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Peripheral Arterial Disease Hub

Peripheral arterial disease (PAD) is atherosclerotic occlusive disease of the lower extremity arteries causing reduced blood flow. This module covers recognition, classification, workup, medical therapy, revascularization concepts, and limb salvage — including critical limb-threatening ischemia.

Cardiology APPsNursesMAsInterventional Cardiology Staff

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🦵PAD

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Pre-Test — Peripheral Arterial Disease

~2 min

Answer a few quick questions before starting to measure your learning gain.

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Overview

Learning Objectives

1.Define PAD and identify common risk factors
2.Interpret Ankle-Brachial Index (ABI) values
3.Distinguish claudication, rest pain, and critical limb-threatening ischemia (CLTI)
4.Describe the Fontaine and Rutherford classification systems
5.Identify key physical exam findings in PAD
6.Understand the diagnostic workup including duplex ultrasound and CTA
7.Review evidence-based medical therapy: antiplatelet, statin, ACEi, and cilostazol
8.Recognize when urgent referral for revascularization is required
9.Apply limb salvage and wound care concepts
10.Communicate effectively with Spanish-speaking patients about PAD

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APP Lesson: PAD Foundations

Audience: Cardiology APPs, nurses, and MAs working with a physician who performs peripheral vascular procedures.

What is PAD?

›Peripheral arterial disease (PAD) is atherosclerotic occlusive disease of the lower extremity arteries. Atherosclerotic plaques narrow the arterial lumen, reducing blood flow to the legs and feet.
›PAD is a manifestation of systemic atherosclerosis — patients with PAD have significantly elevated cardiovascular risk and frequently have coexisting coronary artery disease and cerebrovascular disease.
›The global prevalence is estimated at over 200 million people. In the United States, PAD affects approximately 8–12 million individuals, with higher rates in older adults, diabetics, and smokers.

Risk Factors

›Smoking — the strongest modifiable risk factor; increases PAD risk 2–4x and accelerates progression
›Diabetes mellitus — increases PAD risk 2–4x; associated with atypical presentations and poor wound healing
›Hypertension — promotes atherosclerosis; uncontrolled HTN accelerates plaque progression
›Hyperlipidemia — elevated LDL and non-HDL cholesterol drive plaque formation
›Age >65 years — prevalence increases dramatically with age
›Chronic kidney disease (CKD) — independent risk factor; calcified vessels common
›Prior ASCVD (coronary artery disease, stroke, prior MI)
›Family history of PAD or premature ASCVD
›Obesity and physical inactivity

Fontaine and Rutherford Classification

›Fontaine Classification (practical clinical staging):
› Stage I: Asymptomatic — PAD present on testing but no symptoms
› Stage IIa: Mild claudication — claudication with >200m walking distance
› Stage IIb: Moderate-to-severe claudication — claudication with <200m walking distance
› Stage III: Rest pain — ischemic pain at rest, typically forefoot, worse at night
› Stage IV: Tissue loss — ulceration or gangrene
›Rutherford Classification is a more detailed 7-category system (0–6) used in vascular surgery and research; Rutherford categories 4–6 correspond to Critical Limb-Threatening Ischemia (CLTI).
›CLTI (Critical Limb-Threatening Ischemia): rest pain, ischemic wounds, or gangrene — requires urgent evaluation and revascularization to prevent amputation.

Ankle-Brachial Index (ABI)

›The ABI is the ratio of systolic blood pressure at the ankle to the higher brachial systolic blood pressure. It is the primary non-invasive test for PAD diagnosis.
›ABI Interpretation:
› ≥1.00 — Normal
› 0.91–0.99 — Borderline
› 0.70–0.90 — Mild PAD
› 0.40–0.69 — Moderate PAD
› <0.40 — Severe PAD
› >1.30 — Non-compressible vessels (calcification) — seen in diabetes and CKD; falsely elevated; toe-brachial index (TBI) preferred in these patients
›ABI <0.90 is diagnostic of PAD. ABI <0.40 suggests severe ischemia and risk for tissue loss.
›Normal ABI does not exclude PAD — exercise ABI testing can unmask disease in patients with exertional symptoms and normal resting ABI.

