Survival of the heart in different cardioplegic solution delivery systems under extracorporeal normothermic perfusion conditions: an experimental study

Introduction: Preservation of isolated hearts in cardioplegic solution at normothermia is a promising strategy for increasing the organ lifespan. Further development of this strategy and search for new products for solution delivery can help optimize the technology of donor heart transportation. Objective: The study was aimed to test the efficacy of device for normothermic constant perfusion flow with innovative lines for the cardioplegic solution delivery (CardioSystemPharma, Khimki, Moscow Region, Russia) according to the Langendorff mode in comparison with a system based on nodes and tubes of Radnoti Langendorff Constant Perfusion Flow Apparatus (ADInstruments, Colorado Springs, USA) in a series of experiments on rat hearts. Methods: The innovative cardioplegic delivery system (CardioSystemPharma) and traditional perfusion system (Radnoti) were compared in experiments on rat hearts at normothermia without cardioplegic solution and using the cardioplegic solution Normacor (Mosfarm, Moscow Region, Russia). The time until complete cardiac arrest and the changes in the NADH coenzyme fluorescence were recorded. After cardiac arrest, immunohistochemical staining of ventricular sections was performed to detect myocardial injury during perfusion. Results: It was shown that the innovative cardioplegic delivery system was not inferior to the traditional perfusion system (Radnoti) and even surpassed it in terms of the time duration for preservation of the isolated heart. It was found that the using of elevated glucose concentration during normothermic perfusion could significantly increase the organ lifespan. The efficacy of normothermic perfusion in the experiment was confirmed by monitoring cellular respiration through recording the NADH fluorescence. Conclusion: Testing showed that long-term preservation under normothermia with usage of an innovative delivery system of Russian manufacture is a promising replacement for Radnoti solution delivery system.