What distinguishes NSTEMI from unstable angina?

The key difference that distinguishes non-ST elevation myocardial infarction (NSTEMI) from unstable angina is the elevation of troponin levels. Troponins are proteins released into the bloodstream when there is damage to the heart muscle. In NSTEMI, there is enough myocardial injury caused by a lack of blood supply that it leads to elevated troponin levels, which indicates that myocardial necrosis has occurred.

In cases of unstable angina, although the patient experiences chest pain that may mimic an NSTEMI, there is no significant myocardial damage and, therefore, troponin levels remain normal. This distinction is crucial for diagnosis and management, as NSTEMI typically involves more aggressive treatment strategies to restore blood flow and prevent further cardiac damage compared to unstable angina.

Understanding this differentiation is vital in the clinical setting, as it influences patient care pathways, including the decision to perform invasive procedures, start anticoagulation therapy, or utilize other treatment options aimed at myocardial protection and recovery.