SCAD: Spontaneous Coronary Artery Dissection, the Heart Attack That Doesn't Look Like One

A 38-year-old runner finishes a hard workout, gets into her car, and feels a crushing pressure in the center of her chest. She has no risk factors. She doesn't smoke. Her cholesterol panel from her last physical was excellent. She isn't overweight, doesn't have diabetes, and has no family history of early heart disease. She drives herself to the emergency room because she's not sure if she's overreacting. Her troponin comes back markedly elevated. Her EKG shows ST changes consistent with a heart attack. She gets taken urgently to the cath lab, expecting the cardiologist to find a blocked plaque and place a stent. What he finds instead is a long, smoothly tapered narrowing in her left anterior descending coronary artery, with no calcium and no plaque. The diagnosis: spontaneous coronary artery dissection.

I'm Dr. Damian Rasch, a cardiologist in Encinitas. SCAD is one of the most under-recognized causes of heart attack, especially in younger women, and the way it's managed is meaningfully different from a classic atherosclerotic heart attack. This article walks through what SCAD is, who tends to get it, how we diagnose it, why we usually do not stent it, and what life looks like after a SCAD event. The reason I write about this is that patients are often discharged with a SCAD diagnosis they barely understand, on a medication regimen that should be matched to their specific case, and without anyone explaining why their heart attack didn't fit the picture they thought they knew.

What SCAD Actually Is

In a typical heart attack, an atherosclerotic plaque ruptures and a clot forms on top of it, blocking the artery from outside in. The vessel wall is intact; the obstruction is inside the lumen. SCAD is the opposite. The vessel wall itself develops a tear, blood seeps into the layers of the wall, and a hematoma forms within the wall and compresses the lumen from outside in. The lumen narrows or closes off, the heart muscle downstream loses its blood supply, and the patient has a heart attack. But it's a heart attack caused by a structural injury to the artery, not by atherosclerotic plaque biology.

There are different morphologic types described in the literature. Type 1 SCAD shows multiple radiolucent lumens or contrast staining of the vessel wall on angiogram, which is the most obviously dissecting picture. Type 2 SCAD shows a long, smooth, diffuse narrowing of the vessel, which is the most common appearance and the easiest to miss because it can look like vasospasm or even a normal-looking vessel that's slightly underfilled. Type 3 SCAD shows a focal stenosis that mimics atherosclerosis. Type 4 is a complete occlusion of a distal vessel without any obvious plaque, often only suspected because the patient doesn't fit a classic atherosclerotic profile.

Knowing the type matters because the treatment decisions depend on it. Type 1 lesions are usually unmistakable. Type 2 and 3 lesions can be confused with atherosclerosis or spasm, and getting the diagnosis right is the difference between a conservative management plan and an aggressive stenting plan that can make things worse.

Who Gets SCAD

The classic SCAD patient is a woman between roughly thirty and sixty, often without traditional cardiovascular risk factors. Roughly ninety percent of SCAD events occur in women, and the median age in published series is around fifty. About a third of all heart attacks in women under fifty are caused by SCAD rather than by atherosclerosis. That single statistic should change how we approach a younger woman with chest pain.

Several conditions cluster with SCAD. Fibromuscular dysplasia, an arteriopathy that causes beading and tortuosity in arteries, is found in roughly half of SCAD patients when they are properly screened. Pregnancy and the postpartum period are well-recognized triggers; the highest-risk window is the first month after delivery, when hormonal shifts and hemodynamic changes seem to combine to make the arterial wall vulnerable. Connective tissue disorders like Ehlers-Danlos and Marfan syndrome predispose to SCAD, although they account for only a small fraction of cases. Systemic inflammatory conditions, including lupus and giant cell arteritis, can be associated. And intense emotional stress or extreme physical exertion sometimes precedes the event by hours.

There's a smaller group of male SCAD patients who tend to be older and to have intense isometric activity, like heavy weightlifting, as a precipitant. These patients also benefit from screening for fibromuscular dysplasia, even though the condition is less commonly identified in men.

