Is atherosclerosis of the aorta considered Coronary Artery Disease (CAD)?

Atherosclerosis of the Aorta is Not Considered Coronary Artery Disease (CAD)

Atherosclerosis of the aorta is not considered coronary artery disease (CAD), but rather represents a distinct manifestation of systemic atherosclerosis that frequently coexists with CAD. 1

Understanding the Distinction

Atherosclerosis can affect multiple vascular territories, but each manifestation is classified differently based on anatomical location:

• Coronary Artery Disease (CAD): Specifically refers to atherosclerotic disease affecting the coronary arteries that supply the heart muscle
• Aortic Atherosclerosis: Refers to atherosclerotic disease affecting the aorta (thoracic or abdominal)
• Peripheral Arterial Disease (PAD): Refers to atherosclerotic disease affecting the peripheral arteries, particularly in the lower extremities

Relationship Between Aortic Atherosclerosis and CAD

While aortic atherosclerosis is not CAD, there is a significant association between them:

• According to the 2024 ESC guidelines, approximately 5-9% of patients with CAD have concomitant carotid stenosis >70%, and atherosclerosis frequently affects multiple vascular territories 1
• Patients with atherosclerosis in one vascular territory often have disease in others, representing "polyvascular disease" 1
• The REACH registry data shows that patients with atherosclerosis in one territory frequently develop disease in other territories over time 1

Clinical Significance

The distinction between aortic atherosclerosis and CAD is important for several reasons:

• Diagnostic approach: Different imaging modalities are used to evaluate each condition
• Risk stratification: Aortic atherosclerosis serves as a marker for possible CAD
• Treatment implications: Management strategies may differ based on the affected vascular bed

Aortic Atherosclerosis as a Marker for CAD

Aortic atherosclerosis has significant predictive value for CAD:

• Thoracic aortic atherosclerosis detected by transesophageal echocardiography (TEE) has been shown to be associated with significant CAD 2, 3
• A Thoracic Aorta Atherosclerosis Burden Index (TAABI) >6 has been associated with a 16-fold increase in the probability of CAD with 88% specificity and 81% sensitivity 4
• Complex plaque in the descending aorta is the strongest predictor of CAD among aortic atherosclerotic findings 3

Treatment Considerations

Despite being distinct entities, both conditions share common risk factors and treatment approaches:

• Statins: In patients with atherosclerotic aortic aneurysms, statin therapy at moderate or high intensity is reasonable 1
• Antiplatelet therapy: Low-dose aspirin (75-162 mg/day) may be considered in patients with aortic atherosclerosis or penetrating aortic ulcer 1
• Risk factor modification: Smoking cessation, blood pressure control, and other cardiovascular risk factor management are essential for both conditions 1

Polyvascular Disease Implications

When atherosclerosis affects multiple vascular territories (polyvascular disease):

• Risk of major cardiovascular events roughly doubles with each additional affected arterial bed 1
• Systematic screening for multisite atherosclerotic disease in high-risk CAD patients has not been shown to improve outcomes 1
• Targeted screening may be beneficial in specific clinical scenarios, such as before coronary artery bypass grafting or vascular surgery 1

Key Takeaway

While atherosclerosis of the aorta and CAD frequently coexist and share pathophysiological mechanisms, they represent distinct manifestations of atherosclerotic disease affecting different vascular territories. The presence of aortic atherosclerosis should prompt consideration of possible CAD, but they remain separate diagnostic entities.