Spontaneous coronary artery dissection (SCAD) is a rare cause of chest pain, acute coronary syndrome and death.2
It is more common in younger patients with an average age of 46 years in men and 39 years in women.3 4
It is also approximately three times more common in women than men.2
Sudden cardiac death is often the first manifestation and the majority of cases are diagnosed at autopsy. Mortality is high at 70%.2
In women, the risk of SCAD appears to be increased during the peripartum period with 25–30% of reports occurring in this setting.1 5
Myocardial infarction surrounding pregnancy has been associated with SCAD in 16–54% cases.1
Most pregnancy related cases occur after delivery of the baby at 13 days postpartum on average,2
although the latest reported case occurred at 3 months.2 6
Short-term mortality is as high as 38% although up to 82% of survivors were still alive at 3 years.1 6
Women have a higher proportion of LAD artery involvement and LMS involvement whereas men are more likely to have RCA dissection. The Cx artery is infrequently involved in men and women.7
Approximately 40% of SCADs are multifocal in nature.8
The aetiology is not fully understood. Most patients presenting with SCAD do not have risk factors for coronary artery disease. The haemodynamic stresses of pregnancy and delivery of the baby are thought to play a part.2 8 9
Other theories include structural changes in the arterial walls related to the hormones of pregnancy and eosinophilic infiltration resulting in separation of the tunicae intima and media.2
Often dissection occurs without an initial tunica intimal damage suggesting the mechanism lies in degeneration of the tunicae media and adventitia.1
Histologically, an inflammatory reaction in the adventitia has been described suggestive of periarteritis. The inflammatory infiltrate in this case's histology contained lymphocytes and neutrophils. However, this inflammatory response may be reactive rather than causative.9
SCAD should be suspected in all young patients without risk factors for coronary artery disease who present with chest pain, acute coronary syndromes or sudden death. This is especially true for women who present in the peripartum period.
Diagnosis is usually made by emergency coronary angiography,2 5
although trans-oesophageal ultrasound, intravascular ultrasound, optical coherence tomography and CT coronary angiography have also been used where there is diagnostic difficulty or to guide management.1 2 5 6
Non-invasive methods such as CT angiography to diagnose and monitor may also decrease the risk of complications.2 6
The high mortality is falling thanks to early diagnosis and aggressive management.5
The rarity of SCAD means that there is uncertainty and a lack of consensus in its management.1 2 5
Medical management may be successful in half of women initially thought suitable for this approach. The remainder may still require intervention later.2 5
Medical management involves treatment with heparin, antiplatelets, nitrates and β-blockers.1 2 5
Antiplatelets and heparin are thought to help decrease thrombus formation in the false lumen; thus, allowing a more normal flow through the true lumen.5 8 10
The use of glycoprotein IIb/IIIa inhibitors is contraindicated.5
The use of thrombolysis remains controversial as some cases have reported benefit while others have shown no difference or even extension of the dissection.3 5 11–13
Immunosuppressive treatment with prednisone and cyclophosphamide, along with standard treatment, has also been used beneficially in one case lending potential support to the argument that SCAD is an inflammatory process.14
Where medical treatment is inappropriate (eg, due to haemodynamic compromise or the type of lesion) percutaneous coronary intervention, sometimes assisted by intravascular ultrasound, and coronary artery bypass grafting can be considered.5
A LV assist device implant followed by heart transplantation has also been successful.15
Peripartum SCAD is not an absolute contraindication to future pregnancies. Data on the risk of recurrence are limited and so it may be best to avoid further pregnancies.16
As such, pre-pregnancy counselling should be considered.
- SCAD is a rare cause of acute coronary syndromes and sudden death.
- It should be considered in all peripartum women who present with chest pain.
- Thrombolytic treatment may be harmful.
- It should be diagnosed expediently by coronary or CT angiography.