1. From the Divisions of Cardiology (P.Y.H., J.E.H., H.H.F., A.S., A.F.B.), Positive Health Program of the Department of Medicine (P.W.H., R.H., S.G.D., J.N.M.), San Francisco General Hospital; and Department of Epidemiology and Biostatistics (J.N.M.), University of California, San Francisco, Calif.