Development and Evaluation of a Novel Solution, Somah, for the Procurement and Preservation of Beating and Nonbeating Donor Hearts for Transplantation

Background—Injury to myocytes, endocardium, and the coronary endothelium during harvesting and storage can compromise outcomes after heart transplantation. Safeguarding of structure and function of cardiomyocytes and endothelium in donor hearts may lead to improved patient survival after transplantation. Information gained from porcine hearts stored in standard transplant solution was used to design a superior preservation solution that would optimally protect and maintain organs from beating heart and/or nonbeating heart donors during long-term storage.Methods and Results—Multiphoton microscopy was used to image deep within cardiac biopsies and coronary artery tissue harvested from porcine hearts obtained from beating heart and nonbeating heart donors for analysis of myocyte and endothelial cell structure and function. Cell structural integrity and viability, calcium mobilization, and nitric oxide generation were determined with fluorescence viability markers, immunofluorescence, and Western blots. During hypothermic storage in standard preservation solution, Celsior, myocyte, and endothelial viability was markedly attenuated in hearts obtained from beating heart donors. In contrast, hearts from beating and nonbeating heart donors stored in the newly formulated Somah solution demonstrated an increase in high-energy phosphate levels, protection of cardiac myocyte viability, mitochondrial membrane polarization, and structural proteins. Similarly, coronary artery endothelial organization and function, calcium mobilization, and nitric oxide generation were well maintained during temporal storage in Somah.Conclusions—The Celsior preservation solution in clinical use today has led to a profound decline in cardiomyocyte and endothelial cell viability, whereas the newly designed Somah solution has safeguarded myocyte and endothelial integrity and function during organ storage. Use of Somah as a storage medium may lead to optimized graft function and long-term patient survival after transplantation.