Coronary Artery Aneurysms

  • Key Points

  • CCT angiography is the test of choice to define coronary artery aneurysms.

  • The common occurrence of mural thrombosis of larger coronary artery aneurysms renders cardiac CT particularly able to determine the full size of the coronary artery aneurysm, beyond the means of conventional coronary angiography and beyond that of CMR.

Coronary aneurysms have been identified in 0.5% to 4% of patients undergoing coronary angiograms. The incidence among patients undergoing coronary CT angiography (CTA) has not been determined.

The most common definition of a coronary artery aneurysm is focal dilation of the artery, 1.5 times normal (adjacent reference segment or elsewhere maximal vessel) diameter, and limited to spherical or saccular dilation—a standard and borrowed convention of the definition of an aneurysm. Although generally small (just millimeters in diameter), coronary artery aneurysms may be extremely large. Aneurysms measuring 12 cm have been found.

Aneurysms are encountered most commonly in the right coronary artery but may be found in any coronary artery and may be multiple, especially in the setting of prior Kawasaki disease, where large aneurysms also are common. The left main stem coronary artery appears to be the least common site for coronary aneurysms, although this site is heavily represented in the literature.

Some reviews suggest male dominance of coronary aneurysms.

Formation of coronary aneurysm after percutaneous coronary intervention is relatively common in patients with Kawasaki disease, and the incidence varies from 15% to 18%.

Etiologies and Associations

  • Half of all coronary artery aneurysms (50%) are associated with atherosclerotic coronary artery disease. Associated stenoses are common.

  • Coronary artery disease (CAD)–associated

    • Drug-eluting stents

    • Cutting balloon

    • Coronary ectasia

    • Extensive coronary calcification

    • Saphenous bypass grafts

  • Vasculitis

    • Aortitis of all forms extending onto the proximal coronary arteries

    • Polyarteritis nodosa (PAN)

    • Kawasaki disease

    • Hyperesoinophilic syndrome

    • Other

  • Vascular disease–or syndrome-associated

    • Fibromuscular dysplasia

    • Supravalvular aortic stenosis

  • Marfan syndrome

  • Infection (mycotic)

  • Coronary artery arteriovenous fistulae

  • Myocardial bridging

  • Idiopathic


The risk from coronary artery aneurysms appears to be due mainly to the development of mural thrombus within the aneurysm sac and subsequent embolization of thrombus down the ongoing coronary artery or branch vessels. Because thromboembolism is the late outcome of large coronary aneurysms, the amount of embolized thrombus, and the ensuing coronary event, may be large.

  • Acute coronary syndrome (ACS)

  • Myocardial infarction not associated with stenosis in the same vessel

  • Myocardial infarction and post-infarction tamponade

  • Rupture and tamponade

  • Myocardial infarction and right ventricular infarction/shock

  • Cardiac arrest

  • Sudden death

  • Breakdown of the wall of the aneurysm with:

    • Fistulization into an adjacent cavity

    • Pericardial tamponade

  • Aneurysms also may compress adjacent structures:

    • Chambers

    • Superior vena cava (SVC): SVC syndrome

    • Pulmonary artery

  • Aortic insufficiency

  • Vasospasm elsewhere

  • Thrombosis of a bare-metal stent inserted into an unappreciated aneurysm with extensive mural thrombus, which may dissolve and result in stent dislodgement


  • Prevention: Established for Kawasaki disease using intravenous gamma globulin and aspirin

  • Observation

  • Active treatment

    • Anti-platelet and anticoagulation

    • Percutaneous covered stent closure

    • Percutaneous coil embolization (saphenous graft aneurysm)

    • Surgical repair

      • Ligation at the inflow and/or outflow and internal thoracic/mammary or saphenous bypass. Use of arterial conduits is anticipated to provide more lasting benefit to younger patients.

      • Aneurysmectomy and end-to-end repair

      • Resection with bypass

      • Patch repair/reconstruction

Potential Coronary CTA Findings of Coronary Artery Aneurysms

  • Aneurysmal dilation

    • Solitary or multiple

    • Spherical or saccular

  • Coronary ectasia

  • Coronary stenoses

  • Mural thrombus within the aneurysm

  • Calcification of the aneurysm

  • Fistulous drainage of the aneurysm

  • Aneurysm located within a fistulous coronary anomaly

  • Compression of adjacent chambers and structures

  • Associated aneurysms of the aorta or other vessels

CCT Images of Coronary Artery Aneurysms

Examples are shown in Figures 11-1 through 11-15 and

Figure 11-1

Multiple volume-rendered and curved reformatted cardiac CT images demonstrate a small focal aneurysm extending from the proximal circumflex artery in a patient with Kawasaki disease. There is multifocal ectasia of the proximal to mid-right coronary artery (RCA) and a mild (30%) stenosis of the mid-RCA.

Figure 11-2

Chest CT ( A and B ) and cardiac CT ( C and D ). Two large, calcified, and extensively thrombus-containing coronary artery aneurysms are present, one arising off the left circumflex artery and the other off a diagonal branch of the left anterior descending artery.

Figure 11-3

A and B, Two-dimensional echocardiography images show a large echogenic mass compressing the right atrium (RA) and tricuspid annulus. C and D, ECG-gated axial CT images. C , Before contrast injection, showing a large mass in the right atrioventricular groove; note peripheral and central calcifications ( arrows ). D, After contrast injection, a large mural thrombus with small eccentric residual lumen ( arrow ) is seen. Compression of the right atrium, right appendage ( arrowhead ), and right ventricle inlet are noted. Coronal multiplanar ( E ) and maximum intensity projection reconstructed images ( F ) show the maximal diameter of the giant right coronary artery aneurysm; the thrombus and lumen ( arrows ) can be appreciated. G and H, Three-dimensional volume-rendered reformats show the giant right coronary artery aneurysm in relation to the cardiac chambers and the angiographic view, demonstrating the residual lumen ( arrows ). Note that the actual size of the aneurysm is largely underestimated if evaluation is made only on the basis of the angiogram. AO, aorta; LA, left atrium; LAD, left anterior descending artery; LCx, left circumflex artery; LMA, left main coronary artery; LV, left ventricle; RCA, right coronary artery; RV, right ventricle; RVOT, right ventricle outflow tract; T, thrombus.

(Reprinted with permission from Pasian SG, Tan KT, Pen V, et al. Giant right coronary artery aneurysm on 64-MDCT. J Cardiovasc Med ( Hagerstown ). 2010;11(7):544-546.)

Figure 11-16

A 69-year-old woman with dyspnea. A, The chest radiograph was notable for a mass shadow. A transthoracic echocardiogram revealed a mosaic pattern in the pulmonary artery (PA). B, Multislice CT angiography and coronary angiography showed the giant aneurysm in the coronary artery fistula arising from the left main coronary trunk (LMT) and entering in the PA. The aneurysm measured 55 × 45 mm with calcification and thrombus formation ( C and D ). Cardiac catheterization revealed an oximetry step-up of 9% at the main PA, and a left-to-right shunt of 1.84:1 (Qp:Qs) was found. Aneurysmorrhaphy and closure of the fistula outlet from the PA were performed ( E and F ), and the symptoms disappeared, probably due to resolution of a coronary steal phenomenon.

(Reprinted with permission from Maeda S, Nishizaki M, Hashiyama N, Mo M. Giant aneurysm in coronary artery fistula. J Am Coll Cardiol . 2009;54(24):e119.)

Apr 10, 2019 | Posted by in COMPUTERIZED TOMOGRAPHY | Comments Off on Coronary Artery Aneurysms

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