Impact of mechanical circulatory support on pediatric heart transplant candidates with elevated pulmonary vascular resistance

Abstract

With the new era of increasing use of mechanical circulatory support (MCS) in children, seemingly more patients with elevated pulmonary vascular resistance (PVR) are having positive outcomes. The purpose of this study was to define the effect of MCS on pediatric patients listed for heart transplant with an elevated PVR. The United Network for Organ Sharing (UNOS) database was used to identify patients aged 0‐18 at the time of listing for heart transplant between 2010 and 2019 who had PVR documented (n = 2081). Patients were divided into MCS (LVAD, RVAD, BiVAD, and TAH) and No MCS groups, then divided by PVR (PVR) at the time of listing: <3, 3‐6, and >6 Wood units (WU). MCS was used in 20% overall (n = 426); 57% of those with PVR <3, 27% with PVR 3‐6, and 16% with PVR >6. MCS, PVR <3 patients had a higher chance of positive waitlist outcome than all No MCS groups (vs. PVR <3, P = .049; vs. PVR 3‐6, P = .004; vs. PVR >6, P < .001). MCS, PVR 3‐6 patients had a higher chance of positive waitlist outcome than all No MCS groups (vs. PVR <3, P = .048; vs. PVR 3‐6, P = .009; vs. PVR >6, P < .001). MCS, PVR >6 patients had a higher chance of positive waitlist outcome than No MCS, PVR >6 patients (P = .012). Within the No MCS group, patients with a PVR >6 had a higher incidence of negative waitlist outcome compared to PVR <3 (17% vs. 10%, P = .002); this was not the case in the MCS group (5% vs. 6%, P = .693). More patients in the MCS group were ventilator dependent (15% vs. 9%, P < .001) at the time of listing and less likely to have a functional status >50% (43% vs. 73%, P < .001). No significant differences in post‐transplant survival were found in pairwise comparisons of MCS and No MCS PVR subgroups. Patients supported with MCS had a significantly higher chance of a positive waitlist outcome than those without such support regardless of PVR status. This was most pronounced with a PVR greater than 6 WU. MCS compared to No MCS patients had better waitlist survival and equivalent post‐transplant survival. MCS patients, despite being more ill, had better overall survival regardless of PVR.

Heart Transplantation in Children With Down Syndrome

“…Evolution of mechanical circulatory support strategies, donor selection, and posttransplant management has helped to mitigate some of the risks associated with elevated PVR. 52 , 53 , 54 Therefore, although elevated PVR may identify higher risk patients, it may not be prohibitive to HTx in the current era.…”

Focus on Paediatric Restrictive Cardiomyopathy: Frequently Asked Questions

“…Recent data from children awaiting heart transplant show that those with an PVRI >6 W.U. m 2 had better waitlist outcomes when placed on MCS compared to those who were not [109][110][111][112], leading long-term MCS implantation to be considered in advanced stages of the disease as a bridge to HT by improving haemodynamics and reducing post-capillary PH. Figure 5 shows the management of paediatric RCM base on right heart catheterization [5].…”

Pulmonary Vasodilator Therapy in Pediatric Patients on Ventricular Assist Device Support: A Single-Center Experience and Proposal for Use

“…19 Thangappan et al . 21 showed that children with PVRs in three categories (<3, 3–6, and >6) had improved survival to transplant or recovery when a VAD was used versus children without VAD support and outcomes were similar amongst the three PVR categories. This suggests that there is a decrease in PVR and positive outcome with the use of VAD alone.…”

“…20 The most common causes of mortality include multisystem organ failure (27.5% of all mortalities), neurologic injury (20.3%), and Gastrointestinal (GI) failure (16.3%), followed by circulatory failure (15.7%). 19 Thangappan et al 21 showed that children with PVRs in three categories (<3, 3-6, and >6) had improved survival to transplant or recovery when a VAD was used versus children without VAD support and outcomes were similar amongst the three PVR categories. This suggests that there is a decrease in PVR and positive outcome with the use of VAD alone.…”