10/10/2015

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Peripheral Vascular Disease

Ganesh Muthappan, MD, FACC

Disclosures

• I work for St. Charles Heart and Lung

Center

• I am trying to build a practice in central

Oregon

• I do own a small amount of St. Jude stock

as part of a retirement portfolia

– I use what I consider the best product

available for my patients (including a Volcano

corporation product where St. Jude and

Volcano compete)

What is Peripheral Vascular

Disease?• Any vascular disease that isn’t in the heart

• Areas of special concern include cerebral

arteries, mesenteric arteries, renal

arteries, and leg arteries

• Usually due to atherosclerosis, but may be

due to other disease as well (trauma,

autoimmune)

• Don’t pay as much attention to veins:

bypassess are generally easier to form

(with exceptions)

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Epidemiology

• Risk factors include diabetes, tobacco use,

renal disease, age

• Up to 30% prevalence in patients with

concomitant diabetes and tobacco use

• Incidence increasing over time

• Incidence increases with age; appx 15-

20% of persons older than 70 have LE

PAD

Natural History

• Poor prognosis: diagnosis can lead to

disease course modification

• 5 year mortality rate for patients with

intermittent lower extremity claudication is

30%

• 5 year amputation rate is 4%

• Continued smoking and poor diabetes

control portends very severe prognosis

Weitz et al. Circulation 1996; 94: 3026-49

Natural History

McDermott et alJ Gen Intern Med. 1994;9:445-44

Severity of peripheral arterial

disease, as measured by ABI, has a

strong correlation with mortality, as

well as hard cardiovascular

endpoints (stroke, heart attack)

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Lower Extremity Arterial

Disease

Symptoms of Lower Extremity

Claudication (Intermittent)

• Lower extremity claudication: crampy, achey

pain that comes on (or worsens) with exertion

and gets better with rest. Often unilateral

• Pseudoclaudication (spinal stenosis):

paresthetic pain that occurs both with standing

and with walking, relieved by sitting and/or

leaning forward. Almost always bilateral.

Climbing steps will often not bring on the

pain.

Classification of Claudication

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Diagnosis of Lower Extremity

Peripheral Arterial Disease

• Ankle Brachial Index

• Toe Brachial Index

• Walking ABI

• Lower Extremity Arterial Duplex

• CT/MR angiography

• The gold standard is invasive angiography

Ankle Brachial Index

• The higher of the DP or PT pressure for

each leg divided by the higher arm

pressure (brachial)

Normal 1.00 – 1.40

Borderline 0.91 – 0.99

PAD ≤ 0.90

Pain/Ulceration ≤ 0.60

Non-Compressible ≥ 1.40

ACC/AHA 2011 PAD Management Guidelines

Diagnostic Methods: Ankle-Brachial Index (ABI)

• The resting ABI should be used to establish the diagnosis of patients at high risk for PAD, defined as patients

- with exertional leg symptoms,

- with nonhealing wounds,

- who are 65 years and older,

- or who are 50 years and older with a history of smoking or diabetes.

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What does a Normal ABI Mean?

So what to do?

• In a patient with exertional angina,

treadmill stress test is much more

revealing than resting ECG/echo

• In a patient with exertional claudication,

treadmill ABI is much more revealing than

resting ABI

• Treadmill ABI: patient walks at 1-2 MPH at

10% incline for 5 minutes; if ankle

pressure decreases by 15 mmHg, then

positive

Duplex Ultrasonography

• Most common secondary test for LE PAD

at St. Charles

• 5-7.5 MHx transducer

• Painless

• >90% sensitivity and specificity

• Can be used to estimate severity of

disease

• May overestimate stenosis (especially

following interventions)

