Spontaneous coronary artery dissection overview: Difference between revisions

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__NOTOC__
__NOTOC__
{{Spontaneous coronary artery dissection}}
{{Spontaneous coronary artery dissection}}
{{CMG}} {{AE}}{{NRM}}
{{CMG}}; {{AE}} {{Sara.Zand}} {{NRM}} {{AKK}}


{{SK}} SCAD
{{SK}} SCAD


==Overview==
==Overview==
Spontaneous coronary artery dissection (SCAD) is a rare, but under recognized cause of [[acute coronary syndrome]] and [[sudden death|sudden cardiac death]],<ref name="pmid8665336">{{cite journal| author=Basso C, Morgagni GL, Thiene G| title=Spontaneous coronary artery dissection: a neglected cause of acute myocardial ischaemia and sudden death. | journal=Heart | year= 1996 | volume= 75 | issue= 5 | pages= 451-4 | pmid=8665336 | doi= | pmc=PMC484340 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8665336  }} </ref> which predominantly affects young, healthy women with few to no traditional cardiovascular risk factors. Heightened awareness along with advances in intracoronary imaging techniques have led to an increase in the number of SCAD cases reported antemortem. Multiple risk factors and precipitating stressors have been identified for SCAD, including [[fibromuscular dysplasia]] (FMD), connective tissue disorders, systemic inflammatory disorders, [[pregnancy]] and the peripartum state, hormonal therapy, and extreme physical exertion and/or emotional stress. 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. 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. 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.
[[Spontaneous coronary artery dissection]] ([[SCAD]]) is a rare but under recognized cause of [[acute coronary syndrome]] and [[sudden death|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]] [[atheroma|atheromatous]] [[aneurysm]] in the [[right coronary artery]] following repetitive [[retching]] and [[vomiting]]. In the [[autopsy|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 disease#Risk factors|cardiovascular risk factors]], little or no evidence of [[coronary atherosclerosis]], [[Peripartum|peripartum state]], history of [[fibromuscular dysplasia]], and history of [[connective tissue disorder]] or [[systemic inflammation|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., [[exercise|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 disease#Risk factors|cardiovascular risk factors]], little or no evidence of [[coronary atherosclerosis]], [[peripartum|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 [[autopsy|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.[[Coronary angiography]] is the standard for diagnosing [[spontaneous coronary artery dissection]].  Adjunctive [[imaging]] modalities such as [[intravascular ultrasonography]] ([[IVUS]]), [[optical coherence tomography]] ([[OCT]]), [[computed tomography angiography]] ([[CTA]]), and [[magnetic resonance angiography]] ([[MRA]]) may offer complementary details for establishing a definitive diagnosis.The hallmark [[symptom]] of [[spontaneous coronary artery dissection]] ([[SCAD]]) is [[angina pectoris]], similar to other [[acute coronary syndromes]], which may radiate to the [[jaw]] or [[left arm]]. [[SCAD]] should be suspected with these [[symptoms]] in relatively [[young]] [[women]], especially those in [[Postpartum|postpartum status]]. However, many [[patients]] do not have [[typical]] [[risk factors]] of [[coronary artery disease]]. Patients are typically [[asymptomatic]] on follow-up.Physical exam in [[SCAD]] may include [[tachycardia]], [[bradycardia]], [[hypertension]], [[hypotension]], [[rale]], [[syncope]] based on the the [[coronary arteries]] involvement and [[ventricular dysfunction]].Laboratory findings consistent with the [[diagnosis]] of [[spontaneous coronary artery dissection]] is similar to [[myocardial infarction]] as it most commonly presents with this manifestation. It includes elevated levels of [[troponin]] which may be absent in 27% of the [[patients]].[[Electrocardiogram]] findings vary according to the [[coronary]] [[flow-limitation]] by the [[dissection flap]] or [[intramural hematoma]]. There can be no changes in [[ECG]] in some cases. In other cases [[ECG]] may show any of changes.The current [[gold standard]] for diagnosing [[spontaneous coronary artery dissection ]] ([[SCAD]]) is [[coronary angiography]], as it is widely available and the first-line [[imaging]] modality for [[patients]] presenting with the [[acute coronary syndrome]].  The predominant [[angiographic]] feature of [[SCAD]] consists of diffuse smooth narrowing of varying severity involving mid-to-distal [[coronary]] segments, secondary to compression of the true [[lumen]] and/or expansion of the false [[lumen]] by the development of an intramural [[hematoma]]. The typical appearance of extraluminal contrast staining, multiple radiolucent [[lumens]], spiral [[dissection]], or [[intraluminal]] filling defects is less commonly observed. Other [[angiographic]] findings associated with [[SCAD]] include [[coronary tortuosity]], [[myocardial bridging]], and [[fibromuscular dysplasia|coronary fibromuscular dysplasia]].