1. Department of Cardiac Surgery, University Hospital Augsburg, 86156 Augsburg, Germany
2. Department of Cardiothoracic Surgery, Cairo University, Giza P.O. Box 12613, Egypt
3. Department of Cardiology and Angiology, Regiomed Klinikum Coburg, 3396450 Coburg, Germany
4. Department of Cardiology, Helios Clinic Erfurt, 99089 Erfurt, Germany
5. Department of Cardiology, Heart Center, Zentralklinik Bad Berka, Robert-Koch-Allee 9, 99437 Bad Berka, Germany