What is the management for a patient with 45% extra cranial artery narrowing due to atherosclerosis, already on single antiplatelet (antiplatelet) therapy, with no history of stroke symptoms?

Management of Asymptomatic 45% Extracranial Carotid Stenosis

Continue single antiplatelet therapy with aspirin 75-325 mg daily (or clopidogrel 75 mg daily if already on it), add high-intensity statin therapy targeting LDL <70 mg/dL, optimize blood pressure to <140/90 mmHg, and do NOT perform revascularization procedures. 1, 2

Antiplatelet Therapy

• Continue your current single antiplatelet agent as this is the cornerstone of therapy for asymptomatic extracranial atherosclerosis 1
• Aspirin 75-325 mg daily is recommended for prevention of myocardial infarction and other ischemic cardiovascular events, though the stroke prevention benefit specifically has not been established in asymptomatic patients 1
• If the patient is on clopidogrel 75 mg daily, this is an acceptable alternative and should be continued 1, 3
• Do NOT add a second antiplatelet agent (dual antiplatelet therapy) as this increases bleeding risk without proven benefit in asymptomatic disease and is specifically not recommended 1
• Antiplatelet agents are preferred over oral anticoagulation for asymptomatic extracranial atherosclerosis 1

Intensive Medical Therapy (Critical Component)

Lipid Management

• Start high-intensity statin therapy immediately regardless of baseline LDL levels—statins are indicated for plaque stabilization independent of lipid values 1, 3
• Target LDL cholesterol to <70 mg/dL (1.8 mmol/L) 1
• If statin therapy alone does not achieve target, add ezetimibe or PCSK9 inhibitors 1, 4
• For patients with statin intolerance, use bile acid sequestrants and/or niacin 1

Blood Pressure Control

• Target blood pressure <140/90 mmHg 1
• Preferentially use thiazide diuretics, ACE inhibitors, or angiotensin II receptor blockers 4

Diabetes Management (if applicable)

• Target HbA1c ≤7% for most patients through combination of diet, insulin, and hypoglycemic drugs 1, 4

Lifestyle Modifications

• Mandatory smoking cessation with counseling and pharmacotherapy if the patient smokes 1
• Encourage at least moderate physical activity—minimum 10 minutes of moderate-intensity aerobic activity 4 times per week 1, 4
• Diet modification focusing on Mediterranean or DASH-style eating patterns 1

Surveillance Strategy

• Perform annual noninvasive imaging (carotid duplex ultrasound, CTA, or MRA) initially to assess disease progression 2, 3
• Once arterial stability is confirmed over 1-2 years, imaging frequency can be reduced 2, 3
• More frequent surveillance may be warranted if the patient has diabetes, chronic kidney disease, dyslipidemia, or continues smoking 3

Revascularization: NOT Indicated

• Do NOT perform carotid endarterectomy or carotid stenting for this patient 2, 3
• Revascularization procedures should NOT be performed in asymptomatic patients with <70% stenosis, and even at 70% stenosis, the benefit is controversial given modern medical therapy 1
• The 45% stenosis is well below any threshold where revascularization would be considered 1

Critical Pitfalls to Avoid

• Do not withhold statin therapy based on "normal" lipid levels—the indication is plaque stabilization, not just lipid lowering 3
• Do not add dual antiplatelet therapy in asymptomatic disease as this increases bleeding risk without proven benefit 1
• Do not consider revascularization at this degree of stenosis—it provides no benefit and carries procedural risk 2, 3
• Do not use anticoagulation (warfarin, DOACs) instead of antiplatelet therapy for asymptomatic carotid disease 1

Special Considerations

• If the patient develops any neurological symptoms (TIA, stroke, amaurosis fugax), this changes management entirely and requires urgent re-evaluation for potential revascularization if stenosis progresses to >50-70% 1
• The combination of aggressive medical therapy has been shown to reduce stroke rates to approximately 2% per year in asymptomatic patients, which is lower than the procedural risk of revascularization 1