Coronary artery aneurysm

Coronary artery aneurysms are an uncommon, predominantly incidental finding.

Epidemiology

Coronary artery aneurysms are most common in men ³, likely reflecting the increased rates of atherosclerosis in men compared to women. Prevalence varies in the literature between 0.1-5% ⁴.

Clinical presentation

Most coronary artery aneurysms are asymptomatic. They can be associated with cardiac murmurs or present with chest pain or congestive cardiac failure.

Pathology

Coronary artery aneurysms are defined as a focal dilatation of the coronary artery by at least 50% compared to a nearby artery or adjacent arterial segment and involve <50% of the artery length ^2,4. They can be classified by ⁴

• type: true or false aneurysms

• shape: saccular or fusiform

• aetiology (see below)

The term coronary artery ectasia is is applied when there is dilatation but it involves >50% of the artery length ⁴. The giant coronary artery aneurysms subtype measure >5 cm and >0.8 cm in the adult and the young paediatric populations respectively ⁶.

Aetiology

Pathologically, coronary artery aneurysms can be classified into three groups ⁶:

• atherosclerotic: most common (50%)

• inflammatory

  • vasculitis, e.g.Kawasaki disease

  • mycotic, e.g. syphilis

• non-inflammatory

  • congenital (~17%)

  • connective tissue disorders, e.g.systemic lupus erythematosus

  • trauma

  • iatrogenic, e.g. stent placement

  • drug-related, e.g. cocaine abuse

Associations

Coronary artery aneurysms may be associated with coronary arteriovenous fistulas to to either cardiac veins or cardiac chambers.

Radiographic features

Imaging modalities used in evaluating coronary artery aneurysms include transthoracic echocardiography, ECG-gated CT angiography, MRI and/or MR angiography, and angiographic cardiac catheterisation.

Role of imaging

• depiction of coronary artery anatomy

• detection of coronary artery aneurysms

• evaluation of aneurysm shape and structure

  • morphology (fusiform or saccular)

  • aneurysm diameter

  • wall calcification

  • luminal thrombosis

  • presence of associated stenosis

  • origin and termination

  • monitoring of growth rate

• exclude potential complications

  • myocardial perfusion abnormalities

  • fistula formation

  • extrinsic mass compression

  • rupture and haemopericardium

Treatment and prognosis

There is no established treatment for coronary artery aneurysms with medical and surgical options available ⁴. The five-year survival of coronary artery aneurysms is ~70% ^3,4.

Differential diagnosis

The differential diagnosis includes:

• sinus of Valsalva aneurysm

• aneurysm of a surgically placed coronary arterial or venous graft

• neoplasms of the heart, pericardium, or mediastinum

See also

• coronary arterial ectasia

• coronary arteriovenous fistulas