1. Department of Medicine, Harvard Medical School, 330 Mount Auburn St, Cambridge, MA, USA
2. Division of Cardiology, Johns Hopkins University School of Medicine, Johns Hopkins Hospital, 600 N. Wolfe Street, Blalock 524, Baltimore, MD, USA
3. Division of Cardiology, Universidade of Sao Paulo, Av. Bandeirantes, 3.900 Monte Alegre, Ribeirão Preto, SP, Brazil
4. Department of cardiology, Oslo University hospital, Sognsvannsveien 20, Oslo, Norway
5. Department of Preventive Medicine, Northwestern University, 675 N St Clair St STE 19-100, Chicago, IL, USA
6. Division of Epidemiology and Community Health, University of Minnesota, 1300 S 2nd St, Minneapolis, MN, USA
7. Division of preventive medicine, University of Alabama, 619 19th St, Birmingham, AL, UK
8. Division of Pediatrics Cardiology, Nemours Cardiac Center, 1600 Rockland Road Wilmington, DE, USA