What is the workup for peripheral arterial disease?

Workup for Peripheral Arterial Disease

The comprehensive workup for peripheral arterial disease (PAD) should include a targeted history, thorough vascular physical examination, ankle-brachial index measurement, and appropriate imaging studies based on clinical presentation. 1

Clinical History Assessment

Symptoms to Evaluate:

• Walking impairment and claudication characteristics (fatigue, aching, numbness, pain)
• Location of discomfort (buttock, thigh, calf, foot)
• Relationship of symptoms to rest or exertion
• Presence of poorly healing or non-healing wounds on legs/feet
• Pain at rest in lower leg or foot and its association with position
• Postprandial abdominal pain with associated weight loss 1

Risk Factor Assessment:

• Smoking history
• Diabetes mellitus
• Dyslipidemia
• Hypertension
• Family history of PAD or abdominal aortic aneurysm
• Age (≥65 years or 50-64 years with risk factors) 1, 2

Physical Examination

Key Components:

1. Blood pressure measurement in both arms (noting any asymmetry)

2. Comprehensive pulse examination:

   • Palpation of carotid, brachial, radial, ulnar, femoral, popliteal, dorsalis pedis, and posterior tibial pulses
   • Record pulse intensity numerically: 0 (absent), 1 (diminished), 2 (normal), 3 (bounding) 1

3. Vascular auscultation:

   • Carotid arteries for bruits
   • Abdomen and flank for bruits
   • Femoral arteries for bruits 1

4. Lower extremity examination:

   • Inspection of feet with shoes and socks removed
   • Assessment of skin color, temperature, and integrity
   • Evaluation of intertriginous areas
   • Documentation of ulcerations
   • Observation for signs of severe PAD (distal hair loss, trophic skin changes, hypertrophic nails) 1, 3

5. Abdominal examination:

   • Palpation for aortic pulsation and assessment of maximal diameter 1

Diagnostic Testing

First-Line Testing:

• Ankle-Brachial Index (ABI): Most important initial diagnostic test

  • ABI ≤0.9 indicates PAD
  • ABI values: Normal (1.0-1.4), Borderline (0.91-0.99), Mild-moderate PAD (0.41-0.90), Severe PAD (≤0.40) 1, 4
  • For incompressible arteries or ABI >1.40, use alternative methods:
    • Toe-brachial index
    • Doppler waveform analysis
    • Pulse volume recording 1

• Post-exercise ABI for patients with normal resting ABI but symptoms of claudication 2

Vascular Imaging:

• Duplex Ultrasound: First-line imaging method to confirm and characterize PAD lesions 1

• Advanced Imaging (when revascularization is being considered):

  • CT Angiography (CTA)
  • MR Angiography (MRA)
  • Conventional angiography (for definitive lesion characterization prior to intervention) 1

Special Considerations

Diagnostic Pitfalls:

• Peripheral neuropathy (especially in diabetics) can mask symptoms of PAD 2
• Pseudoclaudication must be distinguished from true vascular claudication:
  • Venous obstructive disease
  • Chronic compartment syndrome
  • Lumbar disease and spinal stenosis
  • Osteoarthritis
  • Inflammatory muscle diseases 2

Comprehensive Assessment:

• Evaluate impact on daily activities and quality of life
• Consider overall cardiovascular risk, not just leg symptoms
• Assess for coexisting coronary and cerebrovascular disease 2, 1

Clinical Pathway Algorithm

1. Initial Assessment: History, physical examination, and ABI measurement
2. If ABI ≤0.9: Confirm PAD diagnosis
3. If ABI >1.4 or incompressible vessels: Proceed to alternative tests (toe-brachial index, etc.)
4. If PAD confirmed: Assess severity and functional impact
5. For anatomical characterization: Order duplex ultrasound as first-line imaging
6. If revascularization being considered: Proceed to CTA or MRA
7. For complex cases or prior to intervention: Consider conventional angiography 1

Remember that PAD is a marker for systemic atherosclerosis, and patients with PAD have a significantly increased risk of cardiovascular events including myocardial infarction, stroke, and vascular death 2, 4.