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A 36-year-old healthy gravida 3, para 3 woman with a history of asthma and elective cesarean delivery 11 days prior presented to the emergency department with 3 days of exertional chest pain. The pain was described as crushing and substernal, but she denied radiation or associated dyspnea, nausea, vomiting, or diaphoresis. On physical examination, her blood pressure was 167/105 mm Hg bilaterally, heart rate was 71/min, respiratory rate 18/min, and oxygen saturation 98% on room air. Initial laboratory evaluation revealed a troponin I level of 0.12 ng/mL (reference range, 0.00-0.04 ng/mL). An electrocardiogram showed normal sinus rhythm with diffuse ST-segment depressions but without q waves or ST-segment elevation (Figure, left). Computed tomography angiography did not show pulmonary embolism or aortic dissection. Echocardiography demonstrated a left ventricular ejection fraction of 53%, with apical akinesis and no valvular disease.
Clinical findings from 12-lead electrocardiography (left) and right anterior oblique cranial angiography of the left anterior descending artery during diastole (right).
The patient was started on aspirin and ticagrelor, heparin infusion, and metoprolol tartrate for treatment of non–ST-segment elevation myocardial infarction. She underwent coronary angiography (Figure, right; Video).
Administer thrombolytic therapy
Continue medical therapy alone, with a β-blocker and antiplatelet therapy
Perform percutaneous coronary intervention (PCI)
Refer for coronary artery bypass graft (CABG) surgery
Spontaneous coronary artery dissection (SCAD)
B. Continue medical therapy alone, with a β-blocker and antiplatelet therapy
The keys to the correct diagnosis are the epidemiology and unique angiographic characteristics of SCAD. Expert consensus recommends medical therapy for this condition. Thrombolysis carries risk of propagation, as does mechanical revascularization with PCI or CABG surgery; these interventions are thus reserved for select patients.
SCAD is increasingly recognized as an etiology of acute coronary syndrome (ACS). The prevalence of SCAD in ACS is estimated to be between 1% and 4% but may be underrecognized and underdiagnosed.1 Women account for more than 90% of cases,2 and the prevalence has been reported to be as high as 35% in women younger than 50 years with ACS.1 Conditions that adversely affect vessel wall integrity or increase shear stress are thought to increase the risk of dissection.3 Fibromuscular dysplasia is present in 25% to 86% of patients in cohort studies.1 Pregnancy, including multiparity, is another important risk factor, with most cases occurring within 4 weeks of delivery.1
In atherosclerotic coronary artery disease, plaque rupture or erosion initiates the intravascular thrombotic cascade, causing ischemia. The pathophysiology of SCAD is less well defined. One hypothesis is that hematoma within the coronary artery wall initiates the dissection.4 Intramural hematoma may form through a tear in the intima or by spontaneous bleeding from the vasa vasorum.5 The true coronary lumen is compressed, and thrombus formation may also occur. Ultimately, this leads to myocardial ischemia or infarction.1
The clinical presentation of SCAD is often indistinguishable from that of atherosclerotic ACS. Patients report chest pain and may have ischemic electrocardiographic abnormalities or elevated levels of cardiac biomarkers. Rarely, patients with SCAD present with ventricular arrhythmias or sudden cardiac death.6 ACS, whether atherosclerotic or due to SCAD, often warrants coronary angiography. SCAD can have 1 of 3 angiographic appearances. Type 1 indicates multiple visible lumens, with contrast staining of the arterial wall; type 2, diffuse stenosis and an abrupt change in artery caliber at either end of that stenosis; and type 3, focal or tubular stenosis that mimics artherosclerosis.7 Type 1 is pathognomonic for SCAD, type 2 most common, and type 3 most deceiving. The lesion in this case is most consistent with type 2 SCAD. A high index of suspicion is necessary to distinguish SCAD from atherosclerotic coronary artery disease or vasospasm.
Treatment recommendations for SCAD are primarily based on expert consensus. β-blockers are widely recommended for acute and long-term management of SCAD, because they decrease coronary artery wall stress and myocardial oxygen demand.1 A prospective cohort study demonstrated a significant decrease in recurrence of SCAD in patients treated with β-blockers.6 Antiplatelet therapy, whether single- or dual-agent, is reasonable given the known benefits of aspirin in other forms of ACS.8 Statin therapy is appropriate for patients when indicated for primary prevention of atherosclerotic cardiovascular disease.1
Revascularization can be technically difficult or hazardous and should be reserved for patients for whom intensive medical therapy has failed or for those who have high-risk clinical features (eg, left main coronary artery involvement, persistent ischemia, ventricular arrhythmias, or shock). PCI is technically difficult because of the potential of entering the false lumen with the guidewire and carries risk of extending the dissection proximally or distally.8 CABG surgery has been performed successfully, but data are limited to case reports and small series. There may be a high incidence of graft failure, and CABG surgery is not protective for recurrent SCAD. Thus, CABG surgery should be reserved for patients with multiple or proximal dissections, those with left main coronary artery disease not amenable to PCI, or those for whom PCI has failed.1 Thrombolytic therapy should be avoided because of the risk of worsening coronary artery intramural hematoma.9
In a recent study of 310 patients, the rate of de novo SCAD recurrence was 11%, with a median time to recurrence of 4 years.10 Vessel tortuosity is the only risk factor identified for recurrence.1 Follow-up is generally clinically driven; repeat imaging may be useful if patients have recurrent symptoms or other evidence of recurrent ischemia.
The patient was prescribed metoprolol succinate, aspirin, and clopidogrel. Her chest pain resolved, and her troponin I level peaked at 1.25 ng/mL. At 4-month follow-up, an echocardiogram showed resolution of the apical wall motion abnormality. She remained active and asymptomatic at 9-month follow-up.
Corresponding Author: Keith H. Benzuly, MD, Bluhm Cardiovascular Institute, Northwestern University Feinberg School of Medicine, 251 E Huron St, Feinberg Pavilion, Ste 8-503, Chicago, IL 60611 (email@example.com).
Published Online: November 19, 2018. doi:10.1001/jama.2018.17045
Conflict of Interest Disclosures: None reported.
Additional Contributions: We thank the patient for providing permission to share her information.
Youmans QR, Unger ED, Benzuly KH. A Young Woman With Chest Pain. JAMA. Published online November 19, 2018. doi:10.1001/jama.2018.17045
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