[[coronary]] [[computed tomography angiography]] maybe helpful in the diagnosis of [[spontaneous coronary artery dissection]]. Findings on [[coronary]] [[computed tomography angiography]] suggestive of [[spontaneous coronary artery dissection]] include abrupt luminal [[stenosis]] of the [[coronary]] lumen, [[intramural]] [[hematoma]],tapered [[luminal stenosis]], [[epicardial fat strand]], [[coronary tortuosity]], [[coronary bridging]], [[myocardial hypoperfusion]], [[regional wall motion abnormality]].[[Cardiac magnetic resonance]] ([[CMR]]) is a valuable tool for diagnosis of [[spontaneose coronary artery dissection]] ([[SCAD]]) in [[patients]] as follows:
[[pregnant]] women for avoiding  [[radiation]] of [[coronary angiography]], unclear evidence of [[acute coronary syndrome]] during [[coronary angiography]], differentiating of [[SCAD]] from [[myocarditis]], [[takotsubo cardiomyopathy]]. Findings of [[CMR]] associated with [[SCAD]] include evidence of [[myocardial infarction]] with subendocardial [[LGE]],[[microvascular obstruction]], [[ myocardial edema]].[[Echocardiography]] is helpful in the assessment of [[regional wall motion abnormalities]], [[chamber size]], and [[diastolic  function]] and monitoring of [[ventricular ]] recovery after [[SCAD]]. Contrast and [[strain echocardiography]] may be useful for evaluation of  underlying [[perfusion]] and [[myocardial dysfunction]] in [[SCAD]].When the [[diagnosis]] of spontaneous coronary artery dissection ([[SCAD]]) cannot be ascertained by the standard [[coronary angiography]], intracoronary [[imaging]] such as [[intravascular ultrasound]] ([[IVUS]]) or [[optical coherence tomography]] ([[OCT]]) may provide complementary information for establishing a definitive diagnosis.  [[Coronary]] [[computed tomography angiography]] (CCTA) may be useful for non-invasive follow-up of [[SCAD]] involving proximal or large-caliber [[coronary]] [[arteries]]. [[OCT]] findings suggestive of [[SCAD]] may include the presence of two [[lumen]]s and intramural [[hematoma]].Long-term treatment for [[spontaneous coronary artery dissection]] pursues several main goals including [[antianginal]] therapy, prevention of [[recurrence]], assessment, and management of extra [[coronary]] [[vascular]] abnormalities, and improvement of [[quality of life]]. Acute management of [[myocardial infarction]] in [[SCAD]] is [[medical therapy]] in approximately 80% of the [[patients]]. [[Myocardial infarction]] in the context of [[SCAD]] is different from the [[myocardial infarction]] in the context of [[atherosclerosis]] and therefore makes it unfavorable for [[revascularization]] approaches.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]]. In the majority of cases, [[SCAD]] may be managed successfully with [[medical treatment]] alone in the absence of ongoing [[myocardial ischemia]] or [[hemodynamic instability]].
Initial [[conservative]] management typically includes [[antithrombotic therapy]] with [[heparin]], [[aspirin]], [[clopidogrel]] and [[glycoprotein IIb/IIIa inhibitors]], and [[antiischemic]] therapy with [[beta blockers]] and [[nitrate]]s.  However, the use of [[antithrombotic]] therapy may increase the risk of [[bleeding]] in the [[false lumen]] causing an expansion of the [[intramural hematoma]], resulting in a decreased [[flow]] through the [[true lumen]].[[Fibrinolytic]]s should be avoided. [[Calcium channel blocker]]s may offer relief in [[coronary artery spasm]].Conservative management should be the first choice if emergent [[revascularization]] is not necessary. However, optimal [[management]] is in question due to insufficient [[clinical]] experience. There are some treatment options including conservative management, emergency revascularization ([[PCI]] or [[CABG]]), [[fibrinolytic]] therapy, [[mechanical hemodynamic support]], and even [[cardiac transplantation]] have been reported.The preference of the approach should be tailored to the patient’s clinical status.[[Coronary artery bypass graft]] ([[CABG]]) is an important [[reperfusion]] therapy in a selected group of [[SCAD]] [[ patients]] and also a rescue strategy in the management of failed [[PCI]].Indications for [[surgical revascularization]] include [[multivessel]] involvement, [[Left main coronary artery]] involvement, progression/worsening of [[dissection]], significant narrowing of the [[arterial]] lumen, refractory or recurrent [[myocardial ischemia]]. In the event of severe refractory [[heart failure]], [[heart transplantation]] may be considered. There is no established [[primary prevention]] measurement for [[spontaneous coronary artery dissection]].[[Secondary prevention]] strategies following [[spontaneous coronary artery dissection]] include avoidance of [[extreme isometric ]] or [[competitive]] [[physical exercise]] and also [[psychosocial support]].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.


