Organ allocation in adults with congenital heart disease listed for heart transplant: Impact of ventricular assist devices

Abstract

Background Adults with congenital heart disease (CHD) listed for heart transplantation infrequently are supported with ventricular assist devices (VADs). This may disadvantage their priority for organ allocation. We sought to determine the relationship between VAD implantation and successful transplantation among patients listed for heart transplant. Methods Adults with CHD patients (N=1,250) were identified in the United Network for Organ Sharing (UNOS) database from 1985 – 2010 and compared to patients without congenital etiology for heart failure (N=59,606). VAD use at listing, listing status, status upgrades, and reasons for upgrade prior to transplant were trended at 5 year intervals and appropriate statistical comparisons were made between groups. Results Since 1985, VAD use prior to transplant has increased significantly in patients without CHD but not in CHD patients (17% vs. 3% in 2006–2010, p<0.0001). CHD patients were more likely to be listed as status 2, compared to those without (66% vs. 40%, p<0.001 for 2006–2010), and less likely to be upgraded to status 1 after listing (43% vs. 55%, p=0.03). Among those upgraded to status 1, CHD patients were less likely to have a VAD at transplant than those without (3% vs. 18%, p=0.005). VAD use was more likely to result in death in CHD patients. Conclusions VAD use is less common in CHD patients than patients without CHD, both at the time of listing and transplantation. Reduced VAD use appears to contribute to lower listing status and organ allocation. These differences have grown more disparate over time. Separate criteria for organ allocation for CHD patients may be justified.

Transplantation and Mechanical Circulatory Support in Congenital Heart Disease

“…6 Despite this, adults with CHD are less likely to receive implantable cardioverterdefibrillator therapy, more likely to be listed at lower urgency status, less likely to have a status upgrade, and less likely to receive a transplant at any given time after listing than patients without CHD. 7,8 Although there are limited outcome data, ACHD patients are also less likely to receive a ventricular assist device (VAD) as a bridge to transplantation. Moreover, listed ACHD patients are more likely to experience cardiovascular death (including sudden death and death caused by HF) than adults with acquired HF.…”

“…Moreover, listed ACHD patients are more likely to experience cardiovascular death (including sudden death and death caused by HF) than adults with acquired HF. 7 There has been a significant increase in MCS use in patients with acquired HF as a bridge to transplantation (17%) 8 ; however, there has been little change in MCS use in ACHD patients, with only 3% receiving a VAD at the time of transplantation 8 and a higher mortality in patients receiving MCS independent of the type of support. 9 …”

“…8 Specifically, since UNOS changed the allocation algorithm in 2006, transplant recipients were more likely to receive transplants as status 1A candidates (48% versus 37% before 2006), with an additional 40% receiving a transplant as status 1B candidates. 11 Allocation policies may further disadvantage the ACHD group because of the higher priority given to wait-listed patients on MCS, a therapy infrequently used in ACHD.…”

Challenges in Long-Term Mechanical Circulatory Support and Biological Replacement of the Failing Heart

“…29, 30 Approximately 3% of all heart transplants in the adult population are in patients with CHD. 31, 32 Despite a growing number of adults with CHD, the percentage of patients transplanted has remained relatively constant. It has been argued that higher mortality is observed on the waiting list because of decreased relative use of VAD implantation as a BTT.…”

“…It has been argued that higher mortality is observed on the waiting list because of decreased relative use of VAD implantation as a BTT. 32 Peri-transplant mortality is also generally higher in the CHD population, 29 attributed to a number of factors: the need for complex cannulation for cardiopulmonary bypass, 33 adhesions from prior operations, unique extracardiac manifestations of disease such as pulmonary vascular disease, 34 protein-losing enteropathy, coagulopathies and hepatic fibrosis, 35 and frequent need for complex reconstruction at the time of surgery. 3 Despite increased 30-day mortality, long-term outcomes for CHD patients post transplant are excellent and comparable to those for other populations.…”