Dialysis preserves heart function during ex situ heart perfusion

Ex situ heart perfusion (ESHP) has been used to optimize donor organs before heart transplantation. However, cardiac function often deteriorates with the development of myocardial edema. The use of dialysis during ESHP could assist in cardiac preservation.

Male Yorkshire pig hearts were subjected to ESHP for 8 hours with or without dialysis. Hearts were supported during nonworking mode and working mode, and pressure-volume loops and coronary vasomotor function were evaluated. Finally, tissue biopsies were assessed for mitochondrial function, oxidative stress, and inflammation.

Adding dialysis to ESHP significantly enhanced cardiac function, with improved preload recruitable stroke work at 4 hours (64.09 ± 20.13 vs 35.08 ± 13.52, p = 0.010) and 8 hours (64.31 ± 9.08 vs 23.30 ± 19.25, p = 0.0002), maximal elastance at 8 hours (24.67 ± 10.75 vs 10.62 ± 8.471, p = 0.0477), and end diastolic pressure volume relationship at 8 hours (644.7 ± 566.68 vs 86.63 ± 72.05, p = 0.0187). Coronary vasomotor function improved in the dialysis group in endothelium dependent (LogIC50 -7.39 ± 0.25 vs -2.22 ± 0.76, p < 0.0001) and independent (LogIC50 -6.11 ± 0.19 vs -4.79 ± 0.11, p < 0.0001) vasorelaxation. Dialyzed hearts also had reduced sensitivity to endothelin-1 (LogEC50 -7.94 ± 0.5 vs -8.54 ± 0.06, p = 0.0449) and significant changes in endothelin receptor-related protein expression related and oxidative stress.

The combination of dialysis with ESHP improves myocardial and coronary vasomotor preservation and may allow for longer perfusion times.