1. Institute for Cardiovascular Diseases “Dedinje”, 11000 Belgrade, Serbia
2. Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
3. Cardiac Surgery, University Clinical Center of Serbia, 11000 Belgrade, Serbia
4. Faculty of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia
5. Transfusiology Clinic, University Clinical Center of Serbia, 11000 Belgrade, Serbia
6. Institute of Medical Statistics and Informatics, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia