Outcomes With Ventricular Assist Device Versus Extracorporeal Membrane Oxygenation as a Bridge to Pediatric Heart Transplantation

Abstract

Extracorporeal membrane oxygenation (ECMO) has long been the sole means of mechanical support for pediatric patients with end-stage cardiac failure, but has a high waitlist mortality and a reported survival to hospital discharge of less than 50%. The purpose of this study was to compare waitlist mortality and survival for ECMO versus ventricular assist device (VAD) support. A review was conducted of all patients listed for heart transplantation (HTx) since 2002 and requiring mechanical support. VAD support has been available from 2004 (Berlin Heart Excor Pediatrics). Competing risks analysis was used to model survival to one of four outcomes (HTx, death on waitlist, delisting, improvement). Thirty-six patients were on mechanical support while awaiting HTx (21 ECMO, 12 VAD, three both). Median age at listing was 1.2 years (birth-16.6 years) for ECMO and 11.3 years (0.3-14.6 years) for VAD. Diagnosis was cardiomyopathy in 33% for ECMO and 93% for VAD. Median time to HTx was 37 days (1-930) overall, 20 days (1-85) for ECMO, and 39 days (5-108) for VAD. Mechanical support was associated with increased odds of HTx (hazard ratio [HR] 2.4 [1.7-3.3], P < 0.0001) but also delisting or death waiting (HR 3.0 [1.1-7.8], P = 0.03). Waitlist mortality of 38% on ECMO was reduced to 13% with VAD use. Survival post-HTx to hospital discharge was better in the group on VAD support (92 vs. 80%). Pediatric patients requiring mechanical support as a bridge to HTx have short wait times but high waitlist mortality. Those patients who survived to be put on the Berlin Heart Excor Pediatric device based on individualized clinical decision making then had a lower waitlist mortality, a longer duration of support, and a higher survival to transplantation and hospital discharge.

Berlin Heart EXCOR Pediatric Ventricular Assist Device for Bridge to Heart Transplantation in US Children

“…5,6,[17][18][19][20][21][22][23] The wide variability in risk estimates stems from limitations of earlier studies, including small sample size 18,19,22,24 or single-institution experiences, 6,24,25 which has made it difficult for clinicians to know precisely when to offer EXCOR support to their patients or to provide families with or a standardized device treatment protocol 6,25 with uniform adverse event definitions, anticoagulation guidelines, and algorithm for pursuing BIVAD support, thus precluding the ability to know whether adverse events are related to the device itself or differences in patient management. Moreover, studies have tended to pool bridge-to-transplantation and bridge-to-recovery patients, 6,25 making it difficult to interpret transplantation success rates.…”

Current state of pediatric cardiac transplantation

“…However, serious morbidity including stroke, bleeding, infection and device malfunction remains common (14). As depicted in Figure 9, more infants require ECMO support, especially those with congenital heart disease, with the resultant suboptimal outcomes (13,15). Mechanical support options for single ventricle patients and outcomes pre-and post-transplant remain poor (7).…”

Prospective Trial of a Pediatric Ventricular Assist Device

“…As a result, only 40 to 60% of children requiring support with ECMO survive long enough to undergo heart transplantation. 9 The Excor Pediatric ventricular assist device (Berlin Heart) is a paracorporeal, pneumatically driven, pulsatile-flow mechanical circulatorysupport device available in a wide range of sizes. We conducted a prospective study to evaluate this device as bridge therapy in children who were on waiting lists for orthotopic heart transplantation.…”