Abstract 1921: Biventricular Assist Devices as a Bridge to Heart Transplantation in Children
Background: Experience with the use of biventricular assist device (BiVAD) support to bridge small children to heart transplantation is limited.
Methods: We utilized BIVAD support (Berlin EXCOR®) in 8 pediatric heart transplant candidates less than 40 kg from 4/05–4/07. The median patient age was 1.7 years (12 days to 17 years). The median patient weight was 9.9 kg (3–38 kg). All children were supported with multiple intravenous inotropes ± mechanical ventilation (5) or ECMO (3) prior to BiVAD implantation. All had moderate (1) to severe (7) right ventricular dysfunction. The median pulmonary vascular resistance index (Rpi) was 6.0 WU/m2.
Results: Seven patients were successfully bridged to heart transplantation after a median duration of BiVAD support of 22.5 days (range 1–77). One death occurred after 10 days of support from perioperative renal failure in a 3 kg infant. Four patients required at least 1 blood pump change. There were no acute neurologic complications, no thromboembolic events, and no bleeding complications. One patient had a drive line infection requiring treatment. In 2 patients with Rpi > 10 WU/m2 unresponsive to pulmonary vasodilator therapy, Rpi dropped to 1.4 and 4.6 WU/m2 after 33 and 41 days of support, respectively. All 7 survivors underwent successful heart transplantation. Of 4 patients supported > 30 days, 3 developed an extremely elevated (> 90%) panel reactive antibody by ELISA that was not confirmed by other methods; none had a positive donor-specific retrospective crossmatch. There was 1 episode of rejection (with hemodynamic compromise) in the 7 transplanted patients. Rpi was normal (< 3 WU/m2) without pulmonary vasodilators in all patients within 3 months after transplant. There have been no deaths following transplant with a median follow-up of 15 months.
Conclusions: BiVAD support can be utilized effectively in children as a bridge to heart transplantation and can be accomplished with low mortality and morbidity. BiVAD support may offer an additional means to reverse extremely elevated pulmonary vascular resistance. Surveillance for HLA antibody sensitization during BiVAD support may be complicated by the development of non-HLA antibodies which may not reflect true HLA presensitization.