CardioNerds (Amit Goyal and Daniel Ambinder) join Dr. Phoo Pwint Nandar (former FIT Ambassador), Dr. Deep Shah (current FIT Ambassador), and Dr. Sugat Wagle from the Summa Health Cardiology Department for an afternoon at Cuyahoga National Valley Park. We discuss a case of a post-partum woman who presented with ventricular fibrillation arrest due to SCAD. She had ongoing advanced cardiac life support (ACLS) for nearly 60 minutes before obtaining return of spontaneous circulation. We discuss the broad differential of VF arrest, including acute coronary syndrome and spontaneous coronary artery dissection (SCAD) – among many others. We also go over the etiology and management of SCAD as well the complications. Pregnancy is a crucial stressor to the cardiovascular system and understanding its hemodynamic changes is crucial to all physicians. The E-CPR segment is provided by Dr. Grace Ayafor, Interventional cardiology faculty, Summa Health.
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Episode Schematics & Teaching – SCAD
Pearls – SCAD
- SCAD remains underdiagnosed. It has a wide range of clinical presentations, including chest pain, ACS, VT/VF arrest, and cardiogenic shock.
- Underlying etiologies of SCAD include autoimmune diseases, connective tissue disorders, fibromuscular dysplasia, external stressors, and pregnancy.
- There are 3 types of SCAD, and coronary angiogram is the gold standard for diagnosis.
- Common areas of involvement of SCAD include left anterior descending and left circumflex arteries; however, SCAD can manifest in any coronary artery as well as simultaneously in multiple coronary arteries. Left main trunk involvement is rare, more likely to be associated with the peri-partum state, and requires complex management decisions guided by a heart team approach.
- Most SCAD cases are benign and treated conservatively, however, some require intervention (PCI or CABG) depending on clinical severity and course.
- Recurrent SCAD has been reported in 10-30% of the patients and aggressive management of hypertension is recommended.
- Guidelines regarding SCAD management are largely based on expert consensus due to a dearth of high-quality data. Efforts to raise awareness and study this syndrome are of paramount importance.
Notes – SCAD
1. What is SCAD and how does it present?
- Spontaneous coronary artery dissection (SCAD) is defined as an epicardial coronary dissection that is not associated with atherosclerosis or instrumentation.
- This occurs with hematoma formation within the tunica media, thereby potentially compressing the arterial true lumen leading to ischemia.
- There are two proposed mechanisms of hematoma formation: “inside-out” and “outside-in”. The inside-out hypothesis posits that the hematoma arises from the true lumen via a dissection flap – an endothelial-intimal disruption. Conversely the outside-in hypothesis posits that the hematoma arises de novo within the media through disruption of traversing microvessels.
- There is a wide range of clinical presentation for SCAD varying in severity including asymptomatic / benign presentation, anginal syndromes, acute myocardial infarction, VT/VF arrest, and cardiogenic shock. Our patient presented with VF arrest and ACS.
- SCAD epidemiology is confounded by a lack of awareness. A high index of suspicion is warranted. Diagnosis can be missed in young or mid-life without CV risk factors who would present with atypical/mild chest pain.
2. What are the etiologies of SCAD?
- SCAD is associated with the peripartum state (presumed due to combination of hormonal mediated vessel wall integrity changes and hemodynamic stressors), illicit substance use, autoimmune disorders, connective tissue disorders, fibromuscular dysplasia, and vigorous external stressors.
- Many patients recall extreme physical or emotional stress preceding the event. Men are more likely to present in the setting of a physical stressor whereas women are more likely to report an emotional stressor.
- Pregnancy-associated SCAD is most common in the first week after delivery like our patient.
- Genetic evaluation for connective tissue disorders and aortopathy syndromes (i.e., Marfan, Loeys-Dietz, and Ehlers-Danlos) should be considered.
- Arterial imaging to identify significant extracoronary vascular abnormalities is recommended since there is the association of SCAD with fibromuscular dysplasia.
3. What is the gold standard to diagnose SCAD?
- Coronary angiography performed by an experienced interventional cardiologist is the gold standard to diagnose SCAD. The left anterior descending artery is most commonly affected, and most cases of SCAD occur in the mid-distal arteries.
- There are 3 angiographic variants SCAD.
- Type 1 is with evident with the contrast dye staining the arterial wall with multiple radiolucent lumen.
- Type 2 (majority of the cases including the present case) is diffuse stenosis of varying severity with subtle abrupt changes in arterial caliber (long smooth narrowing).
- Type 3 mimics atherosclerosis and is often difficult to differentiate from it.
4. What is the management of SCAD in acute setting?
- Management of SCAD depends on clinical severity. Thrombolytics should be avoided. Most cases are benign and treated conservatively with work up for secondary causes. 95% of conservatively treated patients with mild SCAD such as minimal ongoing ischemia with preserve coronary flow will heal within 30 days. More severe cases of SCAD require intervention such as PCI or CABG. Surgical approaches are preferred in left main involvement, long segments, and with diffuse coronary artery involvement like in our case. Utilizing vein grafts is preferred as most SCAD cases heal with eventual graft closure. Off note, PCI in SCAD is associated with higher complication rates and suboptimal outcomes, including risk of iatrogenic dissection or propagation of hematoma.
5. What is the management of SCAD in pregnant patient?
- The management strategy of SCAD during pregnancy is similar to that in the nonpregnant state, with additional considerations to optimize maternal and fetal outcomes. After 20 weeks gestation, recommend left lateral recumbent positioning whenever possible to reduce aortocaval compression and optimize venous return. If necessary, consider maternal stabilization and optimization of cardiac status followed by planned delivery under controlled conditions. For more, enjoy Episode #167 – Cardiac Interventions During Pregnancy with Dr. Michael Luna.
5. What is the prognosis of SCAD and long-term management?
- Recurrent SCAD has been reported in 10-30% of patients. Post-SCAD chest pain is common and may persist for many months. Due to iatrogenic risk from invasive angiography, serial electrocardiography and biomarker assessment, and noninvasive cardiac computed tomography angiography should be considered. Standard heart failure medications are indicated for left ventricular dysfunction, and hypertension should be treated.
6. How to prevent recurrent SCAD?
- The factors associated with recurrence remain poorly understood. After SCAD, further pregnancy should perhaps be discouraged and contraception should be discussed. Women who strongly desire pregnancy should receive thorough preconception counseling.
- Macaya, F., Salinas, P., Gonzalo, N., Fernández-Ortiz, A., Macaya, C., & Escaned, J. (2018). Spontaneous coronary artery dissection: contemporary aspects of diagnosis and patient management. Open Heart, 5(2), e000884.
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- McGrath-Cadell, L., McKenzie, P., Emmanuel, S., Muller, D. W. M., Graham, R. M., & Holloway, C. J. (2016). Outcomes of patients with spontaneous coronary artery dissection. Open Heart, 3(2), e000491.
- Alonso-Fernández-Gatta, M., Uribarri, A., Diego-Nieto, A., & Sánchez, P. L. (2017). Progressive spontaneous coronary artery dissection secondary to fibromuscular dysplasia requiring mechanical circulatory support. Journal of Cardiology Cases, 16(6), 216–218.
- Cepas-Guillén, P. L., Flores-Umanzor, E. J., Sabate, M., & Masotti, M. (2019). Multivessel spontaneous coronary artery dissection involving the left main coronary artery: a case report. European Heart Journal – Case Reports, 3(1).
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- Hayes SN, Tweet MS, Adlam D, et al. Spontaneous Coronary Artery Dissection: JACC State-of-the-Art Review. J Am Coll Cardiol 2020;76:961-984.