What is the suspected cause of a patient's leg pain and tiredness that relieves with rest, characterized by intermittent claudication?

Peripheral Arterial Disease

The provider should suspect peripheral arterial disease (PAD) as the cause of these symptoms. The presentation of leg pain and tiredness that occurs with activity and requires prolonged rest (30 minutes) to resolve is characteristic of intermittent claudication, the hallmark symptom of PAD caused by atherosclerotic stenosis of the lower extremity arteries 1.

Clinical Reasoning

Classic Claudication Pattern

• Intermittent claudication is defined as fatigue, discomfort, or pain in specific limb muscle groups during effort that is relieved with rest 1.
• The typical presentation involves pain that is induced by walking, does not start at rest, and is usually relieved within approximately 10 minutes of rest 2, 3.
• However, this patient requires 30 minutes or more of rest for relief, which may indicate more severe disease or atypical presentation 1.

Why PAD is Most Likely

• PAD affects approximately 8-12% of the adult population, increasing to 20% in those over age 70 1.
• Only about 10% of PAD patients present with classic claudication symptoms; many have atypical presentations including prolonged recovery times 4.
• The bilateral nature of symptoms is consistent with PAD, which commonly affects both legs 1.
• PAD is caused by atherosclerotic stenosis or occlusion of arteries supplying the lower extremities 1.

Why Not the Other Options

Buerger's Disease (Thromboangiitis Obliterans):

• This is a rare inflammatory arteritis that typically affects young male smokers 1.
• It usually presents with more severe ischemic symptoms including rest pain, ulcers, or gangrene rather than simple claudication 1.
• The prolonged rest requirement in this case is more consistent with PAD than Buerger's disease.

Diabetic Neuropathy:

• Neuropathic pain is typically present at rest and does not follow the exercise-induced, rest-relieved pattern described 2, 5.
• Neuropathic symptoms include burning, tingling, or shooting sensations that are constant or positionally variable, not exercise-dependent 1, 2.
• The clear relationship between activity and symptom onset, with relief after rest, points away from neuropathy toward vascular claudication 1, 3.

Diagnostic Approach

Initial Testing

• Measure resting ankle-brachial index (ABI) bilaterally as the primary diagnostic test 5, 4.
• An ABI ≤0.90 confirms PAD diagnosis 5, 4.
• If resting ABI is normal or borderline (0.91-1.00) but clinical suspicion remains high, perform exercise treadmill ABI testing 5, 4.

Physical Examination Findings

• Assess for diminished or absent lower extremity pulses 3.
• Look for other signs of PAD including skin changes, hair loss, or cool extremities 1.

Clinical Significance and Prognosis

Critical Point: PAD is a marker of systemic atherosclerosis with profound implications for mortality and morbidity 1.

• Mortality in PAD patients is 2-3 times higher than age-matched controls, with 75% dying from cardiovascular events 1.
• All-cause mortality is 3.1 times greater and cardiovascular mortality is 5.9 times greater in PAD patients compared to those without PAD 1.
• The risk of myocardial infarction and stroke is markedly elevated in all PAD patients, regardless of symptom severity 1.
• However, the risk of limb loss in claudication is relatively low, with only 1-3% requiring major amputation over 5 years 6, 7.

Management Priorities

Once PAD is confirmed, treatment must address both symptom relief and cardiovascular risk reduction 1:

• Structured supervised exercise therapy (most effective conservative treatment) 4, 6.
• Single antiplatelet agent (clopidogrel preferred) 4.
• High-intensity statin therapy regardless of baseline cholesterol 4.
• Blood pressure control and antidiabetic agents (GLP-1 agonists and SGLT-2 inhibitors when applicable) 4.
• Smoking cessation if applicable 4, 7.
• Cilostazol as first-line pharmacotherapy for symptom relief 8, 6.