1. Department of Cardiovascular Medicine, Heart, Vascular and Thoracic Institute, Cleveland Clinic , 9500 Euclid Avenue, J2-3, Cleveland, OH 44195 , USA
2. Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center, University Hospital Essen , Essen , Germany
3. Krannert Cardiovascular Research Center, Division of Cardiovascular Medicine, Indiana University School of Medicine , Indianapolis, IN , USA