Spontaneous coronary artery dissection (SCAD)
Spontaneous coronary artery dissection (SCAD) is a non‑atherosclerotic cause of acute myocardial infarction that disproportionately affects younger and middle‑aged women and is relatively common in the peripartum period.
It has distinct pathophysiology and diagnostic challenges; management decisions frequently differ from routine atherosclerotic ACS pathways and require early specialist cardiology/tertiary input.
Routine ACS guidance (NICE NG185) explicitly excludes SCAD - local protocols should therefore prioritise rapid cardiology review rather than automatic application of standard ACS algorithms.
Epidemiology and clinical importance
- Predominantly affects women (≈70% of cases).
- Accounts for a notable proportion of postpartum AMI (around 20% in published series).
- Left anterior descending artery is most commonly involved (≈40-70% of cases).
- Associated with significant early morbidity and a non‑trivial mortality risk.
- Recurrence and extracoronary arteriopathies (for example, fibromuscular dysplasia) are important longer‑term issues.
Pathophysiology (concise)
SCAD results from an intimal tear or intramural haemorrhage originating from the vasa vasorum within a coronary artery wall. This creates an intramural haematoma and/or a false lumen that compresses the true lumen and produces ischaemia. The dissection can extend dynamically after presentation; lesions are typically non‑atherosclerotic.