Department of Medicine, John H Stroger Jr. Hospital of Cook County, Chicago, IL, USA. Department of Medicine, Dow University of Health Sciences, Karachi, Pakistan. Department of Medicine, Memorial Healthcare System, Pembroke Pines, USA. Department of Internal Medicine, Dow University of Health Sciences, Karachi, Pakistan. Department of Medicine, Khaja Bandanawaz Institute of Medical Sciences Gulbarga, India. Department of Medicine, Ziauddin Medical University, Karachi, Pakistan. Department of Medicine, RCSI University of Medicine and Health Sciences, Dublin, Ireland. Department of Cardiology, St.Mary Medical Center, Langhorne, PA, USA.