1. Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston (D.K.).
2. Statistical Consultant, Lifespan Cardiovascular Institute, Providence, RI (K.F.K.).
3. Division of Cardiovascular Medicine, Case Western Reserve University and University Hospitals, Cleveland, OH (M.H.S.).
4. Division of Cardiology, Lifespan Cardiovascular Institute, Warren Alpert Medical School of Brown University, Providence, RI (S.T.M., O.N.H., P.S., H.D.A.).
5. Division of Vascular Surgery, Warren Alpert Medical School of Brown University, Providence, RI (L.S.).