This study is testing a new way to keep donor hearts healthy for heart transplants. The tool used is called the XVIVO Heart Preservation System (XHPS). It helps preserve and move hearts that might not usually be accepted for transplant. The study is part of a project called PRESERVE that needs more information to ensure this technique is safe and works well. This approach lets doctors use the system even while waiting for official approval.

• This study is only for adults aged 18 or older.
• Participants must be on the list for a heart transplant.
• The study excludes people with previous organ transplants or those needing multiple organ transplants.

Participants will be asked to sign a form to show they understand and agree to participate. The study does not accept participants involved in other trials, except for observational studies. If you're on certain types of heart support or have severe kidney or lung issues, you may not qualify. Donor hearts need to meet specific health criteria to be used in this study. Please ask your doctor if you have any questions or need more information about this study.