Type 2 MI and SCAD — structured written assessment

SAQ 1 (10 marks)

Practice scenario. An 81-year-old woman with known coronary artery disease is admitted with urosepsis, hypotension and a fast atrial fibrillation. She becomes breathless, her ECG shows new widespread ST-segment depression, and serial troponin rises and falls with values above the sex-specific 99th percentile.^[1][8] She has no persistent or recurrent chest pain once the sepsis and rhythm are controlled.^[1]

1. Under the Fifth UDMI (2026), what term replaces "type 2 MI" for this situation, and how did the Fourth UDMI type 2 category differ? (2)^[1]
2. Name two features of her presentation that make secondary MI considered and one that makes it likely under Box 4. (2)^[1]
3. Give the Box 4 imaging findings that would confirm the diagnosis. (2)^[1]
4. When is invasive coronary angiography indicated in suspected secondary MI, and what is the alternative timing otherwise? (2)^[1]
5. What does the 2023 ESC guideline say about drug treatment for type 2 MI, and what should management focus on? (2)^[2]

Model answers — SAQ 1

1. Secondary myocardial infarction (1 mark).^[1] The Fourth UDMI type 2 MI also included acute coronary pathology other than atherothrombosis, such as SCAD, coronary embolism and vasospasm, which the Fifth UDMI places in primary MI (1 mark).^[1]
2. Considered: acute myocardial injury with an alternative acute condition causing supply–demand mismatch, plus a clinical or ECG feature such as new ischaemic ECG changes (1 mark for any two features named).^[1] Likely: known coronary artery disease (1 mark; also accept a strong clinical suspicion from the extent of ECG ischaemia or troponin elevation).^[1]
3. Where coronary and/or cardiac imaging is feasible and appropriate, the diagnosis is confirmed by one or more of: obstructive coronary artery disease, defined as ≥70% stenosis in an epicardial vessel by angiography or ≥50% stenosis in an epicardial vessel that is flow-limiting on physiological assessment, without an acute coronary pathology (1 mark).^[1] A new or presumed new regional wall motion abnormality or absence of viable myocardium in a pattern consistent with an ischaemic aetiology (1 mark).^[1]
4. Invasive coronary angiography is indicated if there is persistent or recurrent myocardial ischaemia and primary MI is a differential diagnosis (1 mark).^[1] Otherwise imaging is often deferred until the acute condition has been treated, so that non-invasive approaches such as CCTA can be used (1 mark).^[1]
5. ESC 2023: there are currently no specific recommended pharmacological interventions for type 2 MI (1 mark).^[2] Management should focus on identifying and treating the precipitating conditions, such as anaemia or hypoxia, alongside strict control of cardiovascular risk factors (1 mark).^[2]

SAQ 2 (10 marks)

Practice scenario. A 46-year-old woman with no cardiovascular risk factors presents with chest pain. The ECG shows anterior ST-segment depression and troponin is raised. Angiography shows a long, smooth, diffuse narrowing of the mid left anterior descending artery, bordered by normal segments proximally and distally, consistent with spontaneous coronary artery dissection.^[5][6] Her pain has settled, she is haemodynamically stable, there are no ongoing ischaemic changes and antegrade flow is preserved.^[2][6]

1. Name the Saw angiographic type and give one reason this pattern is easily missed. (2)^[5]
2. Give the ESC 2023 Class I row on PCI in SCAD, and state whether it applies to her. (2)^[2]
3. How long should she be monitored in hospital, and why? (2)^[5]
4. Summarise what ESC 2023 says on pharmacological therapy in SCAD, and what the 2025 ESC pregnancy guideline says on antiplatelet therapy in its section on pregnancy-associated SCAD. (2)^[2][7]
5. Which drug class has been associated with less recurrent SCAD, and what was the hazard ratio in the 2017 Vancouver cohort? (2)^[11][5]

Model answers — SAQ 2

1. Type 2A: diffuse narrowing bordered by normal segments proximal and distal to the intramural haematoma (1 mark).^[5] Type 2 lacks the classic multiple lumens or contrast staining; AHA 2018 notes that relying on those features alone would miss more than 70% of SCAD (1 mark).^[5]
2. In patients with spontaneous coronary artery dissection, PCI is recommended only for patients with symptoms and signs of ongoing myocardial ischaemia, a large area of myocardium in jeopardy, and reduced antegrade flow (ESC 2023, Class I, Level C) (1 mark).^[2] It does not support PCI for her: she has no ongoing ischaemia and her flow is preserved, so conservative medical management, which ESC 2023 generally recommends, applies (1 mark).^[2]
3. AHA 2018: patients with acute MI caused by SCAD are typically admitted for a minimum of 48 hours, and a prolonged period of in-hospital monitoring (3–5 days) is justified as part of a conservative strategy; ESC ACCA 2018 suggests ∼5 days in conservatively managed SCAD (1 mark).^[5][6] Early recurrent MI may develop in 5% to 10% of conservatively managed patients, mostly from extension of dissection within the first 7 days (1 mark).^[5]
4. ESC 2023: until evidence from ongoing prospective trials becomes available, patients with SCAD should receive the same pharmacological therapy as other ACS patients (1 mark).^[2] ESC 2025 pregnancy guideline, section on pregnancy-associated SCAD: the role of antiplatelet therapies in conservatively managed SCAD has been controversial, with evidence favouring single antiplatelet therapy with aspirin (1 mark).^[7]
5. β-blockers (1 mark).^[11][5] Hazard ratio 0.36 for recurrent SCAD in multivariate modelling of the prospective Vancouver cohort of 327 patients with nonatherosclerotic SCAD (median follow-up 3.1 years); this was observational, not randomized (1 mark).^[11][6]