NSTEMI

• Patients with NSTE-ACS are classified based on the presence (NSTEMI) or absence (UA) of significantly elevated cardiac troponin (cTn) levels.

• A key element of management is to assess the necessity for and timing of PCI (fibrinolytics are not indicated in NSTE-ACS).

• Multiple risk scores (e.g., HEART, TIMI, GRACE) can help to determine an adequate strategy but are no substitute for individual clinical judgment.

• Dual antiplatelet therapy and anticoagulation is indicated initially and the preferred regimens vary based on patient risk factors and timing of revascularization.

• Some low-risk NSTE-ACS patients can be managed conservatively.

• No ST elevations present

• Nonspecific signs of ischemia may be present, including:

  • ST depression, especially if horizontal or downsloping

  • Transient ST deviations

  • T-wave inversions

To identify STEMI or STEMI-equivalent ECG findings, repeat ECGs if the initial one is inconclusive or any changes in symptoms occur.

• Management of NSTE-ACS depends on a patient's mortality risk (e.g., TIMI score), clinical findings, and the availability of resources.

• Invasive strategy for NSTE-ACS (very high- to intermediate-risk patients): coronary angiography within 2–72 hours

• Ischemia-guided strategy for NSTE-ACS (in stable, low-risk patients): noninvasive cardiac stress testing (e.g., exercise ECG, stress echocardiography) to evaluate the need for coronary angiography

Fibrinolytic therapy is not indicated in patients with unstable angina or NSTEMI.