The ‘obesity paradox’ does exist in patients undergoing transcatheter aortic valve implantation for aortic stenosis: a systematic review and meta-analysis

Most recent studies have proposed the paradoxical benefits of obesity in surgical populations. For patients who underwent transcatheter aortic valve implantation (TAVI) for aortic stenosis, the prognostic roles of obesity and high body mass index remain controversial. Therefore, the objective of this meta-analysis was to evaluate whether the 'obesity paradox' exists in patients undergoing TAVI. We searched in PubMed and EMBASE to identify the eligible articles. Odds ratios and hazard ratios with the corresponding 95% confidence intervals (CI) were adopted for synthesizing short-term and long-term survival outcomes, respectively. The level of heterogeneity and the publication bias between studies were also estimated. Finally, there were 16 studies with 12 330 patients who met the eligibility criteria and who were thus included in this review. When body mass index was analysed as a continuous variable, each increase of 1 kg/m2 was significantly associated with the lower 30-day mortality rate (odds ratio = 0.95; 95% CI = 0.93-0.97; P < 0.001) and better long-term overall survival (hazard ratio = 0.96; 95% CI = 0.94-0.97; P < 0.001) for patients undergoing TAVI. The obese patients had a significantly lower risk of 30-day mortality after TAVI than did normal patients (odds ratio = 0.69; 95% CI = 0.50-0.95; P = 0.024). Further analyses indicated that the obesity could be predictive of more favourable long-term overall survival of TAVI (hazard ratio = 0.84; 95% CI = 0.72-0.97; P = 0.021). However, we found no difference in procedural complications between the obese and normal patients. In conclusion, higher body mass index and obesity seem to have protective benefits on both short-term and long-term survival of TAVI patients. Current evidence suggests that the 'obesity paradox' may really exist in TAVI.