Morbidity and Mortality in Heart Transplant Candidates Supported with Mechanical Circulatory Support. Is Reappraisal of the Current UNOS Thoracic Organ Allocation Policy Justified?

Omar Wever-Pinzon; Stavros G. Drakos;Abdallah G. Kfoury; Jose N. Nativi; Edward M. Gilbert; Melanie Everitt; Rami Alharethi; Kim Brunisholz; Feras M. Bader; Dean Y. Li; Craig H. Selzman; Josef Stehlik

CIRCULATIONAHA.112.100123 Published online before print December 27, 2012,

Abstract

Background—Survival of patients on left ventricular assist devices (LVADs) has improved. We examined the differences in risk of adverse outcomes between LVAD supported and medically managed candidates on the heart transplant waiting list.

Methods and Results—We analyzed mortality and morbidity in 33,073 heart transplant candidates registered on the United Network for Organ Sharing (UNOS) waiting list between 1999 and 2011. Five groups were selected: patients without LVADs in urgency Status 1A, 1B and 2, patients with pulsatile-flow (PF) and patients with continuous-flow (CF) LVADs. Outcomes in patients requiring biventricular assist devices (BIVADs), total artificial heart (TAH) and temporary VADs were also analyzed. Two eras were defined based on the approval date of the first CF-LVAD for bridge-to-transplant in the US (2008). Mortality was lower in the current compared with the first era - 2.1% vs. 2.9%/month, p<0.0001. In the first era, mortality of PF-LVAD patients was higher than in Status 2 (HR 2.15, p<0.0001) and similar to Status 1B patients (HR 1.04, p=0.61). In the current era, patients with CF-LVADs had similar mortality compared to Status 2 (HR 0.80, P=0.12) and lower mortality compared with Status 1A and 1B patients (HR 0.24 and 0.47, p<0.0001 for both comparisons). However, status upgrade for LVAD-related complications occurred frequently (28%) and increased the mortality risk (HR 1.75, p=0.001). Mortality was highest in patients with BIVADs (HR 5.00, p<0.0001) and temporary VADs (HR 7.72, p<0.0001).

Conclusions—Mortality and morbidity on the heart transplant waiting list have decreased. Candidates supported with contemporary CF-LVADs have favorable waiting list outcomes; however, these worsen significantly once a serious LVAD-related complication occurs. Transplant candidates requiring temporary and biventricular support have the highest risk of adverse outcomes. These results may help to guide optimal allocation of donor hearts.