FMD and SCAD (Spontaneous coronary artery dissection)

What is SCAD?

SCAD is a rare cause of Myocardial Infarction (heart attack).

The diagnosis of SCAD can be considered when a heart attack is seen in younger women, typically less than 50 years old, with few cardiovascular risks.

SCAD is more commonly seen in women (90% of cases), in 10% of cases during pregnancy or following child birth. In other cases, a history of strenuous physical effort or intense stress or a combination of both may be reported just prior to the heart attack. In a proportion of cases, SCAD may occur in patients with an underlying arterial disease, most commonly FMD.

What happens in case of SCAD?

As in other arterial dissections, there is a tear in the artery wall causing a false lumen (channel) that fills with blood which is unable to escape and subsequently blocks the artery and reduces the blood flow to the heart, eventually causing chest pain and myocardial infarction (heart attack)
Apart from rare familial cases, the majority of SCAD events are sporadic, that is to say there are no familial predisposing factors to be found.

Why is it important to distinguish SCAD from other causes of heart attack?

I. In the majority of cases the coronary dissection will heal spontaneously. Angioplasty with stenting or bypassing of coronary arteries carries a higher risk of complications in SCAD patients than in patients experiencing a heart attack caused by atherosclerosis (cholesterol deposits). Therefore, unless there is vital risk, in most cases a conservative approach is recommended.

II. The medical treatment of SCAD cannot be extrapolated from the treatment recommended in case of heart attack caused by atherosclerosis. Statins are not recommended for SCAD patients in the absence of hyperlipidemia (raised plasma cholesterol). Treatment with low dose aspirin and beta blockers is recommended by some experts. Other medicaments ( ACE inhibitors…..) remain recommended in the case of secondary cardiac dysfunction.

III. Following a SCAD event, it is recommended to screen other arteries for signs of FMD or less frequently genetic or inflammatory arterial diseases.

What is the link between SCAD and FMD?

Recent research has shown that patients who have suffered a SCAD often (30-80% of cases) harbour FMD lesions of the multifocal subtype (“string of beads”), particularly in the renal, cerebrovascular and iliac arteries. Although the prevalence of FMD is higher in patients who suffered a SCAD than in the general population, SCAD remains a rare event in patients primarily diagnosed with FMD.

Practical consequences.

According to these observations, expert panels from Europe and the US have made the following recommendations:

1. Patients who have suffered a SCAD should undergo a one-time head to pelvis scan (by CTA, or MRA if contra-indicated) to screen for FMD lesions or other vascular abnormalities.

2. Imaging of coronary arteries is not recommended in patients with FMD in the absence of chest pain (angina) or other suggestive symptoms.

Do you need more information about SCAD ? Links to SCAD Information/Associations

SCAD Associations :

BeatSCADUK : www.beatscad.org.uk

SCAD Research ( USA) : www.scadresearch.org

SCAD Alliance ( USA) : www.scadalliance.org

VanSCAD Facebook page (Canada) : www.facebook.com/canscad/

Clinic info pages :

SCAD info from Ottawa Heart : www.ottawaheart.ca/heart-condition/spontaneous-coronary-artery-dissection

SCAD Cleveland clinic page
https://my.clevelandclinic.org/health/diseases/17503-spontaneous-coronary-artery-dissection-scad

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