Improvement in experimental cardiac preservation based on metabolic considerations

Viability of rat hearts preserved in the standard Euro-Collins and a modified preservation medium utilizing the Euro-Collins medium as the base were assessed. The additions for the modified medium were chosen in order to attenuate the various forms of damage that may occur to an organ during cold ischemia. The viability of the hearts was assessed biochemically via 31P nuclear magnetic resonance spectroscopy and functionally during reperfusion in an isolated Langendorff preparation. It was noted that a modified medium containing magnesium, adenosine, allopurinol, glutathione, and polyethylene glycol provided superior protection of the cold ischemic myocardium as compared with the standard Euro-Collins medium in the isolated heart perfusion apparatus. Both physiologic function (dp/dt) and metabolic status (Pi/PCr ratio) were superior with the modified compared with the control medium (325 +/- 83 vs. 90 +/- 35 mmHg/sec and 0.42 +/- .09 vs. 0.68 +/- .05, respectively, both P less than 0.05). Moreover, this modified solution resulted in more rapid development of contractions, as well as improved Pi/PCr ratio (0.71 +/- .32 vs. 2.02 +/- .59, P less than 0.05) in the in vivo heterotopic transplant model. It seems likely that a combination of pharmacologic additives may be developed that synergistically attenuate damage to the preserved myocardium.