10.8%) vs. 1 (1.4%) vs. 3 (8.1%); p = 0.05]. There was no difference between groups in all-cause mortality at 30 days (p = 0.15). However, 12-month all-cause mortality was the lowest in obese patients [12 (32.4%) vs. 10 (13.7%) vs. 2 (5.4%); p = 0.004]. Increase in BMI was independently associated with lower all-cause mortality [HR (95%CI) per 1 kg/m² increase: 0.91 (0.845-0.98); p = 0.018].

CONCLUSIONS: Increased BMI was independently associated with survival benefit after TAVI.