PAD

Clinical Presentations
 Common femoral artery (4-6 cm long) Lies
superficially in the groin
Divides to SFA & PFA
Superficial femoral artery
Extends down medial thigh
Passes deep through adductor hiatus
Popliteal artery
Commences below adductor hiatus
Passes vertically through popliteal fossa
Divides to tibio-peroneal trunk & ATA

Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
 There are several interconnection
So that each artery can supply all regions

Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
Coronary Artery Disease
44.6% 8.4% Cerebral Artery
Disease 16.6%
1.7%
1.2%
4.6%

PAD
4.6%

TASC II Recommendation,
2007
This guideline recognizes that:

Individuals With PAD Present in Clinical Practice With

Distinct Syndromes

Asymptomatic: Without obvious symptomatic complaint (but

usually with a functional impairment).

Classic claudication: Lower extremity symptoms confined to

the muscles with a consistent (reproducible) onset with
exercise and relief with rest.

“Atypical” leg pain: Lower extremity discomfort that is

exertional but that does not consistently resolve with rest,
consistently limit exercise at a reproducible distance, or meet
all “Rose questionnaire” criteria.
This guideline recognizes that:

Individuals With PAD Present in Clinical Practice With

Distinct Syndromes

Critical limb lschemia: Ischemic rest pain, nonhealing wound, or

gangrene/

Acute limb ischemia: The five “P”s, defined by the clinical

symptoms and signs that suggest potential limb jeopardy:
 Pain
 Pulselessness
 Pallor
 Paresthesias
 Paralysis (& polar, as a sixth “P”).
 Clinical Presentations of PAD
~15%
Classic (Typical)
Claudication
50%
Asymptomatic

~33%
Atypical
Leg Pain
(functionally limited)

1%-2%
Critical
Limb Ischemia
 Claudication vs. Pseudoclaudication

Claudication Pseudoclaudication
Characteristic of Cramping, tightness, Same as claudication
discomfort aching, fatigue plus tingling, burning,
numbness
Location of Buttock, hip, thigh, Same as
discomfort calf, foot claudication

Exercise-induced Yes Variable

Distance Consistent Variable
Occurs with standing No Yes
Action for relief Stand Sit, change position
Time to relief <5 minutes 30 minutes

Also see Table 4 of Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.

Leg Pain Has a Differential Diagnosis

• Spinal canal stenosis

• Peripheral neuropathy
• Peripheral nerve pain
– Herniated disc impinging on sciatic nerve
• Osteoarthritis of the hip or knee
• Venous claudication
• Symptomatic Baker’s cyst
• Chronic compartment syndrome
• Muscle spasms or cramps
• Restless leg syndrome

Also see Table 3 of Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.

Factors That Increase Risk of Limb Loss in Patients
With Critical Limb Ischemia

• Factors that reduce blood flow to the microvascular bed

 Diabetes
 Severe renal failure
 Severely decreased cardiac output (severe heart failure or shock)
 Vasospastic diseases or concomitant conditions (e.g., Raynaud’s
phenomenon, prolonged cold exposure)
 Smoking and tobacco use
• Factors that increase demand for blood flow to the
microvascular bed
 Infection (e.g., cellulitis, osteomyelitis)
 Skin breakdown or traumatic injury

Also see Table 5 of Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.

 Differential Diagnosis of
Common Foot Ulcers
Neuropathic Ulcer Neuroischemic Ulcer
Painless Painful
Normal pulses Absent pulses
Typically punches-out appearance Irregular margins
Often located on sole or edge of foot or Commonly located on toes
metatarsal head
Presence of calluses Calluses absent or infrequent
Loss of sensation, reflexes, and vibration Variable sensory findings
sense
Increase in blood flow Decrease in blood flow
(arteriovenous shunting)
Dilated veins Collapsed veins
Dry, warm foot Cold foot
Bone deformities No bony deformities
Red appearance Pale, cyanotic
Reprinted with permission from Dormandy JA, Rutherford RB. J Vasc Surg. 2000;31:S1-S296.
 Etiologic Classification of Foot
and Leg Ulcers

