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 the influence of body mass index (BMI) on outcomes among patients undergoing transcatheter aortic valve implantation (TAVI).

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

METHODS

A total of 148 consecutive patients were categorised using baseline BMI according to the World Health Organization criteria. Baseline patient characteristics, frailty, and procedural and clinical outcomes including 30-day and 12-month all-cause mortality were compared between the 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 (49.7%) patients were overweight, and 37 (25.2%) had normal weight. Prevalence of lower frailty as assessed by five-metre walk 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%] in normal-weight, overweight, and obese patients, respectively; p = 0.06) and less frequent blood transfusions (18 [48.6%] vs. 17 [23.3%) vs. 8 [21.6%]; p = 0.016) was observed in overweight and obese groups. The rate of grade 3 acute kidney injury was lowest in the overweight group (4 [10.8%] vs. 1 [1.4%] vs. 3 [8.1%]; p = 0.05). There was no difference between the groups in terms of 30-day all-cause mortality (p = 0.15). However, 12-month all-cause mortality was lowest in obese pa-tients (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 (hazard ratio [95% confidence interval] 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.