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CTA and MRA

• Highly sensitive and specific

• CTA uses iodinated contrast

• MRA may be limited by the presence of

clips, pacemakers/defibrillators

• I will often order prior to diagnostic

angiography/intervention learn the lay of

the land

• However, selective angiography is the

gold standard

Catheter Based Angiography

• Access is gained to the leg contralateral to

the one where intervention is planned

• A 5F or 6F sheath (2mm) is inserted into

the common femoral artery

• Pigtail catheter is advanced to the aortic

bifurcation and digital subtraction

angiography is performed

• Catheter is then worked over the

bifurcation and selective angiography is

performed

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How to Treat Lower Extremity PAD

• Lifestyle changes

• Prevent cardiac/cerebral

morbidity/mortality (aspirin, statin, ace

inhibitor)

• Decrease symptoms (exercise therapy,

cilostazole, endovascular intervention)

• Limb salvage (endovascular intervention,

open revascularization)

Exercise Therapy Works

• Monitored exercise program (treadmill walking)

• Control patients had a 60% decrease in walking

distance over the course of 6 months

• Exercise therapy patients had a 80%

improvement in walking distance over 6 months

• Insurance generally does not pay

Gardner AW, Poehlman ET. JAMA. 1995;274:975-

980.

Cilostazole

• Phosphodiesterase 3 inhibitor

• Has both antiplatelet as well as vasodilating

properties

• Increases walking distance by approximately

80% over placebo

• Often limited by side effects (nausea, diarrhea,

headaches). CONTRAINDICATED WITH LOW

EF

• 100 mg BID

• Approximately $120 for a month’s supply

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Endovascular Intervention

• CLASS IA indication for endovascular

intervention for lifestyle limiting claudication

when the patient has failed conservative

measures and/or there is a very favorable

risk/benefit ratio for endovascular intervention

(e.g focal aorto-iliac occlusive disease)

• Technology and technique continues to improve:

superficial femoral arterial disease is now just as

safe (or safer) than aorto-iliac disease

Aortoiliac Disease

• Symptoms in hips, buttocks, thighs

• Can occur in younger patients

– In patients in their 50s with claudication, I

think of aortoiliac disease first

– Often healthier than patients with PAD

involving more peripheral arteries

Open vs. Endovascular Approach

for Aorto-iliac disease

• Surgery is the gold standard. Excellent

success rate (80-90% at 5 years), but

carries 1-3% mortality in major trials (these

are sick patients!)

• Endovascular approach: good patency

(70%) at 5 years, similar morbidity and

mortality

• Endovascular technology improves every

year

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Procedural Considerations

• Usually ipsilateral access (if femoral artery

is patent)

• Retrograde wire

• Balloon angioplasty

• Stenting with either self expanding or

balloon expandable stents is often

preferred

• If truly aortoiliac disease, “kissing” stents

are often used

Sample Case

• Left external iliac lesion

• Left CFA approach

• Cross lesion with wire

• Angioplasty/stent

Femoropopliteal Disease

• This anatomical location is more prone to scarring/thrombosis

• Surgery has appx. 70% 5 year patency for reverse vein grafts, appx. 40% 5 year patency for PTFE grafts

• Endovascular approach: 70% 2 year patency for drug coated stent, 50% 2 year patency for angioplasty alone.

• Current generation of drug coated stents are being improved, and atherectomy/drug coated balloon success rates are still being tabulated (80% 2 year success rates)

• Endovascular approach carries less morbidity/mortality than open approach

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Procedural Considerations

• Usually contralateral access

• Crossover and place a sheath just

proximal to area of disease

• Cross disease with wire

• Deliver equipment

• Angioplasty alone is preferred, but stenting

often used as well

• Self expanding stents have greater

resiliency in this location

Sample Case 1

• 67 year old man with poorly controlled

diabetes, CAD s/p CABG, prior tobacco

use and ongoing marijuana (smoked) use.

• Referred for nonhealing ulcer x 3 months

with noxious smell.

