What is the diagnosis, management, and prognosis of Takayasu arteritis?

Takayasu Arteritis: Diagnosis, Management, and Prognosis

Takayasu arteritis is an idiopathic vasculitis of elastic arteries primarily affecting the aorta and its major branches, requiring high-dose corticosteroids as initial therapy followed by immunosuppressive agents, with revascularization procedures reserved for the quiescent phase of disease. 1, 2

Clinical Presentation and History

• Takayasu arteritis predominantly affects women (10:1 female-to-male ratio) and typically presents in the third decade of life 3
• The disease follows two distinct phases:
  • Acute inflammatory phase with constitutional symptoms (fever, weight loss, malaise)
  • Chronic phase with symptoms related to arterial stenosis and occlusion 2
• Two geographical distribution patterns exist:
  • Japanese type: primarily affecting thoracic aorta and great vessels
  • Indian type: primarily affecting abdominal aorta and renal arteries 1

Physical Examination Findings

• Diminished or absent peripheral pulses (hence the term "pulseless disease") 1
• Blood pressure discrepancy >10 mmHg between arms 1, 3
• Vascular bruits over subclavian arteries or aorta 1, 3
• Hypertension (often due to renal artery stenosis) 2
• Carotidodynia (tenderness over carotid arteries) 4
• Retinopathy in some cases 4

Etiology

• The exact cause remains unknown, but it is considered a T-cell-mediated panarteritis 1, 2
• The inflammatory process proceeds from adventitial vasa vasorum inward 1
• The disease leads to two pathological outcomes:
  • Destruction causing aneurysm formation
  • Fibrosis causing arterial stenosis 1, 2

Diagnostic Approach

• Diagnosis can be made using the 1990 American College of Rheumatology criteria when 3 of 6 criteria are present (90.5% sensitivity, 97.8% specificity):

  1. Age of onset <40 years
  2. Intermittent claudication
  3. Diminished brachial artery pulse
  4. Subclavian artery or aortic bruit
  5. Systolic blood pressure variation >10 mmHg between arms
  6. Angiographic evidence of aorta or branch vessel stenosis 1, 3

• Initial evaluation should include:

  • Laboratory tests: ESR and CRP to establish baseline inflammatory markers 3
  • Imaging: Thoracic aorta and branch vessel CT or MRI to detect aneurysms or occlusive disease 1, 3

Differential Diagnosis

• Giant cell arteritis (typically affects older patients)
• Atherosclerosis
• Fibromuscular dysplasia
• Behçet's disease (involves both arteries and veins) 2
• Aortic coarctation 1
• Other large vessel vasculitides

Management

Medical Treatment

1. Initial Corticosteroid Therapy:

   • High-dose oral prednisone 40-60 mg daily (or equivalent) 1, 3
   • Daily dosing preferred over alternate-day schedules 3

2. Add Non-Glucocorticoid Immunosuppressive Agent:

   • Methotrexate (20-25 mg/week) or azathioprine (2 mg/kg/day) as steroid-sparing agents 1, 3
   • For refractory cases, consider:
     • Leflunomide 5
     • TNF inhibitors 1, 5
     • Tocilizumab (IL-6 inhibitor) 5

3. Monitoring and Dose Adjustment:

   • Evaluate treatment success with physical examination and inflammatory markers (ESR/CRP) 1, 3
   • Aim to taper prednisone to 15-20 mg/day within 2-3 months, and to ≤10 mg/day within 1 year 3
   • Low-dose aspirin may be beneficial to prevent ischemic events 1, 5

Surgical/Interventional Management

• Key principle: Elective revascularization should be delayed until the acute inflammatory state is treated and quiescent 1

• Indications for intervention:

  • Critical stenosis causing organ ischemia
  • Aneurysm formation with risk of rupture
  • Uncontrollable hypertension due to renal artery stenosis 6, 7

• Intervention options:

  • Endovascular: Balloon angioplasty or stent placement (higher restenosis rate) 1, 6
  • Surgical: Bypass grafting (superior results for long-segment stenosis) 6, 8

Complications

• Arterial stenosis (occurs in 53% of patients) 2
• Aneurysm formation (23-32% of patients) 2
• Hypertension due to renal artery involvement 2
• Anastomotic aneurysm after surgical repair (cumulative incidence of 13.8% at 20 years) 7
• Vascular complications occur in 38% of patients after median follow-up of 6.1 years 4
• Progressive clinical course in 45% of patients 4
• Congestive heart failure (major cause of late death) 7

Prognosis

• The 5-year and 10-year complication-free survival rates are 69.9% and 53.7%, respectively 4
• The overall cumulative survival rate at 20 years is 73.5% 7
• Poor prognostic factors include:
  • Progressive disease course 4
  • Thoracic aorta involvement 4
  • Retinopathy 4
  • Male sex and elevated CRP are associated with higher relapse rates 4
• Mortality rates have improved in recent years with more effective medical treatments and appropriate use of endovascular interventions 5

Monitoring

• Regular clinical assessment and measurement of inflammatory markers (ESR/CRP) 1, 3
• Periodic imaging with MRI or CT to assess disease activity and detect complications 1
• Lifelong follow-up is essential, particularly after surgical intervention, with imaging at least once every several years to detect anastomotic aneurysms 7