What is SCAD?

Spontaneous Coronary Artery Dissection (SCAD) is an uncommon heart condition that can’t be predicted or prevented – yet.

A bruise or tear develops in the wall of a coronary (heart) artery, creating a 'false lumen', which compresses the artery (the true lumen) and prevents normal blood flow. This leads to a heart attack and occasionally heart failure or cardiac arrest which, rarely, can be fatal. 

The cause of false lumen formation is unclear but there are currently two theories for the mechanism:

• ‘Outside-in’: micro-vessels within the artery wall haemorrhage, creating a bruise (called an intramural haematoma), which causes vessel narrowing and sometimes ruptures to form a dissection flap. Growing evidence suggests this is the likely predominant or exclusive mechanism of SCAD.
• ‘Inside-out’: a tear develops in the artery wall forming a dissection flap that interferes with blood supply.

Patients who have had a SCAD may be treated just with medication or need surgical intervention, such as stents or even bypass surgery.

SCAD has been reported across a wide age range (18-84 years) but the majority of cases are in young- to middle-aged women with an average age of 50. Around 10% of patients have their SCADs around the time of pregnancy, with 21-27% of heart attacks in pregnancy and 50% of post-partum coronary events reportedly due to SCAD. For more about P-SCAD, have a look at these videos.

Around 10% of patients are male and, because SCAD patients are predominantly female and it's thought there is a hormonal association, this is an area of interest to researchers as men don't go through the hormonal fluctuations women do, so may provide clues about what causes SCAD.

SCAD patients have few or none of the traditional risk factors associated with heart disease (atherosclerosis). More research is needed to understand why fit, healthy people have SCADs.

Most patients find that being diagnosed with SCAD is a shock as it comes out of the blue. You may be worried and scared and doubtless have many questions. If you are a new patient, a good place to start is the Recovery section and the SCAD Information Pack. 

SCAD can have an impact on your emotional wellbeing, but there is help and support, including our Buddy Service, where you can talk to another patient who can help you navigate your post-SCAD journey. You are not alone!