A 58-year-old man with a 10-year history of hypertension and type 2 diabetes presents to the emergency department with acute-onset crushing substernal chest pain radiating to the left arm, associated with diaphoresis and nausea for the past 2 hours. On examination, blood pressure is 145/92 mmHg, heart rate 102/min, and respiratory rate 20/min. A 12-lead ECG shows ST-segment elevation of 3 mm in leads II, III, and aVF, with reciprocal ST depression in leads I and aVL. Troponin I is 0.8 ng/mL (normal <0.04). The patient is on aspirin 75 mg daily at home. What is the most appropriate immediate management?

Explanation

## Diagnosis: Inferior Wall STEMI **Key Point:** This patient presents with acute ST-elevation myocardial infarction (STEMI) of the inferior wall, evidenced by ST elevation in the inferior leads (II, III, aVF) with reciprocal changes and elevated troponin in the appropriate clinical context. ## Immediate Management Strategy **High-Yield:** The 2017 ESC and 2015 ACC/AHA guidelines mandate **primary percutaneous coronary intervention (PCI)** as the gold standard reperfusion strategy for STEMI when performed by an experienced team within 120 minutes (ideally 90 minutes) of first medical contact. ### Step-by-Step Approach: 1. **Dual antiplatelet therapy (DAPT):** - Aspirin 300–500 mg loading dose (already on 75 mg maintenance) - P2Y₁₂ inhibitor loading: **Clopidogrel 600 mg** OR ticagrelor 180 mg OR prasugrel 60 mg - Clopidogrel is preferred in this case because ticagrelor requires IV access and has more bleeding risk in elderly; prasugrel contraindicated if age >75 or weight <60 kg 2. **Anticoagulation:** - Unfractionated heparin (UFH) bolus: 70–100 U/kg IV (preferred during PCI for easier reversal) - Alternative: Enoxaparin 0.5 mg/kg IV if PCI delayed 3. **Reperfusion:** - **Primary PCI within 90 minutes** is superior to thrombolysis in reducing mortality, reinfarction, and stroke - No contraindication to PCI in this patient 4. **Adjunctive therapy:** - IV nitroglycerin (if SBP >90 mmHg and no RV involvement) - Beta-blocker (metoprolol 25–50 mg) to reduce heart rate and myocardial oxygen demand - Morphine for analgesia and anxiolysis **Clinical Pearl:** Inferior STEMI may involve the right ventricle (RV infarction) — assess for elevated JVP or hypotension with bradycardia. RV infarction is preload-dependent; avoid nitrates and diuretics; consider IV fluids if RV involvement suspected. ## Why This Option is Correct Option 0 combines **DAPT (clopidogrel 600 mg loading) + UFH + primary PCI**, which aligns with guideline-recommended reperfusion strategy and achieves the fastest door-to-balloon time for STEMI.