What is the treatment for fibromuscular dysplasia?

Treatment of Fibromuscular Dysplasia

Antiplatelet therapy is the first-line treatment for all patients with fibromuscular dysplasia (FMD), while percutaneous transluminal angioplasty without stenting is the treatment of choice for symptomatic renal or cerebrovascular FMD. 1

Understanding FMD

Fibromuscular dysplasia is a non-atherosclerotic, non-inflammatory vascular disease that primarily affects medium-sized arteries. It most commonly involves the renal and carotid arteries but can affect almost any arterial bed. FMD predominantly affects women between 30-50 years of age, though it can occur in men and across all age groups.

Treatment Approach Based on Arterial Involvement

1. General Management for All FMD Patients

• Antiplatelet therapy: Administration of platelet inhibitor medication (typically aspirin 81-325 mg daily) is beneficial for all FMD patients to prevent thromboembolism 2, 1
• Regular surveillance: Annual non-invasive imaging of affected arteries is reasonable to detect changes in disease extent or severity 2, 1
• Specialist referral: Patients should be referred to specialized centers with multidisciplinary expertise 1

2. Renal Artery FMD

Medical Management

• Antihypertensive therapy: RAS blockers (ACE inhibitors or ARBs) are commonly used for hypertension management but require careful monitoring of renal function, especially in bilateral renal artery stenosis 2, 1

Interventional Management

• Percutaneous transluminal renal angioplasty (PTRA) without stenting is the treatment of choice for:

  • Patients with hypertension due to renal FMD 2, 1
  • Patients with resistant hypertension or medication intolerance 2
  • Patients with deteriorating renal function 2

• Long-term outcomes of PTRA for renal FMD show:

  • Technical success rates approaching 100% 3
  • Primary patency rates of 66% at 5 years 3
  • Assisted primary patency rates of 87% at 5 years 3
  • Clinical benefit in hypertension control maintained in 73% at 5 years 3

3. Cerebrovascular FMD (Carotid/Vertebral)

Medical Management

• Antiplatelet therapy: First-line treatment for all patients 2, 1

Interventional Management

• Carotid angioplasty with or without stenting is reasonable for:

  • Patients with retinal or hemispheric cerebral ischemic symptoms related to FMD of the ipsilateral carotid artery 2, 1
  • Patients who have not responded to antiplatelet therapy after acute carotid dissection 2

• Important: Revascularization is NOT recommended for patients with asymptomatic FMD of a carotid artery, regardless of stenosis severity 2, 1

4. FMD-Related Dissection

• Anticoagulation with intravenous heparin followed by warfarin (target INR 2.0-3.0) or low molecular weight heparin followed by warfarin for 3-6 months, then transition to antiplatelet therapy 2
• Carotid angioplasty and stenting might be considered when ischemic neurological symptoms have not responded to antithrombotic therapy 2

5. Upper Extremity FMD

• Medical therapy is first-line for symptomatic upper extremity FMD 4
• Angioplasty or surgical bypass may be necessary for patients with residual symptoms after medical therapy 4

Treatment Algorithm

1. Diagnosis confirmation via contrast-enhanced CTA, MRA, or catheter-based angiography
2. Determine if symptomatic:
   • If asymptomatic: Antiplatelet therapy + annual surveillance imaging
   • If symptomatic: Proceed to step 3
3. Identify arterial bed involved:
   • Renal FMD with hypertension: Optimize BP control with antihypertensives; if resistant hypertension or medication intolerance, proceed to PTRA without stenting
   • Cerebrovascular FMD with ischemic symptoms: Antiplatelet therapy; if symptoms persist, consider angioplasty with/without stenting
   • FMD with dissection: Anticoagulation for 3-6 months followed by antiplatelet therapy; if symptoms persist, consider angioplasty and stenting

Important Considerations

• FMD is a systemic disease that can affect multiple vascular beds; comprehensive vascular evaluation is important 1
• Stenting is generally avoided in FMD except in cases of dissection or aneurysm 5
• Surgical revascularization is reserved for cases where endovascular approaches fail or are not feasible 2
• Predictors of better long-term outcomes after intervention include shorter duration of hypertension (<8 years), normal renal function, and absence of metabolic syndrome 3

Monitoring After Treatment

• Regular clinical follow-up to assess symptom control
• Annual non-invasive imaging of treated arteries
• Lifelong antiplatelet therapy is generally recommended 1