1. Indication for standard-of-care surgery (including valve surgery, placement of left-ventricular assist device, or imminent heart transplantation), coronary artery bypass grafting (CABG) procedure, and/or percutaneous coronary intervention (PCI) for the treatment of ischemic and/or valvular heart disease. Subjects who require or undergo PCI should undergo these procedures a minimum of 3 months in advance of randomization. Subjects who require or undergo CABG should undergo these procedures a minimum of 4 months in advance of randomization. In addition, subjects who develop a need for revascularization following enrollment should undergo revascularization without delay. Indication for imminent heart transplantation is defined as a high likelihood of transplant prior to collection of the 12 month study endpoint. Candidates cannot be UNOS status 1A or 1B, and they must have documented low probability of being transplanted