1. Department of Cardiothoracic Surgery, Heart Center, University Hospital Cologne Kerpener Strasse 62, Cologne, Germany
2. University of Cardiology and Pneumology, Heart Center, University Hospital Cologne Kerpener Strasse 62, Cologne, Germany
3. Clinic for Pneumology and Allergology, Hospital Bethanien, Aufderhöher Strasse, Solingen, Germany