1. Department of Internal Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY (J.I.N.).
2. Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA (E.W.G., T.R.-C., M.S., P.Q., S.M., L.M.F., R.S., J.E.H., A.R.G.).
3. Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center, Boston, MA (E.W.G., K.K.).
4. Extracorporeal Life Support Organization, Ann Arbor, MI (J.E.T.).
5. Division of Cardiothoracic Surgery and Emergency Medicine, University of Utah, Salt Lake City (J.E.T.).