Congratulations to our winner with the most complete answer: Dan Zeccola! Julie and Nathan both correctly identified parts of the answer. Well done all!
Our patient was having a Spontaneous Coronary Artery Dissection (SCAD) in her mid-LAD.
To answer the questions:
- The EKG was concerning for Wellens’ Sign and in this clinical picture, for Wellens’ Syndrome.
- If you are concerned about Wellens’, you may guess these stents would be in the proximal LAD (or at least not much farther) and you would be right – she had two placed initially in the mid-LAD shortly after this EKG was taken with a 99% occlusion yet no plaques.
- This patient has a Spontaneous Coronary Artery Dissection. It presents so atypically that many patients who are diagnosed prior to autopsy call themselves “SCAD survivors.”
- Underlying conditions associated with SCAD include Fibromuscular dysplasia (which this patient had, with her flexibility), Ehlers-Danlos, pregnancy or post-partum, Autosomal Dominant Polycystic Kidney Disease, extreme physical exertion (more common in men) or emotional stress, hypertensive crisis, coronary vasospasm (from cocaine or otherwise), neurofibromatosis and systemic inflammatory conditions including SLE (which is prevalent in our population but this patient did not have).
Wellens’ carries a high risk of anterior wall MI from proximal LAD occlusion and death in days to weeks. Wellens’ can have either symmetric and deep T-wave inversions or biphasic T waves in 2 contiguous leads of V2-V4, is usually with negative or small troponin elevation and can persist when patient is pain-free. In our patient, she had biphasic T waves in V3-V4 and met the other criteria as well.
Wellens’ is not specifically associated with SCAD, but our patient happened to have EKG findings that were concerning. SCAD presents in a different patient than the more typical acute coronary syndrome caused by atherosclerotic plaque rupture. Patients range from teens to elderly, median age is 42, and 80% are female. The prevalence is now reported at 1-4% of all ACS. One should be extra suspect in the peri-partum period with 25% of women diagnosed with SCAD occurring after birth.
One proposed mechanism is from an intimal tear in the coronary artery, which then dissects along the outer tunica media, allowing blood to collect with further tearing. Eventually, a clot and flap of dissected intima will occlude the artery. While this is not an atherosclerotic plaque, the effect is the same with occlusion of the artery and STEMI or NSTEMI.
Patients may often be like our patient – no smoking, minimal HTN, no hyperlipidemia, no diabetes, no family risk factors. She was not obese, was active and fit, and had very subtle symptoms of discomfort and vague shortness of breath. She did had no plaques found on her cath, and in her later medical reports no plaques in her carotids. She did, however, have a 30% occlusion in one carotid that was read as a sequelae of the FMD, and places her at a higher risk of carotid dissection.
There is current debate whether immediate PCI is beneficial as it can propagate dissection so some experts advocate conservative medical management if there is preserved coronary flow with CCU monitoring for one week to monitor for progression. In several studies the success rate of PCI in SCAD patients is only 60-65% compared to 92% in atherosclerotic ACS.
Patients will often have recurrent nitrate-responsive angina after MI and they can be started on low-dose aspirin with or without statins. Without the typical risk factors of hyperlipidemia, there is no known benefit in these patients as opposed to atherosclerotic patients. Patients are targeted with specific medications to their conditions, such as anti-platelet therapy after stenting or an ACEi for LV dysfunction.
Recurrence is approximately 30% at 10 years and more common in women. Our patient had persistent, worsening angina after the first cath, was taken back to the cath lab one week later with a 3rd stent placed at the distal LAD. This was deemed an extension of the first dissection rather than a true native-vessel recurrence.
SCAD is different than our usual atherosclerotic ACS patients and represents a small but significant portion of women with chest pain. In post-partum patients, inflammatory condition patients (such as SLE) and in those with connective tissue disorders, SCAD should be added to your differential diagnosis.
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by Elizabeth Abram, MD and supervised by Jennifer Martindale, MD.