• Venous obstruction and insufficiency • Infectious

• Arterial etiologies  Leprosy
 Larger arteries  Mycotic
 Atherosclerotic lower extremity PAD • Hematologic
 Thromboemboli, atheroemboli  Sickle cell anemia
 Thromboangiitis obliterans  Polycythemia
• Microcirculatory  Thrombocytosis
 Diabetic microangiopathy • Malignancy
 Vasculitis  Squamous cell carcinoma
 Collagen vascular diseases  Kaposi’s sarcoma
• Neuropathic • Artifactual or factitious
 Diabetes mellitus

Also see Table 10 of Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.

 The Vascular History and
Physical Examination

I IIa IIb III

Individuals at risk for lower extremity PAD
should undergo a vascular review of
symptoms to assess walking impairment,
claudication, ischemic rest pain, and/or the
presence of nonhealing wounds.

I IIa IIb III

Individuals at risk for lower extremity PAD
should undergo comprehensive pulse
examination and inspection of the feet.
 Identification of the Asymptomatic
Patient With PAD

I IIa IIb III A history of walking impairment, claudication,

and ischemic rest pain is recommended as a
required component of a standard review of
systems for adults >50 years who have
atherosclerosis risk factors, or for adults >70 years.

I IIa IIb III

Individuals with asymptomatic PAD should be
identified in order to offer therapeutic
interventions known to diminish their
increased risk of myocardial infarction, stroke,
and death.
 Identification of the Symptomatic
Patient With Intermittent Claudication

I IIa IIb III

Patients with symptoms of intermittent
claudication should undergo a vascular
physical examination, including measurement
of the ABI.

I IIa IIb III

In patients with symptoms of intermittent
claudication, the ABI should be measured after
exercise if the resting index is normal.
 Evaluation of the Patient With
Critical Limb Ischemia

I IIa IIb III

Patients at risk of CLI (ABI less than 0.4 in a
nondiabetic individual, or any diabetic
individual with known lower extremity PAD)
should undergo regular inspection of the feet
to detect objective signs of CLI.

I IIa IIb III

The feet should be examined directly, with
shoes and socks removed, at regular intervals
after successful treatment of CLI.
Guideline for the Management of Patients
with PAD

Smoking Cessation
Recommendations for Smoking Cessation

I IIa IIb III Patients who are smokers or former smokers should be
asked about status of tobacco use at every visit.

NEW

I IIa IIb III

Patients should be assisted with counseling and
developing a plan for quitting that may include
pharmacotherapy and/or referral to a smoking
NEW cessation program.
Recommendations for Smoking Cessation
I IIa IIb III Individuals with lower extremity PAD who
smoke cigarettes or use other forms of tobacco
should be advised by each of their clinicians to stop
MODIFIED smoking and offered behavioral and
pharmacological treatment.

I IIa IIb III In the absence of contraindication or other

compelling clinical indication, 1 or more of the
following pharmacological therapies should be
NEW offered: varenicline, bupropion, and nicotine
replacement therapy.
 Comprehensive Vascular Examination
Key components of the vascular physical examination include:

• Bilateral arm blood • Pulse Examination

pressure (BP) – Carotid
– Radial/ulnar
• Cardiac examination – Femoral
• Palpation of the – Popliteal
abdomen for – Dorsalis pedis
– Posterior tibial
aneurysmal disease
• Scale:
• Auscultation for bruits – 0=Absent
• Examination of legs – 1=Diminished
and feet – 2=Normal
– 3=Bounding (aneurysm or AI)
 The First Tool to Establish the PAD Diagnosis:
A Standardized Physical Examination
Pulse intensity should be assessed and should be recorded
numerically as follows:

– 0, absent
– 1, diminished
– 2, normal
– 3, bounding

Use of a standard I IIa IIb III

examination should
facilitate clinical
communication
 Differential Diagnosis of PAD

