see also: [[ACS]] > As high sensitivity troponin assays have become more available, there has been fewer patients diagnosed with unstable angina simple because many who would previously be classified as UA are now found to have AMI. Angina plus any of the following = unstable angina - pain at rest - new pain starting < 2 weeks ago - increasing severity - haemodynamic changes associated with pain ***Unstable Angina Definition:*** Myocardial ischaemia at rest or on minimal exertion in the absence of acute cardiomyocyte injury/necrosis. UA is characterised by angina pectoris that occurs without stress or activity, or with decreasing stress or activity compared with stable angina and has been present for <2 weeks. ECG changes of ACOMI and elevated troponin values are not seen in UA. **Note** that unstable angina is included ==within the definition of ACS and is considered high risk== > [!Quote] > Where contemporary cTn assays are in use, **Unstable Angina** should be considered in the presence of *normal cTn results* if ***clinical suspicion for ACS is high based on ECG interpretation and/or clinical history***. Further serial cTn testing over 6–8 hours should occur. Management may include initial treatment for presumed ACS, a period of continuous cardiac monitoring and/or transfer to a PCI-capable centre. - [2025 ACS Guideline](x-devonthink-item://943750C1-A66C-4BDB-8619-5655C54B9191?page=43), page 37 People with ongoing or recurrent ischaemic symptoms, or new ECG findings suggestive of ischaemia during initial or repeat testing, should be classified as high risk for ACS. If clinical suspicion remains high, serial cTn testing is recommended, as late cTn rises have been described in <1% of people with NSTEMI