RESUMO
The timing of an invasive diagnosis and treatment strategy in patients with an acute coronary syndrome without ST-elevation (NSTE-ACS) depends on the patient's risk profile. In addition to the clinical symptoms, ST/T alterations in the resting ECG as well as an increase and kinetics of troponin are of crucial importance in this setting. For the majority of patients the highly sensitive troponin enables a rapid rule in or rule out strategy of a non-ST-segment elevation myocardial infarction (NSTEMI) with a 0/3 h algorithm. An even faster 0/1 h algorithm is increasingly being used; however, troponin only helps to identify patients with NSTEMI. Troponin-negative patients can still suffer from unstable angina pectoris. A dual antiplatelet therapy (DAPT) with acetylsalicylic acid (ASS) and an ADP receptor antagonist should be initiated in the acute phase and continued for 12 months, irrespective of the initial treatment strategy, e.g. percutaneous coronary intervention (PCI), bypass surgery or conservative treatment. In patients with a high bleeding risk a duration of 6 months only may be considered, whereas in patients with a high risk of ischemia the DAPT might be prolonged for up to 36 months.