In vivo comparative study of two lactobionate based solutions for prolonged heart preservation

The duration of safe heart preservation must be improved. Using a heterotopic heart transplantation model, we compared in vivo the recovery of rabbits hearts preserved with a K+Lactobionate based fluid (UW: University of Wisconsin solution) or with a Na+Lactobionate based fluid. In the "preservation" group, hearts were cold stored (4 degrees C) for 6 hours with UW (n = 9) or Na+Lactobionate solution (n = 9). In the "transplantation" group, cold storage was followed by 3 hours of reperfusion (UW: n = 8, Na+Lactobionate solution: n = 7). Functional recovery, adenine nucleotide pool, circulating blood cardiac enzymes, circulating blood and tissue malondialdehyde (MDA) were measured. Left ventricular end-diastolic and developed pressures at different preload levels were better after preservation with UW than with Na+Lactobionate solution (p < 0.05). Also with UW, adenosine diphosphate and total adenine nucleotide content were significantly higher than with Na+Lactobionate solution (p < 0.05) whereas adenosine triphosphate, monophosphate and energy charges were similar. Cardiac enzymes and tissue MDA were similar with UW and Na+Lactobionate solution. In circulating blood, MDA was not detected. These results enhance the superiority of UW solution over a Na+Lactobionate based solution for long term heart preservation.