Cardiology > Intermittent Claudication 

Background

Intermittent claudication (IC) refers to exertional pain, typically in the lower extremities, caused by insufficient arterial blood flow due to peripheral arterial disease (PAD). The pain is reproducible with physical activity (usually walking) and relieved by rest. It is a hallmark symptom of atherosclerotic obstruction in peripheral arteries, reflecting systemic vascular disease. 

II) Classification/Types

By Arterial Involvement (Anatomic Level): 

• • Aortoiliac disease: Buttock, hip, or thigh claudication. 

• • Femoropopliteal disease: Calf pain (most common). 

• • Infrapopliteal/tibial disease: Foot claudication, typically seen in diabetics. 

By Functional Impairment: 

• • Mild: Walks >200 meters before pain. 

• • Moderate: Walks 100–200 meters. 

• • Severe: Walks <100 meters or lifestyle-limiting. 

By Progression: 

• • Intermittent Claudication: Pain only with exertion. 

• • Rest Pain: Pain at night or when supine, relieved by hanging foot off the bed. 

• • Critical Limb Ischemia: Rest pain with tissue loss (ulcers/gangrene). 

III) Pathophysiology 

Atherosclerosis leads to narrowing or occlusion of peripheral arteries, especially in the lower extremities. During exercise, increased muscle demand for oxygen exceeds the restricted blood supply, resulting in ischemic pain. Rest allows oxygen demand to fall, relieving the pain. Chronic hypoperfusion also leads to impaired wound healing and risk of limb loss in advanced cases. 

IV) Epidemiology

Sex: More common in men, though prevalence in women rises with age. 
Age: Incidence increases sharply after age 60. 
Geography: More common in high-income countries due to lifestyle and dietary risk factors. 
Comorbidities: Commonly associated with coronary artery disease, diabetes, hyperlipidemia, hypertension, and smoking. 

Etiology

I) Causes

• • Atherosclerosis (most common) 

• • Thromboangiitis obliterans (Buerger’s disease) 

• • Arterial embolism or thrombosis 

• • Fibromuscular dysplasia 

• • Vasculitis (e.g., Takayasu arteritis) 

• • External compression (e.g., popliteal artery entrapment) 

II) Risk Factors

• • Smoking (most significant modifiable risk factor) 

• • • Diabetes mellitus 

• • • Hypertension 

• • • Hyperlipidemia 

• • • Chronic kidney disease 

• • • Obesity 

• • • Sedentary lifestyle 

• • • Family history of cardiovascular disease 

Clinical Presentation

I) History (Symptoms)

• • Cramping, aching, or fatigue in calf, thigh, or buttock muscles during walking 

• • Pain relieved by rest within minutes 

• • Reduced walking distance over time 

• • In severe disease: rest pain, ulcers, or gangrene 

II) Physical Exam (Signs)

Vital Signs: 

• • May show signs of comorbid hypertension or diabetes 

Vascular Exam: 

• • Diminished or absent distal pulses (e.g., dorsalis pedis, posterior tibial) 

• • Bruits over femoral or iliac arteries 

• • Cool, pale extremities with poor capillary refill 

• • Trophic changes: hair loss, shiny skin, nail thickening 

• • Dependent rubor, elevation pallor 

Functional Tests: 

• • Buerger’s test: limb pallor on elevation, rubor on dependency 

• • ABI (ankle-brachial index) measurement 

Differential Diagnosis (DDx)

• • Spinal stenosis (neurogenic claudication) 

• • Chronic venous insufficiency 

• • Musculoskeletal pain (e.g., osteoarthritis, tendonitis) 

• • Compartment syndrome (chronic exertional) 

• • Peripheral neuropathy 

• • Deep vein thrombosis 

• • Popliteal artery entrapment syndrome 

Diagnostic Tests

Initial Tests: 

Ankle-Brachial Index (ABI): 

• • ABI < 0.90 confirms PAD 

• • ABI 0.4–0.9: claudication 

• • ABI < 0.4: critical limb ischemia 

Exercise ABI Testing: 

• • ABI may be normal at rest but decrease after exercise in early disease 

Duplex Ultrasonography: 

• • Identifies site and severity of arterial stenosis 

Advanced Imaging: 

• • CTA (CT Angiography): High-resolution vascular mapping 

• • MRA (Magnetic Resonance Angiography): Good for surgical planning 

• • Conventional Angiography: Gold standard; used when intervention is planned 

Laboratory Tests: 

• • Lipid profile 

• • HbA1c 

• • Renal function (for contrast safety) 

• • CBC (anemia can worsen claudication) 

Treatment

I) Medical Management

Lifestyle Modification: 

• • Smoking cessation (single most important intervention) 

• • Structured walking/exercise program (30–45 mins, ≥3 times/week) 

• • Weight loss and dietary changes 

Pharmacotherapy: 

• • Antiplatelet agents: Aspirin or clopidogrel 

• • Statins: To reduce cardiovascular risk and plaque progression 

• • Cilostazol: Phosphodiesterase inhibitor that improves walking distance 
    (contraindicated in heart failure) 

• • Antihypertensives and glucose control as indicated 

II) Interventional/Surgical

Indications: 

• • Lifestyle-limiting claudication refractory to medical therapy 

• • Critical limb ischemia (rest pain, ulcers, gangrene) 

Endovascular (preferred): 

• • Percutaneous transluminal angioplasty (PTA) 

• • Stenting for significant lesions 

Surgical: 

• • Bypass grafting (e.g., femoropopliteal bypass) 

• • Endarterectomy 

• • Amputation (last resort in severe tissue loss) 

Patient Education, Screening, Vaccines

• • Importance of regular walking to promote collateral formation 

• • Smoking cessation programs 

• • Foot care and hygiene (especially in diabetics) 

• • Monitor for new or worsening symptoms 

• • Control of blood pressure, lipids, glucose 

• • Vaccinations: 

• • Influenza annually 

• • Pneumococcal vaccine 

• • COVID-19 vaccine 

Consults

• • Vascular Surgery: For patients with refractory symptoms or critical limb ischemia 

• • Cardiology: For concomitant CAD or elevated cardiovascular risk 

• • Endocrinology: For diabetes management 

• • Primary Care/Internal Medicine: For comprehensive risk factor control 

• • Podiatry: For foot care and ulcer prevention 

• • Physical Therapy: For supervised exercise therapy 

Follow-Up

• • ABI every 6–12 months or with symptom progression 

• • Monitor for signs of critical limb ischemia (e.g., rest pain, ulcers) 

• • Reassess walking capacity and modify therapy accordingly 

• • Regular follow-up for risk factor management (lipids, glucose, BP) 

• • Reinforce lifestyle interventions at each visit