What is the initial treatment approach for patients with fibromuscular dysplasia?

Initial Treatment Approach for Fibromuscular Dysplasia

All patients with fibromuscular dysplasia require antiplatelet therapy (aspirin 81-325 mg daily), blood pressure control, and lifestyle modification as the foundation of treatment, regardless of symptoms or vascular territory involved. 1, 2

Medical Management (First-Line for All Patients)

Antiplatelet Therapy

• Initiate aspirin 81-325 mg daily immediately for all patients with FMD, whether symptomatic or asymptomatic, particularly those with cranial involvement. 2, 3 This is a Class I recommendation from the American Heart Association and should not be withheld even in asymptomatic carotid FMD patients. 2

• Continue antiplatelet therapy long-term, especially when radiographic abnormalities persist. 2

• For patients with stroke/TIA attributable to dissection with FMD and no evidence of intraluminal thrombus, antiplatelet therapy (not anticoagulation) is the appropriate choice. 1, 2

Blood Pressure Control

• Start RAS blockers (ACE inhibitors or ARBs) as first-line antihypertensive agents when percutaneous intervention is not immediately feasible. 4, 3

• Critical caveat: Monitor renal function carefully when using RAS blockers, particularly in bilateral stenoses or solitary functioning kidney, as acute renal failure can occur. 4

• Alternative agents include calcium channel blockers (dihydropyridine or non-dihydropyridine) and alpha-receptor antagonists if RAS blockers are contraindicated. 4

Lifestyle Modification

• Address modifiable risk factors including smoking cessation, as smoking is implicated in the etiology of FMD. 5

Systemic Evaluation (Essential Initial Step)

FMD is a systemic arterial disease requiring comprehensive vascular evaluation at diagnosis—never assume isolated disease. 2, 4

• Perform CT or MRI angiography from head to pelvis at diagnosis to identify involvement in multiple vascular beds, particularly carotid, vertebral, renal, and iliac arteries. 4, 3

• Screen for intracranial aneurysms, as they can complicate cervicocranial FMD. 2

• Duplex ultrasonography serves as the initial screening test (Class I recommendation). 3

• Catheter angiography remains the gold standard when clinical suspicion is high and noninvasive tests are inconclusive, particularly in young patients who more often have lesions in branches of the renal artery. 3, 5

When to Consider Revascularization

Renal Artery FMD

Percutaneous transluminal renal angioplasty (PTRA) without stenting is the first-line revascularization technique for symptomatic renal FMD. 2, 4 This should be considered when:

• Hypertension cannot be controlled with antihypertensive drugs. 5
• Patients have impaired renal function or ischemic nephropathy. 5
• Hemodynamically significant renal artery stenosis is present (Class IIa recommendation). 4

Critical pitfall to avoid: Stenting should be reserved only for dissection or balloon angioplasty failure—never use stents as first-line therapy for renal FMD. 2, 4

Cerebrovascular FMD

• Do not revascularize asymptomatic carotid FMD, regardless of stenosis severity (Class III recommendation). 4, 3

• Carotid angioplasty with or without stenting may be reasonable for patients with cervical carotid artery FMD and recurrent ischemic stroke without other attributable causes despite optimal medical management (Class IIb recommendation). 1

• For patients with retinal or hemispheric cerebral ischemic symptoms related to FMD of the ipsilateral carotid artery, carotid angioplasty with or without stenting is reasonable (Class IIa recommendation). 4, 3

Surveillance Strategy

• Perform annual non-invasive imaging of carotid arteries initially to detect changes in disease extent or severity. 2, 4

• Imaging frequency may be reduced once stability is confirmed over time. 2, 4

• Use contrast-enhanced CTA, MRA, or catheter-based angiography for baseline imaging. 2

Critical Pitfalls to Avoid

• Never withhold antiplatelet therapy in asymptomatic carotid FMD patients—guidelines clearly support its use. 2

• Never use anticoagulation for intracranial dissections due to increased subarachnoid hemorrhage risk. 2

• Never perform revascularization based solely on stenosis severity in asymptomatic patients. 2

• Never use stenting as first-line therapy for renal FMD—balloon angioplasty alone is superior. 2, 4

• Perform procedures in experienced centers due to technical complexity and risk of complications. 4