==Historical Perspective==
==Historical Perspective==
*Historical perspective of a disease discusses the initial discovery of the disease, the major outbreaks/events associated with the disease, and the initial diagnostic and therapeutic discoveries related to the disease.
[[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]] [[atheroma|atheromatous]] [[aneurysm]] in the [[right coronary artery]] following repetitive [[retching]] and [[vomiting]]. In the [[autopsy|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.
*This section should contain the name of the disease you are describing in the first sentence.
*The overview of the historical perspective of a disease should be a short description of the landmark discoveries associated with the disease. It is ideally written after the main historical perspective microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview that is seen on the historical perspective microchapter.
*To view a template and examples of the Historical Perspective overview statement, click [[Historical perspective template#Overview|'''here''']].


==Classification==
==Classification==
*Classification of a disease varies based on the type of disease. For example, certain cancers may be classified based on stage and grade, whereas a drug allergy may be classified based on the type of drug reaction.
[[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]]). Type 4 [[SCAD]] [[lesion]] is characterized by [[dissection]] leading to an abrupt total [[occlusion]], usually of a distal [[coronary]] segment. The [[total occlusion]] occurs as a result of diminished true [[lumen]] due to external compression by [[intraluminal]] [[hematoma]] rather than [[embolism]]. The intermediate type 1/2 [[SCAD]] [[lesion]] is characterized by the appearance of type 1 in conjunction with type 2 [[lesion]].
* This section should contain the name of the disease you are describing in the first sentence.
 
* The overview of the classification of a disease should be a short description of the way in which the disease is classified. It is ideally written after the main classification microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview statement that is seen on the classification microchapter.
*To view a template and examples of the Classification overview statement, click [[Classification template#Overview|'''here''']].


==Pathophysiology==
==Pathophysiology==
*Pathophysiology is the study of the biological and physical manifestations of a disease as they correlate with the underlying abnormalities and physiological disturbances.
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. In a [[SCAD]] registry, a total of 5% to 8% of [[patients]] were carriers of [[genetic]] [[mutations]] for [[connective tissue disorders]]. [[SCAD]] may also be associated with a variety of disorders including but not limited to [[fibromuscular dysplasia]], [[Connective tissue disorders]], and [[autoimmune diseases]] such as [[systemic lupus erythematous]].  


* This section should contain the name of the disease you are describing in the first sentence.
* The overview of the pathophysiology of a disease should be a short description of the basic disease process. It is ideally written after the main pathophysiology microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview statement that is seen on the pathophysiology microchapter.
*To view a template and examples of the Pathophysiology overview statement, click [[Pathophysiology template#Overview|'''here''']].


==Causes==
==Causes==
* This section summarizes the main causes of the disease.
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]], and [[connective tissue disorders]].
* The overview for causes of a disease should ideally be written after the main causes microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview statement found on the main causes microchapter for the disease.
*To view a template and examples of the Causes (Non-microbiology) overview statement, click [[Crowdiagnosis project template#Overview|'''here''']].
*To view a template and examples of the Causes (Microbiology) overview statement, click [[Microbiology template#Overview|'''here''']].


==Differentiating (Disease name) from other Conditions==
==Differentiating Spontaneous Coronary Artery Dissection from Other Conditions==
* In this section, give a brief description of the main diseases that need to be differentiated from the disease you are describing.  
[[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 disease#Risk factors|cardiovascular risk factors]], little or no evidence of [[coronary atherosclerosis]], [[peripartum|peripartum state]], history of [[fibromuscular dysplasia]], and history of [[connective tissue disorder]] or [[systemic inflammation|systemic inflammatory disorder]].
*The overview of the differentiation of a disease should ideally be written after the main microchapter is written. It can be the same as the overview statement found on the main "differentiating disease from other conditions" microchapter for the disease.
*To view a template and examples of the Differential Diagnosis overview statement, click [[Differentiating (disease name) from other diseases page#Overview|'''here''']].


==Epidemiology and Demographics==
==Epidemiology and Demographics==
* Epidemiology is the scientific study of the causes, distribution, and control of disease populations. Demographics are the objective characteristics of a population age, marital status, family size, racial origin, present or prior disease, religion, income, and education and how they relate to a specific disease.
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 [[case fatality rate]] of [[SCAD]] is relatively low compared with other causes of [[ACS]], with an estimated in-hospital mortality rate of 0 to 4%. The average age at diagnosis of [[SCAD]] in [[females]] ranges from 44 to 53 years, although [[patients]] may present with [[SCAD]] in their second through ninth decades of life. [[SCAD]] has a strong predilection for young [[women]] with no or minimal traditional [[Cardiovascular disease#Risk factors|cardiovascular risk factors]]. It has been reported in all major [[racial]] and [[ethnic]] groups, with the majority of [[patients]] being [[white]].
* This section should contain the name of the disease you are describing in the first sentence.  
 
*The overview of the epidemiology and demographics of a disease should ideally be written after the main epidemiology and demographics microchapter is written. It can be the same as the overview statement found on the main epidemiology and demographics microchapter for the disease.
*To view a template and examples of the Epidemiology and Demographics overview statement, click [[Epidemiology and demographics template#Overview|'''here''']].


==Risk Factors==
==Risk Factors==
* Risk factors are variables associated with an increased risk of disease or infection.This section should outline the risk factors that have the highest correlation with the disease.
The [[risk factors]] for [[spontaneous coronary artery dissection]] include predisposing factors ( [[vasculopathy]], [[pregnancy]], [[connective tissue disorder]], [[systemic inflammation]]) and precipitating stressors (e.g., [[exercise|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 disease#Risk factors|cardiovascular risk factors]], little or no evidence of [[coronary atherosclerosis]], [[peripartum|peripartum state]], history of [[fibromuscular dysplasia]], history of [[connective tissue disorder]] or [[systemic inflammation]].
* The overview of the risk factors of a disease should ideally be written after the main risk factors microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview statement found on the main risk factors microchapter for the disease.
 
