1. Research Unit of Internal Medicine, Medical Research Centre Oulu, Finland
2. Oulu University Hospital, and University of Oulu, Finland
3. Department of Health, National Institute for Health and Welfare, Helsinki, Finland
4. University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
5. North Karelia Central Hospital, Joensuu, Finland
6. University of Eastern Finland, Kuopio, Finland
7. Heart Centre, Turku University Hospital, Finland