Peripheral arterial disease (PAD) is a common condition where the arteries that supply blood to the legs and feet become narrowed due to a build-up of fattyCommentHighlight deposits, known as atherosclerosis. It reduces blood flow, which can lead to symptoms like pain when walking (claudication) and in severe cases, critical limb ischaemia. PAD is an important marker for systemic atherosclerosis and indicates a higher risk of heart attack and stroke
Causes
- Atherosclerosis (primary cause)
- Diabetes mellitus
- Smoking
- High blood pressure (hypertension)
- High cholesterol (hyperlipidaemia)
- Obesity
- Inflammatory conditions such as vasculitis
- Blood vessel injury or trauma
- Radiation exposure damaging blood vessels
Pathophysiology
PAD develops mainly due to atherosclerosis. In this process, cholesterol and fatty substances build up inside the walls of the arteries forming plaques. These plaques harden over time, narrowing the artery and reducing blood flow to tissues. During physical activity, the increased demand for oxygen cannot be met, causing pain and cramps. Over time, the lack of oxygen can cause tissue damage, leading to ulcers, infections, and possibly limb loss.
Signs and Symptoms
- Pain, cramping or tiredness in the legs or hips during walking or exercise, relieved by rest (intermittent claudication)
- Weak or absent pulses in the legs or feet
- Numbness, weakness, or heaviness in the legs
- Cold or pale legs and feet
- Sores or wounds on the toes, feet, or legs that do not heal
- Shiny skin, hair loss on legs, or brittle toenails
- Severe cases may present with resting pain, ulcers, or gangrene (critical limb ischaemia)
Risk Factors
- Smoking (the strongest modifiable risk factor)
- Diabetes mellitus
- Age over 60 years
- Hypertension
- Hyperlipidaemia
- Chronic kidney disease
- Obesity and sedentary lifestyle
- Family history of cardiovascular diseases
Investigation
- Ankle-Brachial Pressure Index (ABPI): measures the ratio of the blood pressure at the ankle to that in the arm; an ABPI less than 0.9 suggests PAD
- Duplex ultrasound scan: assesses blood flow and identifies narrowed arteries
- Magnetic Resonance Angiography (MRA) or CT Angiography: provides detailed imaging of arteries
- Digital Subtraction Angiography (DSA): gold standard for vascular imaging when interventions are planned
- Blood tests: lipid profile, HbA1c (for diabetes), kidney function, and inflammatory markers
- Electrocardiogram (ECG): to assess for underlying cardiac disease
Management
1. Non-Pharmacological Management
- Smoking cessation: essential for preventing progression
- Exercise programme: supervised exercise therapy (walking to the point of maximal pain) is recommended to improve symptoms and walking distance
- Diet: heart-healthy diet rich in fruits, vegetables, and whole grains; low in saturated fats
- Weight management: if overweight or obese
- Patient education: regarding symptom awareness, foot care, and when to seek medical help
2. Pharmacological Management
- Antiplatelet therapy: either aspirin or clopidogrel is recommended to reduce the risk of heart attack or stroke
- Statins: to lower cholesterol and stabilise plaques; atorvastatin 80 mg is often used
- Blood pressure control: using ACE inhibitors or calcium channel blockers according to NICE guidelines
- Glycaemic control: good diabetes control to reduce vascular complications
- Pain management: sometimes cilostazol may be considered to improve walking distance, although it is not a first-line treatment in the UK
3. Surgical Management
- Percutaneous transluminal angioplasty: minimally invasive procedure to widen narrowed arteries
- Stenting: insertion of a small mesh tube to keep the artery open
- Bypass surgery: creating a new route for blood flow around a blockage using a graft
- Amputation: only considered in cases of non-salvageable limb due to severe critical limb ischaemia
Complications
- Critical limb ischaemia (severe reduction of blood flow to the leg)
- Ulcers and infections
- Gangrene and possible limb loss
- Increased risk of myocardial infarction and stroke
- Significant reduction in mobility and quality of life
- Psychological impact such as depression or anxiety
References
- National Institute for Health and Care Excellence (NICE) Guideline NG158:
Peripheral arterial disease: diagnosis and management - Royal College of Physicians Clinical Guidance on Peripheral Arterial Disease
- General Medical Council (GMC) Good Medical Practice 2024
- European Society of Cardiology Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases (adapted for UK practice)