What is Peripheral Artery Disease (PAD) in Cardiology?
Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis affecting the arteries supplying the lower extremities, and it represents a critical marker of cardiovascular disease that places patients at very high risk for myocardial infarction, stroke, and death. 1
Definition and Clinical Significance
PAD is characterized by blockage of peripheral arteries, most commonly those supplying the legs, typically resulting from atherosclerosis and thrombosis. 2 The disease affects over 200 million people worldwide, with prevalence increasing due to population aging and cardiovascular risk factors. 3, 2
PAD is fundamentally a cardiovascular disease, not merely a limb circulation problem. Patients with PAD—even without clinical evidence of coronary artery disease—have the same relative risk of death from cardiac or cerebrovascular causes as those with diagnosed coronary disease, reflecting the systemic nature of atherosclerosis. 4
Four Clinical Subsets
The 2024 ACC/AHA guidelines define PAD into four distinct clinical presentations: 1
- Asymptomatic PAD (may have functional impairment despite lack of classic symptoms)
- Chronic symptomatic PAD (including intermittent claudication—reproducible leg pain with exercise, relieved by rest) 5
- Chronic limb-threatening ischemia (compromised limb viability requiring urgent intervention)
- Acute limb ischemia (requires emergent evaluation to preserve the limb) 1
Why PAD Matters to Cardiologists
Cardiologists are uniquely positioned to screen, diagnose, and treat PAD because it shares common pathogenesis and risk factors with coronary artery disease. 6 The same risk factors—smoking, diabetes, hypertension, dyslipidemia, age, male sex, and Black race—drive both conditions. 7
However, PAD remains severely underdiagnosed and undertreated with significant medico-legal implications. 6 Only about 10% of PAD patients present with classic claudication symptoms, and asymptomatic PAD is the most frequent form worldwide. 7, 5 This creates a dangerous gap in care, as most patients with PAD have concomitant coronary disease, and much of their morbidity and mortality stems from myocardial infarction and stroke. 4
Cardiovascular Risk Profile
Patients with PAD are classified as very high cardiovascular risk and face substantially increased rates of major adverse cardiovascular events (MACE) and major adverse limb events (MALE). 1, 7 The burden includes: 3, 2
- Increased risk of myocardial infarction
- Elevated stroke risk
- Higher cardiovascular mortality
- Risk of limb amputation
- Substantially poorer walking performance and quality of life
Detection and Diagnosis
Detection is accomplished through history, physical examination, and resting ankle-brachial index (ABI), which is the primary diagnostic tool. 1 An ABI ≤0.9 confirms PAD diagnosis, while ABI ≥1.4 is noncompressible (common in diabetes and end-stage renal disease) and requires alternative testing. 5 If clinical suspicion is high with normal ABI, exercise ABI testing should be performed. 5
Core Management Principles from 2024 Guidelines
Medical therapy is the foundation of PAD management and must be prescribed to all patients to prevent cardiovascular and limb events: 1
Antithrombotic Therapy
- In symptomatic PAD: Low-dose rivaroxaban 2.5 mg twice daily combined with aspirin 81 mg daily is effective to reduce MACE and MALE (Class 1 recommendation). 8, 1
- In asymptomatic PAD: Single antiplatelet therapy is reasonable to reduce MACE risk (Class 2a). 8
- After revascularization: Rivaroxaban 2.5 mg twice daily plus aspirin is recommended (Class 1). 8
- After endovascular revascularization: Dual antiplatelet therapy (P2Y12 inhibitor plus aspirin) is reasonable for 1-6 months (Class 2a). 8
Lipid Management
- High-intensity statin therapy for all patients 1, 5
- For patients on maximally tolerated statins with LDL-C ≥70 mg/dL: Adding PCSK9 inhibitors or ezetimibe is reasonable (Class 2a). 8
Additional Medical Therapies
- Antihypertensive therapy for blood pressure control 1
- Antidiabetic agents, particularly GLP-1 receptor agonists and SGLT2 inhibitors 5
- Mandatory smoking cessation 1, 7
Exercise Therapy
Structured exercise is a core component of care for all PAD patients, including supervised exercise therapy and community-based programs. 8, 1 This improves functional status and quality of life. 1
Revascularization Indications
Revascularization (endovascular, surgical, or hybrid) should be used to: 1
- Prevent limb loss in chronic limb-threatening ischemia
- Improve quality of life and functional status in claudication patients not responsive to medical therapy and structured exercise
About 1 in 3 symptomatic PAD patients receive early revascularization, with more extensive disease burden and higher Rutherford class being the main predictors. 9
Multidisciplinary Care
Care for PAD patients, especially those with chronic limb-threatening ischemia, is optimized when delivered by a multispecialty care team. 1 This includes cardiologists, vascular surgeons, podiatrists, and wound care specialists. 8, 1
Health Disparities
Clinicians and healthcare systems must actively pursue evidence of health disparities in PAD diagnosis, treatment, and outcomes, and implement efforts to limit their impact (Class 1 recommendation). 8 This is a top priority given that disparities are associated with poor limb and cardiovascular outcomes. 1