*To view a template and examples of the Risk Factors overview statement, click [[Risk factor template#Overview|'''here''']].
==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==
==Natural History, Complications and Prognosis==
* The natural history of a disease describes how the disease would progress without treatment. The complications describe the negative consequences of the disease and treatment, and the prognosis describes the outcomes of the disease.
The [[natural history]] of [[spontaneous coronary artery dissection]] has not been well characterized.  Early reports based on [[autopsy|post-mortem examinations]] after [[sudden cardiac death]] suggest a dismal [[prognosis]]. However, recent studies demonstrate that the majority of [[patients]] survive initial hospitalization and have a favorable [[prognosis]] following clinical stabilization. Some of the [[complications]] of [[SCAD]] include extension of [[dissection]], recurrence of [[dissection]], [[myocardial stunning]], [[myocardial infarction]], [[congestive heart failure]], [[cardiogenic shock]], [[ventricular arrhythmia]], and [[Sudden death|sudden cardiac death]].
* This section should contain the name of the disease you are describing in the first sentence.
* The overview of the natural history, complications and prognosis is ideally written after the main microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview statement that is seen on the natural history, complications and prognosis microchapter page.
*To view a template and examples of the Natural History, Complications and Prognosis overview statement, click [[Natural history, complications and prognosis template#Overview|'''here''']].


==Diagnosis==
==Diagnosis==
* The diagnosis of a disease details the most important signs, symptoms, tests, and other studies that lead to the diagnosis of a disease.
[[Coronary angiography]] is the standard for diagnosing [[spontaneous coronary artery dissection]].  Adjunctive [[imaging]] modalities such as [[intravascular ultrasonography]] ([[IVUS]]), [[optical coherence tomography]] ([[OCT]]), [[computed tomography angiography]] ([[CTA]]), and [[magnetic resonance angiography]] ([[MRA]]) may offer complementary details for establishing a definitive diagnosis.
* This section should contain the name of the disease you are describing in the first sentence.
 
* The overview of the diagnosis of a disease should ideally be written after the main diagnosis microchapters are written, to summarize the key points of the microchapters.


===History and Symptoms===
===History and Symptoms===
* Describe the main aspects of the patient history that should be focused on, and the symptoms that lead to, or exclude the diagnosis of the disease you are describing. You should use the name of the disease in the first sentence. For an example of this subsection, click [[Myocarditis overview#Diagnosis|here]].
The hallmark [[symptom]] of [[spontaneous coronary artery dissection]] ([[SCAD]]) is [[angina pectoris]], similar to other [[acute coronary syndromes]], which may radiate to the [[jaw]] or [[left arm]]. [[SCAD]] should be suspected with these [[symptoms]] in relatively [[young]] [[women]], especially those in [[Postpartum|postpartum status]]. However, many patients do not have [[typical]] [[risk factors]] of [[coronary artery disease]]. Patients are typically [[asymptomatic]] on follow-up.
* This section can be the same as the overview section on the history and symptoms page.
*To view a template and examples of the History and Symptoms overview statement, click [[History and symptoms template#Overview|'''here''']].


===Physical Examination===
===Physical Examination===
* Describe the main physical examination findings that can lead to or exclude the diagnosis of the disease you are describing. You should include the name of the disease in the first sentence. For an example, click [[Pericarditis overview#Diagnosis|here]]
Physical exam in [[SCAD]] may include [[tachycardia]], [[bradycardia]], [[hypertension]], [[hypotension]], [[rale]], [[syncope]] based on the the [[coronary arteries]] involvement and presence of [[ventricular dysfunction]].
* This section can be the same as the overview section physical examination page.
*To view a template and examples of the Physical Examination overview statement, click [[Physical examination template#Overview|'''here''']].


===Laboratory Findings===
===Laboratory Findings===
* List the main laboratory studies that can lead to or exclude the diagnosis of the disease you are describing. You should include the name of the disease in the first sentence.
Laboratory findings consistent with the [[diagnosis]] of [[spontaneous coronary artery dissection]] is similar to [[myocardial infarction]] as it most commonly presents with this manifestation. It includes elevated levels of [[troponin]] which may be absent in 27% of the [[patients]].
* This section should be the same as the overview statement on the laboratory findings page.
*To view a template and examples of the Laboratory Findings overview statement, click [[Laboratory findings template#Overview|'''here''']].


===Electrocardiogram===
===Electrocardiogram===
* If EKG findings are pertinent to the diagnosis of the disease you are describing, you can provide the findings here.
* This section can be the same as the overview statement found on the Electrocardiogram page.
*To view a template and examples of the Electocardiogram overview statement, click [[Electrocardiogram template#Overview|'''here''']].


===Chest X Ray===
[[Electrocardiogram]] findings vary according to the [[coronary]] [[flow-limitation]] by the [[dissection flap]] or [[intramural hematoma]]. There can be no changes in [[ECG]] in some cases. In other cases [[ECG]] may show any of changes.
* If chest x ray findings are pertinent to the disease page you are making, you can briefly describe them here.
 
