Management of Coronary Artery Aneurysms

Classification and Risk Stratification

The American College of Cardiology classifies coronary artery aneurysms based on Z-scores and absolute dimensions, with small aneurysms having a Z-score ≥2.5 to <5 1
The American Heart Association defines medium aneurysms as those with a Z-score ≥5 to <10 and an absolute dimension <8 mm 1
Large or giant aneurysms are defined as those with a Z-score ≥10 or an absolute dimension ≥8 mm 1

The American College of Cardiology recommends low-dose aspirin (3-5 mg/kg daily) monotherapy for small aneurysms (Z-score ≥2.5 to <5) 2, 1
For medium aneurysms (Z-score ≥5 to <10, absolute dimension <8 mm), the American Heart Association suggests dual antiplatelet therapy with low-dose aspirin plus a second antiplatelet agent (typically clopidogrel) 1
The American College of Cardiology recommends combination therapy with low-dose aspirin (3-5 mg/kg daily) plus systemic anticoagulation for large or giant aneurysms (Z-score ≥10 or absolute dimension ≥8 mm) 2, 3, 1

The risk of thrombosis in coronary aneurysms is related to abnormal flow conditions with low blood flow velocities and stasis within the aneurysm, according to the American Heart Association 3, 4
The American College of Cardiology notes that stenoses at proximal or distal ends of aneurysms can create turbulent flow, increasing the risk of thrombosis 3

The American Heart Association recommends thrombolytic therapy that targets multiple steps in the coagulation process for acute coronary thrombosis 3, 5
For larger patients, the American College of Cardiology suggests considering mechanical restoration of coronary blood flow via catheterization 5

The American Heart Association recommends frequent echocardiography for patients with giant aneurysms, especially during the first 3 months when thrombosis risk is highest 5, 1
The American College of Cardiology suggests monitoring for sudden worsening in ventricular function or changes in ECG findings, which should raise suspicion for coronary thrombosis 4, 1

The American College of Cardiology notes that failure to increase antithrombotic therapy intensity when aneurysms are rapidly expanding is a major contributor to sudden cardiovascular events 4
The American Heart Association warns that standard thrombolytic protocols for atherosclerotic disease may not be optimal for aneurysm-related thrombosis, as the pathophysiology differs 3