1. Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology at Beth Israel Deaconess Medical Center, Boston, MA (Z.I.A., R.W.Y.).
2. Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, MA (Z.I.A.).
3. Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA (R.W.Y.).