• No palpable pulses on either foot

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Sample Case 1

Sample Case 1

Sample Case 1

• Post procedure had

booming dorsalis pedis

pulse

• Wound did heal several

months post procedure

(sugars in 200s)

• Angiogram 3 months later

of LLE did not show

significant popliteal

disease

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Sample Case 2

• 68 year old man with longstanding history of

tobacco use (ongoing), dyslipidemia, well

controlled diabetes, coronary artery disease s/p

CABG with EF 35%

• 6 months of left calf aching, initially >50 yards

but now 10 yards (can’t walk around his house

without having to stop and rest his calf)

• Had bilateral iliac stenting in March, but still with

left calf symptoms and now nonhealing ulcer

Sample Case 2

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• Patient with barely dopplerable pulse

before procedure, now had palpable pulse

after procedure

• Able to walk around house, but still limited

by pain with >100 yards of walking

So my patient has had a LE procedure

for claudication: what should I do?

• Aspirin 81 mg daily indefinitely

• Clopidogrel 75 mg daily for at least one month

(depending on intervention, complexity of stent

left behind)

– Bigger vessels with more flow are less likely to

thrombose

• Refer to PAD rehab if possible (the magic

unicorn)

• Encourage patient to walk

• Follow up exam/imaging at 1 month, 3-6 months,

then yearly

Critical Limb Ischemia

• Limb threatening ischemia seen in 1-2% of

patients with PAD >50 years old Circulation.

2006;113(11):e463.

• At 1 year, 25% of these patients are dead

and 25% have had an amputation

• Most of these patients have significant

comorbidities

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Chronic Limb Ischemia

• Amputation portends an especially poor

prognosis

• 40-50% 2 year mortality (Risk factors as

well as co-existent vascular disease in

cardiac/cerebral beds)

• Also the after effects of amputation:

depression, decreased mobility,

institutionalization

Get these patients a cardiovascular

evaluation!

• 40-60% of these patients don’t have a

vascular referral

• Amputations are preventable

• Even if not preventable, they are healable.

BASIL trial: endovascular therapy vs.

open revascularization for critical limb

ischemia

Survival benefit seen for

surgery at 2 years.

For patients expected to

have <2 year life expectancy,

endovascular approach might

be better than open

revascularization

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Treat inflow first

Inflow disease (aorta, iliac) has 80%

success rates

SFA-Popliteal disease has 30-70%

success rates

Tibioperoneal disease has 30-75%

success rates

Wound healing vs. long term

success

Angiosome guided therapy

• Below the knee

interventions have

lower technical

success rates, but

inline flow to an

ulcer will improve

healing

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Other LE PAD conditions to

know about• Buerger’s disease: inflammatory vasculitis of

small and medium sized arteries, veins and

sometimes nerves. Strongly associated with

tobacco use, and cannot be treated without

tobacco cessation.

• Peripheral Aneurysm: Atherosclerosis mediated

weakness in the arterial wall causes dilation.

Associated with pain, mass effect on nearby

structures (e.g. veins) and embolic disease.

Treatment is primarily surgical.

Renal Artery Stenosis

www.radblazer.com

When to Consider Renal Artery

Stenosis• Unstable cardiac syndromes

– Recurrent flash pulmonary edema

– Refractory heart failure

– Refractory unstable angina

• HTN (RAS is the second most common cause)

– Accelerated hypertension

– Resistant hypertension (unable to controle with 3 or more

agents)

– Onset at a young age (<30 years old)

• Renal Dysfunction (especially if worsened by ACE

inhibitor or ARB)

• Asymmetric atrophic kidney

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Pathophysiology of

Renovascular Hypertension• With unilateral renal artery stenosis, decreased

blood flow to the affected kidney is sensed as

decreased plasma volume

• The kidney then produces more renin, which

makes more angiotensin II

• Angiotensin II is a direct vasconstrictor

• Angiotensin II also increases aldosterone

secretion: sodium and fluid are retained

• The healthy kidney can at least partly

compensate for this process

Bilateral Renal Artery Stenosis

• Decreased blood flow to both kidneys

results in increased renin->angiotensin->

aldosterone

• Volume expansion occurs, somewhat

compensating for the stenosis

• If ACE-inhibitors or angiotensin receptor

blockers are administered, volume

expansion is blocked and the kidneys see

MUCH less flowacute renal insufficiency

How to Make the Diagnosis?

