Sub-analysis
A sub-analysis was performed which included only patients that had been waitlisted ≥90 days prior to OHT. This resulted in a total of 11,623 patients, 8,669 (74.6%) with stable weight, 1,262 (10.9%) with ≥5% weight loss, and 1,692 (14.6%) with ≥5% weight gain. Ninety-day (94.5% vs 92.9% vs 95.6%) and one-year (91.4% vs 88.9% vs 92.3%) mortality were lowest in patients with ≥5% weight loss (Figure 3 ) (P =0.0044). In multivariable model, ≥5% weight loss was associated with 33% increased hazards for posttransplant mortality (HR 1.33, 95% CI 1.11 to 1.61, P=0.003). ≥5% weight gain was not found to have significant impact on mortality (HR 0.87, 95% CI 0.72 to 1.06, P=0.173) (Supplemental Table 2 ). When examined as a continuous variable, decreasing weight was associated with increased hazards for mortality (per 1% weight lost, HR 1.02, 95% CI 1.01 to 1.03, P<0.001) (Supplemental Table 3 ). Other factors associated with increased hazards for mortality included increasing BMI, congenital heart disease, increasing total bilirubin and serum creatinine, pretransplant mechanical ventilation, extracorporeal membrane oxygenation, increasing donor age, and increasing graft cold ischemia time.
Additional sub-analysis investigated the outcomes of patients with initial waitlist BMI ≥35 kg/m2. This subgroup was comprised of 1,470 patients, 1,205 (82.0%) who were transplanted with a BMI ≥ 35 kg/m2, and 265 (18.0%) who dropped to a BMI < 35 kg/m2 prior to OHT. Comparison of baseline characteristics are shown in SupplementalTable 4 . Patients who were transplanted at a BMI < 35 kg/m2 had a higher utilization of left ventricular assist device as a bridge to OHT (66.9% vs 56.9%, P<0.001), and also had a longer median waitlist time (397 days [IQR 172 to 727] vs 111 days [IQR 31 to 343], P<0.001) compared those who were transplanted with a BMI ≥ 35 kg/m2.Figure 4a displays Kaplan Meier posttransplant survival between groups. Additionally, recipients with waitlist BMI ≥ 35 kg/m2 were stratified into weight change while on waitlist (stable weight, ≥5% weight loss, ≥5% weight), and Kaplan Meier survival comparisons are shown in Figure 4b . In both comparisons, there were no differences in one-year survival among groups.