Outcomes Associated with Obesity in Patients Undergoing Left Ventricular Assist Device Implantation: A Systematic Review and Meta-Analysis

Current data suggest that obesity does not impact survival, but may predispose patients to a higher rate of adverse events during left ventricular assist device (LVAD) support. We performed a systematic review and meta-analysis to assess the effects of obesity on clinical outcomes in LVAD recipients. We searched Medline, Scopus, Cochrane library, and clinicaltrials.gov from inception to February 2019 for studies comparing outcomes in obese (body mass index [BMI]> or ≥30 kg/m²) and nonobese (BMI< or ≤30 kg/m²) heart failure (HF) patients after LVAD implantation. Our primary endpoint was short-term (≤1 year) and long-term (>1 year) all-cause mortalities. The estimates are presented as random-effects risk ratios (RR) with 95% confidence intervals. In this meta-analysis of 15 observational studies (n = 26,842), obese patients receiving LVAD had significantly decreased 6 months (RR = 0.79 [0.73, 0.86]; p < 0.001, I²= 0%) and 1 year all-cause mortality (RR = 0.87 [0.79, 0.97]; p = 0.008, I²= 69%) compared with nonobese patients. However, both groups showed no significant difference in all-cause mortality at 2 years (RR = 0.95 [0.87, 1.04]; p = 0.12, I²= 55%) or 3 years (RR = 0.84 [0.61, 1.15]; p = 0.28, I²= 43%). Obese patients had significantly higher risk of device-related infections (RR = 1.48 [1.25, 1.75]; p < 0.001, I²= 37%), right heart failure (RR = 1.41 [1.21, 1.65]; p < 0.001, I²= 28%), and pump thrombosis (RR = 1.55 [1.37, 1.76]; p < 0.001, I²= 0%) compared with nonobese patients. This meta-analysis suggests that obese patients with HF have short- but not long-term survival benefit after LVAD implantation when compared to nonobese patients, although bias may have impacted these findings.