Higher Body Mass Index is Associated with End Stage Renal Failure after Left Ventricular Assist Device Implantation

PURPOSE Elevated body mass index (BMI) is a well-established risk factor for post-operative adverse events. We hypothesized that patients with higher BMI are more likely to develop end stage renal failure (ESRD) after LVAD implantation, a complication regarded as a strong negative prognostic marker for survival. METHODS A single center continuous flow LVAD cohort (n=456) was queried for BMI at the time of LVAD implantation. To determine the relationship between BMI and the probability of ESRD, a multivariable Cox regression analysis was performed. Patients were stratified into 3 groups by BMI ( 30 kg/m2) for analysis. RESULTS The mean age of the cohort was 57±14 years. 80% were male, 54% had ischemic cardiomyopathy, 57% were designated as bridge to transplant and the median pre-implant creatinine was 1.2. The median follow-up time on LVAD support was 1.3 years. 25 of the 456 patients in our cohort (5.5%) developed ESRD. BMI >30 kg/m2 was associated with a significantly increased risk for renal failure (adjusted HR: 6.5, CI: 1.4-29.4; p=0.015). While there was a trend, the risk for the intermediate BMI group did not reach statistical significance (p=0.079) when compared to BMI<25 kg/m2. The model was adjusted for age, sex, INTERMACS profile, bridge to transplant status and pre-implant renal function. CONCLUSION BMI above 30 kg/m2 at the time of LVAD implantation was associated with a significantly increased post-operative risk for renal failure in our cohort. Further studies are warranted to determine the pathophysiology and to develop strategies to mitigate this risk.