Spontaneous coronary artery dissection overview
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Spontaneous Coronary Artery Dissection Microchapters |
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Differentiating Spontaneous coronary artery dissection from other Diseases |
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Diagnosis |
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Treatment |
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Case Studies |
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Type 1 Type 2A Type 2B Type 3 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Nate Michalak, B.A. Arzu Kalayci, M.D. [2]
Synonyms and keywords: SCAD
Overview
Spontaneous coronary artery dissection (SCAD) is a rare but under recognized cause of acute coronary syndrome and sudden cardiac death, which predominantly affects young, healthy women with few or no traditional cardiovascular risk factors.Spontaneous coronary artery dissection (SCAD) was first described by Pretty in 1931 in which a 42-year-old woman presented with nausea and chest pain died unexpectedly due to rupture of a dissecting atheromatous aneurysm in the right coronary artery following repetitive retching and vomiting. In the post-morterm examination, heart muscle and valve appeared normal, and there was extensive hemorrhage between aorta and pulmonary artery secondary to coronary artery rupture presumably during the sudden and violent retching attack. Spontaneous coronary artery dissection can be classified based on angiographic appearance into type 1 (evident arterial wall stain with multiple radiolucent lumens), type 2 (diffuse smooth stenosis of varying severity), and type 3 lesions (focal or tubular stenosis mimicking atherosclerosis). At present, the pathophysiology of non-atherosclerotic spontaneous coronary artery dissection (NA-SCAD) continues to be poorly understood due to the rarity of this condition and its heterogeneous pathology. Although intimal tear or bleeding of vasa vasorum with intermedial hemorrhage seems to be the most probable reason, the exact underlying mechanism is still unknown.The exact etiology of spontaneous coronary artery dissection remains elusive; however, fibromuscular dysplasia and takotsubo cardiomyopathy have been considered as the potential cause of spontaneous coronary artery dissection. The underlying causes associated with SCAD include emotional stress, physical stress such as extreme valsalva maneuver, retching, vomiting, coughing, isometric exercise, history of using stimulant medications or illicit drugs, pregnancy, systemic lupus erythematosus, sarcoidosis, inflammatory bowel disease, celiac disease, vascular Ehlers–Danlos syndrome, Marfan’s syndrome, Loeys–Dietz syndrome. Spontaneous coronary artery dissection should be differentiated from other causes of acute coronary syndrome. Features suggestive of spontaneous coronary artery dissection include myocardial infarction in young women (age ≤50), absence of traditional cardiovascular risk factors, little or no evidence of coronary atherosclerosis, peripartum state, history of fibromuscular dysplasia, and history of connective tissue disorder or systemic inflammatory disorder.The annual incidence of spontaneous coronary artery dissection is estimated at 0.26 per 100,000 persons (0.33 in women and 0.18 in men), corresponding to approximately 800 new cases per year in the United States. The true prevalence of spontaneous coronary artery dissection in the general population remains unknown; however, retrospective angiographic registries have reported a SCAD detection rate of 0.1 to 1.1% among all coronary angiograms performed.The risk factors for spontaneous coronary artery dissection include predisposing factors ( vasculopathy, pregnancy, connective tissue disorder, systemic inflammation) and precipitating stressors (e.g., strenuous exercise, emotional stress, recreational drugs).Features that raise the index of suspicion for SCAD include myocardial infarction in young women (age ≤50), absence of traditional cardiovascular risk factors, little or no evidence of coronary atherosclerosis, peripartum state, history of fibromuscular dysplasia, history of connective tissue disorder or systemic inflammation. SCAD usually is the result of an underlying vascular or connective tissue disorders. In order to provide the best care to patients with SCAD, the scientific statement from the American Heart Association (AHA) recommended a detailed review of systems and personal and family history of SCAD-associated symptoms and conditions. In addition, AHA scientific statement recommended a complete vascular exam. Routine clinical or genetic screening of asymptomatic relatives of patients with SCAD is not recommended. However, genetic screening is recommended in first-degree family members of patients with SCAD in whom a monogenic vascular disease has been identified.The natural history of spontaneous coronary artery dissection has not been well characterized. Early reports based on post-mortem examinations after sudden cardiac death suggest a dismal prognosis. However, recent studies demonstrate that most patients survive initial hospitalization and have a favorable prognosis following clinical stabilization.
Historical Perspective
Spontaneous coronary artery dissection (SCAD) was first described by Pretty in 1931 in which a 42-year-old woman presented with nausea and chest pain died unexpectedly due to rupture of a dissecting atheromatous aneurysm in the right coronary artery following repetitive retching and vomiting. In the post-morterm examination, heart muscle and valve appeared normal, and there was extensive hemorrhage between aorta and pulmonary artery secondary to coronary artery rupture presumably during the sudden and violent retching attack.
