1. Department of Medicine, Harrington Heart and Vascular Institute, University Hospitals, Case Medical Center; Cleveland Ohio
2. Department of Medicine, Institute of Cardiology, University of Latvia, Pauls Stradins Clinical University Hospital; Riga Latvia
3. Department of Cardiology; Vivantes Klinikum Im Friedrichshain Und Am Urban, Berlin, Germany and Rostock University Medical Center; Rostock Germany
4. Division of Cardiovascular Medicine; the Ohio State University; Columbus Ohio