Improved heart preservation with University of Wisconsin solution: experimental and preliminary human experience.

We tested the ability of University of Wisconsin solution (UWS) to extend hypothermic nonperfused heart preservation in baboons and then proceeded to human transplantation. Orthotopic transplantation was performed in five baboons (UWS cardioplegia and storage [4 degrees C]; preservation time 10.3 +/- 0.6 hours). Four survivors were immunosuppressed for 45 days and killed. One animal died from disruption of the aortic anastomosis due to technical error. Preservation did not alter histology under light and electron microscopy or heart weight (at harvest, 51.4 +/- 11.6 g; before implant, 52.5 +/- 11.1 g). Animals were weaned from bypass (mean, 23 +/- 12 minutes) and returned to their cages without intravenous support within 3.6 +/- 0.6 hours. Weekly biopsy, electrocardiogram, enzyme analysis, echocardiogram, and right heart catheterization demonstrated excellent cardiac function. Following success in baboons, UWS was applied to human transplantation (n = 2, UWS cardioplegia and storage [4 degrees C]; preservation time 4.2 and 2.1 hours). The hearts returned to sinus rhythm within 4 minutes of reperfusion without defibrillation, and enzymatic and hemodynamic data reveal excellent heart preservation. Preliminary data suggest the ability of UWS to prolong heart preservation in baboons and be used safely in humans. Further studies are required to compare UWS with crystalloid cardioplegia and saline storage and to prolong donor heart preservation in humans.