Na + /H + Exchange Inhibition Improves Post-Transplant Myocardial Compliance in 4-Hour Stored Donor Hearts

Abstract

Na⁺/H⁺ exchange inhibitors have cardioprotective properties. The effects of the new Na⁺/H⁺ exchange inhibitor, HOE642 on myocardial function were assessed after transplantation of canine brain-dead and non-brain-dead donor hearts preserved for 4 h. Four groups were studied: brain-dead donors; non-brain-dead donors; brain-dead donors and recipients treated with HOE642 (2 mg/kg): and treated non brain-dead donors and recipients. Donor hearts were stored in NIH2. At the end of 60 min reperfusion after transplantation, pressure–volume curves were constructed. Biopsies were analysed histologically and ultrastructurally. Afterwards, weaning from cardiopulmonary bypass was accomplished. H0E642 improved compliance in hearts from both brain-dead and non-brain-dead donors. No differences in myocardial water content nor in myocardial performance were detected. No irreversible damage was seen ultrastructurally. It is concluded that myocardial compliance after transplantation was improved by administration of HOE642. The use of this inhibitor might improve the current myocardial preservation technique for transplantation.