Guideline for the management of patients with acute coronary syndromes without persistent ECG ST segment elevation British Cardiac Society Guidelines and Medical Practice Committee, and Royal College of Physicians Clinical EVectiveness and Evaluation Unit

3. Patients with a suspected acute coronary syndrome should be observed, with repeat 12 lead ECG recording, during symptoms if the opportunity arises. Blood samples for cardiac troponin (troponin T or I) should be taken a minimum of 12 hours after the onset of symptoms. New ischaemic changes on the ECG or elevation of troponin confirm the diagnosis (see table 1 and recommendation 5). A 4. If at least 12 hours after the onset of symptoms of a suspected acute coronary syndrome: + the symptoms have not recurred; + the cardiac troponin is normal; + the ECG remains normal (or unchanged compared with a recording from before the current presentation); + and the cardiac enzymes are not raised; the patient can be mobilised and discharged. Risk assessment with stress testing should be performed unless contraindicated, preferably before discharge from hospital. ✓A