* This can be the same as the overview statement on the chest x ray page.
===Angiography===
*To view a template and examples of the Chest X Ray overview statement, click [[Chest x ray template#Overview|'''here''']].
The current [[gold standard]] for diagnosing [[spontaneous coronary artery dissection ]] ([[SCAD]]) is [[coronary angiography]], as it is widely available and the first-line [[imaging]] modality for [[patients]] presenting with the [[acute coronary syndrome]]. The predominant [[angiographic]] feature of [[SCAD]] consists of diffuse smooth narrowing of varying severity involving mid-to-distal [[coronary]] segments, secondary to compression of the true [[lumen]] and/or expansion of the false [[lumen]] by the development of an intramural [[hematoma]].  The typical appearance of extraluminal contrast staining, multiple radiolucent [[lumens]], spiral [[dissection]], or [[intraluminal]] filling defects is less commonly observed.  Other [[angiographic]] findings associated with [[SCAD]] include [[coronary tortuosity]], [[myocardial bridging]], and [[fibromuscular dysplasia|coronary fibromuscular dysplasia]].
===CT Scan===
 
*If CT findings are pertinent to the page you are making, you can briefly describe them here.
===CT===
*This section can be the same as the overview section on the CT page.
[[coronary]] [[computed tomography angiography]] maybe helpful in the diagnosis of [[spontaneous coronary artery dissection]]. Findings on [[coronary]] [[computed tomography angiography]] suggestive of [[spontaneous coronary artery dissection]] include abrupt luminal [[stenosis]] of the [[coronary]] lumen, [[intramural]] [[hematoma]],tapered [[luminal stenosis]], [[epicardial fat strand]], [[coronary tortuosity]], [[coronary bridging]], [[myocardial hypoperfusion]], [[regional wall motion abnormality]].
*To view a template and examples of the CT Scan overview statement, click [[CT template#Overview|'''here''']].
 
===MRI===
[[Cardiac magnetic resonance]] ([[CMR]]) is a valuable tool for [[diagnosis]] of [[spontaneose coronary artery dissection]] ([[SCAD]]) in [[patients]] as follows:
[[pregnant]] women for avoiding  [[radiation]] of [[coronary angiography]], unclear evidence of [[acute coronary syndrome]] during [[coronary angiography]], differentiating of [[SCAD]] from [[myocarditis]], [[takotsubo cardiomyopathy]]. Findings of [[CMR]] associated with [[SCAD]] include evidence of [[myocardial infarction]] with subendocardial late gadolinium enhancement, [[microvascular obstruction]], [[ myocardial edema]].


===Echocardiography or Ultrasound===
===Echocardiography===
*If echocardiography or ultrasound findings are pertinent to the page you are making, you can describe them here.
[[Echocardiography]] is helpful in the assessment of [[regional wall motion abnormalities]], [[chamber size]], and [[diastolic  function]] and monitoring of [[ventricular ]] recovery after [[SCAD]]. Contrast and [[strain echocardiography]] may be useful for evaluation of underlying [[perfusion]] and [[myocardial dysfunction]] in [[SCAD]].
*This section can be the same as the overview section on the echocardiography and ultrasound page.
*To view a template and examples of the Echocardiography or Ultrasound overview statement, click [[Echocardiography or ultrasound template#Overview|'''here''']].


===Other Imaging Findings===
===Other Imaging Findings===
* List the most important diagnostic studies, such as imaging and other studies, that can lead to or exclude the diagnosis of the disease you are describing. You should name any "gold standard" studies here, and include the name of the disease in the first sentence.
When the [[diagnosis]] of spontaneous coronary artery dissection ([[SCAD]]) cannot be ascertained by the standard [[coronary angiography]], intracoronary [[imaging]] such as [[intravascular ultrasound]] ([[IVUS]]) or [[optical coherence tomography]] ([[OCT]]) may provide complementary information for establishing a definitive diagnosis.  [[Coronary]] [[computed tomography angiography]] (CCTA) may be useful for non-invasive follow-up of [[SCAD]] involving proximal or large-caliber [[coronary]] [[arteries]]. [[OCT]] findings suggestive of [[SCAD]] may include the presence of two [[lumen]]s and intramural [[hematoma]].
*To view a template and examples of the Other Imaging Findings overview statement, click [[CT template#Overview|'''here''']].
 
===Other Diagnostic Studies===


==Treatment==
==Treatment==
* Treatment describes the various, most commonly used methods in treating the disease you are describing.
Acute management of [[myocardial infarction]] in [[SCAD]] is [[medical therapy]] in approximately 80% of the [[patients]]. [[Myocardial infarction]] in the context of [[SCAD]] is different from the [[myocardial infarction]] in the context of [[atherosclerosis]] and therefore makes it unfavorable for [[revascularization]] approaches. Long-term treatment for [[spontaneous coronary artery dissection]] pursues several main goals including [[antianginal]] therapy, prevention of [[recurrence]], assessment, and management of extra [[coronary]] [[vascular]] abnormalities, and improvement of [[quality of life]]. To improve the qualityof life in [[patients]] with [[SCAD]], consider [[cardiac rehabilitation]] referral and manage [[patients]] [[comorbidities]].  
* This section should contain the name of the disease you are describing in the first sentence.
 
* The overview of the treatments for a disease should ideally be written after the main treatment microchapter is written, to summarize the key points of the microchapter. It can be the same as the overview statement found on the main risk factors microchapter for the disease.


===Medical Therapy===
===Medical Therapy===
* Medical therapy describes all non-surgical therapies that are provided for the patient.
 
