A Bridge to the Fridge? Changes in BMI Post Left Ventricular Assist Device Implant

Abstract

Background Weight gain after left ventricular assist device (LVAD) implant may result in transplant listing loss in obese patients. We studied weight changes post LVAD amid BMI categories based on the hypothesis that changes in BMI impact transplant candidacy. Methods We retrospectively reviewed patients of LVAD implant at an academic medical center between 1/1/2012 and 12/31/2018. We collected demographic and clinical data, then stratified them into 4 groups based on BMI at implantation: 40. BMI data was collected at 12 and 6 months prior to implant, time of implant, and post implant at 3 and 6 months. A BMI cutoff >35 provided contraindication for transplant listing candidacy. Descriptive summary of variables was given with median and range or group frequency and percentages or mean and standard deviation. Scatter plot visualized correlation between weight difference changes over time. Additional lines overlaid on the plots indicate correlation trend. Mixed effects model was performed to estimating associations between weight difference and variables (time, BMI Implant). Bar plots were performed displaying move from 35 BMI after 6 months post LVAD and the move from >35 BMI at the time of implant to Results A total of 108 patients underwent LVAD implant at our center with complete data available for 59 patients. Baseline characteristics included mean age: 56 ±11.9 years, gender (male 70%), mean implant BMI: 30.1 ±6.9 kg/m2. Number of patients in each implant BMI group ( 40) was 30, 16, 9, and 4 respectively. There was no consistent pattern with weight change across differing implant BMIs as illustrated in Figure 1. Among patients with implant BMI's of 40, the percentage that lost transplant candidacy due to high BMI were 0, 31, 55, and 100 percent respectively in Figure 2. Conclusion Patients with a BMI within 5 points of the typical threshold of 35 for transplant candidacy demonstrate significant variability in response to LVAD therapy. However, all patients with implant BMIs >40 failed to regain transplant candidacy due to high BMI. These data support the concept of implementing aggressive weight loss protocols as a standard of post LVAD treatment in obese patients.