Dr. Koo currently serves as a Neurologist at Hospital Sungai Buloh and Hospital Selayang. As the Stroke Lead for Selangor State under the Ministry of Health Stroke Champion Programme, he plays a key role in developing and implementing the Selangor Stroke Action Plan, with a particular focus on advancing hyperacute stroke reperfusion therapies and improving stroke care outcomes across the state. Dr. Koo has been involved in complex stroke treatment decision-making for many years and his clinical interests include stroke etiology, post-reperfusion acute stroke care, and treatment strategies for patients with large-core acute ischemic stroke.

Dr. Koo is the founder of the Malaysia Acute Stroke Education for Reperfusion (MASTER) Programme, a national initiative dedicated to advancing stroke education and strengthening clinical competencies among neurologists and other specialists involved in acute stroke care. He is actively engaged in the training and mentorship of healthcare professionals in acute stroke management and contributes to the Ministry of Health Stroke Thrombolysis Training Programme, supporting the development of stroke expertise across Malaysia.