• Atherosclerosis • Popliteal entrapment

• Vasculitis • Cystic adventitial disease
• Fibromuscular dysplasia • Coarctation of aorta
• Atheroembolic disease • Vascular tumor
• Thrombotic disorders
• Iliac syndrome of the cyclist
• Trauma
• Pseudoxanthoma elasticum
• Radiation
• Popliteal aneurysm • Persistent sciatic artery
(thrombosed)
• Thromboangiitis obliterans
(Buerger’s disease)
 ACC/AHA Guideline for the Management of PAD:
Steps Toward the Diagnosis of PAD
Recognizing the “at risk” groups leads to recognition of the five main PAD
clinical syndromes:
Obtain history of walking impairment and/or limb ischemic symptoms:
Obtain a vascular review of symptoms:
• Leg discomfort with exertion
• Leg pain at rest; non-healing wound; gangrene

No leg pain “Atypical” Classic Chronic Acute limb

leg pain claudication critical limb ischemia
ischemia (ALI)
(CLI)

Perform a resting ankle-brachial index measurement

 Recommendations for ABI, Toe-Brachial
Index, and Segmental Pressure Examination

I IIa IIb III The resting ABI should be used to establish the lower
extremity PAD diagnosis in patients with suspected
lower extremity PAD, defined as individuals with 1 or
MODIFIED
more of the following: exertional leg symptoms,
nonhealing wounds, age ≥65 years, or ≥50 years with
a history of smoking or diabetes.
 Recommendations for ABI, Toe-Brachial
Index, and Segmental Pressure Examination

I IIa IIb III The ABI should be measured in both legs in all new
patients with PAD of any severity to confirm the
diagnosis of lower extremity PAD and establish a
baseline.
 Recommendations for ABI, Toe-Brachial
Index, and Segmental Pressure Examination

I IIa IIb III The toe-brachial index should be used to establish the lower
extremity PAD diagnosis in patients in whom lower
extremity PAD is clinically suspected but in whom the ABI
test is not reliable due to noncompressible vessels (usually
patients with long-standing diabetes or advanced age).

I IIa IIb III Leg segmental pressure measurements are useful to establish
the lower extremity PAD diagnosis when anatomic
localization of lower extremity PAD is required to create a
therapeutic plan.
 Recommendations for ABI, Toe-Brachial
Index, and Segmental Pressure Examination

I IIa IIb III ABI results should be uniformly reported with

noncompressible values defined as >1.40,
normal values 1.00 to 1.40, borderline 0.91 to
NEW 0.99, and abnormal ≤0.90.
 How to Perform an ABI Exam

• Performed with the patient resting in the supine position

• All pressures are measured with an arterial Doppler and

appropriately sized blood pressure cuff (edge 1-2 inches
above the pulse; cuff width should be 40% of limb
circumference).

• Systolic pressures will be measured in the right and left

brachial arteries followed by the right and left ankle
arteries.
 ABI Procedure

• Step 1: Apply the appropriately sized blood pressure cuff on the arm
above the elbow (either arm).

• Step 2: Apply Doppler gel to skin surface.

• Step 3: Turn on the Doppler and place the probe in the area of the
pulse at a 45-60° angle to the surface of the skin, pointing to the
shoulder.

• Step 4: Move the probe around until the clearest arterial signal is
heard.
 ABI Procedure

http://www.nhlbi.nih.gov/health/dci/Diseases/pad/pad_diagnosis.html
 ABI Procedure
• Step 5: Inflate the blood pressure cuff to approximately 20
mmHg above the point where systolic sounds are no longer
heard.

• Step 6: Gradually deflate until the arterial signal returns.

Record the pressure reading.

• Step 7: Repeat the procedure for the right and left posterior
tibial and dorsalis pedis arteries. Place the probe on the
pulse and angle the probe at 45o toward the knee.

• Step 8: Record the systolic blood pressure of the

contralateral arm.
 Understanding the ABI

The ratio of the higher brachial systolic pressure and the

higher ankle systolic pressure for each leg:

Ankle systolic pressure

ABI =
Higher brachial artery systolic pressure
 Calculate the ABI
1. For the left side, divide the left ankle pressure by the highest
brachial pressure and record the result.
2. Repeat the steps for the right side.
3. Record the ABIs and place the results in the medical record.

