1. Division of Respiratory Medicine, Department of Medicine; Ng Teng Fong General Hospital; Singapore
2. Department of Cardiology; National University Heart Centre Singapore; Singapore
3. Division of Cardiology, Department of Medicine; Ng Teng Fong General Hospital; Singapore
4. Clinical Research Unit; Ng Teng Fong General Hospital; Singapore
5. Yong Loo Lin School of Medicine; National University of Singapore; Singapore
6. Cardiovascular Research Institute; National University of Singapore; Singapore
7. Department of Medicine; University of Otago; Christchurch New Zealand