Symptoms

›Claudication: Reproducible cramping, aching, or fatigue in the calf, thigh, or buttock with walking — relieved within 10 minutes of rest. The location of claudication reflects the level of disease: calf (femoro-popliteal), thigh (iliac), buttock (aorto-iliac — may also cause erectile dysfunction in males).
›Rest pain: Ischemic pain in the forefoot (not calf) occurring at rest or at night. Relief occurs by dangling the foot dependent (gravity improves perfusion). This indicates severely reduced resting perfusion and is a hallmark of CLTI.
›Tissue loss: Non-healing wounds, ulcers, or gangrene — typically on the toes, heel, or pressure points. These wounds fail to heal because blood flow is insufficient to support tissue repair.
›Atypical presentation: Patients with diabetes or neuropathy may have PAD without classic claudication due to concurrent peripheral neuropathy masking ischemic pain.
›Acute limb ischemia (ALI): Sudden severe ischemia — the "6 Ps": Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia. This is a vascular emergency.

Physical Examination

›Pulse assessment — Femoral, popliteal, dorsalis pedis (DP), and posterior tibial (PT) pulses bilaterally. Document as present/diminished/absent.
›Skin changes — Hair loss on legs and feet, thickened or brittle nails, thin and shiny skin, dependent rubor (reddish discoloration when foot is dependent), pallor on elevation
›Skin temperature — Cool extremity compared to contralateral side or proximal limb
›Capillary refill — Prolonged (>2 seconds) in significant ischemia
›Wound/ulcer assessment — Location, size, depth, base appearance, surrounding tissue, signs of infection, necrosis, or gangrene
›Buerger test — Pallor on leg elevation followed by dependent rubor suggests significant arterial insufficiency
›Auscultation — Femoral bruits suggest proximal disease

Diagnostic Workup

›ABI — First-line non-invasive test; bilateral; perform at rest; exercise ABI if resting ABI normal but symptoms present
›Duplex ultrasound — Non-invasive; identifies location and severity of stenosis; useful for pre-procedural planning
›CTA angiography — Detailed anatomic mapping; gold standard for pre-procedural planning; requires contrast and radiation
›MRA (Magnetic Resonance Angiography) — Good anatomic detail; no radiation; limited in patients with metal implants; may overestimate stenosis
›Conventional (catheter-based) angiography — Gold standard for diagnosis and allows simultaneous intervention; used when endovascular treatment is planned
›Toe-Brachial Index (TBI) — Preferred over ABI when vessels are non-compressible (ABI >1.3); TBI <0.70 is abnormal
›Wound/tissue assessment — Wound cultures, plain X-rays to evaluate for osteomyelitis in diabetic foot wounds

Medical Therapy

›Antiplatelet therapy — Aspirin 75–100mg/day OR clopidogrel 75mg/day (clopidogrel preferred in some guidelines; both acceptable). Reduces MACE risk.
›High-intensity statin therapy — Atorvastatin 40–80mg or rosuvastatin 20–40mg. LDL goal <70 mg/dL (or <55 mg/dL in very high-risk patients). Statins reduce cardiovascular events and may slow PAD progression.
›ACEi or ARB — Benefit demonstrated in PAD; reduce cardiovascular events and may improve walking distance.
›Blood pressure control — Target <130/80 mmHg per current guidelines. Avoid severe hypotension which can worsen limb ischemia.
›Smoking cessation — Most critical modifiable intervention; markedly slows progression and reduces amputation risk. Refer to cessation programs.
›Supervised exercise therapy (SET) — Proven to increase pain-free walking distance and quality of life; recommended as first-line for claudication before revascularization.
›Cilostazol (Pletal) 100mg twice daily — Phosphodiesterase inhibitor; improves claudication symptoms and walking distance. CONTRAINDICATED in heart failure of any severity. Not a cardiovascular risk-reduction drug — symptom management only.
›Diabetes management — Tight glucose control reduces microvascular complications and infection risk; critical for wound healing.
›Vorapaxar — Antiplatelet agent that may be considered in PAD patients without prior stroke/TIA in select cases.

