Beating heart technique for orthotopic heart transplantation after ex vivo heart perfusion: Clinical application and experience

Background Beating heart cardiac transplantation was introduced as a complement to ex vivo heart perfusion (EVHP) to allow implantation of the allograft without a second period of ischemia. We report our single-center experience of systematic use of the beating heart technique. Methods We retrospectively studied 75 consecutive heart transplantations performed using the Transmedics Organ Care System (OCS) over 24 months at our center, where hearts were implanted with the beating heart technique. Of the 75 recipients, UNOS status was 1 or 2 in 37 (49%) and 3 to 6 in 38 (51%), and 44 (59%) underwent reoperations, including 32 with a durable ventricular assist device, 5 with complex congenital heart disease, and 3 retransplants. Results Hearts were procured from donors after circulatory death (n = 35; 46.6%) or from extended criteria brain-dead donors (n = 40; 53.4%). Donors included 8 (10.6%) age ≥50 years, 13 (17.3%) with left ventricular hypertrophy, 19 (25.3%) with an undersized heart (predicted heart mass ratio <0.9); 2 (2.6%) on hemodialysis, and 11 (14.6%) with diabetes. One-quarter lived >650 miles away. The median clamp and OCS perfusion times were 7.1 hours (interquartile range [IQR], 6.4-7.6 hours) and 5.4 hours (IQR, 4.7-5.9 hours), respectively. The median cold ischemic time was 36 minutes (IQR, 29-40 minutes). Beating heart implantation was completed successfully without technical issues or complications in all patients, with no conversions to cardioplegic arrest. The period of EVHP through the cardiopulmonary bypass machine averaged 63 minutes (IQR, 56-70 minutes). Despite the higher donor risk profile, we experienced only 1 case (1.3%) of severe primary graft dysfunction (PGD) requiring mechanical circulatory support. The median vasoactive-inotropic score was 21.4 on leaving the operating room and 10.3 at 24 hours. There were 4 (5.3%) in-hospital mortalities, none directly attributable to the beating heart technique. Conclusions Beating heart transplantation is a safe, feasible, and reproducible technique. Despite an unselected surgical cohort and our high use of extended criteria donors, we experienced a low incidence of PGD. The beating heart technique may facilitate the use of extended criteria donor hearts and increase the access to heart transplantation for complex surgical recipients.