*This section should contain the name of the disease you are describing in the first sentence followed by the indication to treat the patient (if applicable) and the name of the 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]]. In the majority of cases, [[SCAD]] may be managed successfully with [[medical treatment]] alone in the absence of ongoing [[myocardial ischemia]] or [[hemodynamic instability]].
*To view a template and examples of the Medical Therapy overview statement, click [[Medical therapy template#Overview|'''here''']].
Initial [[conservative]] management typically includes [[antithrombotic therapy]] with [[heparin]], [[aspirin]], [[clopidogrel]] and [[glycoprotein IIb/IIIa inhibitors]], and [[antiischemic]] therapy with [[beta blockers]] and [[nitrate]]s.  However, the use of [[antithrombotic]] therapy may increase the risk of [[bleeding]] in the [[false lumen]] causing an expansion of the [[intramural hematoma]], resulting in a decreased [[flow]] through the [[true lumen]].[[Fibrinolytic]]s should be avoided. [[Calcium channel blocker]]s may offer relief in [[coronary artery spasm]].
 
===Percutaneous Coronary Intervention===
Conservative management should be the first choice if emergent [[revascularization]] is not necessary. However, optimal [[management]] is in question due to insufficient [[clinical]] experience. There are some treatment options including conservative management, emergency revascularization ([[PCI]] or [[CABG]]), [[fibrinolytic]] therapy, [[mechanical hemodynamic support]], and even [[cardiac transplantation]].The preference of the approach should be tailored to the patient’s clinical status.
 
===Surgery===
===Surgery===
*Surgery describes all surgeries and therapeutic procedures that are provided for the patient.
[[Coronary artery bypass graft]] ([[CABG]]) is an important [[reperfusion]] therapy in a selected group of [[SCAD]] [[patients]] and also a rescue strategy in the management of failed [[PCI]].Indications for [[surgical revascularization]] include [[multivessel]] involvement, [[Left main coronary artery]] involvement, progression/worsening of [[dissection]] , significant narrowing of the [[arterial]] lumen, refractory or recurrent [[myocardial ischemia]]. In the event of severe refractory [[heart failure]], [[heart transplantation]] may be considered.
*This section should contain the name of the disease you are describing in the first sentence followed by the indication to surgically manage the patient (if application) and the name of the surgery.
 
*To view a template and examples of the Surgery overview statement, click [[Surgery template#Overview|'''here''']].
===Primary Prevention===
There is no established [[primary prevention]] measurement for [[spontaneous coronary artery dissection]].


===Prevention===
===Secondary Prevention===
*Prevention describes all strategies that prevent from the occurrence of the disease. Prevention may be either primary (prevent occurrence of the disease), secondary (diagnose and treat existent disease in early stages), tertiary (reduce the negative impact of extant disease), and quaternary (methods to avoid results of unnecessary interventions). At least primary and secondary prevention are usually discussed in each chapter.
[[Secondary prevention]] strategies following [[spontaneous coronary artery dissection]] include avoidance of [[extreme isometric]] or [[competitive]] [[physical exercise]] and also [[psychosocial support]].
*This section should contain the name of the disease you are describing in the first sentence. The availability or lack of vaccine availability of a vaccine against the disease should be clearly written. Other strategies for the prevention of the disease should be outlined and classified as either primary, secondary, tertiary, or quaternary.
*To view a template and examples of the Prevention overview statement, click [[Prevention template#Overview|'''here''']].


==References==
===Future or Investigational Therapies===
{{Reflist|2}}
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.


[[Category:Cardiology]]
[[Category:Cardiology]]
[[Category:Angiographic Definitions]]
[[Category:Angiographic Definitions]]
[[Category:Disease]]
[[Category:Disease]]

Latest revision as of 20:55, 10 April 2021

Spontaneous Coronary Artery Dissection Microchapters

Home

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Spontaneous coronary artery dissection from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Approach

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Angiography

CT

MRI

Echocardiography

Other Imaging Findings

Other Diagnostic Studies

Treatment

Treatment Approach

Medical Therapy

Percutaneous Coronary Intervention

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Type 1

Type 2A

Type 2B

Type 3

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Zand, M.D.[2] Nate Michalak, B.A. Arzu Kalayci, M.D. [3]

