Successful orthotopic pig heart transplantation from non-heart-beating donors

Background: With the aim to expand the severely limited donor pool by use of non-heart-beating donors we developed a technique for successful transplantation of hearts after 30 minutes of normothermic ischemia without donor pretreatment. Methods: In control groups hearts were transplanted in a conventional fashion using crystalloid cardioplegia (Group I, n = 6) or BCP (Group II, n = 8) for induction of cardiac arrest. In the ischemic groups hearts were harvested after 30 minutes of normothermic ischemia, perfused with blood cardioplegia (BCP) (Group III, n = 9) or BCP containing the Na+-H+-exchange inhibitor HOE 642 (Group IV, n = 8) and transplanted orthotopically. Results: All animals could be weaned from cardiopulmonary bypass. Low dose inotropic support was necessary in the ischemic groups only. Recovery of the maximal left ventricular stroke work index (LVSWImax) in Groups I vs II was 62.6 +/- 19.6% vs 73.3 +/- 23.3% (NS), maximal right ventricular stroke work index (RVSWImax) averaged 61.1 +/- 18.8 vs 87.8 +/- 31.7% (NS) as compared to the preoperative level. In the ischemic groups (III vs IV) LVSWImax was 27.3 +/- 11.7 vs 59.5 +/- 32.4% (p = 0.038), RVSWImax was 27.4 +/- 20.9 vs 64.2 +/- 46.6% (NS). Conclusions: The results indicate that (a) successful pig heart transplantation after 30 minutes of normothermic ischemia is possible without donor pretreatment, and (b) that HOE 642 improves posttransplant LVSWImax significantly.