Right Leg ABI Left Leg ABI

Right Ankle Pressure Left Ankle Pressure

Highest Arm Pressure Highest Arm Pressure

ABI Interpretation
≤ 0.90 is diagnostic of peripheral arterial disease
Hiatt WR. N Engl J Med. 2001;344:1608-1621; TASC Working Group. J Vasc Surg. 2000;31(1Suppl):S1-S296.
 The Ankle-Brachial Index
Lower extremity systolic pressure
ABI = Brachial artery systolic pressure
• The ankle-brachial index is 95% sensitive and 99% specific for PAD
• Establishes the PAD diagnosis
• Identifies a population at high risk of CV ischemic events
• The “population at risk” can be clinically and epidemiologically defined:
Age less than 50 years with diabetes, and one additional
risk factor Age 50 to 69 years and history of smoking or
diabetes
Age 70 years and older
Leg symptoms with exertion (suggestive of claudication) or
ischemic rest pain
Abnormal lower extremity pulse examination
Known atherosclerotic coronary, carotid, or renal artery
disease
• Toe-brachial index (TBI) useful in individuals with
non-compressible pedal pulses Lijmer JG. Ultrasound Med Biol 1996;22:391-8; Feigelson HS. Am J Epidemiol 1994;140:526-34;
Baker JD. Surgery 1981;89:134-7; Ouriel K. Arch Surg 1982;117:1297-13; Carter SA. J Vasc Surg 2001;33:708-14
Interpreting the Ankle-Brachial Index

ABI Interpretation
1.00–1.29 Normal
0.91–0.99 Borderline
0.41–0.90 Mild-to-moderate disease
≤0.40 Severe disease
≥1.30 Noncompressible

Adapted from Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192. Figure 6.

 Using the ABI: An Example
Right ABI Left ABI ABI
80/160=0.50 120/160=0.75 (Normal >0.90)

Brachial SBP Brachial SBP Highest

150 mm Hg 160 mm Hg brachial SBP

PT SBP 40 mm Hg PT SBP 120 mm Hg Highest of PT

DP SBP 80 mm Hg DP SBP 80 mm Hg or DP SBP

ABI=ankle-brachial index; DP=dorsalis pedis; PT=posterior tibial; SBP=systolic blood pressure.

 ABI Limitations

• Incompressible arteries (elderly patients, patients

with diabetes, renal failure, etc.)
• Resting ABI may be insensitive for detecting mild
aorto-iliac occlusive disease
• Not designed to define degree of functional
limitation
• Normal resting values in symptomatic patients
may become abnormal after exercise
• Note: “Non-compressible” pedal arteries is a
physiologic term and such arteries need not be
“calcified”
Toe-Brachial Index Measurement
• The toe-brachial index
(TBI) is calculated by
dividing the toe pressure
by the higher of the two
brachial pressures.
• TBI values remain
accurate when ABI values
are not possible due to
non-compressible pedal
pulses.
• TBI values ≤ 0.7 are
usually considered
diagnostic for lower
extremity PAD.
 Hemodynamic Noninvasive Tests

• Resting Ankle-Brachial Index (ABI)

• Exercise ABI

• Segmental pressure examination

• Pulse volume recordings

These traditional tests continue to provide a simple, risk-free,

and cost-effective approach to establishing the PAD diagnosis
as well as to follow PAD status after procedures.
Segmental Pressures (mm Hg)
150 Brachial 150

150 150

110 146

108 100

62 84

0.54 ABI 0.44

Pulse Volume Recordings
 Exercise ABI Testing

• Confirms the PAD diagnosis

• Assesses the functional
severity of claudication
• May “unmask” PAD when
resting the ABI is normal
• Aids differentiation of
intermittent claudication
vs. pseudoclaudication
diagnoses
 Exercise ABI Testing: Treadmill

• Indicated when the ABI is

normal or borderline but
symptoms are consistent with
claudication;
• An ABI fall post-exercise
supports a PAD diagnosis;
• Assesses functional capacity
(patient symptoms may be
discordant with objective
exercise capacity).

