1. Health Sciences Department, CAS, Qatar University, P.O. Box 2713, Doha, Qatar
2. Cardiology Unit, Ahmed Maher Teaching Hospital, Cairo, Egypt
3. Clinical Medicine, Weill Cornell Medical School, P.O. Box 24144, Doha, Qatar
4. Cardiology Unit, Al-Emadi Hospital, P.O. Box 5804, Doha, Qatar
5. Clinical Chemistry Department, Hamad Medical Corporation (HMC), P.O. Box 3050, Doha, Qatar
6. Cardiology Department, Heart Hospital, Hamad Medical Corporation (HMC), P.O. Box 3050, Doha, Qatar