Abstract
BACKGROUND: Donation after circulatory death (DCD) hearts requires machine perfusion preservation, the conditions of which are not well defined. METHODS: To achieve this, rat hearts were procured following a DCD or control beating-heart donation (CBD) model, and perfused for 60 min with one of three machine perfusion solutions-St. Thomas (ST), University of Wisconsin (UW), or Polyethylene Glycol-20k (PEG)-at one of two temperatures, 4°C or 15°C. At 15-min intervals, perfusion pressure was measured as a marker of vascular resistance. Colored microspheres were added to capture the distribution of perfusate into the metabolically active sub-endocardium, and the eluate was collected for troponin assays. Analyses compared groups using Wilcoxon rank-sum and ANOVA. RESULTS: Perfusion pressure was significantly higher for DCD than CBD hearts at 15°C regardless of solutions. The lowest rise in perfusion pressure over time was observed with PEG at 15°C. Except for PEG at 15°C, ST and UW solutions at 4 or 15°C had decreased sub-endocardial perfusion in DCD hearts. Troponin release from DCD hearts with UW and PEG solutions was comparable to CBD hearts but was significantly higher with ST solution at 15°C. CONCLUSIONS: Optimal preservation conditions for DCD hearts were observed with PEG machine perfusion solution at 15°C.