When I see a younger woman with chest pain, especially one without traditional risk factors, SCAD is high on my differential before the angiogram even happens. The history, the demographics, the absence of classic atherosclerotic risk factors, and the way the symptoms came on all push me toward considering SCAD. The angiogram either confirms or refines the diagnosis.

Recognizing the Symptoms

The chest pain of SCAD often feels different from classic anginal chest pain in subtle ways, although there's overlap. Patients describe a sudden, sharp or pressure-like pain that radiates to the left arm, shoulder, jaw, or back. Some patients describe it as a tearing sensation, similar to the way aortic dissection patients describe their pain, although less dramatic in most cases. Shortness of breath is common. Nausea and vomiting can accompany it. Some patients have a brief loss of consciousness if the dissection compromises blood flow severely enough.

The trigger story is sometimes informative. A SCAD event that follows intense emotional stress or a major argument is a recognizable pattern. So is one that follows extreme exertion, like a heavy gym session or a difficult delivery. So is one that comes a few weeks postpartum, often during something as mundane as bending over to pick up a baby. The trigger isn't always there, but when it is, it points away from atherosclerotic biology.

The thing I worry about, and the reason I push for low-threshold evaluation, is that younger patients with chest pain are sometimes not taken seriously enough. A 35-year-old woman with chest pain has a much higher pretest probability of SCAD than of atherosclerotic disease, but she's also often the one who gets sent home from the urgent care with a diagnosis of "anxiety" or "musculoskeletal pain." If the troponin is elevated, the EKG has changes, or the symptoms are persistent and severe, the patient deserves the same workup we'd give anyone with possible cardiac symptoms.

How SCAD Gets Diagnosed

The diagnostic test for SCAD is coronary angiography, but it's important to note that not every angiographer recognizes SCAD on first look. Subtle lesions, especially Type 2 morphology, can be misread as spasm, normal variants, or atherosclerosis with a focal narrowing. Centers that see a lot of SCAD have developed an eye for it, and they tend to use intracoronary imaging more readily.

Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) are the imaging modalities that help confirm the diagnosis when the angiogram is ambiguous. OCT can directly visualize the false lumen, the intramural hematoma, and the intimal flap that defines SCAD. The catch is that passing an imaging catheter through a freshly dissected vessel can extend the dissection. So the decision to do intracoronary imaging is balanced against the risk, and many centers reserve it for cases where the diagnosis would change management.

Coronary computed tomography angiography (CCTA) is a less invasive option for some patients, although the resolution is lower than invasive angiography and subtle SCAD lesions can be missed. CCTA is more useful for follow-up imaging in patients who have already had a SCAD diagnosis confirmed invasively, where we want to track healing without putting another catheter into a previously injured vessel.

Once SCAD is identified, the workup expands to look for associated conditions. Imaging of the carotid, vertebral, renal, and iliac arteries with CT or MR angiography looks for fibromuscular dysplasia. A pregnancy and obstetric history is taken in detail. A connective tissue disease evaluation is appropriate when there are clinical clues like skin elasticity changes, joint hypermobility, or skeletal features that suggest Marfan or Ehlers-Danlos. A drug history covering stimulants, both prescription and recreational, is taken, since cocaine and amphetamines can also dissect coronaries.

Why We Usually Don't Stent

This is the single most important practical point about SCAD management, and the one most likely to be missed by clinicians who don't see SCAD often. In classic atherosclerotic heart attacks with a culprit lesion, a drug-eluting stent placed across the lesion saves heart muscle and reduces mortality. Stenting is the right move. In SCAD, stenting is often the wrong move.

The reason is mechanical. A SCAD lesion has a tear and a hematoma in the vessel wall. When you push a stent across that tear, you can extend the dissection in either direction, propagate the hematoma, and end up with a longer, more complicated lesion than the one you started with. Multiple registry analyses have shown higher complication rates with stenting in SCAD than with conservative management for stable patients. The DISCO registry and the Mayo Clinic SCAD program have both reported this consistently.

