(20) - Heart Transplantation From Donors Outside Standard Acceptability Criteria Using Ex-Vivo Normothermic Perfusion: The End of Donor Shortage?

Abstract

Purpose: Utilization of the organs from high-risk donors may increase the number of orthotopic heart transplants (OHTx), however, with possible detrimental effect on outcomes. The Organ Care System (OCS) (TransMedics, MA, USA) allows organ evaluation during normothermic perfusion and reduces the cold ischemic time below 100 minutes with potential benefit for post-transplant results when transplanting extended criteria allografts. In this study we analyze the results of OHTx from donors outside standard criteria following ex vivo perfusion. Methods: Between February 2013 and September 2014 (n= 40) patients underwent heart transplantation at our institution using the OCS as a method of graft preservation and assessment. Fifteen patients received organs from standard criteria donors (group I) and 25 from extended criteria donors (group II) with at least one of the following risk factors; LVEF ≤ 50%, LV hypertrophy (LVH); interventricular septum in diastole > 14 mm, donor cardiac arrest, coronary artery disease or donor death due to cocaine. Results: Donor age: 41±11 (17-59 yo) gender F/M: 22.5/77.5%. Transport time was ≥ 2.5 hours in 19 donors. Seven donors had reduced LVEF ≤ 50%, seven had LVH, two donors died due to cocaine overdoses, ten had a previous cardiac arrest; 30±9 min and six palpable coronary artery disease. Both groups (standard vs. extended criteria) were statistically comparable regarding recipient characteristics. Ex vivo perfusion parameters; lactate trend, haemodynamic data and ischemic times were also unaffected. No significant differences were observed on postoperative outcome. There was a trend towards less duration of mechanical ventilation in hours in the extended criteria group 56 (21; 125) vs. 100 (41; 336) (p= 0.074). At follow up of 268 ± 84 days, biventricular graft function was comparable. 30-days, 90 days and 1-year survival (group I vs. II) was also similar: 92.9 vs.91.8; 84.4 vs. 87.5 and 84.4 vs. 81.6% (log rank p= 0.832) Conclusion: Transplantation of hearts from extended criteria donors with moderate left ventricular dysfunction, donor cardiac arrest, left ventricular hypertrophy or coronary artery disease is safe and feasible with normothermic ex vivo preservation as a method of graft assessment pre-implantation and therefore should be considered in times of donor shortage.