1. National Institutes of Health (NIH), 9000 Rockville Pike, Bethesda, MD 20892, USA
2. Section of Cardiology, Department of Internal Medicine, Morehouse School of Medicine, Atlanta, GA 30310, USA
3. Department of Public Health, Rollins School of Public Health, Emory University School of Medicine, Atlanta, GA 30329, USA
4. Department of Internal Medicine, Morehouse School of Medicine, Atlanta, GA 30310, USA