Friday, August 01, 2025

by Adam Irvine, Staff Writer, Physicians Office Resource

Peripheral Artery Disease (PAD) is a manifestation of systemic atherosclerosis that primarily affects the lower extremities. It is a common but often underdiagnosed condition, with significant implications for cardiovascular morbidity and mortality. As the population ages and diabetes and smoking rates continue to impact vascular health globally, early recognition and optimal management of PAD are crucial for reducing adverse outcomes. This article provides a brief overview of PAD, focusing on its pathophysiology, clinical presentation, diagnostic approaches, and evidence-based management.

Pathophysiology and Epidemiology

PAD is caused by atherosclerotic narrowing or occlusion of arteries, most commonly in the legs. It shares the same risk factors as coronary artery disease (CAD), including smoking, diabetes mellitus, hypertension, dyslipidemia, and advanced age.

An estimated 8.5 million people in the United States and over 200 million globally are affected by PAD. Despite its prevalence, PAD is underrecognized, especially in patients who are asymptomatic or who attribute their symptoms to aging or arthritis.

PAD is more than a localized limb problem. Patients with PAD have a significantly higher risk of myocardial infarction, stroke, and cardiovascular death, highlighting the importance of systemic risk factor management.

Clinical Presentation

PAD presents on a spectrum from asymptomatic disease to critical limb ischemia (CLI):

1. Asymptomatic PAD

Many patients (up to 50%) have no limb symptoms but have abnormal ankle-brachial index (ABI) measurements or imaging findings. These individuals remain at increased cardiovascular risk.

2. Intermittent Claudication

This is the most classic symptom—exertional muscle pain (typically in the calf, thigh, or buttocks) relieved by rest. It reflects hemodynamically significant arterial obstruction.

3. Atypical Leg Symptoms

Some patients present with leg fatigue or exertional discomfort without classic claudication. These cases are frequently misdiagnosed, underscoring the need for a high index of suspicion.

4. Critical Limb Ischemia (CLI)

Characterized by rest pain, non-healing wounds, or gangrene. CLI indicates advanced disease and a high risk of limb loss and cardiovascular death.

Diagnostic Evaluation

The goal of diagnostic testing is to confirm the presence of PAD, assess its severity, and guide treatment decisions.

1. Ankle-Brachial Index (ABI)

• Method: Ratio of systolic blood pressure at the ankle to that in the brachial artery.
• Interpretation:
• 1.30: Non-compressible vessels (often seen in diabetes, requires further testing)
• 1.00–1.30: Normal
• 0.91–0.99: Borderline
• 0.41–0.90: Mild to moderate PAD
• ≤0.40: Severe PAD
• Advantages: Inexpensive, non-invasive, and widely available.
• Limitations: May be falsely elevated in patients with calcified vessels (e.g., diabetes, ESRD).

2. Toe-Brachial Index (TBI)

• Used when ABI is unreliable due to non-compressible arteries. Toe pressures are typically unaffected by arterial calcification.

3. Segmental Limb Pressures and Pulse Volume Recordings (PVRs)

• Help localize the level of disease.
• Useful in conjunction with ABI to assess severity and guide revascularization planning.

4. Exercise ABI Testing

• Performed in patients with normal resting ABI but exertional symptoms.
• A post-exercise drop in ABI indicates flow-limiting disease.

5. Duplex Ultrasonography

• Provides anatomical and hemodynamic data.
• Useful for identifying the location and severity of stenosis or occlusion.
• First-line imaging for patients being considered for intervention.

6. Computed Tomography Angiography (CTA) and Magnetic Resonance Angiography (MRA)

• Offer detailed visualization of arterial anatomy.
• CTA is quick and widely available but requires iodinated contrast and radiation.
• MRA avoids radiation and uses gadolinium, but is contraindicated in certain renal patients.

7. Digital Subtraction Angiography (DSA)

• Gold standard for vascular imaging.
• Invasive but offers therapeutic potential during the same procedure.

Risk Factor Modification

The cornerstone of PAD management is aggressive risk factor modification to reduce cardiovascular risk and slow disease progression.

1. Smoking Cessation

• Strongly associated with PAD incidence and progression.
• All patients should receive counseling and access to pharmacotherapy (e.g., varenicline, nicotine replacement, bupropion).

2. Diabetes Management

• Tight glycemic control (A1c <7%) reduces microvascular complications and may slow PAD progression.
• Consider SGLT2 inhibitors or GLP-1 receptor agonists with cardiovascular benefit.

3. Hypertension Control

• Target <130/80 mmHg for most PAD patients.
• ACE inhibitors or ARBs are preferred for their cardiovascular benefits.

4. Lipid Management

• Statins are indicated for all PAD patients.
• High-intensity statin therapy reduces CV events and may improve walking distance.

5. Antiplatelet Therapy

• Aspirin (75–325 mg daily) or clopidogrel (75 mg daily) is recommended to reduce CV events.
• Dual antiplatelet therapy is not routinely recommended unless there's a recent revascularization.

Symptom Management and Functional Improvement

1. Exercise Therapy

• Supervised Exercise Therapy (SET) is first-line for patients with intermittent claudication.
• Typically consists of 30–45 minutes, 3 times/week for at least 12 weeks.
• Shown to improve walking distance more than pharmacologic therapy or revascularization alone.

2. Pharmacologic Therapy for Claudication

• Cilostazol (a phosphodiesterase III inhibitor) can improve walking distance in patients with claudication.
• Contraindicated in heart failure.
• Pentoxifylline is less effective and rarely used.

Revascularization

Indicated for patients with lifestyle-limiting symptoms unresponsive to medical therapy or those with CLI.

1. Endovascular Therapy

• Preferred first approach for many patients due to lower risk.
• Techniques include angioplasty, stenting, atherectomy.
• Best suited for focal disease, particularly in the iliac and superficial femoral arteries.

2. Surgical Revascularization

• Considered in patients with long-segment occlusions or those unsuitable for endovascular procedures.
• Includes bypass grafting using autologous vein or prosthetic conduit.

3. Hybrid Approaches

• Combine open and endovascular techniques for complex disease.

Management of Critical Limb Ischemia

CLI requires urgent evaluation by a vascular specialist. Goals are to relieve ischemia, promote wound healing, and prevent limb loss.

• Wound care and infection control are critical.
• Prompt revascularization (endovascular or surgical) is often necessary.
• Multidisciplinary care (vascular, wound, infectious disease, podiatry) improves outcomes.

Long-Term Monitoring and Follow-up

• Monitor ABI annually or more frequently in symptomatic patients.
• Assess for new or worsening symptoms.
• Reinforce adherence to medications, exercise, and lifestyle modification.
• Coordinate care with cardiology, endocrinology, and vascular surgery as needed.

Special Populations

1. Diabetic Patients

• Higher risk of CLI and limb loss.
• Foot care education and regular podiatric evaluations are essential.

2. Patients with Chronic Kidney Disease

• Increased risk of arterial calcification.
• Non-invasive testing (e.g., TBI, duplex) preferred over contrast-based imaging when possible.

Conclusion

Peripheral Artery Disease is a common, systemic atherosclerotic disease with significant implications for patient morbidity and mortality. For physicians, early recognition and proactive management—including risk factor control, symptom relief, and timely revascularization—are essential for improving outcomes.

An individualized approach, incorporating non-invasive diagnostics, lifestyle interventions, pharmacotherapy, and procedural options, ensures comprehensive care. Given the high cardiovascular risk associated with PAD, physicians must remain vigilant not only for limb symptoms but also for broader systemic disease implications.