Does University of Wisconsin solution harm the transplanted heart?

Background: University of Wisconsin solution (UW) has been shown to be an e ffective preservative for the cardiac allograft. Recently, the high potassi um content of UW has been implicated in causing coronary endothelial damage , allegedly contributing to development of cardiac allograft vasculopathy ( CAV) and eventually to poorer survival. Methods: We examined our experience using UW for preservation of cardiac al lografts between 1990 and 1994 (n = 94), and compared these to hearts prese rved with the lower potassium-containing Stanford solution used at our cent er between 1986 and 1990 (n = 65). indices of graft function, ischemic inju ry, CAV incidence, CAV severity, and survival were evaluated. Results: The 2 groups were similar in age, gender, diagnosis, donor inotrop ic support, donor-recipient weight ratio, incidence of acute graft failure, and cytomegalovirus seroconversion. UW-preserved hearts came from older do nors (30.5 vs 24.1 years; p < .001), and were transplanted into more status 1 recipients (56% vs 22%, p < .001), consistent with current trends. Mean ischemic time of UW-preserved hearts was significantly longer (184 vs 155 m inutes, p < .005) although time required to wean from bypass was less (45.5 vs 73.8 minutes, p < .001) and there was a trend towards less inotropic re quirement. CPK-MB release was less with UW preservation (63 vs 87 mu g/dL, p = .001). Three years after transplantation, both groups were similar in t he incidence of CAV (UW, 27.3%; STNF, 37.5%; p = 0.27), and also the severi ty of CAV (p = 0.78). Deaths attributed to CAV were equal in each group (UW , 11.4% vs STNF, 10.7%; p = 0.79). Kaplan-Meier survival analysis revealed equivalent survival curves (p = 0.26). Conclusions: We conclude that UW is a safe and effective myocardial preserv ative, allowing longer ischemic times with equivalent graft function. Our d ata suggest that when UW is used for cardiac allograft preservation, both C AV and survival are comparable to the experience with other preservatives c ontaining lower concentrations of potassium.