Body Mass Index Impacts Immediate and Long-Term Survival of Heart Transplant Recipients

Abstract

Purpose Obesity in heart failure may be associated with improved outcomes. We sought to assess the impact of pre-transplant body mass index (BMI) on post-heart transplant survival. Methods and Materials We analyzed The United Network for Organ Sharing data registry for adult orthotopic heart transplant recipients from 1987 to 2012. Recipients with right or bi-ventricular support or total artificial hearts were excluded. Patients were stratified based on body mass index (BMI in kg/m²) at time of transplant based on conventional thresholds for transplantation into BMI 15-18.4 (UNDERWEIGHT), 18.5- 29.9 (NORMAL), 30-34.9 (OVERWEIGHT) and 35-40 (OBESE). Kaplan-Meier estimates were used to evaluate survival. Results 52,903 heart transplant recipients were identified and 45,261 were included. Of the overall cohort, 78.4% - NORMAL, 15.2% - OVERWEIGHT, 3.3% - UNDERWEIGHT and 3.1% - OBESE. Pre-transplant BMI affected survival significantly at 30 days, 1, 5, and 10 years post-transplant (p figure 1 ] In the proportional hazards model, OVERWEIGHT and UNDERWEIGHT patients had decreased survival. Factors negatively affecting survival include female donor to male recipients, African-American recipients, pulmonary hypertension, LVAD, increasing age and ischemic times. Conclusions In a population based analysis, BMI influences survival in the short and long term. Underweight recipients may not have physiologic reserves for optimum results. Hazard ratio 95% Hazard Ratio Confidence Limits OBESE 1.101 0.927–1.308 OVERWEIGHT 1.165 1.066–1.274 UNDERWEIGHT 1.367 1.117–1.672 Female donor to male recipient 1.176 1.060–1.305 African-American 1.419 1.296–1.554 PH 1.113 1.031–1.201 LVAD at transplant 1.022 0.930–1.123