1. Department of Cardiology, Dong-A University Hospital , Busan 49201 , Republic of Korea
2. Department of Clinical Epidemiology and Biostatistics, University of Ulsan College of Medicine, Asan Medical Center , Seoul 05505 , Republic of Korea
3. Division of Cardiology, UCLA Medical Center , Los Angeles, CA , USA
4. Department of Biomedical Laboratory Science, Daegu Health College , Youngsong-ro, Buc-gu, Daegu 41453 , Republic of Korea