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.Coronary angiography is the standard for diagnosing spontaneous coronary artery dissection. Adjunctive imaging modalities such as intravascular ultrasonography (IVUS), optical coherence tomography (OCT), computed tomography angiography (CTA), and magnetic resonance angiography (MRA) may offer complementary details for establishing a definitive diagnosis.The hallmark symptom of spontaneous coronary artery dissection (SCAD) is angina pectoris, similar to other acute coronary syndromes, which 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 exam in SCAD may include tachycardia, bradycardia, hypertension, hypotension, rale, syncope based on the the coronary arteries involvement and ventricular dysfunction.Laboratory findings consistent with the diagnosis of spontaneous coronary artery dissection is similar to myocardial infarction as it most commonly presents with this manifestation. It includes elevated levels of troponin which may be absent in 27% of the patients.Electrocardiogram findings vary according to the coronary flow-limitation by the dissection flap or intramural hematoma. There can be no changes in ECG in some cases. In other cases ECG may show any of changes.The current gold standard for diagnosing spontaneous coronary artery dissection (SCAD) is coronary angiography, as it is widely available and the first-line imaging modality for patients presenting with the acute coronary syndrome. The predominant angiographic feature of SCAD consists of diffuse smooth narrowing of varying severity involving mid-to-distal coronary segments, secondary to compression of the true lumen and/or expansion of the false lumen by the development of an intramural hematoma. The typical appearance of extraluminal contrast staining, multiple radiolucent lumens, spiral dissection, or intraluminal filling defects is less commonly observed. Other angiographic findings associated with SCAD include coronary tortuosity, myocardial bridging, and coronary fibromuscular dysplasia.coronary computed tomography angiography maybe helpful in the diagnosis of spontaneous coronary artery dissection. Findings on coronary computed tomography angiography suggestive of spontaneous coronary artery dissection include abrupt luminal stenosis of the coronary lumen, intramural hematoma,tapered luminal stenosis, epicardial fat strand, coronary tortuosity, coronary bridging, myocardial hypoperfusion, regional wall motion abnormality.Cardiac magnetic resonance (CMR) is a valuable tool for diagnosis of spontaneose coronary artery dissection (SCAD) in patients as follows: pregnant women for avoiding radiation of coronary angiography, unclear evidence of acute coronary syndrome during coronary angiography, differentiating of SCAD from myocarditis, takotsubo cardiomyopathy. Findings of CMR associated with SCAD include evidence of myocardial infarction with subendocardial LGE,microvascular obstruction, myocardial edema.Echocardiography is helpful in the assessment of regional wall motion abnormalities, chamber size, and diastolic function and monitoring of ventricular recovery after SCAD. Contrast and strain echocardiography may be useful for evaluation of underlying perfusion and myocardial dysfunction in SCAD.When the diagnosis of spontaneous coronary artery dissection (SCAD) cannot be ascertained by the standard coronary angiography, intracoronary imaging such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT) may provide complementary information for establishing a definitive diagnosis. Coronary computed tomography angiography (CCTA) may be useful for non-invasive follow-up of SCAD involving proximal or large-caliber coronary arteries. OCT findings suggestive of SCAD may include the presence of two lumens and intramural hematoma.Long-term treatment for spontaneous coronary artery dissection pursues several main goals including antianginal therapy, prevention of recurrence, assessment, and management of extra coronary vascular abnormalities, and improvement of quality of life. Acute management of myocardial infarction in SCAD is medical therapy in approximately 80% of the patients. Myocardial infarction in the context of SCAD is different from the myocardial infarction in the context of atherosclerosis and therefore makes it unfavorable for revascularization approaches.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. In the majority of cases, SCAD may be managed successfully with medical treatment alone in the absence of ongoing myocardial ischemia or hemodynamic instability. Initial conservative management typically includes antithrombotic therapy with heparin, aspirin, clopidogrel and glycoprotein IIb/IIIa inhibitors, and antiischemic therapy with beta blockers and nitrates. However, the use of antithrombotic therapy may increase the risk of bleeding in the false lumen causing an expansion of the intramural hematoma, resulting in a decreased flow through the true lumen.Fibrinolytics should be avoided. Calcium channel blockers may offer relief in coronary artery spasm.Conservative management should be the first choice if emergent revascularization is not necessary. However, optimal management is in question due to insufficient clinical experience. There are some treatment options including conservative management, emergency revascularization (PCI or CABG), fibrinolytic therapy, mechanical hemodynamic support, and even cardiac transplantation have been reported.The preference of the approach should be tailored to the patient’s clinical status.Coronary artery bypass graft (CABG) is an important reperfusion therapy in a selected group of SCAD patients and also a rescue strategy in the management of failed PCI.Indications for surgical revascularization include multivessel involvement, Left main coronary artery involvement, progression/worsening of dissection, significant narrowing of the arterial lumen, refractory or recurrent myocardial ischemia. In the event of severe refractory heart failure, heart transplantation may be considered. There is no established primary prevention measurement for spontaneous coronary artery dissection.Secondary prevention strategies following spontaneous coronary artery dissection include avoidance of extreme isometric or competitive physical exercise and also psychosocial support.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.

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). Type 4 SCAD lesion is characterized by dissection leading to an abrupt total occlusion, usually of a distal coronary segment. The total occlusion occurs as a result of diminished true lumen due to external compression by intraluminal hematoma rather than embolism. The intermediate type 1/2 SCAD lesion is characterized by the appearance of type 1 in conjunction with type 2 lesion.


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. In a SCAD registry, a total of 5% to 8% of patients were carriers of genetic mutations for connective tissue disorders. SCAD may also be associated with a variety of disorders including but not limited to fibromuscular dysplasia, Connective tissue disorders, and autoimmune diseases such as systemic lupus erythematous.


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 or illicit drugs, pregnancy, and connective tissue disorders.

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. The case fatality rate of SCAD is relatively low compared with other causes of ACS, with an estimated in-hospital mortality rate of 0 to 4%. The average age at diagnosis of SCAD in females ranges from 44 to 53 years, although patients may present with SCAD in their second through ninth decades of life. SCAD has a strong predilection for young women with no or minimal traditional cardiovascular risk factors. It has been reported in all major racial and ethnic groups, with the majority of patients being white.


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

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 the majority of patients survive initial hospitalization and have a favorable prognosis following clinical stabilization. Some of the complications of SCAD include extension of dissection, recurrence of dissection, myocardial stunning, myocardial infarction, congestive heart failure, cardiogenic shock, ventricular arrhythmia, and sudden cardiac death.

Diagnosis

Coronary angiography is the standard for diagnosing spontaneous coronary artery dissection. Adjunctive imaging modalities such as intravascular ultrasonography (IVUS), optical coherence tomography (OCT), computed tomography angiography (CTA), and magnetic resonance angiography (MRA) may offer complementary details for establishing a definitive diagnosis.


