Trend and Outcome of Patients with Body Mass Index ≥ 40 Kg/m2 Who Are listed for Heart Transplantation in the Contemporary Era

Abstract

<h3>Purpose</h3> Post heart transplantion (HT) outcomes of patients with body mass index ≥ 40 kg/m² (morbidly obese) remain suboptimal. However, outcomes of morbidly obese patients listed for heart transplant (HT) is unknown. We sought to examine the characteristic and outcome of such patients who were listed for HT in the United States. <h3>Methods</h3> Adults listed for HT with BMI information on the Scientific Registry of Transplant Recipients database between 2000 and 2018 were included. Characteristics and outcomes of patients with BMI≥ 40 kg/m² or = 18.5-39.99 kg/m² were compared. The patients were followed until death, transplant or end of data availability. Waitlist mortality and successful HT were compared between groups using a Fine and Gray competing risk hazard regression model adjusted for known risk factors. <h3>Results</h3> 55,717 patients identified: 656 (1.2%) had a BMI ≥ 35 kg/m²; 13,058 (23.4%) were female. The median (25^th, 75^th percentile) age was 55 (45, 61) years, and the median waitlist time was 101 (27, 299) days. Severely obese patients were significantly younger (46 vs. 55 years; p<0.0001), had higher hypertension (57.2% vs. 49.1%; p<0.0001), diabetes (40.3% vs. 27.6%; p<0.0001), and LVAD use (27.2% vs. 18.1%; p<0.0001). Annual listing of severely obese patients is on decline (from a peak of 47 in 2009 to a low of 14 in 2016, p_Trend<0.0001). The waitlist mortality (sub-hazard ratio [SHR] 2.07, 95% confidence interval [CI] 1.70-2.51) and likelihood of receiving HT (SHR 0.60, 95% CI 0.52-0.69) were significantly lower for those with a BMI≥ 40 kg/m² at the time of listing. <h3>Conclusion</h3> Listing of patients with BMI≥ 40 kg/m² is declining. This cohort is at significantly higher risk for death and lower HT rates.