UNIVERSITY-OF-WISCONSIN SOLUTION PROVIDES SUPERIOR MYOCARDIAL PRESERVATION COMPARED WITH STANFORD CARDIOPLEGIC SOLUTION

The efficacy of the University of Wisconsin solution to safely prolong preservation times for kidney, pancreas, and liver transplantation is established, but its efficacy in enhancing myocardial preservation is not yet clear. We studied the effects of Stanford cardioplegic soluti on and the University of Wisconsin solution both in preserving the myo cardium and in protecting it from the effects of reperfusion injury af ter 6 hours of preservation. In 28 rat hearts we measured changes in h igh-energy phosphate content (with magnetic resonance spectroscopy) an d histologic changes (edema, endothelial changes, myocyte architecture ) during preservation and changes in high-energy phosphate content, hi stologic status, and performance (aortic systolic and diastolic pressu re, heart rate, rhythm) in Langendorff and working hearts during reper fusion. No significant differences in the kinetics of high-energy phos phate changes were noted between the two cardioplegic solutions during preservation. However, at the end of 6 hours of preservation, hearts in the Stanford cardioplegic solution group were more edematous (p < 0 .01) than those in the University of Wisconsin group. During reperfusi on, no significant differences in the kinetics of high-energy phosphat es were noted between the two cardioplegic solutions. None of the hear ts in the University of Wisconsin solution group developed ventricular fibrillation at the start of reperfusion, but all hearts in the Stanf ord group did so. Once sinus rhythm was established no significant dif ferences in developed pressure or heart rate were found between the tw o solutions. After 2.5 hours of reperfusion, hearts in the Stanford gr oup were more edematous (p < 0.002) and had a greater disruption of my ocyte architecture (p < 0.002) and greater arteriolar endothelial inju ry (p < 0.004). In conclusion, the University of Wisconsin solution be tter protects the myocardium in this rat model than does Stanford solu tion. The mechanism for this beneficial effect of the University of Wi sconsin solution appears to be due to its better preservation of the m icrovasculature rather than differences in preservation of high-energy phosphates.