History and Symptoms

The hallmark symptom of spontaneous coronary artery dissection (SCAD) is angina pectoris, similar to other acute coronary syndromes, which 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

Physical exam in SCAD may include tachycardia, bradycardia, hypertension, hypotension, rale, syncope based on the the coronary arteries involvement and presence of ventricular dysfunction.

Laboratory Findings

Laboratory findings consistent with the diagnosis of spontaneous coronary artery dissection is similar to myocardial infarction as it most commonly presents with this manifestation. It includes elevated levels of troponin which may be absent in 27% of the patients.

Electrocardiogram

Electrocardiogram findings vary according to the coronary flow-limitation by the dissection flap or intramural hematoma. There can be no changes in ECG in some cases. In other cases ECG may show any of changes.

Angiography

The current gold standard for diagnosing spontaneous coronary artery dissection (SCAD) is coronary angiography, as it is widely available and the first-line imaging modality for patients presenting with the acute coronary syndrome. The predominant angiographic feature of SCAD consists of diffuse smooth narrowing of varying severity involving mid-to-distal coronary segments, secondary to compression of the true lumen and/or expansion of the false lumen by the development of an intramural hematoma. The typical appearance of extraluminal contrast staining, multiple radiolucent lumens, spiral dissection, or intraluminal filling defects is less commonly observed. Other angiographic findings associated with SCAD include coronary tortuosity, myocardial bridging, and coronary fibromuscular dysplasia.

CT

coronary computed tomography angiography maybe helpful in the diagnosis of spontaneous coronary artery dissection. Findings on coronary computed tomography angiography suggestive of spontaneous coronary artery dissection include abrupt luminal stenosis of the coronary lumen, intramural hematoma,tapered luminal stenosis, epicardial fat strand, coronary tortuosity, coronary bridging, myocardial hypoperfusion, regional wall motion abnormality.

MRI

Cardiac magnetic resonance (CMR) is a valuable tool for diagnosis of spontaneose coronary artery dissection (SCAD) in patients as follows: pregnant women for avoiding radiation of coronary angiography, unclear evidence of acute coronary syndrome during coronary angiography, differentiating of SCAD from myocarditis, takotsubo cardiomyopathy. Findings of CMR associated with SCAD include evidence of myocardial infarction with subendocardial late gadolinium enhancement, microvascular obstruction, myocardial edema.

Echocardiography

Echocardiography is helpful in the assessment of regional wall motion abnormalities, chamber size, and diastolic function and monitoring of ventricular recovery after SCAD. Contrast and strain echocardiography may be useful for evaluation of underlying perfusion and myocardial dysfunction in SCAD.

Other Imaging Findings

When the diagnosis of spontaneous coronary artery dissection (SCAD) cannot be ascertained by the standard coronary angiography, intracoronary imaging such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT) may provide complementary information for establishing a definitive diagnosis. Coronary computed tomography angiography (CCTA) may be useful for non-invasive follow-up of SCAD involving proximal or large-caliber coronary arteries. OCT findings suggestive of SCAD may include the presence of two lumens and intramural hematoma.

Other Diagnostic Studies

Treatment

Acute management of myocardial infarction in SCAD is medical therapy in approximately 80% of the patients. Myocardial infarction in the context of SCAD is different from the myocardial infarction in the context of atherosclerosis and therefore makes it unfavorable for revascularization approaches. Long-term treatment for spontaneous coronary artery dissection pursues several main goals including antianginal therapy, prevention of recurrence, assessment, and management of extra coronary vascular abnormalities, and improvement of quality of life. To improve the qualityof life in patients with SCAD, consider cardiac rehabilitation referral and manage patients comorbidities.


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. In the majority of cases, SCAD may be managed successfully with medical treatment alone in the absence of ongoing myocardial ischemia or hemodynamic instability. Initial conservative management typically includes antithrombotic therapy with heparin, aspirin, clopidogrel and glycoprotein IIb/IIIa inhibitors, and antiischemic therapy with beta blockers and nitrates. However, the use of antithrombotic therapy may increase the risk of bleeding in the false lumen causing an expansion of the intramural hematoma, resulting in a decreased flow through the true lumen.Fibrinolytics should be avoided. Calcium channel blockers may offer relief in coronary artery spasm.

Percutaneous Coronary Intervention

Conservative management should be the first choice if emergent revascularization is not necessary. However, optimal management is in question due to insufficient clinical experience. There are some treatment options including conservative management, emergency revascularization (PCI or CABG), fibrinolytic therapy, mechanical hemodynamic support, and even cardiac transplantation.The preference of the approach should be tailored to the patient’s clinical status.

Surgery

Coronary artery bypass graft (CABG) is an important reperfusion therapy in a selected group of SCAD patients and also a rescue strategy in the management of failed PCI.Indications for surgical revascularization include multivessel involvement, Left main coronary artery involvement, progression/worsening of dissection , significant narrowing of the arterial lumen, refractory or recurrent myocardial ischemia. In the event of severe refractory heart failure, heart transplantation may be considered.

Primary Prevention

There is no established primary prevention measurement for spontaneous coronary artery dissection.

Secondary Prevention

Secondary prevention strategies following spontaneous coronary artery dissection include avoidance of extreme isometric or competitive physical exercise and also psychosocial support.

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.