Peripheral Artery Disease
(PAD) & Ankle Brachial Index
(ABI)
Marge Lovell RN CCRC CVN BEd MEd
London Health Sciences Centre
London, Ontario, Canada
Faculty/Presenter Disclosure
• Faculty: Marge Lovell
• Program: 51st Annual Scientific Assembly
• Relationships with commercial interests:
– NONE
Disclosure of Commercial
Support
• This program has received NO financial support
• This program has received NO in-kind support
• Potential for conflict(s) of interest:
– NONE
Mitigating Potential Bias
• N/A
Objectives
• Provide an overview of PAD
• Demonstrate the ABI technique
• Provide Hands on Practice
• 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
• Myocardial Infarction
• Unstable angina pectoris
• Renovascular hypertension
• Erectile dysfunction
• Claudication
• Critical limb ischemia, rest pain,
gangrene, amputation
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
LIPIDS
HYPERTENSION
DIABETES
DIET
VASCULAR
DISEASE
SMOKING
AGE
GENDER
SEDENTARY
LIFESTYLE
FAMILY HISTORY
THROMBOGENIC
FACTORS
GENETIC FACTORS
ENVIRONMENTAL FACTORS
OBESITY
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
examination
•
ABI
•
Vascular lab
Adapted American Diabetes Association. Diabetes Care. 2003:26;3333-3341.
Questions to Ask Patients
Presenting with Symptoms of PAD
1.Do you have pain in either
leg when you walk?
2. Do you have a similar pain
when you are bending, sitting
or lying down?
3. How far can you walk
without stopping?
4. What stops you when
you are walking?
5. Do you walk?
6. Why not?
Olson, KWP, et al. J of Vascular Nursing. 2004:22;72-77.
Physical Exam Findings of PAD
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
Lesho EP, et al. Am Fam Physician. 2004; 69:525-533.
Concept of ABI
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.
Leg pressure
÷
Arm pressure
ABI has been found to be 95% sensitive and 99%
specific for angiographically diagnosed PAD.
Adapted from Weitz JI, et al. Circulation. 1996;94:3026-3049.
≈1
Measuring the Ankle-Brachial Index (ABI)
Step 1: Gather Equipment Needed
Equipment needed:
1. Blood Pressure
Cuff
2. Hand-held 5-10
MHz Doppler
probe
3. Ultrasound Gel
American Diabetes Association. Diabetes Care 2003: 26; 3333–3341.
Stabilizing hand
Calculating the ABI
Example Calculation
Right Leg ABI
60 mm Hg
= 0.50
120 mm Hg
Left Leg ABI
66 mm Hg
120 mm Hg
= 0.55
ABI Interpretation
≤ 0.90 is diagnostic of peripheral arterial
disease
Hiatt WR. N Engl J Med. 2001;344:1608-1621.
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
with right gangrenous toe and rest pain:
Calculate the ABI
R Brachial Pressure:
L/Brachial Pressure:
_160____
__156___
Dorsalis Pedis SBP : __60_____
Dorsalis Pedis SBP: ___140____
Posterior Tibial SBP : __58____
Posterior Tibial SBP: ___138_____
R/ ABI= _____
L/ ABI= _____
ABI Interpretation:
Normal, Borderline, Mild, Moderate, Severe, Noncompressible
Correct answers are: R/ABI= 0.37
L/ABI= 0.87
Severe PAD R/Side, mild PAD L/side
A 76 year old male, heavy smoker, hypertensive &
previous MI presents with right calf pain after 2 blocks:
Calculate the ABI
R Brachial Pressure:
L/Brachial Pressure:
_130____
__134___
AT SP: ___140____
AT SBP: __90_____
PT SP: ___138_____
PT SBS: __96_____
R ABI= _____
L ABI= _____
ABI Interpretation:
Normal, Borderline, Mild, Moderate, Severe, Noncompressible
Correct answers are: R/ABI= 0.71
L/ABI= 1.04
Mild 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:
mandatory