Classification
Spontaneous coronary artery dissection can be classified based on angiographic appearance into type 1 (evident arterial wall stain with multiple radiolucent lumens), type 2 (diffuse smooth stenosis of varying severity), and type 3 lesions (focal or tubular stenosis mimicking atherosclerosis).
Pathophysiology
At present, the pathophysiology of non-atherosclerotic spontaneous coronary artery dissection (NA-SCAD) continues to be poorly understood due to the rarity of this condition and its heterogeneous pathology. Although intimal tear or bleeding of vasa vasorum with intermedial hemorrhage seems to be the most probable reason, the exact underlying mechanism is still unknown.
Causes
The exact etiology of spontaneous coronary artery dissection remains elusive; however, fibromuscular dysplasia and takotsubo cardiomyopathy have been considered as the potential cause of spontaneous coronary artery dissection. The underlying causes associated with SCAD include emotional stress, physical stress such as extreme valsalva maneuver, retching, vomiting, coughing, isometric exercise, history of using stimulant medications orillicit drugs, pregnancy, systemic lupus erythematosus, sarcoidosis, inflammatory bowel disease, celiac disease, vascular Ehlers–Danlos syndrome, Marfan’s syndrome, Loeys–Dietz syndrome.
Differentiating Spontaneous Coronary Artery Dissection from Other Conditions
Spontaneous coronary artery dissection should be differentiated from other causes of acute coronary syndrome. Features suggestive of spontaneous coronary artery dissection include myocardial infarction in young women (age ≤50), absence of traditional cardiovascular risk factors, little or no evidence of coronary atherosclerosis, peripartum state, history of fibromuscular dysplasia, and history of connective tissue disorder or systemic inflammatory disorder.
Epidemiology and Demographics
The annual incidence of spontaneous coronary artery dissection is estimated at 0.26 per 100,000 persons (0.33 in women and 0.18 in men), corresponding to approximately 800 new cases per year in the United States. The true prevalence of spontaneous coronary artery dissection in the general population remains unknown; however, retrospective angiographic registries have reported a SCAD detection rate of 0.1 to 1.1% among all coronary angiograms performed.
Risk Factors
The risk factors for spontaneous coronary artery dissection include predisposing factors ( vasculopathy, pregnancy, connective tissue disorder, systemic inflammation) and precipitating stressors (e.g., strenuous exercise, emotional stress, recreational drugs).Features that raise the index of suspicion for SCAD include myocardial infarction in young women (age ≤50), absence of traditional cardiovascular risk factors, little or no evidence of coronary atherosclerosis, peripartum state, history of fibromuscular dysplasia, history of connective tissue disorder or systemic inflammation.
Screening
SCAD usually is the result of an underlying vascular or connective tissue disorders. In order to provide the best care to patients with SCAD, the scientific statement from the American Heart Association (AHA) recommended a detailed review of systems and personal and family history of SCAD-associated symptoms and conditions. In addition, AHA scientific statement recommended a complete vascular exam. Routine clinical or genetic screening of asymptomatic relatives of patients with SCAD is not recommended. However, genetic screening is recommended in first-degree family members of patients with SCAD in whom a monogenic vascular disease has been identified.
Natural History, Complications and Prognosis
Based on the limited outcomes data, SCAD survivors typically have a good long-term prognosis; however, there is an increased risk for recurrent SCAD events as well as other major cardiovascular events.
Diagnosis
Heightened awareness along with advances in intracoronary imaging techniques have led to an increase in the number of SCAD cases reported antemortem.
History and Symptoms
The hallmark symptom of spontaneous coronary artery dissection (SCAD) is angina pectoris, similar to to other acute coronary syndromes, that may radiate to the jaw or left arm. SCAD should be suspected with these symptoms in relatively young women, especially those in postpartum status. However, many patients do not have typical risk factors of coronary artery disease. Patients are typically asymptomatic on follow up.
Physical Examination
Laboratory Findings
Electrocardiogram
Electrocardiogram findings vary according to the coronary flow-limitation by the dissection flap or intramural haematoma. There can be no changes in ECG in some cases. In other cases ecg may show any of changes.
Angiography
CT
MRI
Echocardiography
Other Imaging Findings
Other Diagnostic Studies
Treatment
In the majority of cases, conservative medical management is the optimal treatment strategy; however, based on the patient's clinical status and anatomy of the coronary dissection, revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) may be warranted.
Medical Therapy
There are no specific guidelines regarding the optimal management of spontaneous coronary artery dissection. Based on the clinical and angiographic scenario, treatment options include conservative medical regimens similar to that for acute coronary syndrome, percutaneous coronary intervention, and/or coronary artery bypass surgery.
Percutaneous Coronary Intervention
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Future studies are needed to further elucidate the underlying pathophysiology of this complex disorder as well as to gain a better understanding of the optimal treatment strategies and long-term outcomes of this unique patient population.