The term ‘acute coronary syndrome’ encompasses STEMI, NSTEMI, and UA. The electrocardiogram identifies those with STEMI. An elevated troponin level measured at least 12 hours after the onset of pain distinguishes NSTEMI from UA. However, the separation of NSTEMI and UA is somewhat artificial, as the management of individual patients is based on their risk score, with troponin being only a small part of the equation. Patients at moderate to high risk of death, MI, or subsequent admission to hospital should be offered early coronary arteriography with a view to revascularisation. The CLARITY and COMMIT studies, when added to the CURE study, support the early use of clopidogrel in all patients with ACS, irrespective of age