Spontaneous coronary artery dissection means heart attacks can hit fit people
Teri Thom spent most of the ’80s and ’90s as a competitive bodybuilder, travelling across the country and winning several championships. She’s been physically active ever since. So when the Surrey resident found out she had a heart attack caused by spontaneous coronary artery dissection (SCAD)—a tear in the lining of an artery—she was in shock. The experience shook her even more when her doctor told her that the condition is usually only detected during an autopsy.
Thom got the diagnosis two years ago after she got her son to drive her to the hospital because she’d been experiencing pain radiating up both her arms and across her chest. But she initially brushed it off as soreness from working out and a little indigestion—so she went to bed, only going to the emergency department the next day when the same discomfort came back. She has since learned that SCAD affects mostly fit, healthy, younger women who, like her, don’t have the typical risk factors associated with heart attacks.
“I remember thinking, ‘How could I possibly be having a heart attack?’ ” Thom recalls in a phone interview. “I had been a fitness buff most of my life…rode my bike for errands, and power-walked regularly. I didn’t eat red meat, smoke, or overindulge in treats or alcohol. I didn’t fit the profile.”
In fact, she wasn’t having the kind of heart attack normally associated with high cholesterol and a buildup of plaque in the arteries. And because that buildup is usually to blame for cardiovascular disease, many women like Thom end up being misdiagnosed, according to Jacqueline Saw, an interventional cardiologist at Vancouver General Hospital.
Saw, who is an associate professor at UBC’s faculty of medicine and who has become one of the country’s leading experts on SCAD, says that the condition is likely far more common than medical professionals or the public realize.
“Last April, I saw three young women in two weeks with coronary dissection, and it piqued my interest because it’s not as rare as it’s thought to be,” Saw says in a phone interview from VGH. “It almost always occurs in women who are healthy and active, who are not smokers, who don’t have type 2 diabetes or traditional cardiovascular risk factors.
“Now we have better tools to investigate minor abnormalities—special imaging techniques such as intravascular ultrasound—that allow us to look inside the arteries to see that narrowings are due to not cholesterol plaque but to tears in the artery wall. I have close to 70 female patients right now with tears.”
When a tear occurs, blood flows into the space between the layers of the artery. As the blood accumulates, it can cause obstruction of normal blood flow within the heart, leading to chest pain, heart attack, and even sudden death.
Saw has conducted research that has found that as many as 85 percent of women with arterial tears have fibromuscular dysplasia (FMD), a condition where there is abnormal growth of the lining of the arteries, which can cause narrowing, predisposing those patients to SCAD.
Although many SCAD cases go both undiagnosed and misdiagnosed, distinguishing between tears and coronary plaque is crucial when it comes to treatment. Those with FMD may need to take certain medication, such as beta blockers, or make specific lifestyle changes because the condition can affect other organs. It can lead to kidney problems and stroke, for instance.
To learn more, Saw is leading a study called the Prospective Registry of Young Women With Myocardial Infarction among women under age 55 whose heart attacks aren’t linked with typical cardiovascular risk factors. It’s just been launched at VGH, will soon also include patients from St. Paul’s Hospital, and will follow women for five years.
Plus, as a result of Saw’s findings, VGH has just started a Healthy Heart program specifically for SCAD patients.
“These women have a different functional capacity than other typical heart-attack patients,” Saw says. “They are very active and healthy and need their own kind of support.”
Thom can certainly relate. She did a Healthy Heart program in Surrey and says she felt out of place.
“At cardiac rehab, like other SCAD survivors, I didn’t fit in,” Thom says. “I would do laps around the other, older, less fit participants.”
Since her heart attack, Thom has reached a “new normal”. “I take medication and can’t push myself as hard as I used to,” she says. “I can still do everything, but I have to scale it back a notch. I can’t challenge myself with steep hills [while cycling]. But I live.”
She’s also found a community of SCAD survivors online. Because of growing public and medical interest in the condition, more research is being done into SCAD elsewhere. The Rochester, Minnesota, location of the Mayo Clinic is conducting two new studies into SCAD to identify patterns of incidence and causes of the condition in women and men.
Pregnancy also may be associated with SCAD, according to the Mayo Clinic, with some cases occurring during late pregnancy or shortly after birth. Pregnancy-related changes in blood vessels, sex hormones, and blood volume could lead to the tears.
According to the Heart and Stroke Foundation of B.C. & Yukon, the most common symptom of heart attack in both men and women is chest pain. Other signs include pain in the arm, throat, or jaw; sweating; and nausea. Cardiovascular disease (which includes stroke) is the leading cause of death in Canadian women.