Investigations in peripheral arterial disease

Routine investigations related to cardiovascular disease include fasting glucose and lipids.

Diagnosis of peripheral arterial disease (PAD) (1)

• a person should be assessed for PAD if:
  • has symptoms suggestive of peripheral arterial disease or
  • has diabetes, non-healing wounds on the legs or feet or unexplained leg pain or
  • are being considered for interventions to the leg or foot or
  • need to use compression hosiery
    
    
• if PAD is suspected then:
  • ask about the presence and severity of possible symptoms of intermittent claudication and critical limb ischaemia
  • examine the legs and feet for evidence of critical limb ischaemia, for example ulceration
  • examine the femoral, popliteal and foot pulses
  • measure the ankle brachial pressure index (2)
    
    
• imaging for revascularisation
  • duplex ultrasound as first-line imaging if PAD for whom revascularisation is being considered (3)
  • contrast-enhanced magnetic resonance angiography is indicated if PAD in (after duplex ultrasound) before considering revascularisation (4)
  • computed tomography angiography should be used in patient with PAD who need further imaging (after duplex ultrasound) if contrast-enhanced magnetic resonance angiography is contraindicated or not tolerated (4)
    
    
• with respect to diagnosing peripheral arterial disease in people with diabetes
  • do not exclude a diagnosis of peripheral arterial disease in people with diabetes based on a normal or raised ankle brachial pressure index alone
  • do not use pulse oximetry for diagnosing peripheral arterial disease in people with diabetes
    
    

Notes:

• non-invasive imaging modalities, include duplex ultrasonography, magnetic resonance angiography (MRA), and computed tomography angiography (CTA) (5)
  • duplex ultrasonography has a high specificity of 95% and a somewhat lower sensitivity of 88% for detecting hemodynamically significant lesions (>50% stenosis or occlusion)
  • gadolinium-enhanced MRA appears to be more accurate than duplex ultrasonography, with a specificity of about 96% and a sensitivity of about 98%
• computed tomography angiography
  • thinner slices, higher spatial resolution, and improvement of multidetector computed tomographic (CT) scanners enable scanning of the whole vascular tree in a limited period with a decreasing (but still substantial) amount of contrast medium. CTA has a reported sensitivity and specificity rates of around 98% for detecting PAD (5)
• claudication distance is an element in the history which quantifies the distance walked before claudication occurs
• exercise testing:
  • motorised treadmill or step tests - foot pressure normally rises with exercise but drops in the presence of occlusive arterial disease
  • the size of the pressure drop indicates the severity of the arterial insufficiency

References:

1. NICE (March 2018). Lower limb peripheral arterial disease: diagnosis and management
2. McDermott MM, Liu K, Greenland P, et al. Functional decline in peripheral arterial disease: associations with the ankle brachial index and leg symptoms. JAMA. 2004 Jul 28;292(4):453-61.
3. American College of Radiology. ACR Appropriateness Criteria. Lower extremity arterial claudication - imaging assessment for revascularization (revised). 2022 [internet publication].
4. American College of Radiology. ACR appropriateness criteria®: sudden onset of cold, painful leg. 2023 [internet publication].
5. Schernthaner R, Stadler A, Lomoschitz F, et al. Multidetector CT angiography in the assessment of peripheral arterial occlusive disease: accuracy in detecting the severity, number, and length of stenoses. Eur Radiol. 2008;18(4):665-671.