The effect of warm ischemic intervals on primary graft dysfunction in normothermic regional perfusion for donation after circulatory death heart transplant
Chen Chia Wang, Mark Petrovic, Awab Ahmad, Walter Navid, Christian Eidson, Douglas I. Walker, Timothy Harris, John M. Trahanas, Swaroop Bommareddi, Duc Nguyen, Tarek Absi, Aaron Williams, E. Quintana, Stephen DeVries, Hasan K. Siddiqi, Kelly Schlendorf, Matthew Bacchetta, Ashish S. Shah, Brian Lima
Abstract
Objectives To clarify the association between warm ischemic time during donation after circulatory death (DCD) and severe primary graft dysfunction (PGD) after heart transplant. Methods DCD heart transplants using normothermic regional perfusion, excluding congenital etiology or multiorgan transplant, at a single institution from January 2020 to December 2024 were reviewed. Donation withdrawal ischemic time (DWIT), functional warm ischemic time, defined by oxygen saturation <80% (FWIT O 2 ), systolic blood pressure <80 mm Hg or <50 mm Hg, and asystolic warm ischemic time were examined. Propensity matching created balanced cohorts to associate warm ischemia and outcomes. Outcomes included incidence of severe PGD, lengths of stay, and mortality. Results The final study cohort had 135 patients, of whom 10 of 135 (7.4%) had severe PGD. When stratified by severe PGD, donor and recipient demographics were similar. DWIT (median 25.0 minutes vs 35.5 minutes, P = .031) and FWIT O 2 (median 22.0 vs 33.0 minutes, P = .025) were lower in those without severe PGD. Logistic regression identified FWIT O 2 as a better predictor compared with DWIT. Receiver operating characteristic curve analysis identified a FWIT threshold of 23 minutes (area under the curve, 0.714). After matching, rates of severe PGD were significantly greater in the FWIT O 2 >23 minutes group (8/59 [13.6%] vs 1/59 [1.7%], P = .032). However, the FWIT O 2 >23 minutes group had similar lengths of stay and mortality. Conclusions In DCD normothermic regional perfusion heart transplant, >23 minutes of FWIT O 2 is associated with increased rates of severe PGD. However, increased FWIT O 2 was not associated with other outcomes, including mortality. Rejection of allografts on the basis of prolonged warm ischemia may lead to unnecessary discard of viable hearts.