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Clinically unstable non-ST-segment-elevation myocardial infarction — MRCEM SBA MCQ

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HardCardiovascular emergenciesClinically unstable non-ST-segment-elevation myocardial infarctionMRCEM SBA

A 64-year-old man attends a district general hospital with 90 minutes of central chest pain. He has received aspirin 300 mg and sublingual glyceryl trinitrate. His initial ECG showed 1 mm ST depression in V4–V6, and high-sensitivity troponin T has risen from 24 to 96 ng/L over three hours (upper reference limit 14 ng/L). His pain persists despite further glyceryl trinitrate, and a repeat ECG shows 3 mm ST depression in the same leads, without ST elevation. His blood pressure is 122/76 mmHg. He has no active bleeding or contraindication to angiography. Monitoring and intravenous access are in place. The regional cardiac centre has accepted him for immediate coronary angiography, with transfer available now. Which treatment and disposition plan is most appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: B — Transfer for immediate angiography; give unfractionated heparin in the catheter laboratory if PCI is performed.

The troponin rise establishes myocardial injury in a presentation consistent with NSTEMI. Persistent pain despite treatment and worsening ST depression make him clinically unstable even though his blood pressure is normal. NICE recommends **immediate coronary angiography** for clinically unstable NSTEMI. Because angiography is available immediately, the usual recommendation to give fondaparinux does not apply; NICE recommends systemic unfractionated heparin in the catheter laboratory if PCI is undertaken. ([nice.org.uk](https://www.nice.org.uk/guidance/NG185/chapter/recommendations)) **A** uses a reasonable angiography timeframe and antithrombin for a *clinically stable* patient at intermediate or higher risk, but delays this patient’s assessment. **C** correctly prioritises transfer but misses the immediate-angiography exception to fondaparinux; fondaparinux would be appropriate if angiography were not immediate and bleeding risk were acceptable. **D** might suit an undifferentiated chest-pain presentation, but the serial findings here already support NSTEMI and demand action rather than another diagnostic wait. **E** is a reperfusion pathway for eligible STEMI when timely primary PCI is unavailable, not for this non-ST-elevation presentation. ([nice.org.uk](https://www.nice.org.uk/guidance/NG185/chapter/recommendations))

Reference: NICE NG185: Acute coronary syndromes — recommendations (18 November 2020) — https://www.nice.org.uk/guidance/NG185/chapter/recommendations NICE QS68: Coronary angiography and PCI for adults with NSTEMI or unstable angina who are clinically unstable (18 November 2020) — https://www.nice.org.uk/guidance/QS68/chapter/quality-statement-4-coronary-angiography-and-pci-for-adults-with-nstemi-or-unstable-angina-who-are