COMPLETE FUNCTIONAL RECOVERY AFTER 24-HOUR HEART PRESERVATION WITH UNIVERSITY-OF-WISCONSIN SOLUTION AND MODIFIED REPERFUSION

Successful long-term myocardial preservation is dependent on optimizing conditions during arrest, storage, and reperfusion. Neonatal piglet hearts were arrested and stored in University of Wisconsin solution (UW) at 4-degrees-C for 24 hours and reperfused on a blood-perfused, adult animal-supported isolated circuit. Results were compared with nonischemic continuously perfused control hearts (group 1, n = 5). The initial 10 minutes of reperfusion in groups 2-4 was modified by aspartate/glutamate-enriched leukocyte-depleted blood cardioplegia (group 2, n = 7), leukocyte depletion alone (group 3, n = 9), and aspartate/glutamate-enriched blood cardioplegia alone (group 4, n = 6). After 10 minutes, perfusion was continued with unmodified whole blood. In group 5 (n = 9), unmodified whole blood was used for initial reperfusion as well as subsequent perfusion. The stroke work index was determined 60 minutes after reperfusion. Biopsies for high-energy phosphates, myocardial water content, and electron microscopy were obtained after functional assessment. The stroke work index at left ventricular end-diastolic pressure of 9 mm Hg did not differ between groups 1 and 2 (19.0 +/- 1.4 x 10(3) and 19.0 +/- 1.5 x 10(3) [mean +/- SEM] erg/g, respectively). These were both different from group 5 (13.3 +/- 0.8 x 10(3) erg/g, p < 0.05). Group 3 showed improved function (15.7 +/- 0.7 x 10(3) erg/g), but this did not reach statistical significance when compared with group 5. No difference was found between groups 4 and 5. Myocardial water content, high-energy phosphate levels, and ultrastructure were similar in all groups. We conclude that UW arrest and storage combined with aspartate/glutamate-enriched leukocyte-depleted blood cardioplegia reperfusion is superior to UW alone and results in complete recovery of hearts after 24 hours of cold ischemia.