1. University Heart Center, Department of Cardiology; University Hospital Zurich; Zurich Switzerland
2. Division of Biostatistics, Epidemiology, Biostatistics and Prevention Institute; University of Zurich; Zurich Switzerland
3. Department of Cardiology and Angiology; Hannover Medical School; Hannover Germany
4. University of Southern California; Keck School of Medicine, Division of Cardiovascular Medicine; Los Angeles CA USA