XVIVO Heart Box (XHB) With Supplemented XVIVO Heart Solution (SXHS) Continued Access Protocol (CAP)

Inclusion Criteria Recipient: To be eligible to participate in this study, a recipient must meet all the following criteria: 1. Age ³18 years. 2. Signed informed consent form (ICF). 3. Listed for heart transplantation. Exclusion Criteria Recipient: 1. Previous solid organ or bone marrow transplantation. 2. Requires a multi-organ transplant. 3. Subject is enrolled and ongoing in another investigational pharmaceutical or medical device clinical trial (Exception: observational studies are permitted). 4. Subject is on mechanical circulatory support pre-transplant other than durable LVAD, Impella or intra-aortic balloon pump (IABP). 5. History of complex congenital heart disease ie: single ventricle physiology (per Investigator's discretion and XVIVO review). 6. Subject on renal replacement therapy/dialysis. 7. Ventilator dependence (subject is intubated at time of transplant/unable to provide consent or re-affirmation of consent). 8. Sensitized participants meeting any of the following: * Participant with calculated Panel Reactive Antibody (cPRA) greater than 50% * Participant undergoing any desensitization treatment (also with cPRA less than 50%) * Participant with a positive prospective crossmatch and/or a positive virtual cross match Donor Inclusion Criteria: To be eligible to participate in this study, the donor heart must meet the following criteria: 1. Estimated Cross Clamp Time ≥4 hours OR 2. Estimated Cross Clamp ≥ 2 hours AND Any one or more of the following: * Age ≥50 years * LVEF 40% - 50% at time of provisional acceptance. (Refer to section 6.3.4 for definition of provisional acceptance). * Down-time ≥20 minutes * Hypertrophy septal thickness \>12 - ≤16mm * Angiographic luminal irregularities with no significant CAD OR 1) Donation after Circulatory Death (DCD) Donor Exclusion Criteria: Donor hearts that meet any of the following criteria will be excluded from transplantation in this study: 1. Unstable hemodynamics requiring high-dose inotropic support. 2. Significantly abnormal coronary angiogram defined as CAD \> 50% stenosis of one or more vessels or if the donor heart exhibits any contusions, structural damage, gross abnormalities, or palpable CAD on final examination. 3. Moderate to severe cardiac valve pathology. 4. Investigator's clinical decision to exclude from trial. 5. Previous sternotomy.