Step 3 CCS: Acute Coronary Syndrome
ACS is the single highest-yield CCS case type on USMLE Step 3. You will manage STEMI, NSTEMI, and unstable angina in real time — ordering ECGs, troponins, antiplatelet therapy, and deciding between PCI and fibrinolytics within strict time windows. Missed door-to-balloon targets or delayed anticoagulation will cost you points.
Clinical Approach — What Attendings Do First
The First Minute
- Order 12-lead ECG immediately — this is your branch point for STEMI vs NSTEMI vs UA
- Aspirin 325 mg PO chewed, not swallowed whole
- Place on continuous telemetry and pulse oximetry
- Two large-bore peripheral IVs, start normal saline
- Morphine 4 mg IV for persistent pain (use cautiously — may drop preload)
Key Orders
- Troponin I (serial q3-6h), CBC, BMP, PT/INR, lipid panel
- Chest X-ray portable
- Heparin IV bolus 60 units/kg then 12 units/kg/hr infusion (max 4,000 unit bolus)
- Ticagrelor 180 mg loading dose OR clopidogrel 600 mg loading dose
- Atorvastatin 80 mg PO
- Metoprolol tartrate 25 mg PO q6h (hold if HR <60, SBP <100, or signs of HF)
- Nitroglycerin 0.4 mg SL q5min x3, then IV drip if pain persists
Time-Sensitive Actions
- STEMI: Door-to-balloon <90 min — order cardiology consult and cardiac catheterization within first 5 simulated minutes
- If PCI unavailable: fibrinolytics within 30 min of arrival (alteplase 15 mg IV bolus → 0.75 mg/kg over 30 min → 0.5 mg/kg over 60 min)
- NSTEMI with TIMI score ≥3: early invasive strategy — cath within 24 hours
- Repeat ECG at 15-30 min intervals if initial ECG is non-diagnostic but suspicion remains high
Common CCS Pitfalls
- Forgetting to order serial troponins — a single negative troponin does not rule out ACS
- Not holding beta-blockers in acute heart failure or cardiogenic shock
- Giving morphine without monitoring — respiratory depression risk
- Failing to advance the clock after initial orders (CCS penalizes idle time)
- Omitting discharge medications — the case does not end at reperfusion
Frequently Asked Questions
What orders should I place first in a CCS ACS case?
Within the first 2 simulated minutes: 12-lead ECG, troponin I, CBC, BMP, PT/INR, chest X-ray. Simultaneously start aspirin 325 mg PO, morphine 4 mg IV if pain persists, oxygen only if SpO2 <94%, and continuous telemetry. Do not delay the ECG — it determines your entire management pathway.
How do I decide between PCI and fibrinolytics in a CCS STEMI case?
If the case scenario allows PCI within 90 minutes (door-to-balloon), order cardiology consult and cardiac catheterization. If PCI is unavailable or transfer time exceeds 120 minutes, administer alteplase (tenecteplase in some protocols) within 30 minutes of arrival. Always give heparin, ticagrelor or clopidogrel, and continue aspirin regardless of reperfusion strategy.
What medications must I order before discharge in a CCS ACS case?
The discharge 'ABCDE' bundle: Aspirin 81 mg daily + P2Y12 inhibitor (ticagrelor 90 mg BID or clopidogrel 75 mg daily), Beta-blocker (metoprolol succinate), ACE inhibitor or ARB (lisinopril 5-10 mg daily), high-intensity statin (atorvastatin 80 mg daily), and Diabetes/Diet counseling. Omitting any of these loses points on CCS.
Related Organ System Topics
Cardiovascular disease is one of the highest-yield areas on USMLE Step 3, spanning acute coronary syndromes, heart failure, arrhythmias, and valvular disease.
Emergency medicine on USMLE Step 3 covers the initial evaluation and stabilization of critically ill and injured patients.
Practice Acute Coronary Syndrome CCS Cases
Simulate real CCS cases with our Step 3 interface. Manage acute coronary syndrome patients in real time — place orders, advance the clock, and get AI-powered clinical feedback.
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