1. Sarver Heart Center, University of Arizona, Tucson (P.R.)
2. Division of Cardiothoracic Surgery, Department of Surgery, University of Arizona, Tucson (Z.K.).
3. Artificial Heart and Perfusion Programs, Banner University Medical Center, Tucson, AZ (R.S.).
4. Cardiovascular Research Foundation, Columbia University Medical Center, New York, NY (D.B.).
5. Advanced Heart Failure and Mechanical Circulatory Support Program, University of Massachusetts Memorial Medical Center, Worcester (R.D.K.).