1. Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology (A.R., R.K.W., E.C., S.C., C.S., R.W.Y., E.A.S.), Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA.
2. Division of Cardiology (R.K.W., R.W.Y., E.A.S.), Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA.
3. Harvard Medical School, Boston, MA (R.K.W., C.S., J.F.F., R.W.Y., E.A.S.).