Peripheral Artery Disease (PAD) & Ankle Brachial
Index (ABI)
Marge Lovell RN CCRC CVN BEd MEd
London Health Sciences CentreLondon, Ontario, Canada
Faculty/Presenter DisclosureFaculty/Presenter Disclosure
• Faculty: Marge Lovell• Program: 51st Annual Scientific Assembly
• Relationships with commercial interests:– NONE
Disclosure of Commercial Disclosure of Commercial SupportSupport
• This program has received NO financial support • This program has received NO in-kind support
• Potential for conflict(s) of interest:– NONE
• Peripheral Artery Disease (PAD, PVD)
A vascular disease in which the arteries supplying a limb are occluded/stenosis
The most common cause is atherosclerosis, resulting in plaque and thrombus deposition on the arterial wall, and lumenal stenosis or occlusion
Peripheral Arterial Disease• PAD is common and will become more
common in the next 2 decades.• PAD is associated with a marked increase
in global cardiovascular health risks:- Heart attack, stroke, and death- Claudication and functional impairment- Gangrene and amputation
• The current knowledge base permits significantly better: prevention, early diagnosis, integrated treatment, and rehabilitation.
Systemic Manifestations of Atherosclerosis
•TIA• Ischemic stroke
• Claudication
• Critical limb ischemia, rest pain, gangrene, amputation
• Renovascular hypertension
• Erectile dysfunction
•TIA• Ischemic stroke•TIA• Ischemic stroke
• Myocardial Infarction• Unstable angina pectoris
Incidence• More common in men• Estimated 27 million people in North
America & Europe suffer from PAD (16%) • 16.5 million are asymptomatic • In Canada: 1 in 4 people with PAD will
have MI or CVA• Common cause of disability, morbidity &
mortality• Under diagnosed and under treated Canadian Cardiovascular Consensus: PAD Executive Summary; Can J Cardiol 2005;
21(12):997-1006
ATHEROSCLEROSIS, A MULTIFACTORIAL DISEASE
EN
VIR
ON
ME
NTA
L FA
CTO
RS
GE
NE
TIC
FA
CTO
RS
AGESMOKING
OBESITY
DIET
FAMILY HISTORYSEDENTARYLIFESTYLE
GENDER
THROMBOGENIC FACTORS
VASCULARDISEASE
LIPIDSHYPERTENSION
DIABETES
Defining a Population “At Risk” for Lower Extremity P.A.D.
• Age > than 40 years with one additional risk factor (e.g., diabetes, smoking, dyslipidemia, hypertension, or hyperhomocysteinemia)
• Age 50 (male) 60 (female) with risk factor• 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
Canadian Cardiovascular Consensus: PAD Executive Summary; Can J Cardiol 2005; 21(12):997-1006
How Is PAD Diagnosed?
• History and physical History and physical examinationexamination
• ABIABI
• Vascular labVascular lab
Adapted American Diabetes Association. Diabetes Care. 2003:26;3333-3341.
Olson, KWP, et al. J of Vascular Nursing. 2004:22;72-77.
Questions to Ask Patients Presenting with Symptoms of PAD
1.Do you have pain in either leg when you walk?
3. How far can you walk without stopping?
4. What stops you when you are walking?
5. Do you walk?
6. Why not?
2. Do you have a similar pain when you are bending, sitting or lying down?
2. Do you have a similar pain when you are bending, sitting or lying down?
Physical Exam Findings of PAD
Lesho EP, et al. Am Fam Physician. 2004; 69:525-533.
The Physical Exam Should Be Performed With Patient’s Pants/Shoes Off
Limb examination (and comparison with the opposite limb) findings might include:
• Absent or diminished femoral or pedal pulses (especially after exercising the limb)
• Hair loss• Poor nail growth (brittle nails)• Dry, scaly, atrophic skin• Dependent rubor• Pallor with leg elevation after 1 minute at 60 degrees (normal
color should return in 10 to 15 seconds; longer than 40 seconds indicates severe ischemia)
• Ischemic tissue ulceration (punched-out, painful, with little bleeding), gangrene
• Arterial bruits
Concept of ABI
ABI has been found to be 95% sensitive and 99% specific for angiographically diagnosed PAD.
