Bridging to Transplant with HeartMate 3 Left Ventricular Assist Device in the 2018 Heart Allocation System

Abstract

Purpose Following MOMENTUM 3 trial and the discontinuation of HeartWare HVAD, Heartmate 3 (HM3) LVAD is the only durable device option for patients bridging to transplantation. The new allocation system was initiated in October 2018 and prioritized LVAD patients as status 4 or 3 in case of LVAD complication. The outcome of bridging patients to heart transplantation with HM 3 in the new heart allocation system is not well described. Methods The United Network for Organ Sharing (UNOS) registry was queried to include adult patients (≥18 years old) listed for heart transplantation. Trends in durable continuous-flow LVAD utilization was investigated in patients who were waitlisted or transplant between January 2010 through June 2020 with HM II, HVAD, or HM 3. Using UNOS registry, we examined patients who were waitlisted or bridged to transplant with Heartmate 3 LVAD in the new vs. old heart allocation system. Results From 2017 to 2020, there was a 28.3% decline (from 1,168 to 837 per year) in the number of patients waitlisted with an FDA approved durable LVAD. 1,094 patients (70.9%) were waitlisted with HM 3 in the new allocation system compared to 449 HM 3 patients (29.1%) in the old allocation system. Cumulative incidence of heart transplantation (50.7% vs. 53.4%, p=0.762) and death or delisting for worsening status (4.2% vs. 5.0%, p=0.43) at 1-year after listing with HM 3 LVAD was comparable in the new vs. old allocation system. However, 1-year post-transplant survival after bridging with HM 3 was significantly lower in the new vs. old heart allocation system (87.3% vs. 93.6%, p<0.001) (figure). Multivariable analysis revealed, old age (> 60), ischemic etiology of HF, poor functional status, elevated creatinine (> 1.8 mg/dL), pulmonary hypertension (PVR > 3 WU), and listing in the new allocation system as significant predictors of post-transplant graft survival. Conclusion While the utilization of durable devices as BTT have declined under the new heart allocation system, bridging with HM 3 LVAD remains a safe strategy. Following MOMENTUM 3 trial and the discontinuation of HeartWare HVAD, Heartmate 3 (HM3) LVAD is the only durable device option for patients bridging to transplantation. The new allocation system was initiated in October 2018 and prioritized LVAD patients as status 4 or 3 in case of LVAD complication. The outcome of bridging patients to heart transplantation with HM 3 in the new heart allocation system is not well described. The United Network for Organ Sharing (UNOS) registry was queried to include adult patients (≥18 years old) listed for heart transplantation. Trends in durable continuous-flow LVAD utilization was investigated in patients who were waitlisted or transplant between January 2010 through June 2020 with HM II, HVAD, or HM 3. Using UNOS registry, we examined patients who were waitlisted or bridged to transplant with Heartmate 3 LVAD in the new vs. old heart allocation system. From 2017 to 2020, there was a 28.3% decline (from 1,168 to 837 per year) in the number of patients waitlisted with an FDA approved durable LVAD. 1,094 patients (70.9%) were waitlisted with HM 3 in the new allocation system compared to 449 HM 3 patients (29.1%) in the old allocation system. Cumulative incidence of heart transplantation (50.7% vs. 53.4%, p=0.762) and death or delisting for worsening status (4.2% vs. 5.0%, p=0.43) at 1-year after listing with HM 3 LVAD was comparable in the new vs. old allocation system. However, 1-year post-transplant survival after bridging with HM 3 was significantly lower in the new vs. old heart allocation system (87.3% vs. 93.6%, p<0.001) (figure). Multivariable analysis revealed, old age (> 60), ischemic etiology of HF, poor functional status, elevated creatinine (> 1.8 mg/dL), pulmonary hypertension (PVR > 3 WU), and listing in the new allocation system as significant predictors of post-transplant graft survival. While the utilization of durable devices as BTT have declined under the new heart allocation system, bridging with HM 3 LVAD remains a safe strategy.