Background Information
Definitions
PAD is defined by the presence of atherosclerotic obstruction in the peripheral arteries of the lower limb
The clinical presentation of PAD can be categorised into 4 subsets: [Ref]
- Asymptomatic
- Chronic symptomatic PAD
- Chronic limb-threatening ischaemia (old term: critical limb ischaemia)
- Acute limb ischaemia: sudden (<2 weeks) decrease in limb perfusion that threatens limb viability (covered in a separate article)
Clinical Features
Patients with PAD often have concomitant cardiovascular risk factors:
- Smoking
- Diabetes
- Hyperlipidaemia
- History of coronary artery disease / cerebrovascular disease
There are 3 main clinical manifestations of chronic PAD: [Ref]
| Presentation | Symptoms | Signs |
|---|---|---|
| Asymptomatic | Note that these patients may self-limit and adapt their activity to remain below their ischemic threshold to avoid leg pain |
|
| Chronic symptomatic PAD | Most commonly presents as intermittent claudication (“angina of the legs”):
Location of pain:
|
|
| Chronic limb-threatening ischaemia (critical limb ischaemia – old term) | Characterised by the presence of
|
Characterised by the presence of tissue loss:
Other findings:
|
Key exam presentations:
- Pain with walking that is relieved by rest = intermittent claudication
- Pain at rest +/- ulcer or gangrene = chronic limb-threatening ischaemia (critical limb ischaemia)
Guidelines
Investigation and Diagnosis
Approach:
- 1st line: clinical history + peripheral vascular examination, including ABPI
- Perform imaging in secondary care if revascularisation is being considered
ABPI (Ankle Brachial Pressure Index)
How to measure:
- Similar to measuring a clinic BP – instead of using a stethoscope, a handheld Doppler is used
- BP cuff placed on the arm and ankle
- Use the Doppler to locate the pulse (DP, PT pulses & brachial pulses)
- Inflate the cuff until the pulse is no longer audible on the Doppler
- Deflate the cuff slowly and note the pressure (systolic BP) when Doppler is audible again
ABPI calculation: highest ankle systolic BP (DP or PT) / highest brachial systolic BP (right or left arm)
ABPI interpretation:
| ABPI | Interpretation |
|---|---|
| >1.4 | May suggest arterial calcification/stiffness (typically diabetes) Unable to rule in or out PAD |
| 1.0 – 1.4 | Normal |
| ≤0.9 | PAD |
| <0.5 | Chronic limb-threatening ischaemia |
Do not exclude PAD in patients with diabetes based on a normal or raised ABPI alone.
ABPI has limited sensitivity for detecting PAD, particularly in people with diabetes or CKD, where arterial calcification may produce falsely normal or elevated readings. [Ref]
Alternative test if ABPI >1.4 (suggesting non-compressible / calcified arteries): toe-brachial index (TBI) [Ref]
- Similar principle to ABPI, but compares toe systolic pressure with brachial systolic pressure
- Toe arteries are less affected by arterial calcification, so TBI can be more reliable when ABPI is falsely elevated
Imaging
Imaging should be performed if revascularisation is being considered:
- 1st line: duplex ultrasound
- 2nd line: MR angiography with contrast
- 3rd line: CT angiography
Management
Definitive Management
Intermittent Claudication
| Step 1 | Supervised exercise programme |
| Step 2 | Revascularisation (ensure to perform imaging to assess suitability – see above for choice of imaging):
|
| Step 3 (if surgery is inappropriate) | Naftidrofuryl oxalate |
Bypass surgery is preferred over angioplasty +/- stenting as 1st line revascularisation in the following: [Ref]
- Multilevel occlusions, or
- Long-segment (>10 cm) occlusions, or
- Lesions involving the common femoral artery and profunda femoris artery origin
Chronic Limb-Threatening Ischaemia (Critical Limb Ischaemia)
Refer all patients to vascular MDT to make treatment decisions with consideration of revascularisation
For those who require revascularisation:
- Offer angioplasty or bypass surgery
- The following factors should be taken into consideration while choosing the type of revascularisation
- Comorbidities
- Pattern of disease
- Availability of a vein
- Patient preference
Do NOT offer major amputation until all revascularisation options have been considered by the vascular MDT
NICE reviewed CG147 in April 2026 and noted that its recommendations on the management of critical limb ischaemia may now be out of date and are due to be updated.
Pending this update, selected recommendations from the 2024 ACC/AHA PAD guideline are summarised below: [Ref]
- Chronic limb-threatening ischaemia should trigger assessment for revascularisation (see imaging section above), and revascularisation is recommended when feasible
- Factors that may favour bypass surgery over endovascular revascularisation:
- Multilevel chronic total occlusions, or
- Long-segment occlusions, esp. involving below-knee popliteal / infrapopliteal arteries, or
- Lesions involving the common femoral artery and profunda femoris artery origin
- Availability of a suitable autologous vein (e.g. great saphenous vein)
Secondary Prevention
- Lifestyle changes (e.g. smoking cessation) + treat comorbidities (e.g. hypertension, diabetes, dyslipidaemia)
- Atorvastatin 80 mg (as per the Lipid Lowering Therapy and Cardiovascular Risk Reduction guidance)
- Antithrombotic therapy options
- Clopidogrel
- Aspirin + rivaroxaban (for symptomatic PAD who are at high risk of ischaemic events)
- Semaglutide (GLP-1 agonist) is recommended if ALL the following are met:
2024 ACC/AHA guidelines recommend low-dose rivaroxaban + aspirin following endovascular or surgical revascularisation. [Ref]
Although not specifically addressed in NICE guideline, this approach is used in UK clinical practice