NSTEMI Workup and Treatment Guide

Non-ST Elevation Myocardial Infarction

I. Initial Evaluation of NSTEMI in ACS

History

  • Symptoms: Chest pressure, tightness, or pain, radiation to jaw/arm, nausea, diaphoresis, SOB
  • Risk factors: CAD, HTN, diabetes, smoking, hyperlipidemia, family history, recent stress/exertion
  • Differentials: Stable angina, pericarditis, PE, aortic dissection, GERD, musculoskeletal pain

Physical Exam

  • Overall: Exam is usually normal
  • Vitals: May be normal or show tachycardia, HTN, or hypotension
  • Cardiac: May be unremarkable; possible S4, new murmur (suggestive of papillary rupture)
  • Pulm/Other: Signs of CHF, rales, peripheral edema

II. Diagnostic Workup

Labs

  • Troponin I/T: Elevated, rising pattern over time
  • EKG: ST depressions, T-wave inversions, or non-specific changes; no ST elevations
  • CBC, CMP: Assess for anemia, renal function, baseline values
  • BNP (optional): If concern for concurrent CHF
  • Coags: Baseline prior to anticoagulation

Imaging

  • Chest X-ray: Rule out other causes of chest pain (e.g., pneumonia, pneumothorax, aortic pathology) and evaluate for new onset CHF
  • Echo: Assess for wall motion abnormalities or reduced EF (perform on inpatient basis)

III. Risk Stratification

Risk Tool Use
GRACE Score Estimates in-hospital and 6-month mortality
TIMI Score Helps guide need for early invasive strategy (PCI)

IV. Treatment

Initial Management (MONA)

  • Morphine: For persistent pain (use sparingly)
  • Oxygen: Only if SpO₂ < 90%
  • Nitroglycerin: SL or IV (unless hypotensive or RV infarct)
  • Aspirin: 324 mg chew immediately – This is the only part of MONA that improves mortality

Antithrombotic Therapy

  • Anticoagulation: Enoxaparin or unfractionated heparin (heparin drip)
  • P2Y12 inhibitor: Clopidogrel, ticagrelor, or prasugrel (if PCI planned)
    • Discuss these with the cardiologist prior to administration as it could interfere with CABG plans if indicated

Additional Management

  • Statin: High-intensity statin (e.g., atorvastatin 80 mg) – Inpatient
  • ACE inhibitor: If EF < 40%, HTN, DM, or CKD – Inpatient
  • Beta-blocker: If not hypotensive – Inpatient
  • Early Cardiology consult: for early invasive strategy or catheterization

V. Disposition Planning

Scenario Disposition Notes
Confirmed NSTEMI, stable Admit to telemetry or cardiology service Initiate anticoagulation, early cardiology evaluation
Recurrent significant chest pain, dynamic EKG changes, hemodynamic instability ICU or step-down unit Urgent angiography ± PCI

VI. Red Flags / Escalation Triggers

  • Refractory or worsening chest pain
  • Hypotension, arrhythmias, or bradycardia
  • ST elevation on repeat EKG (conversion to STEMI)
  • Heart failure or cardiogenic shock
  • Significant troponin rise with ECG changes

✅ Discharge Checklist (Post-Hospitalization)

  • Completed risk stratification and/or angiography
  • Discharge medications: ASA, P2Y12 inhibitor, statin, beta-blocker, ACEi/ARB
  • Follow-up with cardiology arranged
  • Patient educated on lifestyle, diet, and medication adherence

References

  1. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non–ST-elevation acute coronary syndromes.
    J Am Coll Cardiol. 2014;64(24):e139–e228.
    https://doi.org/10.1016/j.jacc.2014.09.017
  2. UpToDate. Non-ST elevation acute coronary syndromes: Initial evaluation and management.
    https://www.uptodate.com. Accessed April 2025.
  3. Antman EM, Cohen M, Bernink PJ, et al. The TIMI risk score for unstable angina/non–ST elevation MI.
    JAMA. 2000;284(7):835–842.
    https://doi.org/10.1001/jama.284.7.835
  4. Fox KA, Dabbous OH, Goldberg RJ, et al. Prediction of risk of death and myocardial infarction in the six months after presentation with acute coronary syndrome.
    BMJ. 2006;333(7578):1091.
    https://doi.org/10.1136/bmj.38985.646481.55