Associate Professor David Sim is the deputy head of cardiology, director of the heart failure programme, and director of clinical and translational research office at the National Heart Centre Singapore. He is the  president of the Heart Failure Society (Singapore) and honorary international advisor to the Hong Kong Heart Failure Society. His sub-specialty interest is in heart failure, mechanical circulatory support, and heart transplantation.

Prof Sim also has an interest in palliative care for heart failure. He is the project director for the Advanced Care Planning Program in NHCS In addition, Prof Sim plays an active role in clinical trials and is the National Leader for Singapore for global pharmacological heart failure trials.