1. From the Division of Cardiovascular Pathophysiology, School of Medicine (B.L., A.G., J.D.), Department of Clinical Chemistry, University Clinic (N.V.), and Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), University of Navarra, Pamplona, Spain; and Division of Nephrology, San Jorge General Hospital (C.L.), Huesca, Spain; and Division of Cardiology, Na Sa de Aránzazu Hospital (R.Q.), San Sebastián, Spain.