1. Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
2. Division of Cardiology, Department of Medicine, Ng Teng Fong General Hospital, Singapore 609606, Singapore
3. Department of Cardiology, National University Heart Centre, Singapore 119074, Singapore
4. Department of Haematology-Oncology, National University Cancer Institute, Singapore 119228, Singapore