Hybrid stage 1 palliation as a bridge to cardiac transplantation in patients with high-risk single ventricle physiology

Background The hybrid stage 1 palliation for hypoplastic left heart syndrome (HLHS) was first described in 1993 as a bridge to heart transplant for HLHS. There are limited data on this strategy as primary heart transplantation for HLHS has become less common. Methods This is an observational, single-center study comparing pre- and post-transplant outcomes of patients listed for transplant following hybrid palliation with those following surgical stage 1 palliation. Results From 2004 to 2017, 21 patients underwent hybrid palliation as a bridge to heart transplant and 28 patients were listed for transplant following surgical stage 1 palliation or aortic arch repair and pulmonary artery band placement. Premature birth and the presence of genetic or anatomic abnormalities were more common in the hybrid group. Need for extracorporeal membrane oxygenation (ECMO) support and ventricular dysfunction was more common in the surgical group. There was a trend toward shorter waitlist times in the surgical cohort (36 days vs 70 days, P = 0.06). There was no difference in waitlist mortality (19% vs 21%, P = 0.61). Survival at 1 and 5 years post-transplant was similar for the hybrid and surgical cohorts (5-year survival, 80% vs 85%, P = 0.94, respectively). There was no difference in the number of post-transplant interventions. Conclusions Although the hybrid patients represented a higher risk cohort and demonstrated longer wait times, the waitlist and post-transplant mortality was equivalent between the two groups. For high-risk patients, the hybrid palliation as a bridge to transplant appears to be a reasonable strategy.