1. From the Department of Cardiothoracic Anesthesia (C.G.K.), the Department of Quantitative Health Sciences (L.L., E.H.B.), the Department of Cardiovascular Medicine (M.H.S.), and the Department of Thoracic and Cardiovascular Surgery (J.S., E.H.B.), the Cleveland Clinic, and the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University (J.W.), Cleveland, Ohio; and the Department of Epidemiology (G.A.K.), University of Michigan School of Public Health, Ann Arbor, Mich.