1 Hartford HealthCare, Heart and Vascular Institute, 80 Seymour St, Hartford, CT 06106, USA.
2 Department of Medicine, University of Connecticut Farmington, CT, USA.
3 The Division of Cardiology, Peter Munk Cardiac Centre, University Health Network, Toronto General Hospital, 585 University Ave, Toronto, ON M5G 2N2, Canada.
4 Lillehei Heart Institute, Department of Medicine, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA.