1. From the Department of Cardiovascular Diseases (S.A., A.M.A.-O., P.A.P., V.T.N., J.K.O., M.M.A., R.B.M.) and Division of Biomedical Statistics and Informatics (C.G.S.), Mayo Clinic, Rochester, MN; and Department of Medical Sciences, University of Torino, Turin, Italy (S.A., A.M.).