Case Files by Dr. George: A Rare Case of Coronary Artery Ectasia Presenting with Thrombus Embolization and Acute Myocardial Infarction

Introduction

Diffuse coronary artery ectasia (CAE) is a relatively infrequent anomaly encountered during coronary angiography. Although most often an incidental finding, patients may present with myocardial ischemia requiring therapeutic interventions. We describe a case of a young patient with CAE that presented with an acute coronary syndrome and subsequently underwent successful percutaneous coronary revascularization.

Case Presentation

A 22-year-old male, with no significant medical history, presented with symptoms of severe mid sternal chest burning and pressure associated with dyspnea for 4 hours. The patient denied any history of drug, tobacco, or alcohol abuse, recent travel, or significant family history of premature coronary artery disease or sudden cardiac death. Vital signs were unremarkable with blood pressure of 115/70, pulse of 92, respiratory rate of 16, and pulse oxygen saturation of 99%. Physical examination revealed normal heart sounds and clear lung fields. Laboratory analysis confirmed myocardial infarction with elevated cardiac enzymes [total creatine kinase (CK) of 579 units/L and CK-MB of 21.6 units/L]. Electrocardiogram obtained upon arrival to the emergency department revealed a sinus rhythm with diffuse 1-mm ST segment depressions and T wave inversions across the precordial leads. The patient received aspirin 325mg orally, a weight-based bolus and infusion of intravenous heparin, and sublingual nitroglycerin with minimal relief of chest pain. The patient was subsequently brought to the cardiac catheterization laboratory for coronary angiography.

Coronary angiogram, via right radial artery access, showed a large, dominant right coronary artery (RCA) with proximal ectasia and no obstructive disease (Figure 1). The left circulation also showed diffuse areas of ectasia involving the proximal left anterior descending (LAD) and left circumflex (LCX) arteries. Moreover, there was a large filling defect within the proximal LAD consistent with thrombus, with no other evidence of obstructive disease (Figure 2). Left ventriculogram revealed a normal ejection fraction with trace mitral regurgitation. Intravenous eptifibatide was initiated with a double bolus and maintenance infusion along with a bolus of heparin to achieve activated clotting time > 250 s. An EBU 3.5 guide (Medtronic Inc., Minneapolis, Minn.) was used to engage the left main coronary artery. A 180-cm Kinetix wire (Boston Scientific Co., Natick, Mass.) was advanced into the distal LAD and aspiration thrombectomy performed with an Export catheter (Medtronic) with modest improvement angiographically. Next, a Veriflex 3.5 x 15 mm bare metal stent (Boston Scientific Co., Natick, Mass.) was deployed in the proximal LAD, and subsequently post-dilated with a 3.5 mm noncompliant balloon with an excellent angiographic result and TIMI-3 flow (Figure 3). The patient had an uncomplicated hospital course with relief of symptoms and was discharged home on hospital day 3 on aspirin, clopidogrel, and dabigatran.

Discussion

CAE is defined as an enlargement of a coronary vessel of at least 1.5 times the diameter of a normal adjacent reference segment.¹ Focal or diffuse CAE, involving one or more vessels, is reported in 0.2% to 4.9% of routine coronary angiograms, and in up to 1.4% of patients in autopsy series.² The etiology of CAE can vary, with atherosclerosis accounting for 50% of cases: 20-30% of patients with congenital origin; 10-20% due to inflammatory processes such as Kawasaki disease³, Takayasu arteritis, or mycotic aneurysms; and additional 10-20% of cases due to collagen vascular disease, including scleroderma, polyarteritis nodosa, or connective tissue diseases.⁴ CAE can be recognized by various imaging modalities, including angiography, computed tomography, or magnetic resonance tomography.⁵ Most cases of CAE are asymptomatic and are found incidentally on coronary angiogram; however, clinical presentation can include angina pectoris, myocardial infarction, and even sudden cardiac death. Regions of coronary dilatation can produce sluggish, turbulent blood flow, leading to a reduction in laminar flow, and activation of the coagulation cascade with subsequent thrombus formation.⁴ Focal CAE is often seen with associated obstructive atherosclerotic coronary disease, yet may still cause angina in the absence of significant plaque by means of distal embolization of thrombi and myocardial injury. Aneurysm rupture or fistula formation with communication into a cardiac chamber is a very rare occurrence.⁶

Due to its close association with coronary atherosclerosis, antiplatelet drugs are the mainstay of medical therapy. Oral anticoagulation may also play a role in the prevention of thrombus formation; but long-term patient follow-up data are currently lacking.⁷ Percutaneous treatment options include a polytetrafluoroethylene-covered stent graft to exclude the affected area; however, in-stent restenosis is common, requiring target lesion revascularization.⁸ Although drug-eluting stents reduce the risk of in-stent restenosis, malapposition of these stents in aneurysmal segments lead to higher risk of stent thrombosis, and may further contribute to aneurysm formation.⁹ Surgical treatment for large aneurysms consists of coronary artery bypass with ligation of the aneurysmal segment.¹⁰ Herein, we present a case of a young patient with diffuse CAE involving all major epicardial vessels, presenting with acute coronary syndrome with a large obstructive thrombus in the proximal LAD. Although the etiology of CAE was not definitively proven, Kawasaki disease is the most likely etiology in this young patient with no additional risk factors or associated anomalies. Successful percutaneous coronary intervention with mechanical thrombectomy and bare metal stent deployment demonstrated excellent angiographic result.

This article received double-blind peer review from members of the Cath Lab Digest editorial board.

The authors can be contacted at jcgeorgemd@hotmail.com.

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