1. Department of Cardiology, Division of Medicine Akershus University Hospital Lørenskog Norway
2. Institute of Clinical Medicine University of Oslo Oslo Norway
3. LHL Hospital Gardermoen Jessheim Norway
4. Department of Cardiology Østfold Hospital Trust Kalnes Grålum Norway
5. Pulmonary Department Akershus University Hospital Lørenskog Norway
6. Health Services Research Unit Akershus University Hospital Lørenskog Norway
7. Department of Circulation and Medical Imaging Norwegian University of Science and Technology Trondheim Norway