Perfusate Biomarkers of DCD Cardiac Graft Quality Identified With Proteomics: Studies in an Isolated Rat Heart Model.

Background: Heart transplantation with donation after circulatory death (DCD) enhances cardiac graft availability, but exposes hearts to potentially damaging conditions, such as warm ischemia. Normothermic machine perfusion (NMP), used for graft transportation, allows biomarker determination in perfusate. Using our isolated, rat heart model of DCD, we evaluated potent.

Methods: Isolated, perfused adult male Wistar rat hearts (n = 5/group) underwent different warm ischemic durations to simulate DCD, followed by reperfusion to simulate NMP. Perfusate samples were collected after 10 min reperfusion, and proteins were analyzed using mass spectrometry. Cardiac recovery was evaluated after 60 min reperfusion. The relationship between perfusate proteins and cardiac recovery was investigated.

Results: Cardiac recovery decreased with increasing ischemic duration. Principal component analysis of perfusate proteins demonstrated segregation by ischemic group. Several proteins demonstrated an On-Off pattern, and correlated with key outcome measurements. Other proteins were released by all hearts and were confirmed as predictors of cardiac recovery, for example, heat shock protein 70 and valosin-containing protein (area under the curve [AUC] = 0.962-0.968, respectively; P < 0.05 for all). Additionally, proteins such as glycogen phosphorylase, muscle associated (AUC = 0.9632; P < 0.05) showed potential as novel biomarkers for evaluating cardiac graft quality, unlike lactate release after 10 min of reperfusion (AUC = 0.60).

Conclusions: Multiple perfusate proteins, such as heat shock protein 70, valosin-containing protein, or glycogen phosphorylase, muscle associated, released during early reperfusion are promising as biomarkers for assessing graft quality during NMP. Perfusate proteins, as biomarkers, offer the possibility of both rapid immune detection and out-of-hospital implementation, and may provide valuable information about graft quality, especially when profiled with serial sampling during NMP.