A multinational randomized controlled trial found that hypothermic oxygenated machine perfusion of donor hearts may reduce the incidence of primary graft dysfunction compared with static cold storage in heart transplantation.

In the NIHP2019 trial, published in The Lancet, researchers demonstrated a 44% risk reduction in a composite primary endpoint of cardiac-related death, primary graft dysfunction (PGD), acute cellular rejection, or graft failure within 30 days posttransplant.

The trial was conducted across 15 transplant centers in eight European countries and enrolled 229 adult heart transplant candidates between November 2020 and May 2023. The patients were randomized 1:1 to receive donor hearts preserved with either hypothermic oxygenated machine perfusion (HOPE) (n = 119) or static cold storage (SCS) (n = 110).

In the modified intention-to-treat analysis (n = 204), the primary endpoint occurred in 19% of HOPE recipients vs 30% of SCS recipients (hazard ratio [HR] = 0.56, 95% confidence interval [CI] = 0.32–0.99, P = .059).

Donor and recipient characteristics were well-balanced between the HOPE and SCS groups. The median donor age was 48 years (interquartile range [IQR] = 38–56) in the HOPE group and 50 years (IQR = 36–56) in the SCS group. Notably, 36% of the HOPE donors and 39% of the SCS donors had experienced cardiac arrest requiring cardiopulmonary resuscitation. Recipient demographics were also similar between groups, with a median recipient age of 56 years (IQR = 47–62) in the HOPE group and 58 years (IQR = 47–63) in the SCS group. Ventricular assist devices were present in 29% of the recipients in both groups. The primary indication for transplantation was dilated cardiomyopathy (50% HOPE, 42% SCS), followed by ischemic heart disease (25% HOPE, 35% SCS).

PGD, a key component of the primary endpoint, occurred in 11% of the HOPE recipients compared with 28% of the SCS recipients. Severe PGD occurred in 5% of the patients in the HOPE group vs 20% of those in the SCS group.

Secondary outcomes, including major adverse cardiac transplant events, favored the HOPE group. There were no statistically significant differences in cardiac deaths or acute cellular rejections between the groups.

The trial used a portable machine perfusion system (XVIVO Heart Assist Transport) for HOPE preservation. Donor hearts were continuously perfused at 8°C with an oxygenated, hyperoncotic solution. All 100 donor hearts preserved with HOPE were deemed transplantable after perfusion.

Serious adverse events occurred in 65% of the HOPE recipients vs 70% of the SCS recipients. Median ICU stay was 8 days for both groups.

The researchers stated that the trial provided evidence supporting HOPE as a method for donor heart preservation. They reported that long-term follow-up and further studies are needed to fully elucidate the benefits of HOPE in heart transplantation.

A declaration of interests can be found in the study.