The systolic blood pressure in the leg should be approximately the same as the systolic blood pressure in the arm.
Therefore, the ratio of systolic blood pressure in the leg vs the arm should be approximately 1 or slightly higher.
Adapted from Weitz JI, et al. Circulation. 1996;94:3026-3049.
Arm pressure
Leg pressure
÷ ≈ 1
Equipment needed:Equipment needed:
1.1. Blood Pressure Blood Pressure CuffCuff
2.2. Hand-held 5-10 Hand-held 5-10 MHz Doppler MHz Doppler probeprobe
3.3. Ultrasound GelUltrasound Gel
American Diabetes Association. Diabetes Care 2003: 26; 3333–3341.
Measuring the Ankle-Brachial Index (ABI)Step 1: Gather Equipment Needed
Calculating the ABIExample Calculation
66 mm Hg
120 mm Hg
Hiatt WR. N Engl J Med. 2001;344:1608-1621.
= 0.50 = 0.55
Right Leg ABIRight Leg ABI Left Leg ABILeft Leg ABI
60 mm Hg
120 mm Hg
Right Leg ABIRight Leg ABI
ABI InterpretationABI Interpretation
≤ ≤ 0.90 is diagnostic of peripheral arterial 0.90 is diagnostic of peripheral arterial diseasedisease
Interpreting the Ankle–Brachial Index: ABI
ABI Interpretation
• 1.0-1.4 Normal
• 0.91-0.99 Borderline
• <0.90 Abnormal
• >1.4 Non-compressible
• 2011 ACCF/AHA Focused Update of the Guideline for the Management of Patients With Peripheral Artery Disease (Updating the 2005 Guideline)
A 65 year male, heavy smoker, hypertensive presents A 65 year male, heavy smoker, hypertensive presents with right gangrenous toe and rest pain: with right gangrenous toe and rest pain:
Calculate the ABICalculate the ABI
R Brachial Pressure: _160____
Dorsalis Pedis SBP: ___140____
Posterior Tibial SBP: ___138_____
Dorsalis Pedis SBP : __60_____
Posterior Tibial SBP : __58____
L/Brachial Pressure: __156___
R/ ABI= _____ L/ ABI= _____
ABI Interpretation: Normal, Borderline, Mild, Moderate, Severe, NoncompressibleCorrect answers are: R/ABI= 0.37 L/ABI= 0.87Severe PAD R/Side, mild PAD L/side
A 76 year old male, heavy smoker, hypertensive & A 76 year old male, heavy smoker, hypertensive & previous MI presents with right calf pain after 2 blocks: previous MI presents with right calf pain after 2 blocks:
Calculate the ABICalculate the ABI
R Brachial Pressure: _130____
AT SP: ___140____
PT SP: ___138_____AT SBP: __90_____
PT SBS: __96_____
L/Brachial Pressure: __134___
R ABI= _____ L ABI= _____
ABI Interpretation: Normal, Borderline, Mild, Moderate, Severe, NoncompressibleCorrect answers are: R/ABI= 0.71 L/ABI= 1.04Mild PAD R/ leg
A Risk Factor “Report Card” for all Individuals with Atherosclerosis
Tobacco smoking
Complete, immediate cessation
Hypertension BP less than 140/90
mmHg and Diabetics 130/80
Hypercholesterolemia LDL Cholesterol < 2.0
Diabetes Hb A1C : <7.0
Inactivity Follow guidelines
Antiplatelet therapy (like aspirin or Plavix) is: Antiplatelet therapy (like aspirin or Plavix) is: mandatorymandatory