BACKGROUND The University of Wisconsin Solution (UW) has extended preservation of abdominal organs but has not allowed equally extended preservation of the heart. Therefore, the impact of UW on clinical heart transplantation has remained unclear. RESULTS Between June 1986 and March 1994, 161 orthotopic heart transplants were performed at our center. Of these, 66 were preserved for > or = 3 hours. Of these, 17 hearts were preserved with Stanford solution (STNF), which was used before 1990, and 49 were preserved with UW. These groups were compared for indexes of ischemic injury, ventricular function, and survival. The UW group contained more status-1 recipients (57% versus 29%, P < 0.05) and a higher mean donor age (30.7 versus 22.1 years, P = 0.008). Mean ischemic time was slightly but not significantly higher with UW (228 versus 205 minutes for UW versus STNF, respectively; P = 0.085). The time to wean from bypass after cross-clamp removal was nearly twice as long with STNF than with UW (80.6 versus 44.3 minutes, P < 0.001). There was no difference in the incidence of primary graft failure (2% for UW versus 6% for STNF, P = 0.43). The average need for inotropic support over the first 8 posttransplant hours was significantly higher with STNF than UW. Neither hospital stay nor survival differed. Nevertheless, the ability to use donor organs from more distant sites was increased. Of all hearts preserved with STNF, 26% were stored for > or = 3 hours, whereas 51% of all hearts preserved in UW were stored for this length of time. Donor use of hearts increased from 20% in 1989 to 63% in 1993, largely because of greater use of more distant donors. CONCLUSIONS We conclude that heart preservation with UW limits ischemic damage from prolonged storage and improves myocardial function in the early posttransplant period, thus allowing greater use of available donors from distant sites to patients awaiting heart transplantation.