Impact of Obesity on Ventricular Assist Device Outcomes

Obesity remains a relative contraindication for heart transplantation, and hence, obese patients with advanced heart failure receive ventricular assist devices (VADs) either as a destination or "bridge to weight loss" strategy. However, impact of obesity on clinical outcomes after VAD implantation is largely unknown. We sought to determine the clinical outcomes of obese patients with body mass index (BMI) ≥ 35 kg/m²) following contemporary VAD implantation.

The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry was queried for patients who underwent VAD implantation. Patients were categorized into BMI groups based on World Health Organization classification.

Of 17,095 patients, 2620 (15%) had a BMI ≥ 35 kg/m². Obese patients were likely to be young, non-white, females with dilated cardiomyopathy and undergo device implantation as destination. Survival was similar amongst BMI groups (P = .058). Obese patients had significantly higher risk for infection (hazard ratio [HR]: 1.215; P = .001), device malfunction or thrombosis (HR: 1.323; P ≤ .001), cardiac arrhythmia (HR: 1.188; P = .001) and hospital readmissions (HR: 1.073; P = .022), but lower risk of bleeding (HR: 0.906; P = .018). Significant weight loss (≥10%) during VAD support was achieved only by a small proportion (18.6%) of patients with BMI ≥ 35 kg/m². Significant weight loss rates observed in obese patients with VAD implantation as destination and bridge to transplant strategy were comparable. Obese patients with significant weight loss were more likely to undergo cardiac transplantation. Weight loss worsened bleeding risk without altering risk for infection, cardiac arrhythmia, and device complications.

Obesity alone should not be considered a contraindication for VAD therapy in contemporary era. Given durability of heart transplantation, strategies should be developed to promote weight loss, which occurs infrequently in obese patients. Impact of weight loss on clinical outcome of obese patients warrants further investigation.