Review Spotlights SCAD Diagnosis and Treatment

Caring for patients with spontaneous coronary artery dissection (SCAD), which differs in important ways from obstructive coronary artery disease, involves a host of medical issues that may linger long after the MI and require vigilant surveillance to avoid recurrence and ensure optimal quality of life, a new review emphasizes.

Esther Kim, MD (Vanderbilt University, Nashville, TN), who authored the review on SCAD published last week in the New England Journal of Medicine, said awareness has increased sharply in recent years.

“There are now groups around the world working on the genetics of SCAD and its related disorders, and more and more cardiologists are aware of this disorder because it's being discussed at national conferences, and we’ve seen publications from several registries,” she said.

Kim, who co-authored the American Heart Association’s 2018 scientific statement on SCAD, notes in the review paper that disproportionately more women are affected—primarily between the ages of 47 and 53—and that the condition accounts for less than < 1% of all acute MIs.

“It's probably underrecognized,” she told TCTMD. “I think that once people start paying closer attention to the angiographic findings, that they will start diagnosing it more.” She also encourages clinicians to have a healthy level of suspicion.

We should have nonatherosclerotic causes on our radar. Esther Kim

“It's human nature to try to always make everyone fit into the categories that we have developed already, but when you have a young, middle-aged woman who doesn't have other cardiac risk factors and who presents with a myocardial infarction, we shouldn't try to pin her with atherosclerotic coronary artery disease as a diagnosis,” Kim said. “We should have nonatherosclerotic causes on our radar.”

Since many patients have never even heard of SCAD, Kim said she often shows them an illustration—included in the review—that she keeps on her phone that shows tears in the layers of the epicardial coronary artery wall that result in the creation of either a false lumen or intramural hematoma.

“I don't like to use the word fragility, but I do tell patients that there is there is a weakness in the artery that predisposed you to have a bruise or a tear in the artery wall. When I show them the picture, most people understand very well,” she added.

Treatment and Follow-up Considerations

The review emphasizes the importance of imaging, specifically that patients with suspected SCAD as a cause of MI should undergo coronary angiography, both to confirm the diagnosis and to look for high-risk anatomy that might warrant consideration for early revascularization.

“SCAD really can be the first presentation of an underlying systemic vascular disorder. And so, as the consensus statements say, if a woman is diagnosed with SCAD, if you suspect that a woman has had a heart attack because of SCAD, she really should undergo some type of extra coronary imaging to look for a vascular disorder that led to it,” Kim said. “We [also] want to catch any asymptomatic aneurysms that would need surveillance and attention down the line.”

While revascularization is appropriate in some patients, the decision is complex and for many the most appropriate management strategy is likely to be medication, Kim notes in her review. Medical therapy may be needed to manage chronic chest pain as well as to prevent recurrence of SCAD by managing hypertension, fibromuscular dysplasia, and migraine headaches. It also may be necessary for some patients who become depressed, anxious, or develop posttraumatic stress disorder.

Kim said she considers it important to see her SCAD patients fairly frequently for follow-up.

“What my experience and the experience of others have shown me is that these patients have a lot of angina even after they've developed what looks like angiographic healing,” she said. “They may be developing some endothelial dysfunction or there might be some psychosocial factors that are causing atypical chest pain. There may be SCAD lesions that haven't healed all the way; maybe there's a flap that is as healed as it's going to get, but it's still causing a stenosis that may need revascularization down the line.”

Even patients who had their blood pressure under control may still be at risk, she added.

“I see them back to make sure that they're not developing blood pressures that need to be addressed, because so many of them gain weight and become depressed after SCAD that their blood pressure starts creeping up because of the weight gain,” Kim explained. She added that while many patients are concerned about recurrence, it’s important to reassure them that recurrence rates are fairly low at 15% over 5 years and that this shouldn’t stop them from living their lives.