Effect of obesity on outcomes in patients undergoing implantation of continuous-flow left ventricular assist devices

Abstract

The purpose of this study was to analyze the effect of obesity on outcomes after continuous-flow left ventricular assist device (CF-LVAD) implantation. A single-center retrospective analysis was performed on 526 chronic heart failure patients who were implanted with the HeartMate II CF-LVAD (n = 403) or HeartWare HVAD (n = 123) between November 2003 and March 2016. Patients were stratified into 4 groups based on BMI: underweight (< 18.5 kg/m², n = 18, 3.4%), normal-weight (18.5-25 kg/m², n = 173, 32.9%), overweight (25-30 kg/m², n = 182, 30.2%), and obese (> 30 kg/m², n = 153, 33.5%). The underweight group was excluded because of its small sample size. Records were reviewed to determine the incidence of postoperative complications and survival. Survival at 1, 6, 12, and 24 months were similar among normal-weight (91.3, 84.4, 76.3, and 67.6%), overweight (90.4, 80.8, 76.5, and 69.6%), and obese patients (90.7, 74.7, 65.3, and 61.3%, p = 0.24). Additionally, obesity was not a significant predictor of mortality in Cox proportional hazard models (hazard ratio 0.98, 95% confidence interval 0.766-1.277, p = 0.13). These findings suggest that appropriately selected obese patients receive similar survival benefit from CF-LVADs compared to non-obese patients, and obesity should not serve as a contraindication to CF-LVAD implantation.

Keywords: Body mass index (BMI); Heart failure; Left ventricular assist device (LVAD); Obesity.