[1] Univ Minnesota, Div Cardiothorac Surg, Minneapolis, MN 55455 USA
[2] Univ Michigan, Ann Arbor, MI 48109 USA
[3] Columbia Univ, New York, NY USA
[4] Johns Hopkins Univ, Baltimore, MD USA
[5] Univ Florida, Gainesville, FL USA
[6] Duke Univ, Durham, NC USA
[7] Thoratec Corp, Pleasanton, CA USA
[8] Texas Heart Inst, Houston, TX 77025 USA