[Management of acute coronary syndrome without ST-segment elevation]

Acute coronary syndrome without persistent ST-segment elevation (non-ST segment elevation myocardial infarction and instable angina pectoris NSTEMI-ACS) is common and is associated with a high mortality. In addition to 12-channel echocardiograph (ECG) assessment, measurement of cardiac troponins I and T are important for risk stratification and diagnosis. The introduction of high-sensitivity cardiac troponin assays and their implementation into clinical practice has influenced risk stratification and treatment of these patients. Additional diagnostic validation must supplement routine clinical chemistry testing following the initial measurement to distinguish between different possible causes of troponin elevation above the 99th percentile. The time point for the additional troponin measurement depends on the different protocols and troponin assays and is stipulated in the current guidelines. The use of both 1‑hour and 3‑hour protocols together with the clinical presentation and work-up of possible differential diagnoses provide optimal care of patients. Patients who test positive for troponin dynamics should undergo invasive diagnostics and treatment within 24 h of presentation and within 2 h is recommended for unstable patients. Clopidogrel is indicated only in patients requiring oral anticoagulation.