Dr. Zainal Hamid was among the first medical officers in Malaysia’s inaugural Cardiology Department at the General Hospital Kuala Lumpur. He played a key role in establishing the National Heart Institute (Institut Jantung Negara, IJN) where he served as its Medical Director overseeing clinical operations, research, and organisational reforms. He introduced primary and trans-radial angioplasty at IJN, now the standard of care. He also served as Personal Physician to the Prime Minister of Malaysia for more than 10years, leading the medical team during official duties and international visits. As medical advisor to PETRONAS, he contributed to the development of Prince Court Medical Centre. He currently serves as Cardiologist and Group Medical Director at Twin Towers Medical Clinic, KLCC. He has been an Independent Expert Witness in medical malpractice litigation, with over 20 accepted expert reports and court testimonies to date.