• Duplex US

• CT Angiography

• MR Angiography

• Catheter angiography is recommended if

other tests are inconclusive

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Renal Artery Interventions

• 90% of disease is atherosclerotic

• Usually ostial or proximal disease;

progression to complete occlusion over

time is common (10% of ESRD is caused

by RAS)

• Technical Success Rate: 95%

• Clinical Response rates much lower

– Patient selection

– Is RAS the cause of hypertension or renal

insufficiency?

Renal Artery Intervention:

Procedural Considerations• Femoral Access is commonly used, but can also use radial or

brachial access (require longer catheters)

• 6F sheath (2 mm)

• Renal Artery is engaged with a guide catheter

• 0.014” wire is used to cross the lesion

• Angioplasty is performed to facilitate stent delivery

– If patient has flank pain, the angioplasty is too aggressive

• A stent is delivered to cover the lesion and deployed

– Normal size of renal artery is 5-6 mm

– For ostial/proximal disease, the stent should extent 1-2 mm into the

aorta to allow full strength of stent to cover atherosclerosis

• Some evidence suggests that drug eluting stents have better long

term outcomes than bare metal stents, especially for smaller vessels

(up to 30% restenosis rate for vessels <4 mm, appx. 10% for 5 and

6 mm vessels)

Sample Case (not mine)

Circulation: November 10, 2009 vol.

120 no. 19e157-e158

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Fibromuscular Dysplasia

• 10% of renal artery stenosis

• Commonly affects young

women; cause unknown

• Typically involves the mid or

distal portion of the renal

artery

• Rarely leads to vessel

occlusion or ischemic

nephropathy (but can lead to

hypertension)

• Responds well to balloon

angioplasty (if necessary)

Renal Artery Denervation

• The adventitia of the renal arteries has a

high concentration of sympathetic nerves

• Surgical denervation used to be a

treatment for resistant hypertension

• Catheter based radioablation might afford

similar results

Simplicity 2 Trial

• Renal Artery denervation vs. medical therapy:

sustained improvement in BP (2032 mmHg in

denervation patients)

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Simplicity 3 Trial

• 535 patients 18-80 years old, randomized

2:1 fashion to denervation vs. sham

procedure (renal angiography)

• Patients had to have 3 office SBP

measurements >160 mmHg

• Patients had to be taking maximally

tolerated doses of at least 3 different

classes of blood pressure drugs, including

diuretic

Bhatt DL et al. N Engl J Med 2014;370:1393-1401.

Home BP Monitoring

Bhatt DL et al. N Engl J Med 2014;370:1393-1401.

Ambulatory BP monitoring

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The Future of Renal

Denervation

• Boston Scientific is currently conducting a 100 patient trial with their own

catheter, which they claim has better technology (circumferential rather than

point ablation)

• May have a role in certain patients with sympathetic overload (how to

diagnose?)

• Hypertension, in large part, is a disease controllable with medications and

lifestyle

• ADHERENCE to medications may be the key

• Diuretics should be used in all patients with “resistant” hypertension

• If the diuretic isn’t making your patient urinate, then increase the dose

Chronic Mesenteric Ischemia

• Intestines are supplied

by 3 main arteries:

celiac, superior

mesenteric and inferior

mesenteric

• Robust collateral

formation can occur,

from these branches as

well as branches of

hepatic, renal or

mammary arteries

Chronic Mesenteric Ischemia

• Suspect in postprandial abdominal pain,

especially in patients with atherosclerosis

in other beds

• Patients will often avoid eating and lose

weight

– A lot of patients will have undergone a

malignancy workup

• Anatomically, generally need to have 2 our

of 3 vessels with significant disease

• Can be treated endovascularly

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Carotid Artery Stenosis

The Carotid artery branches off the aorta (left)

and off the innominate (right), and divides into

the internal (supplies brain) and external

(supplies face and eye) branches

Stenosis can be anywhere, but commonly in

the bulb or at a branch point.

