Amjad AlMahameed, MD, MPH

Division of Cardiology

Beth Israel Deaconess Medical Center

Boston

Differentiating Lower Extremity Pain: Arteries, Veins, and Nerves!

The Value of the ABI

Objectives

• Review the differential diagnosis of lower extremity dysfunction

• Beyond intermittent claudication: Recognize the different clinical presentations of PAD

• PAD as the cause of symptoms: Reflect on clinical evaluation

HTN 50 million

Stroke4.4 million

CHF4.6 mill

Heart 16.8 million

AMI7.2 mill

Angina6.3 mill

68 Million Americans with CVD

PAD8.4 million

PAD incidence expected torise by 40% (M) and 15% (W)

till 2030

Musculoskeletal Causes:

- Arthritis (lumbar disk, hip, knee) - Bursitis - Tendonitis - Tight hamstring/quadriceps

Neurogenic Causes

- Lumbar canal stenosis

- Peripheral neuropathy

Podiatric Causes:

- Planter fasciitis

- Tarsal Tunnel Syndrome

Other Vascular:

- Venous claudication - Takayasu’s, giant cell vasculitis - Thromboangiitis obliterans - Chronic Pernio

D Dx of Leg Pain

PAD Venous Claudication

Neurogenic Claudication

Location muscle group whole leg Poorly localize

Quality of pain Cramping “Bursting” Electric shock-like

Onset Gradual, predictable

Variable Variable

Exacerbation Walking, biking, leg elevation

Dependency (sitting, standing), walking,

biking

Standing, walking, lying prone, exten-ding lumbar spine

Relief Stopping or standing

Leg elevation,

compression Rx

Sitting, flexing

lumbar spine

Legs affected Usually one Usually one Often both

Are the Limb Symptoms Related to PAD?Are the Limb Symptoms Related to PAD?

Intermittent Claudication

Predictable Leg pain induced by walking

Relief with resting (stopping/standing)

Recurs when walking is resumed

Classic triad of

symptomsin patients

with IC is seen in

(11-33%)

of all PAD pts

NormalFatigue,

heaviness Mild Moderate Severe Rest pain

Poor wound

healing

Impendingor overt

gangrene

Claudication Limb-Threatening Ischemia

Worsening Flow Limitation

Spectrum of Peripheral Arterial Disease Presentation

Pain Soreness

Ache Weakness

Tiredness Numbness

Tightness Discomfort

Indications for the ABI

• Non palpable pulses

• Unexplained leg pain

• Rest pain

• Non healing sores or ulcers

• Claudication

• Risk stratification

ABI is 95% sensitive and 99% specific for PAD

A/B Index SEVERITY OF DISEASE

0.9 – 1.0 Normal

0.70 – 0.89 Mild disease

0.40 – 0.69 Moderate disease

< 0.40 Severe disease

Lower extremity systolic pressureLower extremity systolic pressure________________________________________________________________________________________

Brachial artery systolic pressureBrachial artery systolic pressureABI =ABI =

180 mmHg

180 mmHg

170 mmHg

130 mmHg 180 mmHg

170 mmHg

R DP 130 mmHgR PT 110 mmHgABI 0.72

R DP 180 mmHgR PT 180 mmHgABI 1.0

R transmit R Toe L transmit L Toe

Post Exercise

R Ankle L Ankle

Higher R-Ankle SBP

Higher Arm SBPRight ABI

Higher R-Ankle SBP

Higher Arm SBPLeft ABI

Usefulness of the ABI

• Diagnosis, localization, and monitoring PAD progression

• Assess functional capacity (even asymptomatic pts)

• Predictor of cardiovascular morbidity and mortality

PAD Survival as a Factor of the ABI

Year

100

80

60

40

200 108642

Pat

ien

ts S

urv

ival

(%

) ABI >0.85

ABI 0.40–0.85

ABI <0.40

McKenna M, et al. Atherosclerosis. 1991;87:119-128.

PAD and Functional Impairment

•Peripheral arterial disease (PAD) is associated with

– Poorer walking endurance– Slower walking speed– Poorer balance

• Compared to individuals without PAD

Limited leisure and Work activities

Olin JW. AM J Med 10-17,1998.Scherer SA. Arch phys Med Rehab 79:529-531,1998 Regensteiner JG. J Vasc Med Biol2:142-152,1990

McDermott M et al. JAMA 2004; 292:453-461.

Outcome Asymptomatic PAD

Without

PAD

p

Mean annual decline in 6-minute walk performance (ft) (95% CI)

- 76.8(- 135 to - 18.6)

- 8.67(-36.9 to -19.5)

0.04

Walking Performance in Asymptomatic Peripheral Arterial Disease

Clinical Tips

• The DP pulse is congenitally absent in up to 32% of normal individual but the absence of PT pulse is always abnormal

• Lack of hair on the shins is not always a sign of PAD

• Patients with rest pain may present with pitting edema

• Persistence of pallor > 40 second after 1 minute elevation is indicative of severe disease

PAD is NOT the Cause of Leg Symptoms if:

• History and physical exam not suggestive

• Normal rest ABI and treadmill exercise testing

• Presence of alternative diagnosis

• In this process, you may also obtain spine MRI, X-rays of the hips and knees, and even EMG/NCS