The default for SCAD is conservative management, meaning no stent, with close monitoring in a coronary care unit, optimized medical therapy, and serial imaging if needed. About seventy to eighty percent of SCAD lesions heal on their own with no intervention beyond medications. The vessel remodels, the hematoma resorbs, and the lumen reopens.

Stenting is reserved for specific situations: ongoing chest pain with hemodynamic instability, an obstructing dissection of the left main coronary artery, or refractory ischemia despite optimized medical therapy. When stenting is necessary, it's done carefully, often with longer stents that cover the entire dissected segment, sometimes with overlapping stents to ensure coverage. Bypass surgery is occasionally chosen for left main or three-vessel SCAD when stenting isn't feasible.

If you're a patient with a SCAD diagnosis and you were told a stent was placed, that doesn't mean a mistake was made. There are good reasons to stent in some cases. But if you weren't stented and you're wondering why, the answer is almost always that the conservative path is the safer one for SCAD biology, even though it sounds counterintuitive.

The Medication Regimen

Medical therapy for SCAD has evolved over the last decade as more data have accumulated. The current consensus regimen, codified in the 2018 American Heart Association scientific statement and updated through ongoing registry analyses, looks roughly like this.

A beta-blocker is the foundation of long-term therapy. Beta-blockers reduce wall stress on the healing vessel, which is thought to lower the risk of recurrence. Metoprolol succinate or carvedilol are common choices, dosed to target a resting heart rate of around sixty.

Aspirin is usually continued indefinitely after a SCAD event, although the evidence here is more debated than it is for atherosclerotic disease. Some experts argue that low-dose aspirin (81 mg) provides modest benefit; others note that the bleeding risk in young patients without atherosclerosis is non-trivial. Most patients leave the hospital on aspirin and continue it for at least a year, with the long-term decision made by the cardiologist based on individual factors.

Dual antiplatelet therapy (aspirin plus a P2Y12 inhibitor like clopidogrel) was historically given to all SCAD patients, but recent data have suggested that adding clopidogrel to aspirin in non-stented SCAD may not improve outcomes and may increase bleeding. Current practice in many high-volume centers is to use single antiplatelet therapy with aspirin alone for most non-stented SCAD patients. If a stent was placed, dual antiplatelet therapy is given for the standard duration after stenting.

Statins are not routinely added to SCAD regimens unless there's an independent indication, like elevated LDL or established atherosclerosis. SCAD is not an atherosclerotic disease, and treating it as one with high-intensity statin therapy doesn't address the underlying problem.

ACE inhibitors or ARBs are added when there's left ventricular dysfunction or hypertension. Tight blood pressure control is critical for everyone with SCAD, since blood pressure is a direct driver of arterial wall stress.

Recovery, Activity, and the Long View

The first three months after a SCAD event are the most fragile. The dissected vessel is healing, and the goal during this period is to minimize stress on the arterial wall. Most cardiologists recommend that patients avoid intense isometric exercise (heavy lifting, intense Valsalva maneuvers, anything that involves bracing and breath-holding) for at least three months, and often longer. Aerobic exercise at moderate intensity is usually allowed and even encouraged, but the threshold for what counts as "moderate" is set lower than usual during the healing phase.

Cardiac rehabilitation is recommended for nearly every SCAD patient. The structured environment, the gradual exercise progression, and the access to nursing and exercise physiology expertise all help patients rebuild confidence and physical capacity safely. Most cardiac rehab programs have experience with SCAD patients and can tailor the program to the slower, more conservative ramp-up that's appropriate for this population.

Pregnancy after SCAD is a special discussion. The risk of recurrent SCAD during a subsequent pregnancy is thought to be elevated, although the absolute risk numbers are still being refined. For women who want to have another pregnancy after SCAD, the conversation involves a maternal-fetal medicine specialist and a cardiologist with SCAD experience, with careful attention to blood pressure, hormonal management, and delivery planning. It's not a forbidden conversation, but it's not a casual one either.

