Peripheral artery disease

• significant risk factor for:

  • cvs events

  • lower limb amputation

• increased among:

  • elderly

  • smokers

    • four times more likely

  • DM

    • 1/2 of amputations

• pedal pulse easily felt on examination excludes peripheral artery disease

• physical exam:

  • reduced/absent pedal pulses

  • skin =

    • cool

    • shiny

    • hairless

    • thin

  • thickening of nails

  • abnormal CRT

  • pallor of distal extremities on elevation

  • leg pain

  • tissue ulceration or necrosis

• classical symptom only in 10%

  • claudication

    • tight cramp-like pain in muscles of calf, thigh or buttock

    • reproduced with exercise

    • relieved within 10mins of rest

  • 50% have atypical leg pain

  • remainder are asymptomatic

• ischaemic rest pain = increase severity

  • increase risk to limb

  • burning pain in arch or distal foot that occurs when feet elevated

• ddx for claudication

  • venous claudication

  • neurogenic claudication (spinal stenosis)

  • popliteal artery entrapment

  • Raynaud’s phenomenon

  • other vasospastic

Ankle-brachial pressure index

• non invasive way for detecting or ruling-out presence of Peripheral artery disease

• calculation:

  • systolic BP at ankle: arm

• healthy = 1.0-1.4

  • systolic at ankle > arm

• abnormal low (\<0.9)

  • sens 79-95%

  • spec 95%

  • = peripheral artery disease

• \<0.4 = critical limb ischaemia

  • severely reduced circulation

  • ischaemic rest pain

  • tissue loss due to ulceration and/or gangrene

• > 1.4 = inconclusive and refer to vascular lab

• used to assess safety of compression treatment

  • if >0.8 then hoisery considered safe

  • if \<0.8 but >0.5 - low compression (\<30mmHg = safe)

  • if \<0.5 then no hoisery

• insufficient evidence for population screening

• offer @ risk

  • older

  • smoking

  • DM

  • hyperlipidaemia

  • HTN

  • reduced renal function

• in particular:

  • 50-69 who smoke or DM

  • >70yo

  • Framingham >10%

• 12% of gen pop have congenital absence of dorsalis pedis

• limitations

  • doppler measures flow not amount of blood

  • technique not able to determine exact location of arterial stenois/occlusion

  • falsely elevated in patients with calcification of medial arteries

    • dm

    • renal dysfunction

    • rheumatoid arthritis

  • arterial stenosis may present with intermittent claudication and normal ankle pressure @ rest

Referal

urgent:

• ABPI \<0.5

• known eripheral artery disease with new ulcer/area of necrotic tissue

• ulcer that is not responding to Rx

• intermittent claudication when walking for \<200m

• young and otherwise healthy pt with caludication

  • rule out rare causes

    • popliteal artery entrapment

discussion:

• doubt re diagnosis

• uncertainty around significance of ABPI

• doubt about need for treatment

Treatment

• improve QOL

• reduce overall cardiovascualr risk

• if ABPI\<0.9

  • peripheral artery disease

  • 5yr cardiovascular risk >20%

  • intensive risk factor management

• lifestyle

  • smoking

  • walk 20min/day

    • exercise to point of maximal pain

      • improved limb function and general health

        • improved distal blood flow following creation of new collateral blood vessals

        • release of vasodilating compunds

          • nitric oxide

• pharmacological

  • ACEi may improve walking ability

    • 120m

    • painfree increase by 75m

    • ramipril = greatest effect

    • ?class effect

  • antiplatlet

  • statin

    • 17.6% reduction in cardiovascular events in people with PVD simvastatin and TC> 3.5

    • atherosclerotic plaque stabilisation

    • plaque regression

      • independently of lipidlowering ability

  • HTN taget 130/80

  • HbA1c = ≤50-55

  • renal function

    • microalbuminuria = earliest sign of diabetic kidney disease

• beta blockers

  • may be used cautiously continued in patients with PAD

  • cochrane review: no evidecne

    • adversely affected walking distance, calf blood flow or vascular resistance in patients with peripheral artery disease