Introduction
In coronary artery ectasia, there is a dilation of the coronary artery lumen. The term ectasia means diffuse dilation of a coronary artery. Coronary artery ectasia is well-recognized, but the findings are uncommonly encountered during diagnostic coronary angiography. Coronary artery ectasia is classified and subdivided into four groups: type 1- diffuse ectasia of two or three vessels, type 2- localized disease in one vessel and diffuse ectasia in another vessel, type 3 - in one vessel with diffuse ectasia only; and type 4 - localized or segmental involvement. Some of the risk factors for coronary artery ectasia are smoking, hypertension, and the use of illicit drugs like cocaine.
What Is Coronary Artery Ectasia?
Coronary artery ectasia is defined as dilatation exceeding more than one-third of the length of the coronary artery, with the diameter of the dilated segment measuring more than 1.5 times the diameter of a normal adjacent segment.
What Is the Etiology of Coronary Artery Ectasia?
Coronary artery ectasia can be enigmatic in etiology, and in more than 50% of cases, atherosclerosis is the principal etiologic cause in adults, and Kawasaki is common mostly in children and young adults. This disease can rarely be genetic, and mainly, they are acquired, including Kawasaki disease, atherosclerosis, mycotic or septic emboli, Marfan syndrome, Takayasu disease, or systemic lupus erythematosus.
Coronary artery ectasia that is secondary to iatrogenic causes includes:
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Stents.
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Percutaneous transluminal coronary angioplasty.
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Directional coronary atherectomy.
What Is the Pathophysiology and Histopathology of Coronary Artery Ectasia?
The pathophysiology of coronary artery ectasia is not known precisely. It is a clinical constellation or an anatomical variant of coronary artery disease because it may present with coronary syndrome or myocardial ischemia. With high wall tension, coronary artery ectasia is also related to apical hypertrophic cardiomyopathy. Ectasia or aneurysms are formed due to iatrogenic mechanisms due to balloon angioplasty, atherectomy, and stent placement.
The histopathological findings show thickened fibrotic intima with lipid deposition. There is usually disruption in the internal elastic lamina layer that reduces the medial elastic tissue. This is the primary cause, as there is a loss of elastic tissue and chronic vascular inflammation that will lead to ectasia.
What Are the Symptoms of Coronary Artery Ectasia?
The coronary artery ectasia symptoms are associated with concomitant coronary disease, connective tissue disease, or Kawasaki disease, but most of the individuals are asymptomatic. The coronary artery ectasia individuals may present with acute coronary syndrome and angina post-stress tests. When there is a diminished coronary flow speed or stagnant blood flow, it can cause exercise-induced angina without coexistent stenotic coronary artery disease. The trigger of acute coronary syndrome can be due to the formation of intracoronary thrombus or dissipation, leading to distal emboli. The coronary artery ectasia is predisposed to vasospasm, which might elicit angina or acute coronary syndrome.
How Is Coronary Artery Ectasia Diagnosed?
Coronary angiography is used for diagnosing coronary artery ectasia, which is a gold standard method. Intravascular Ultrasound (IVUS) is critical to evaluate luminal characteristics and pathologies. Based on ectasia's severity, flow, and washout distortions are common. Delayed antegrade contrast filling, segmental backflow, and stasis in the ectatic coronary segment are signs of stagnant flow. Magnetic Resonance Angiography (MRA) and Coronary Computed Tomography Angiography (CTA) are other investigative techniques, and MRA is the preferred modality for patient follow-up.
What Is the Use of Magnetic Resonance Angiography (MRA)?
Magnetic resonance angiography is a three-dimensional, non-contrast enhancement that facilitates better visualization of the vast majority of the medial and proximal segments of the coronary arteries. MRA is also a clinical value for assessing abnormal coronary artery disease. Also, it is superior to X-ray coronary angiography in some cases in delineating the course of anomalous vessels. It is considered an investigational technique for assessing stenotic native vessels. It is one of the valuable tools for individuals with severe left ventricular systolic dysfunction.
How Is Coronary Artery Ectasia Managed?
Coronary artery ectasia management is fraught with uncertainty because the rarity of coronary artery ectasia prevents large randomized trials comparing different treatment approaches. It is necessary to modify intense primary and secondary risk factors when coronary artery disease coexists. Along with angina, isolated coronary artery ectasia is managed with ASA, statin, and anti-ischemic medications. Coronary artery ectasia associated with acute coronary syndromes might require thrombolysis, heparin administration, and glycoprotein IIb/IIIa receptor inhibitors.
Despite maximal medical therapy, when angina persists, percutaneous and surgical interventions are beneficial for patients with coronary artery ectasia and stenotic lesions. To prevent misplacement and embolization of stents, optimal stent sizing is essential. Surgery is only done in patients who have recurring complications, and therefore, it is rarely done. Surgery is done where the proximal and distal segments of the ectatic vessels are ligated and replaced with a bypass graft. Attempts should not be made to repair the ectatic vessel as the results could be better.
What Is the Differential Diagnosis of Coronary Artery Ectasia?
The differential diagnosis of coronary artery ectasia are:
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Septic emboli.
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Mycotic aneurysm.
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Marfan's syndrome.
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Giant cell arteritis.
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Fibromuscular dysplasia.
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Ehler-Danlos syndrome.
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Bacterial syphilis.
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Atherosclerosis.
What Is the Prognosis and Complications of Coronary Artery Ectasia?
Based on the severity of concomitant coronary artery disease, the prognosis of coronary artery ectasia is directly related. There is increased potential for adverse cardiac events when there is a dangerous combination of coronary artery ectasia with underlying coronary artery disease. There is a risk of myocardial infarction and infarction with isolated coronary artery ectasia. Type 1 and 2 coronary artery ectasia are of higher risk when compared to type 3 and type 4 coronary artery ectasia. Complications of coronary artery ectasia are distal embolization, thrombosis, fistula formation into cardiac chambers, acute coronary syndrome, thrombus that can lead to myocardial infarction, and complications after stenting that include embolization of stent, stent thrombosis, stent misplacement, and restenosis.
Conclusion
Coronary artery ectasia is a rare disease that is a form of aneurysmal coronary heart disease. It will dilate the coronary artery by more than one-third of its length and diameter 1.5 times of a normal coronary artery adjacent to it.
