Cold Storage Viability of Normothermic Ex Vivo Heart Perfusion

Jacqueline Ko

Research Mentor: Alvaro Rojas-Peña
Mentor Department: Department of Surgery-Transplantation, Medicine
Author(s): Jacqueline Ko, Caitlin Bocks, Sikandar Raza, Spencer Amacher, Anirudh Vinnakot, Gabe Owens , Kristopher Deatrick, Yuliya Tipograf, Alvaro Rojas-Peña
Session: Session 3 (11:00 AM – 11:50 AM)
Presentation Type: Poster 92

Abstract

Cold Storage Viability of Normothermic Ex Vivo Heart Perfusion Jacqueline Ko, Caitlin M. Bocks, BS; S. Sikandar Raza, MD; Spencer G. Amacher, BS; Anirudh Vinnakota, MD; Gabe Owens, MD, PhD; Kristopher B. Deatrick, MD; Yuliya Tipograf, MD; Alvaro Rojas-Peña, MD Normothermic ex vivo heart perfusion (NEHP) enables short-term cardiac preservation, but its capacity to support hearts through multiple cold storage periods remains unexplored. In this study, examining multiple ischemic times following extraction and the response to this condition using blood gases, hemodynamics, thermal imaging, and echocardiography was used to determine how viable the heart will be after cold storage for transplantation. Methods: Four juvenile Yorkshire pigs (n=4) served as heart donors, and the hearts were extracted in accordance with standard procurement measures. These hearts were placed in Histidine-tryptophan-ketoglutarate (HTK) solution and stored at 4-10°C for the first 4-hour period. Following, a 24-hour NEHP period was completed with several variables measured, such as hourly arterial/venous blood gases, hemodynamics, and flow evaluations taken every 30 minutes. At T1, T12, and T24, more advanced evaluations were performed using echocardiography to detail the flow and function of the heart and advanced kinematics. After 24-hours of NEHP, the heart was placed back into the HTK solution to undergo a second cold storage for 4 hours. To assess heart viability, ex vivo reperfusion (simulated transplant) was performed for 4 hours. Results: Mean peak contractility decreased across the cohort during cold storage runs: CS1 (-68.55%), CS2 (-55.34%), CS3 (-16.46%), and CS4 (-3.81%). Echocardiography at T24 established severe left ventricular dysfunction in all subjects. CS3 demonstrated the most robust reperfusion, with a 61% increase in contractility and a 176.6% improvement in the physical strain on the heart. Similarly, CS3 and CS4 had physiologically appropriate chamber pressures, whereas CS1 and CS2 failed to reperfuse, leading to myocardial injury. The kinematic trends that were analyzed to show reperfusion had varying results of percent change, but the overall 24-hour NEHP had a negative percent change. Conclusion: With a better-established protocol, cold storage and transport can be extended through NEHP. Using this protocol, thirty-two hours of ideal heart preservation were achieved after dual ischemic storage runs, supporting the practicality of realistic heart preservation and transport. NEHP was determined to be feasible but not completely viable for the functional parameters of the heart that can later affect reperfusion and transplantation. In future studies, transplantation can be explored to look at post-NEHP functional recovery and viability of the heart after transplantation.