What is the best management approach for a young to middle-aged female patient with Fibromuscular Dysplasia (FMD), presenting with Hypertension (elevated blood pressure) and an audible bruit?

Management of BP 149/74 with Audible Bruit in FMD Patient

Start all FMD patients on antiplatelet therapy (aspirin 81-325 mg daily) immediately and initiate blood pressure control with ACE inhibitors or ARBs as first-line agents, while simultaneously pursuing imaging to confirm the diagnosis and assess for hemodynamically significant stenosis that may warrant percutaneous transluminal renal angioplasty (PTRA). 1, 2, 3

Immediate Medical Management

Antiplatelet Therapy

• Initiate aspirin 81-325 mg daily for all FMD patients, regardless of symptoms or stenosis severity. 2, 3
• Continue antiplatelet therapy long-term, especially when radiographic abnormalities persist. 3
• This is a universal recommendation for FMD patients due to increased cardiovascular risk (13.4% TIA rate, 12% cervical artery dissection rate, 9.8% stroke rate). 1

Blood Pressure Control

• Start RAS blockers (ACE inhibitors or ARBs) as first-line antihypertensive agents. 1, 2
• Your patient's BP of 149/74 mmHg requires treatment to prevent arterial dissection and other complications. 2
• Monitor renal function carefully after initiating RAS blockers, particularly if bilateral stenoses or solitary functioning kidney is present, as acute renal failure can occur. 2
• Alternative agents if RAS blockers are contraindicated include calcium channel blockers (dihydropyridine or non-dihydropyridine) and alpha-receptor antagonists. 2

Diagnostic Workup for the Audible Bruit

Imaging Strategy

• Perform duplex ultrasonography as the initial screening test (Class I recommendation). 1, 2
• If ultrasonography is inconclusive or shows significant stenosis, proceed to CT angiography or MR angiography (Class I recommendation). 1, 2
• Catheter angiography remains the gold standard when clinical suspicion is high and noninvasive tests are inconclusive, particularly for detecting branch vessel involvement common in younger FMD patients. 1, 4

Laboratory Assessment

• Obtain a morning plasma aldosterone and plasma renin activity to screen for primary aldosteronism, as resistant hypertension is common in FMD. 5
• Very elevated renin levels raise suspicion for renovascular hypertension and support consideration for revascularization. 2
• Assess 24-hour urinary sodium or sodium-to-creatinine ratio in morning urine to evaluate sodium intake. 1
• Do NOT use captopril renal scintigraphy, selective renal vein renin measurements, or plasma renin activity as screening tests (Class III recommendation). 1, 2

Indications for Revascularization

When to Proceed with PTRA

Consider percutaneous transluminal renal angioplasty without stenting (Class IIa recommendation) if: 1, 2

• Hypertension remains refractory despite optimal medical management
• Worsening renal function occurs
• Hemodynamically significant stenosis is confirmed on imaging
• Recent onset hypertension in a young patient (your patient fits this profile with an audible bruit)

Technical Approach

• PTRA without stenting is the first-line revascularization technique for symptomatic renal FMD. 1, 2, 3
• Never use stents as first-line therapy—reserve stenting only for dissection or balloon angioplasty failure. 2, 3
• Perform procedures in experienced centers due to technical complexity. 2
• PTRA normally yields excellent results, especially in unifocal disease and young patients, with complete abolition of pressure gradients. 4

Systemic Disease Surveillance

Comprehensive Vascular Evaluation

• FMD is a systemic arterial disease requiring evaluation of multiple vascular beds beyond the initially symptomatic site. 1, 2, 3
• Perform CT or MRI angiography from head to pelvis at diagnosis to identify involvement in carotid, vertebral, renal, and iliac arteries. 2
• Screen for aneurysms, as they represent a potential complication requiring surveillance or intervention. 2

Ongoing Monitoring

• Perform annual non-invasive imaging of carotid arteries initially to detect disease progression (Class IIa recommendation). 1, 2, 3
• Reduce imaging frequency once stability has been confirmed over time. 1, 2, 3
• Regular blood pressure monitoring and renal function assessment are essential for all patients with renal artery FMD. 2

Critical Pitfalls to Avoid

• Never assume isolated disease—the audible bruit indicates renal involvement, but always evaluate other vascular territories. 2
• Never withhold antiplatelet therapy in asymptomatic patients—guidelines clearly support universal use. 3
• Never use stents as first-line therapy for renal FMD—balloon angioplasty alone is superior. 2, 3
• Monitor renal function closely when using RAS blockers to prevent acute kidney injury, particularly in bilateral disease. 2
• Continued follow-up is necessary since stenosis can recur after PTRA. 6
• Delayed diagnosis may result in failure to normalize blood pressure even after successful angioplasty. 6