1. Department of Health and Human Services, National Heart, Lung, and Blood, National Institutes of Health, Building 10, Room B1D416, MSC 1061, 10 Center Drive, Bethesda, MD 20892-1061, USA
2. Zena and Michael A. Wiener Cardiovascular Institute and Marie-Josée and Henry R. Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1030, New York, NY 10029, USA
3. Icelandic Heart Association, Holtasmari 1, Kopavogur, Iceland
4. University of Iceland, 101 Reykjavik, Reykjavik, Iceland
5. Department of Health and Human Services, National Institute on Aging, 31 Center Drive, MSC 2292, Bethesda, MD 20892, USA