Unlike coronary disease or lower extremity

disease, cerebrovascular disease often

seems to be an embolic phenomenon rather

than a fixed perfusion deficit phenomenon.

Crumbly plaques are bad!

Symptomatic Carotid stenosis

• Symptomatic defined as TIA or stroke in

the last 6 months

– Amaurosis Fugax should also be a warning

sign

• >70% stenosis: 26% stroke risk over 2.5

years

• 50-69% stenosis: 18% stroke risk over 5

years

Asymptomatic Carotid Stenosis

• Stroke risk is relatively low

• Risk of ipsilateral stroke 3.2%/year for

asymptomatic stenosis 60-99% (North

American Symptomatic Carotid

Endarterectomy Trial, NEJM 2000)

– This was in an era before high prevalence

statin/antiplatelet use

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Should I listen for a bruit?

• Detection of a carotid bruit has less than

20% correlation with carotid stenosis

(Stroke 1998; 29:750-753)

• Referred murmurs commonly mistaken for

bruits

• Not all atherosclerosis results in

auscultatable bruit, especially if severely

stenosis

• However, I still do it

How to treat medically?

• Aspirin or Plavix

• High dose statin (Atorvastatin 40-80mg,

Rosuvastatin 20-40 mg)

• Aggressive BP control

• Diabetes control

• Lifestyle changes

• If stenosis >60%, regular screening to

monitor for progression

When to intervene?

• Trials of intervention were done when medical

therapy meant aspirin alone

• If patient has >5 year life expectancy and has

asymptomatic stenosis >70%, worth discussing.

• If patient has >5 year life expectancy and

symptomatic carotid stenosis >50%, worth

discussing

• If patient has >5 year life expectancy and has

symptomatic carotid stenosis >70%, benefits

usually outweigh the risks

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Carotid Endarterectomy vs.

Stenting• Carotid endarterectomy carries a higher

risk of MI (2.3% vs. 1.1%)

• Carotid stenting carries a higher risk of

stroke (4.1% vs 2.3%)

• Combined endpoint and quality of life

measures were no different at 1 year

• Medicare doesn’t pay for carotid artery

stenting outside of clinical trials unless

endarterectomy is contraindicated.

Take Home Lessons

• PAD is a very common entity

• Guidelines recommend screening for PAD

in any patient over 65, and in patients >50

with tobacco history or diabetes

• Patients with abnormal ABI should get

aggressive lifestyle and medical therapy to

prevent stroke, heart attack and death

• If amputation crosses your mind, the

question of whether revascularization can

help should also cross your mind

Take Home Lessons

• Consider Renal Artery Stenosis with

unstable cardiac sydromes, accelerated

HTN, or unexplained renal insufficiency

• Treat resistant hypertension with drugs

and counselling for adherence/lifestyle.

• Adequately dosed diuretics are the key

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Take Home Lessons

• Asymptomatic carotid artery stenosis has

a low to moderate risk of stroke with

current therapy. Consider endarterectomy

if stenosis >70%.

• Symptomatic carotid artery stenosis had a

high risk of stroke depending on plaque

burden, and endarterectomy is the

treatment of choice.

PAD physicians in Central

Oregon• You can contact me at

pgmuthappan@stcharleshealthcare.org

• My office phone is (541) 388-4333

• My personal cell phone is (734) 883-3004

• Feel free to call me even if you just want to run a

patient by me

• My partner, Allen Rafael, also seed PAD

patients. Central Oregon also has an excellent

interventional radiologist (Garret Schroeder) and

two excellent vascular surgeons (Wayne Nelson

and Jason Jundt)