Revascularization

›Indications for revascularization: lifestyle-limiting claudication refractory to medical therapy and exercise, rest pain (CLTI), ischemic wounds or gangrene (CLTI), acute limb ischemia.
›Endovascular (preferred when anatomy allows): balloon angioplasty, stenting, atherectomy, drug-coated balloons. Less invasive, shorter recovery. May require reintervention over time.
›Surgical bypass: graft (vein or prosthetic) to bypass the blocked segment. More durable in appropriate candidates. Higher upfront risk but may be preferred for complex anatomy or long segment occlusions.
›Decision based on: anatomy (lesion location, length, calcification), symptom severity, patient surgical risk, patient preference, and availability of conduit for bypass.
›CLTI requires urgent revascularization — limb salvage rates depend on timely intervention. Multidisciplinary team approach (vascular surgery, interventional cardiology/radiology, wound care, endocrinology).
›Hybrid procedures: combination of endovascular and open surgical techniques in the same session.

Critical Limb-Threatening Ischemia (CLTI) and Wound Care

›CLTI is defined by rest pain, ischemic ulceration, or gangrene attributable to arterial occlusive disease. It represents the most severe stage of PAD and carries a high risk of major amputation and death.
›One-year outcomes in CLTI without revascularization: major amputation ~25%, mortality ~25%.
›Wound care principles: moisture balance, debridement of necrotic tissue, infection control, offloading pressure, and — most importantly — adequate perfusion. Wounds will not heal without blood flow.
›Diabetic foot wounds: require specialized wound care team, evaluation for osteomyelitis (MRI most sensitive), and aggressive revascularization when feasible.
›Infection in ischemic limbs can progress rapidly to wet gangrene and sepsis — early recognition and antibiotic therapy are critical.
›Dry gangrene in a non-infected limb may be allowed to auto-amputate if revascularization is not possible.

Diabetes and PAD

›Diabetic patients have 2–4x higher risk of PAD, earlier onset, more aggressive disease, and more distal (below-knee) involvement.
›Diabetic neuropathy can mask ischemic pain — patients may present with wounds as the first sign of PAD without claudication history.
›Calcified vessels from diabetes make ABI unreliable (falsely elevated) — use TBI or waveform analysis instead.
›Poor glycemic control impairs wound healing and immune response — even well-revascularized wounds may fail to heal in patients with uncontrolled diabetes.
›Foot care education is essential: daily foot inspection, proper footwear, no walking barefoot, prompt attention to any wound or skin break.

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Clinical Cheat Sheet

ABI Interpretation

•>1.30 — Non-compressible (DM/CKD) — use TBI
•1.00–1.29 — Normal
•0.91–0.99 — Borderline
•0.70–0.90 — Mild PAD
•0.40–0.69 — Moderate PAD
•<0.40 — Severe PAD / CLTI risk

Fontaine Classification

•Stage I — Asymptomatic
•Stage IIa — Claudication >200m
•Stage IIb — Claudication <200m
•Stage III — Rest pain
•Stage IV — Tissue loss / gangrene
•Stages III–IV = CLTI → urgent referral

Medical Therapy Targets

•LDL <70 mg/dL (or <55 in very high-risk)
•BP <130/80 mmHg
•Antiplatelet: ASA or clopidogrel — pick one
•High-intensity statin required
•ACEi/ARB — cardiovascular benefit
•Cilostazol for claudication (NEVER in HF)
•Smoking cessation — most critical step

Red Flags — Escalate Urgently

•New rest pain (forefoot pain at night)
•New or rapidly enlarging wound / ulcer
•Sudden color change: white/blue/black
•Cold pulseless extremity — acute limb ischemia
•Gangrene with fever / sepsis signs
•Worsening wound despite treatment
•Sudden severe leg pain (acute event)

Wound Assessment Guide

•Location: toe, heel, malleolar, pressure point
•Size: measure in cm (length x width)
•Depth: superficial, deep, tunneling, exposed bone
•Base: granulation tissue vs. fibrin vs. eschar
•Periwound skin: erythema, warmth, induration
•Odor: suggests infection / necrosis
•Signs of osteomyelitis: exposed bone, probe-to-bone

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Nurse Assessment Checklist

Systematic assessment for patients with known or suspected peripheral arterial disease.

