1. King Abdulaziz Cardiac Center, King Abdulaziz Medical City for National Guard Health Affairs, PO Box 22490, Riyadh 11426, Saudi Arabia
2. King Saud bin Abdulaziz University for Health Science, P.O. Box 3660, Riyadh 11481, Saudi Arabia
3. King Abdullah International Medical Research Center, P.O. Box 3660, Riyadh 11481, Mail Code 1515, Saudi Arabia
4. Department of Medicine, King Abdulaziz Medical City for National Guard Health Affairs, Riyadh, Saudi Arabia