"Obesity paradox" in transcatheter aortic valve implantation

To determine whether body mass index (BMI) is associated with mortality in transcatheter aortic valve implantation (TAVI), we performed a mete-analysis of currently available studies.

MEDLINE and EMBASE were searched through September 2015 using PubMed and OVID, to identify all studies investigating an association of BMI with early (in-hospital or 30-day) and mid-term (mean or median follow-up of approximately >6-month) mortality in patients undergoing TAVI.

Our search identified 11 eligible studies including 10,196 patients undergoing TAVI. A pooled analysis of 7 studies (enrolling 4046 patients) reporting a hazard ratio (HR) of BMI as continuous data for mid-term mortality demonstrated that greater BMI was associated with significantly less mid-term mortality (HR per 1-unit increase in BMI, 0.97; 95% confidence interval [CI], 0.94 to 1.00 [0.9982]: P = 0.04). Comparisons of overweight versus normal weight and obesity versus normal weight for mid-term mortality were not statistically significant. A pooled analysis of 3 studies (enrolling 3901 patients) reporting an odds ratio (OR) of BMI as continuous data for 30-day mortality demonstrated that greater BMI was associated with significantly less mortality (OR per 1-unit increase in BMI, 0.95; 95% CI, 0.92 to 0.98: P = 0.001). Comparisons of overweight versus normal weight (P = 0.02) and obesity versus normal weight (P = 0.04) for 30-day mortality were statistically significant.

BMI as continuous data may be associated with better early and mid-term post-TAVI survival. Whereas, overweight or obesity as categorized BMI may be associated with early, not mid-term, post-TAVI survival.