1. Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium (institution where work was performed).
2. Doctoral School for Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
3. Department of Cardiac Surgery, Ziekenhuis Oost-Limburg, Genk, Belgium.
4. Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.