Fibromuscular Dysplasia-Related Renal Artery Stenosis

• workup for FMD if HTN and one of more:
  • Asymmetrical kidneys (>1.5 cm difference)
  • Abdominal bruit without other athersclerosis
  • History of FMD in other vascular bed
  • Family histrory of FMD
• Workup:
  • CTA or MRA
• If FMD confirmed:
  • screen vasculature from head to pelvis with CTA or MRA:
    • cervicocephalic lesions, intracranial aneurysms, etc.

Management of FMD-RAS

• Refer for angioplasty (typically not stented due to risk of periprocedural dissection).

Atherosclerotic Renal Artery Stenosis

• 90% of RAS is due to ARAS (atherosclerotic RAS

Who to Screen?

Patients presenting with 2 or more of the following (HTN 2020 Guidelines): 1) Sudden onset or worsening hypertension age > 55 or < 30 2) Abdominal bruit 3) Resistant hypertension 4) Increase in Cr > 30% with RAASi 5) Other atherosclerotic disease 6) Recurrent flash pulmonary edema

How to screen? Any of: 1) Renal Doppler US 2) Captopril renogram (avoid if GFR < 60) 3) MRA 4) CTA (avoid if GFR < 60)

Landmark Studies Comparing Angioplasty to Medical Management

Study	Year	Summary
EMMA	1998	No difference in BP with angioplasty at 6 months
Scottish and Newcastle	1998	Lower BP in bilateral RAS with angioplasty. No difference in CV events or death
STAR	2009	No difference in renal function at 24 months with angioplasty/stent with >50% stenosis
ASTRAL	2009	After a mean follow up of 34 months, there was no significant difference in kidney outcomes, blood pressure control, or cardiovascular events (p=0.06). However, low risk RAS with 40% of them having less than 70% stenosis.
CORAL	2014	No difference in composite CV/renal outcome at 43 months. Higher risk patients than ASTRAL. Possibly lower SBP with stenting.

Current Management of ARAS

1. Optimal medical management is first-line therapy (IA recommendation)

   • RAAS inhibition (not contraindicated, but need to monitor K/Cr)
   • High intensity statin
   • Smoking cessation
   • HbA1c control
   • Antiplatelet agent

2. Refer for revascularization when medical management has failed (IIb recommendation, 2017 Hypertension Guidelines)

   • Conditions:
     • Refractory hypertension despite maximal medical therapy
     • Progressively worsening renal function
     • Acute pulmonary edema
   • Action:
     • Refer the patient for consideration of revascularization (percutaneous renal artery angioplasty and/or stent placement).

References

1. Landmark Trials in Renal Artery Stenosis
2. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Pra