Pulse Documentation (bilateral)

Right femoral pulse: present / diminished / absent
Left femoral pulse: present / diminished / absent
Right popliteal pulse: present / diminished / absent
Left popliteal pulse: present / diminished / absent
Right dorsalis pedis (DP): present / diminished / absent
Left dorsalis pedis (DP): present / diminished / absent
Right posterior tibial (PT): present / diminished / absent
Left posterior tibial (PT): present / diminished / absent

Symptom Assessment

Claudication: location (calf / thigh / buttock)?
Claudication: how far can they walk before pain?
Claudication: relieved with rest?
Rest pain: forefoot pain at night?
Rest pain: relieved by dangling foot?
Acute change in symptoms: sudden worsening?
Wound or sore on foot or leg?
Duration of wound / sore?

Skin and Extremity Assessment

Skin temperature: warm / cool / cold bilaterally
Skin color: normal / pallor / rubor / cyanosis / black
Capillary refill (<2 sec = normal)
Hair loss on lower extremities
Nail changes (thickened, brittle)
Edema: pitting grade, bilateral or unilateral
Wound measurement: location, size (cm), depth, base, periwound
Signs of infection: erythema, warmth, purulence, odor

When to Escalate Urgently

New rest pain (forefoot at night)
New wound or ulcer
Sudden color change of extremity (white, blue, black)
Cold, pulseless extremity — possible acute limb ischemia
Wound with spreading erythema, fever, or purulence
Rapidly deteriorating wound despite treatment
Any patient concern for gangrene or tissue death

Patient Education Points

Daily foot inspection — especially between toes
Never walk barefoot (especially diabetic patients)
Smoking cessation — critically important
Proper footwear: no tight shoes, no open toes
Wound care instructions if applicable
When to call: new wound, color change, rest pain, sudden worsening
Medication adherence: antiplatelet, statin, BP medications

Medication Reconciliation

Antiplatelet agent (aspirin or clopidogrel) — is patient taking it?
Statin — is patient on high-intensity statin?
ACEi or ARB
Blood pressure medications and current BP control
Cilostazol if prescribed — is patient in heart failure? (contraindication)
Diabetes medications — glycemic control status
Smoking cessation medications if applicable

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Patient Education Handout

What is PAD?

PAD stands for peripheral artery disease. It means that the arteries (blood vessels) that carry blood to your legs and feet have become narrowed or blocked by a buildup of plaque — the same process that causes heart attacks and strokes.
When the blood vessels are narrowed, less blood reaches your legs and feet. This can cause pain when you walk, sores that do not heal, and in severe cases, tissue damage.

Warning Signs — Call Us Right Away

Call your clinic or go to the ER immediately if you notice:
•Pain in your feet or toes while resting, especially at night
•A new sore or wound on your foot or leg that is not healing
•Your foot or leg suddenly becomes cold, pale, blue, or black
•Severe sudden pain in your leg
•Any wound that looks infected (red, hot, swollen, or has drainage)

Checking Your Feet Every Day

Check your feet every single day — especially if you have diabetes.
Look at the tops, bottoms, sides, and between all of your toes.
Use a mirror if you cannot see the bottom of your feet.
Look for cuts, blisters, redness, swelling, or sores — even small ones.
Call the clinic if you find anything concerning.
Never walk barefoot. Even a small cut can become a serious wound when blood flow is poor.

Why Smoking Makes PAD Much Worse

Smoking is the single most harmful thing you can do if you have PAD.
Smoking causes blood vessels to narrow and clot more easily, speeds up plaque buildup, and dramatically increases the risk of losing a limb.
Quitting smoking — even after many years — slows the disease and reduces your risk of amputation and heart attack.
Ask your care team about medications and programs to help you quit. It is the most important step you can take.

