[1] Circulatory Dis Ctr, Augusta, GA USA
[2] Main Line Hlth Heart Ctr, Div Cardiovasc Dis, Philadelphia, PA USA
[3] Cornell Univ, Weill Med Coll, New York, NY 10021 USA
[4] Brigham & Womens Hosp, Div Renal, Boston, MA 02115 USA
[5] Sahlgrenska Hosp Ostra, Dept Med, Gothenburg, Sweden
[6] Glostrup Univ Hosp, Glostrup, Denmark
[7] Umea Univ Hosp, S-90185 Umea, Sweden
[8] Merck & Co Inc, Whitehouse Stn, NJ USA