.
The Plantar Flexion Exercise ABI

Benefits:
• Reproduces treadmill-derived
fall in ABI
• Can be performed anywhere
• Inexpensive
Limitation:
• Does not measure functional
capacity

Reprinted with permission from McPhail, IR et al. J Am Coll Cardiol. 2001;37:1381.

Color Duplex Ultrasonography
 Arterial Duplex Ultrasound Testing
• Duplex ultrasound of the extremities is
useful to diagnose anatomic location and
degree of stenosis of peripheral arterial
disease.

• Duplex ultrasound is useful to provide

surveillance following femoral-popliteal
bypass using venous conduit (but not
prosthetic grafts).
However, the data that
• Duplex ultrasound of the extremities can might support use of
be used to select candidates for: duplex ultrasound to
(a) endovascular intervention assess long-term patency
(b) surgical bypass, and of PTA is not robust.
(c) to select the sites of surgical
anastomosis.
PTA=percutaneous transluminal angioplasty.
 Noninvasive Imaging Tests

Duplex Ultrasound
I IIa IIb III
Duplex ultrasound of the extremities is useful
to diagnose the anatomic location and degree
of stenosis of PAD.

I IIa IIb III

Duplex ultrasound is recommended for routine
surveillance after femoral-popliteal or femoral-
tibial-pedal bypass with a venous conduit.
Minimum surveillance intervals are
approximately 3, 6, and 12 months, and then
yearly after graft placement.
 Magnetic Resonance Angiography (MRA)
• MRA has virtually replaced contrast arteriography
for PAD diagnosis
• Excellent arterial picture
• No ionizing radiation
• Noniodine–based intravenous contrast medium
rarely causes renal insufficiency or allergic reaction
• ~10% of patients cannot utilize MRA because of:
 Claustrophobia
 Pacemaker/implantable cardioverter-
defibrillator
 Obesity
• Gadolinium use in individuals with an eGFR <60
mL/min has been associated with nephrogenic
systemic fibrosis (NSF)/nephrogenic fibrosing
dermopathy
 Noninvasive Imaging Tests
Magnetic Resonance Angiography (MRA)
I IIa IIb III
MRA of the extremities is useful to diagnose
anatomic location and degree of stenosis of
PAD.
I IIa IIb III
MRA of the extremities should be performed
with gadolinium enhancement.

I IIa IIb III

MRA of the extremities is useful in selecting
patients with lower extremity PAD as candidates
for endovascular intervention.
ACC/AHA Guideline for the Management of PAD:
Diagnosis and Treatment of Asymptomatic PAD
Individual at PAD risk: No leg symptoms or atypical leg symptoms
Consider use of the San Diego Walking Impairment Questionnaire

Perform a resting ankle-brachial index measurement

ABI ≥ 1.30 ABI 0.91 to 1.30 ABI ≤ 0.90

(abnormal) (borderline & normal) (abnormal)

Pulse volume recording Measure ABI after

Toe-brachial index exercise test
(Duplex ultrasonography)

Normal results: Abnormal Normal post-exercise ABI:

No PAD results Decreased post-exercise ABI
No PAD

Evaluate other causes of Confirmation of

leg symptoms PAD diagnosis
Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.
ACC/AHA Guideline for the Management of PAD:
Diagnosis and Treatment of Asymptomatic PAD

Confirmation of PAD
diagnosis

Risk factor normalization:

Immediate smoking cessation
Treat hypertension: JNC-7 guidelines
Treat lipids: NCEP ATP III guidelines
Treat diabetes mellitus: HbA 1c less than 7%

Pharmacological Risk Reduction:

Antiplatelet therapy (ACE inhibition; Class IIb, LOE C)

ACE=angiotensin-converting enzyme; JNC-7=Joint National Committee on Prevention ;

