A 58-year-old man from Delhi presents to the emergency department with chest pain of 3 hours duration. The pain is substernal, radiating to the left arm, and associated with diaphoresis. He has a history of hypertension and type 2 diabetes. Vital signs: BP 128/82 mmHg, HR 92 bpm, RR 18/min. Physical examination is unremarkable. ECG shows ST depression of 2 mm in leads II, III, aVF and T-wave inversion in V3–V4. Troponin I measured at 2 hours is 0.02 ng/mL (normal <0.04 ng/mL). Repeat troponin at 4 hours is 0.08 ng/mL. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis **Key Point:** This patient has NSTEMI (Non-ST Elevation Myocardial Infarction) confirmed by: - Typical ischemic chest pain - Dynamic ECG changes (ST depression and T-wave inversion in anatomically contiguous leads) - Rising troponin (0.02 → 0.08 ng/mL over 2 hours) — the rise and/or fall pattern is diagnostic of myocardial necrosis ## Risk Stratification This patient is **high-risk** based on: - Positive troponin (myocardial injury) - ST depression (indicates more extensive ischemia) - Diabetes (independent risk factor) - Multiple risk factors (age, hypertension, diabetes) ## Management Algorithm ```mermaid flowchart TD A[NSTEMI confirmed]:::outcome --> B{Risk stratification}:::decision B -->|High-risk| C[Dual antiplatelet therapy]:::action C --> D[Anticoagulation with LMWH or UFH]:::action D --> E[Urgent coronary angiography within 24 hrs]:::action E --> F[Revascularization based on anatomy]:::outcome B -->|Low-risk| G[Conservative management + stress test]:::action ``` **High-Yield:** According to current guidelines (ESC 2020, ACC/AHA 2014), high-risk NSTEMI patients require: 1. **Dual antiplatelet therapy:** Aspirin + P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor) 2. **Anticoagulation:** LMWH (enoxaparin) or unfractionated heparin 3. **Urgent coronary angiography:** Within 24 hours (preferably <12 hours for very high-risk) 4. **Revascularization:** PCI if culprit lesion identified; CABG if multivessel disease **Clinical Pearl:** The rise in troponin (even if still within normal range at 2 hours) combined with ST depression indicates myocardial necrosis and mandates invasive evaluation. Waiting for stress testing delays necessary revascularization. **Key Point:** Troponin kinetics matter — a rising troponin (0.02 → 0.08) is more diagnostic than an absolute value, as it indicates ongoing myocardial injury. ## Why Urgent Angiography? Early invasive strategy in high-risk NSTEMI reduces: - Recurrent ischemia - Reinfarction - Death - Hospital readmission [cite:Harrison 21e Ch 297]