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