Diagnosis and Management of Unstable Angina

Clinical Presentation and Diagnosis

The American Heart Association defines unstable angina as a condition characterized by acute severe chest pain at rest followed by recurrent symptoms, as seen in patients with recent normal functional capacity 1, 2
Prolonged chest pain at rest (>20 minutes) is a key diagnostic feature of unstable angina, as recommended by the American College of Cardiology 1, 2
Recent onset of severe symptoms, such as new-onset CCS Class III or IV severity angina, is a defining feature of unstable angina, according to the European Society of Cardiology 1, 2
Recurrent symptoms demonstrate the unstable, fluctuating nature of the syndrome, as noted by the American Heart Association 2

High-risk unstable angina is characterized by prolonged rest pain (>20 minutes) and an accelerating tempo of symptoms, as defined by the American College of Cardiology 5
The American Heart Association recommends that patients with high-risk unstable angina undergo immediate evaluation, including ECG and cardiac troponin measurement, to assess for STEMI or NSTEMI 4, 1

The American College of Cardiology recommends urgent transfer to the emergency department for patients with unstable angina, as well as immediate evaluation, including ECG within 10 minutes and cardiac troponin measurement as soon as possible 4, 1
The European Society of Cardiology notes that the distinction between unstable angina and NSTEMI will ultimately depend on troponin results, but both conditions require identical initial management, including urgent evaluation and treatment 2, 3