Spontaneous coronary artery dissection (SCAD) is predominantly a condition that occurs in middle-aged females and is often under-diagnosed, an expert has told the CSANZ ASM.
Speaking at the Women In Cardiology session Dr Jacqueline Saw, an Interventional Cardiologist at Vancouver General Hospital, Canada, told the audience that since SCAD was first reported in 1931 there had been less than 2,000 cases reported in the literature.
“It remains a poorly understood condition and is underdiagnosed… the actual estimate of what the incidence of SCAD is is about 0.2 to 4% of ACS coronary angiograms,” she told the audience.
In a recent paper published by Dr Saw and colleagues, 90% of SCAD patients were women and the average age at presentation was between 45 to 55 but other research had also reported the condition in both younger and older women.
“The spread of age is really a bell curve so I always tell people that for any woman coming in with a heart attack you should think about SCAD… it’s really a young to middle-aged disease,” she said.
Dr Saw explained that SCAD was typically caused by an underlying arteriopathy that causes the architecture of the arterial wall to be weak in the first place, together with a precipitating stressor that increased circulatory stress.
One of the most important predisposing conditions was fibromuscular dysplasia, followed by aneurysms or tears. Other risk factors included five or more pregnancies, being peripartum, fertility treatment, systemic inflammatory conditions, and connective tissue disorders.
Emotional stress also had a role to play, said Dr Saw, citing results from the Canadian SCAD Study in which about half of the patients reported emotional stress prior to the event, and 30% reported physical stress (in 10% this was lifting more than 23 kg).
US and European guidelines recommended conservative therapy as the preferred therapy but how SCAD was treated depended on how patients presented, Dr Saw said.
“This is because in most patients when they present their pain is already resolved …if you look at the natural history of SCAD the arteries tend to heal on their own,” she said.
Most patients could be managed medically post-SCAD, with treatment typically entailing aspirin and beta-blockers.
“Long term, in our retrospective analysis, beta-blockers were the only agent that reduced the recurrent risk of SCAD by about two-thirds,” she told the audience.
Other recommended agents included ACE inhibitors if there was LV dysfunction, statins if the patient had pre-existing dyslipidemia and nitrates if there was recurrent chest pain or vasospasm.
Dr Saw added that while most patients could be managed medically there was a small proportion with high-risk characteristics such as active ischaemia or hemodynamic instability where PCI or CABG should be considered.
She cautioned that patients with SCAD needed to be carefully monitored as research had shown that their mortality rate was about double that of other women without SCAD.
“It’s not a benign condition. Just because you’re treating a patient conservatively it doesn’t mean you can discharge the patient home right after the coronary angiogram, which happens a lot. You need to monitor them in the hospital for three to five days which is what we recommend in the guidelines,” she advised.
In the long term, there were also strategies to prevent the risk of recurrent SCAD, which occurred in about 15 to 25 percent of cases within five years.
These included the use of beta-blockers to reduce arterial shear stress, making sure hypertension management was optimal and advising patients to reduce potential triggers such as emotional and physical stress.
Ideally, hormonal therapies, sympathomimetic drugs, intense coughing, retching, vomiting and bowel straining, and future pregnancies should also be avoided.