From the Guidelines
The estimated bilateral internal carotid artery stenoses of less than 50% indicates mild narrowing of both internal carotid arteries that does not require surgical intervention at this time. For patients with this finding, medical management is recommended, which includes antiplatelet therapy with aspirin 81-325 mg daily or clopidogrel 75 mg daily if aspirin-intolerant, as outlined in the guidelines for the prevention of stroke in patients with stroke or transient ischemic attack 1. Aggressive risk factor modification is essential, including statin therapy (such as atorvastatin 40-80 mg daily) to achieve LDL levels below 70 mg/dL, blood pressure control targeting less than 130/80 mmHg, smoking cessation, diabetes management with HbA1c goal of less than 7%, and lifestyle modifications including regular exercise and a Mediterranean or DASH diet. Some key points to consider in the management of carotid stenosis include:
- The degree of stenosis, with less than 50% considered mild and not requiring surgical intervention 1
- The presence of symptoms, such as transient ischemic attack (TIA) or stroke, which may influence the decision to proceed with surgical intervention 1
- Patient-specific factors, such as age, sex, and comorbidities, which may impact the risk of surgical intervention and the potential benefits of medical therapy 1 Regular follow-up with carotid ultrasound is recommended every 6-12 months to monitor for progression of stenosis. This approach is based on evidence showing that carotid stenosis less than 50% carries a relatively low stroke risk, and the benefits of surgical intervention (endarterectomy or stenting) do not outweigh the procedural risks at this degree of narrowing, as stated in the recent clinical consensus statement of the ESC Council on Stroke and the ESC Working Group on Aorta and Peripheral Vascular Diseases 1. Medical therapy effectively reduces stroke risk by stabilizing plaque and preventing thrombus formation. Key aspects of medical management include:
- Antiplatelet therapy to reduce the risk of thrombus formation
- Statin therapy to stabilize plaque and reduce inflammation
- Blood pressure control to reduce the risk of stroke and cardiovascular disease
- Lifestyle modifications, such as regular exercise and a healthy diet, to reduce the risk of cardiovascular disease.
From the Research
Estimated Bilateral Internal Carotid Artery Stenoses Less Than 50%
- The provided studies do not directly address the management or risks associated with bilateral internal carotid artery stenoses less than 50% 2, 3, 4, 5, 6.
- However, study 6 suggests that even low-grade internal carotid artery stenosis (20-40%) may be associated with an increased risk of ischemic stroke or transient ischemic attack (TIA), particularly if the plaque size is large.
- The study found that a plaque cross-sectional area ≥0.36 cm2 was associated with an increased risk of symptomatic internal carotid artery stenosis 6.
- Study 5 found that early progression from <60% asymptomatic internal carotid artery stenoses to ≥60% asymptomatic stenoses occurs infrequently, and patients who are at the greatest risk of early progression can be identified from the internal carotid artery peak systolic velocity at their initial duplex examination.
- Study 4 examined the natural history of moderate (50% to 79%) internal carotid artery stenosis and found that disease progression occurred in 16% of patients, and ipsilateral stroke occurred more frequently in patients with disease progression than in patients with stable lesions.
- Studies 2 and 3 discuss the use of antiplatelet therapy in patients with carotid artery stenosis, but do not specifically address bilateral internal carotid artery stenoses less than 50%.
- Aspirin is still recommended for prevention of vascular events in asymptomatic carotid stenosis patients 3.
- The use of peri-procedural aspirin-clopidogrel in patients undergoing endovascular treatment is based on one pilot trial, but appears safe 3.