Recurrent SCAD happens in roughly ten to thirty percent of patients over five to ten years of follow-up. The biggest predictors of recurrence are uncontrolled hypertension, ongoing fibromuscular dysplasia, and intense isometric exertion. Patients on optimized medical therapy with good blood pressure control and reasonable activity moderation have lower recurrence rates. Surveillance imaging, usually with CCTA, is sometimes used to monitor known FMD or to look for new lesions in patients with concerning symptoms.

When to Escalate Care

Call 911 immediately if you have severe chest pain at rest, especially if it's accompanied by shortness of breath, sweating, nausea, or fainting. Patients with a known SCAD history should treat any new chest pain as if it might be a recurrence until proven otherwise.

Contact your cardiologist the same day for new mild chest pain, new exertional shortness of breath, palpitations, or any concern that something has changed. Same-day evaluation is the right standard for SCAD survivors with new symptoms, because catching a recurrent dissection early changes the management options.

Schedule a clinic visit within one to two weeks if you have non-specific symptoms that don't fit clearly into either of the above categories but that you're worried about. The threshold for evaluation in SCAD survivors is appropriately low.

Common Patient Questions

I had a SCAD event. Did I do something wrong?

No. SCAD is not caused by lifestyle in the way atherosclerotic heart disease often is. You didn't eat your way to it or smoke your way to it or fail to exercise your way to it. There are some triggers (extreme exertion, intense emotional stress, the postpartum window) that are associated with SCAD events, but these are situational triggers in someone who was already vulnerable, not behaviors that caused the underlying problem. The vulnerability comes from the arterial wall biology, often related to fibromuscular dysplasia or hormonal factors. Patients who beat themselves up over what they "should have done differently" are usually beating themselves up unfairly.

Why didn't my doctors put in a stent?

Because in SCAD, stents tend to make the dissection worse rather than better. The mechanism of injury is a tear in the vessel wall with bleeding into the wall layers, and pushing a metal scaffold through that injury can extend the tear and propagate the hematoma. Multiple large registries have shown worse outcomes when stents are placed for SCAD compared to conservative management. The default is to manage SCAD medically, with stenting reserved for patients who are unstable or who have ongoing ischemia despite medical therapy. About seventy to eighty percent of SCAD lesions heal on their own with no intervention.

Can I exercise after SCAD?

Yes, with some adjustments. Aerobic exercise at moderate intensity (walking, swimming, easy cycling, light jogging) is encouraged and is part of cardiac rehabilitation. What gets restricted is intense isometric exercise, meaning anything that involves bracing, breath-holding, and high blood pressure spikes. Heavy weightlifting, especially the kind where you grunt and hold your breath while pushing a heavy load, is the canonical "avoid this" example. Yoga, light strength training with high reps and low weight, and most outdoor activities are usually fine. The exact restrictions get tailored over time as the vessel heals, often with input from cardiac rehab and an exercise physiologist.

Am I going to have another one?

The recurrence risk is real but not inevitable. Pooled data suggest about ten to thirty percent of SCAD patients have a recurrent event over five to ten years. The biggest predictor is uncontrolled blood pressure, which is also the most modifiable risk factor. Patients who keep their blood pressure tightly controlled, who stay on their beta-blocker, who avoid intense isometric exertion, and who don't have ongoing fibromuscular dysplasia activity have lower recurrence rates. Surveillance is part of the long-term plan, and the threshold for evaluating any new symptoms should be low.

Should my sisters or daughters get screened?

SCAD itself doesn't have a clear single-gene inheritance pattern, but fibromuscular dysplasia, which is associated with SCAD in roughly half of cases, does have familial clustering. There's also growing evidence of a genetic association between SCAD and certain rare genetic variants. The current recommendation is that first-degree relatives of patients with SCAD plus FMD should consider being screened for FMD, especially if they have any unexplained vascular symptoms (severe headaches that might suggest cervical artery involvement, hard-to-control hypertension that might suggest renal artery FMD). The screening is usually CT or MR angiography of the carotids, vertebrals, renals, and iliacs. Routine genetic testing for SCAD itself is not yet standard, but it's an active area of research.

What about birth control or hormone therapy?