NCEP=National Cholesterol Education Program – Adult Treatment Panel III. Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.
 ACC/AHA Guideline for the Management of PAD:
Diagnosis of Claudication and Systemic Risk Treatment
Classic Claudication Symptoms:
Muscle fatigue, cramping, or pain that reproducibly begins
during exercise and that promptly resolves with rest

Chart document the history of walking impairment (pain-

free and total walking distance) and specific lifestyle
limitations

Document pulse
examination
Exercise ABI
ABI greater
ABI (TBI, segmental pressure, or
than 0.90
Duplex ultrasound examination)

ABI less than or equal to 0.90 Abnormal Normal

results results

Confirmed PAD diagnosis

No PAD or consider arterial

entrapment syndromes
Cont’d
ABI=ankle-brachial index; TBI=toe-brachial index. Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.
 ACC/AHA Guideline for the Management of PAD:
Diagnosis of Claudication and Systemic Risk Treatment

Confirmed PAD
diagnosis

Risk factor normalization:

Immediate smoking cessation
Treat hypertension: JNC-7 guidelines
Treat lipids: NCEP ATP III guidelines
Treat diabetes mellitus: HbA1c less than 7%

Pharmacological risk reduction:

Antiplatelet therapy
(ACE inhibition; Class IIa)

Treatment of Claudication

ACE=angiotensin-converting enzyme; JNC-7=Joint National Committee on Prevention ;

NCEP=National Cholesterol Education Program – Adult Treatment Panel III. Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.
Guideline for the Management of Patients
with PAD

Antiplatelet and Antithrombotic Drugs

 Recommendations for Antiplatelet and
Antithrombotic Drugs
I IIa IIb III Antiplatelet therapy is indicated to reduce the risk of MI, stroke, and
vascular death in individuals with symptomatic atherosclerotic lower
extremity PAD, including those with intermittent claudication or CLI,
prior lower extremity revascularization (endovascular or surgical), or
MODIFIED prior amputation for lower extremity ischemia.

I IIa IIb III Aspirin, typically in daily doses of 75 to 325 mg, is

recommended as safe and effective antiplatelet therapy to
reduce the risk of MI, stroke, or vascular death in individuals
with symptomatic atherosclerotic lower extremity PAD,
MODIFIED including those with intermittent claudication or CLI, prior
lower-extremity revascularization (endovascular or surgical),
or prior amputation for lower-extremity ischemia.
Recommendations for Antiplatelet and Antithrombotic
Drugs

I IIa IIb III Clopidogrel (75 mg per day) is recommended as a safe and
effective alternative antiplatelet therapy to aspirin to reduce the
risk of MI, ischemic stroke, or vascular death in individuals with
symptomatic atherosclerotic lower-extremity PAD, including those
MODIFIED with intermittent claudication or CLI, prior lower-extremity
revascularization (endovascular or surgical), or prior amputation
for lower-extremity ischemia.

I IIa IIb III Antiplatelet therapy can be useful to reduce

the risk of MI, stroke, or vascular death in
asymptomatic individuals with an ABI ≤0.90.
NEW
Recommendations for Antiplatelet and Antithrombotic
Drugs

I IIa IIb III The usefulness of antiplatelet therapy to reduce the risk of MI,
stroke, or vascular death in asymptomatic individuals with
borderline abnormal ABI, defined as 0.91 to 0.99, is not well
NEW established.

I IIa IIb III The combination of aspirin and clopidogrel may be

considered to reduce the risk of cardiovascular events in
patients with symptomatic atherosclerotic lower-extremity
PAD, including those with intermittent claudication or CLI,
NEW prior lower-extremity revascularization (endovascular or
surgical), or prior amputation for lower-extremity ischemia
and who are not at increased risk of bleeding and who are at
high perceived cardiovascular risk.
 Recommendations for Antiplatelet
and Antithrombotic Drugs

I IIa IIb III In the absence of any other proven indication for
warfarin, its addition to antiplatelet therapy to reduce
the risk of adverse cardiovascular ischemic events in
No individuals with atherosclerotic lower extremity PAD is
Benefit
MODIFIED of no benefit and is potentially harmful due to
increased risk of major bleeding.