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Aims: Donation after circulatory death (DCD) could improve cardiac graft availability, which is currently insufficient to meet transplant demand. However, DCD organs undergo an inevitable period of warm ischemia and most cardioprotective approaches can only be applied at reperfusion (procurement) for ethical reasons. We investigated whether modifying physical conditions at reperfusion, using four different strategies, effectively improves hemodynamic recovery after warm ischemia.Methods and Results: Isolated hearts of male Wistar rats were perfused in working-mode for 20 min, subjected to 27 min global ischemia (37°C), and 60 min reperfusion (n=43). Mild hypothermia (30°C, 10 min), mechanical postconditioning (MPC; 2x 30 sec reperfusion/ 30 sec ischemia), hypoxia (no O2, 2 min) or low pH (pH 6.8-7.4, 3 min) was applied at reperfusion and compared with controls (i.e. no strategy). After 60 min reperfusion, recovery of left ventricular work (developed pressure*heart rate; expressed as percent of pre-ischemic value) was significantly greater for mild hypothermia (62±7%), MPC (65±8%) and hypoxia (61±11%; p |
