1. Department of Medicine, University of Damascus, Damascus, Syria
2. Department of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
3. Department of Medicine, The University of Texas Health Science at Houston, Houston, Texas, USA
4. Division of Nephrology, Elmhurst Hospital Center, New York, USA
5. Cardiovascular Institute, Mount Sinai Medical Center, New York, USA