CARD27: Morphologic and functional assessment of beating heart in normothermic ex-situ preservation

Abstract

Background: Heart transplantation remains the treatment of choice for patients experiencing end-stage heart failure. The emergence of cardiac ex situ machine perfusion not only facilitates the use of donor heart through the avoidance of potentially damaging ischemia during graft storage, it also opens new horizons for more sensitive monitoring of graft quality in the transplant field, and morphologic-functional assessment. Methods: Twenty-five domestic adult pigs, weighing 93.1±13.1kg were selected for this study. Until cardiectomy, all pigs received Principles of Laboratory Animal Care. The pig heart were cannulated, and then connected to the Portable System for Normothermic Ex-Situ HeartPreservation (our made). In the Heart Preservation System (HPS), oxygenated blood is perfused by a centrifugal pump into the aorta, perfusing the coronary arteries. After the end of experiment, (6-14 hour) pig heart was arrested with normothermic blood cardioplegia and disconnected. The pig isolated heart was conditioned with Levosimendan while in the system and hemofiltration was applied in the HPS in order to protect and improve donor heart function. Ex-Situ Heart Perfusion process was accompanied with morphologic-functional assessment such as echocardiography, contrast-enhanced magnetic resonance, thermodilution technique and biochemistry. Results: Mean (SD) ischemic time was 19.2 (±3.3) min. Mean ex vivo perfusion time was 560 (±143) min. Time of sinus rhythm restoration was 2.3 (5.7) min. All isolated hearts had stable perfusion, biochemical, as well as myocardial functional parameters measured by echocardiography and thermodilution technique, and histological characteristics in the perfusion system. MRI structural images showed no infiltrates alterations in myocardium. Mean venous lactate trend are with normal levels at the end of perfusion 1.6 (±0.6). Conclusion: Normothermic Ex-Situ Heart Perfusion provides near to physiologic, reproducible approach to sustain the isolated heart for long period of time. Multiparametric assessment of organ morphology and function is feasible in Ex-Situ Heart Perfusion, and may improve organ assessment, leading to a better selection for transplant.Figure 1. Simplified schema of the experimental design and protocol.