Giant coronary aneurysm presenting as a cardiac mass on transthoracic echocardiogram

Abstract

A 69-year-old man with a history of ischaemic heart disease and previous stent implantation in the right coronary artery (RCA) was found to have a large well-encapsulated mass attached to the right atrium on a routine transthoracic echocardiogram. Subsequent investigations including transoesophageal echocardiography and CT coronary angiogram suggested an RCA aneurysm formation in relation to the prior stented segment, further confirming on coronary angiogram a large ectatic vessel with a giant aneurysm measuring 2.4×2.7 cm. Giant coronary artery aneurysms are rare and here we present interesting images of a case initially picked up on transthoracic echocardiography.

Background

‘Giant’ coronary artery aneurysm is defined as an aneurysm with a diameter more than 2 cm, and is a rare occurrence. We present an interesting case of such aneurysm initially picked up on a routine transthoracic echocardiography.

Case presentation

A 69-year-old man with a history of non-ST elevated myocardial infarction (NSTEMI) treated with a bare-metal stent (4.5 mm×16 mm) in the distal right coronary artery (RCA) 4 years ago, presented for routine follow-up echocardiogram. On the study, he was noted to have a well encapsulated mass attached to lateral wall of the right atrium (RA). A subsequent transoesophageal echocardiography revealed 2.3×2.7 cm heterogenous, vascular mass with multiple attachments to RA free wall and septal wall adjacent to the coronary sinus (figure 1). A CT coronary angiogram (CTCA) was also performed which demonstrated an aneurysm formation with the neck starting just proximal to the stented segment (figure 2).

Figure 1.

Transthoracic echocardiogram of the giant right coronary artery aneurysm presenting as a right atrial mass (A). Transoesophageal echocardiographic images depicting 2.4×2.6 cm mass (B). Blood flow on colour Doppler (C). Deep tissue imaging (D).

Figure 2.

Cronoary angiography (A) and CT coronary angiography (B) of the giant right coronary artery aneurysm.

A coronary angiogram was then arranged. This showed a large ectatic RCA vessel with aneurysmal segments in mid-RCA. Distal RCA stent before the bifurcation was patent with a large aneurysm measuring 2.4×2.7 cm. There was a focal 50–60% lesion just proximal to the stent.

This patient was managed conservatively and remains well at 2-year follow-up.

Discussion

A coronary artery aneurysm is defined as coronary dilation which exceeds the diameter of normal adjacent segments by 1.5 times and the incidence varies from 1.5% to 5%.¹ An aneurysm with a diameter more than 2 cm is termed as ‘giant aneurysm’ with a reported incidence of 0.02%, only a few cases have been described in the literature.^{2 3} Aetiology may be atherosclerotic, related to stent implantation, or secondary to autoimmune disease such as Kawasaki's or Takayasu disease. Possible complications can include aneurysm rupture, thrombosis and acute coronary syndrome.¹ Optimal management is unknown though cases describing surgical, percutaneous or conservative approaches have been described.^{1 2}

Learning points.

• Giant coronary artery is rare and may be atherosclerotic, related to stent implantation, or secondary to autoimmune disease such as Kawasaki's or Takayasu disease.

• Giant coronary artery may present as asymptomatic mass or acute coronary syndrome.

• Optimal management is unknown though cases describing surgical, percutaneous or conservative approaches have been described.