A 58-year-old man from Mumbai presents to the emergency department with chest pain that started 3 hours ago while he was at rest. The pain is substernal, radiating to the left arm, and associated with diaphoresis. He has a history of hypertension and type 2 diabetes. On examination, blood pressure is 138/88 mmHg, heart rate 92/min, and respiratory rate 18/min. An ECG shows ST-segment depression of 2 mm in leads II, III, and aVF, with T-wave inversion in the same leads. Troponin I is 0.8 ng/mL (normal <0.04 ng/mL). Coronary angiography is planned. What is the most appropriate immediate antiplatelet and anticoagulation strategy?

Explanation

## Diagnosis: NSTEMI with Inferior Wall Involvement This patient meets diagnostic criteria for NSTEMI: - Chest pain at rest lasting >20 minutes - ST-segment depression (not elevation) in inferior leads (II, III, aVF) - Elevated cardiac troponin (0.8 ng/mL, markedly above cutoff) - Risk factors: age, hypertension, diabetes ## Immediate Dual Antiplatelet Therapy (DAPT) **Key Point:** NSTEMI requires dual antiplatelet therapy with aspirin + a P2Y₁₂ inhibitor (clopidogrel, ticagrelor, or prasugrel) started immediately, regardless of whether PCI is planned. | Agent | Loading Dose | Mechanism | Onset | |-------|--------------|-----------|-------| | Aspirin | 300 mg | COX inhibition | Rapid (minutes) | | Clopidogrel | 600 mg | P2Y₁₂ antagonist (prodrug) | 2–6 hours | | Ticagrelor | 180 mg | P2Y₁₂ antagonist (active) | 30 minutes | | Prasugrel | 60 mg | P2Y₁₂ antagonist (active) | 30 minutes | **High-Yield:** Clopidogrel 600 mg is the standard loading dose in resource-limited settings and remains guideline-recommended for NSTEMI when PCI is planned. Ticagrelor and prasugrel are superior in acute coronary syndromes but are more expensive. ## Anticoagulation **Key Point:** Unfractionated heparin (UFH) is the preferred anticoagulant for NSTEMI when PCI is anticipated, because: 1. Shorter half-life (60 minutes) — reversible if bleeding occurs 2. Can be titrated intraoperatively during PCI 3. No dose adjustment needed for renal impairment 4. Allows for intra-arterial measurement of activated clotting time (ACT) Enoxaparin (LMWH) is an alternative if UFH is contraindicated, but UFH is preferred in the acute setting. ## Why Option 0 is Correct - **Aspirin 300 mg:** Standard loading dose for ACS - **Clopidogrel 600 mg:** Guideline-recommended P2Y₁₂ inhibitor loading dose - **UFH bolus + infusion:** Preferred anticoagulant for PCI-eligible NSTEMI This combination achieves rapid dual antiplatelet inhibition and therapeutic anticoagulation. **Clinical Pearl:** In Indian practice guidelines (CSCI/ICMR), this triple-drug regimen (aspirin + clopidogrel + UFH) is the standard of care for NSTEMI with planned coronary intervention. ## Mermaid: NSTEMI Acute Management Algorithm ```mermaid flowchart TD A[NSTEMI Diagnosis Confirmed]:::outcome --> B{PCI Planned?}:::decision B -->|Yes| C[Aspirin 300 mg]:::action C --> D[P2Y12 Inhibitor:<br/>Clopidogrel 600 mg<br/>or Ticagrelor 180 mg]:::action D --> E[Anticoagulation:<br/>UFH preferred<br/>or LMWH]:::action E --> F[Coronary Angiography<br/>& PCI]:::action B -->|No| G[Medical Management<br/>+ Risk Stratification]:::action F --> H[Dual Antiplatelet<br/>for 12 months]:::outcome ```