Heart grafts from DCD display acceptable metabolic preservation and functional recovery compared to BDD.

Abstract

Background: the number of heart transplants is declining since the 2000s because of organ shortage. Donation after cardiac death (DCD) is an alternative source of grafts, but hearts from DCD are not currently utilized due to concerns that they may suffer irreversible cardiac injury with subsequent poor post-transplant function. However, little is known about the quality of those grafts. In this large animal model we compared metabolic preservation and functional recovery of grafts from DCD compared with grafts from brain death donors (BDD). Method: 16 pig hearts were randomized in two groups. In the BDD group, hearts were classically retrieved after cardioplegia. In the DCD group, hearts were recovered after anoxia induced cardiac arrest and cardioplegia. All were preserved on ice for a period of 4 hours. The preservation solution was KPS-1 in both groups. After preserva-tion, the grafts were reperfused on a Langendorff during 60 min. Myocardial biopsies were performed at baseline, post-preservation and post-reperfusion to quantify oxidative metabolism by measuring lactate, nucleotides and phosphocreatine (Pcr). Contractility index (CI) was assessed in vivo before cardioplegia with a Millar catheter and during reperfusion with an intraventricular balloon. Results: Warm ischemic time (WIT) was 0 min in BDD vs 14±2 minutes in DCD (p<0,001). Compared to grafts from BDD, hearts from DCD showed significant lower lactate levels (54,6±23,6 vs 23,7±24,7 μmoles/g heart; p<0,001), similar ATP concentration (8,4±3,1 vs 7,6±2,8 μmoles/g heart; p=ns) and similar PCr concentration (8,0±2,5 vs 9,2±4,6; p=ns) after preservation. Compared to baseline, CI decreased by 25±7 in the BDD group and 26±7% in the DCD group (p=ns). Conclusion: In this ex vivo model, DCD hearts showed similar preservation of the energy states and contractility after reperfusion compared to hearts from BDD, despite the warm ischemic period. This could be explained by is-chemic preconditioning during WIT