Short-term outcomes comparing the use of hypothermic perfusion machine in heart transplantation : a monocentric study

Background Heart transplantation outcomes critically depend on graft preservation quality and ischemic time. Hypothermic machine perfusion of donor hearts has emerged as a promising method to reduce ischemia-reperfusion injury and primary graft dysfunction (PGD). We report our single-center experience comparing short-term outcomes of hypothermic perfusion using the X-Vivo system versus standard static cold storage (CS). Methods This descriptive, comparative study analyzed patients enrolled in the European NIHP2019 randomized controlled trial at our center between November 2020 and May 2023. Twenty-six adult heart transplant recipients were included: 14 in the CS group and 12 in the X-Vivo group. The primary endpoint was the incidence of PGD, defined by the 2014 ISHLT criteria. Secondary endpoints included major adverse cardiovascular events, 30-day mortality, use of extracorporeal membrane oxygenation (ECMO), and ICU length of stay. Results Moderate-to-severe PGD occurred significantly less frequently in the X-Vivo group (33%) compared to CS (79%) (p=0.02). Thirty-day PGD-free survival was higher with X-Vivo (67% vs. 21%, p=0.022). Severe PGD incidence was also reduced (17% vs. 64%, p=0.014). Multivariate analysis confirmed a lower risk of moderate-to-severe PGD (OR 0.04; 95% CI 0.00–0.74; p=0.031) and severe PGD (OR 0.04; 95% CI 0.00–0.84; p=0.038) with X-Vivo. Secondary endpoints, including major adverse cardiovascular and transplant events, 30-day mortality (15% overall), and ECMO use, did not differ significantly. Cold ischemia time was slightly longer in the X-Vivo group (237 vs. 197 minutes), with a mean machine perfusion duration of 137 minutes. Conclusions In this single-center cohort, hypothermic continuous perfusion with the X-Vivo system was associated with a significant reduction in early primary graft dysfunction after heart transplantation without affecting short-term mortality. These findings support hypothermic machine perfusion as a valuable adjunct to standard preservation techniques. Larger, multicenter studies with extended follow-up are needed to confirm these benefits and define optimal clinical use.