Foot Care Instructions

Wash your feet with mild soap and lukewarm water daily. Dry thoroughly, especially between the toes.
Moisturize the tops and bottoms of your feet — but not between the toes.
Trim your toenails straight across. See a podiatrist if you have trouble.
Wear well-fitting shoes with cushioning. Break in new shoes slowly.
Avoid heating pads, hot water bottles, or soaking feet in hot water — you may not feel burns.
Never try to cut corns, calluses, or ingrown nails at home.

Your Medications

Take a blood thinner medication (aspirin or clopidogrel) every day as directed — this helps prevent blood clots.
Take your cholesterol medication (statin) every day. It slows plaque buildup in your blood vessels.
Take your blood pressure medications as prescribed.
If you have diabetes, controlling your blood sugar helps wounds heal.

When to Call the Clinic

•Any new wound, sore, or blister on your feet or legs
•Pain in your foot or toes at rest or at night
•Your foot becomes suddenly cold or changes color
•A wound that is not improving after 1–2 weeks
•Signs of infection: redness spreading, warmth, swelling, drainage, fever
•Questions about your medications or care plan

This handout is for education only and does not replace medical advice from your healthcare team.

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Spanish / Communication Phrases

Interpreter Notice: These phrases are for basic communication and rapport only. Use a certified medical interpreter for diagnosis, treatment decisions, medication changes, consent, discharge instructions, and all complex clinical conversations.

Do you have pain in your legs when you walk?

¿Tiene dolor en las piernas cuando camina?

Does the pain go away when you rest?

¿Se le quita el dolor cuando descansa?

Do you have any wounds or sores on your feet?

¿Tiene alguna herida o llaga en los pies?

We need to check the circulation in your legs.

Necesitamos revisar la circulación en sus piernas.

Your blood flow to the legs is reduced.

El flujo de sangre a sus piernas está reducido.

It is very important to stop smoking.

Es muy importante que deje de fumar.

Please check your feet every day.

Por favor revise sus pies todos los días.

Do you have diabetes?

¿Tiene diabetes?

Is the pain in your feet at night?

¿Tiene dolor en los pies por la noche?

We may need to do a procedure to improve blood flow.

Es posible que necesitemos hacer un procedimiento para mejorar el flujo de sangre.

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Sim Patient Case

Interventional Cardiology / Peripheral Vascular ClinicInteractive

Patient

[EN] 67-year-old Spanish-speaking male with type 2 diabetes and 40 pack-year smoking history presenting with right calf pain after walking one block, now with right foot pain at rest at night and a non-healing wound on the right great toe for 3 weeks. [ES] Hombre de 67 años, hispanohablante, con diabetes tipo 2 y 40 años-paquete de tabaquismo, que presenta dolor en la pantorrilla derecha al caminar una cuadra, dolor en el pie derecho en reposo por la noche, y una herida en el dedo gordo del pie derecho que no sana desde hace 3 semanas.

Chief Complaint

[EN] "My right leg hurts when I walk and now my foot hurts at night too. I have a sore on my toe that won't heal." [ES] "Mi pierna derecha me duele cuando camino y ahora también me duele el pie por la noche. Tengo una llaga en el dedo que no sana."

Vitals

158/92 mmHg

78 bpm

SpO2

96%

Temp

98.8°F

16 breaths/min

Goal

[EN] Interview the patient in Spanish, recognize the transition from claudication to critical limb-threatening ischemia (CLTI), choose appropriate workup, identify urgent management needs, and optimize medical therapy. [ES] Entreviste al paciente en español, reconozca la transición de claudicación a isquemia crónica que amenaza la extremidad (CLTI), elija el estudio apropiado, identifique las necesidades de manejo urgente y optimice el tratamiento médico.

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Disclaimer: This content is for educational purposes only. It is not medical advice, does not replace clinical judgment, and is not a substitute for institutional protocols or certified medical interpreters. No patient health information (PHI) should be entered into this application.