[1] Univ Clin Hamburg Eppendorf, Dept Internal Med, Div Cardiol & Angiol, Hamburg, Germany
[2] Univ Clin Rostock, Dept Internal Med, Div Cardiol & Angiol, Rostock, Germany
[3] Univ Clin Hamburg Eppendorf, Dept Transfusmed & Transplantationimmunol, Hamburg, Germany
[4] Baylor Coll Med, Dept Internal Med, Houston, TX 77030 USA