This is a nuanced conversation. Estrogen-containing contraceptives are usually avoided after SCAD because of the suspected role of hormonal shifts in arterial vulnerability and because of the small but real cardiovascular risk profile of combined oral contraceptives. Progestin-only options (mini-pill, IUD, implant) are usually preferred. Hormone replacement therapy after menopause is a more individualized discussion, balancing menopausal symptom management against any theoretical cardiovascular risk in a patient with a known arterial vulnerability. There isn't a one-size-fits-all answer, and the decision usually involves a cardiologist, a primary care or gynecology specialist, and the patient.

Can I get pregnant after SCAD?

Yes, in many cases, but the conversation is involved. Pregnancy itself has some cardiovascular stress, and the postpartum period is a known SCAD trigger window. Patients who want to pursue pregnancy after SCAD should be co-managed by a high-risk obstetrician and a cardiologist with SCAD experience. Blood pressure management throughout pregnancy is critical. Delivery planning often involves a planned vaginal delivery with epidural analgesia (to avoid the blood pressure spikes of un-medicated labor) and avoiding prolonged Valsalva during pushing. Cesarean delivery isn't routinely required but is chosen in some cases. The risk of recurrent SCAD in a subsequent pregnancy is elevated but not prohibitive for most patients, and many SCAD survivors have gone on to have healthy pregnancies and deliveries.

Should I see a SCAD specialist?

If you have access to one, yes. SCAD is uncommon enough that not every cardiologist sees many cases, and the management nuances (when to stent, what medications, how to handle pregnancy planning, screening for FMD) benefit from the experience that comes from seeing a high volume of SCAD patients. Several academic centers in the United States have SCAD programs, including Mayo Clinic, Cleveland Clinic, and a growing number of women's heart centers. A one-time consultation with a SCAD specialist, with ongoing care managed by a local cardiologist who communicates with the specialist, is a reasonable model for many patients.

A Final Note From Me

SCAD lives at the intersection of cardiology, gender-specific medicine, and arterial wall biology, and it sits awkwardly in a healthcare system designed around classic atherosclerotic heart disease. Patients can fall through the cracks. Younger women presenting with chest pain are sometimes dismissed. Lesions on angiogram are sometimes misread. Stents are sometimes placed when they shouldn't be. Medications are sometimes given that don't match the underlying biology. The best outcomes happen when SCAD is recognized quickly, evaluated by someone with experience in the diagnosis, and managed conservatively whenever possible.

If you've been told you had a SCAD event, the most important things you can do are control your blood pressure tightly, take your beta-blocker reliably, ease back into activity at a measured pace, get screened for fibromuscular dysplasia, and identify a cardiologist who has seen SCAD before. Most SCAD patients do well over the long run. The first year is the most fragile, and the steps you take in that year shape the trajectory for the next decade. Patients who stay engaged with their care, who notice and report new symptoms early, and who do cardiac rehabilitation tend to come through the experience with their lives recognizable on the other side.

If you're a young woman with chest pain that doesn't fit a typical pattern, advocate for yourself. Ask whether SCAD is on the differential. Ask for a troponin if it hasn't been drawn. Ask for an EKG. The diagnosis can be missed, and the cost of missing it is real, but the cost of asking the question is small. The patients I worry about are the ones who didn't get worked up. The patients I'm hopeful about are the ones who got the right diagnosis quickly and who got into a thoughtful management plan.

References

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9. Tweet, Marysia S., Patricia J. M. Best, Sharonne N. Hayes, and Rajiv Gulati. "Pregnancy-Associated Spontaneous Coronary Artery Dissection: Insights from the Multicenter SCAD Registry." Journal of the American College of Cardiology 76, no. 24 (2020): 2810-2820.

10. Kim, Esther S. H., Heather L. Gornik, and Jeffrey W. Olin. "Fibromuscular Dysplasia and Spontaneous Coronary Artery Dissection: Connecting the Dots." Journal of the American College of Cardiology 76, no. 11 (2020): 1349-1351.

Published on damianrasch.com. The above information was composed by Dr. Damian Rasch, drawing on individual insight and bolstered by digital research and writing assistance. The information is for educational purposes only and does not constitute medical advice.