Peripheral Arterial Disease: Update 2009

William Downey, MD, FACCSanger Vascular Medicine and Adult Cardiology

Disclosures

• None

Why Is Peripheral Arterial Disease Important?

• Opportunity to identify and intervene upon vascular disease before a major event (MI, stroke).

• Sometimes debilitating but treatable symptoms.

PAD (Symptomatic or Asymptomatic) is a Coronary Artery Disease Risk Equivalent

0

5

10

15

20

25

30

35

40

45

50

>1.1 1.01-1.1 0.91-1.0 0.71-0.9 <0.71

ABI at baseline

Non-fatal MI

Non-fatal stroke

Death

BMJ 313:1340.

5 year event rate

“Do Your Legs Hurt When You Walk?”

>50% of Symptomatic patients don’t volunteer symptoms

How Do I Identify These Patients: ABI

Normal 0.9 – 1.3Claudication 0.5- 0.89Rest pain 0.21- 0.49Tissue loss < 0.20Calcified > 1.3Significant Δ 0.15

Two main limitations :•Calcified ankle vessels result in falsely “normal” ABI.

•Normal ABI in patients with aortoiliac disease; brought out only with exercise.

greater of DP/PT systolic pressuregreater of arm systolic pressuresABI=

When Should I Check an ABI?

• Anyone with suspected claudication.

• Patients at high risk for atherosclerosis who are not already being aggressively treated:– Framingham risk >10%.– ADA recommends all diabetics >55 (but these

should be aggressively treated already)

• Erectile dysfunction

Atherosclerosis Therapy• Smoking cessation

– Reduces risk of death, MI, CVA, and amputation.

– Questionable benefit on symptoms.

• Antiplatelet agent: aspirin and/or clopidogrel (CAPRIE)

– Reduces risk of death, MI, CVA.

– No effect on symptoms.

• Statin (HPS, 4S, others)

– In patients with PAD in 4S, simvastatin group had 38% reduction in development of or worsening of claudication.

• ACE-inhibitor (HOPE)

– 22% reduction in risk of major vascular event

• Hypertension control -blockers with caution only in severe ischemia (ABI<0.4).

Symptomatic Therapy• Exercise:

– Formal programs increase pain-free walking distance by 180%.– Walk repetitively to the onset of pain at least 3x per week.

• Cilastazol (Pletal):– Modest increases (50-70%) in pain-free walking distance.– Inhibits type III phosphodiesterase contraindicated in CHF.– Common side-effects usually resolve with continued treatment:

headache, palpitations (sinus tachycardia), diarrhea, dyspepsia. • Revascularization for:

– Life-style limiting symptoms which persist despite a trial of exercise and cilastazol.

– Limb-threatening ischemia.– Indications evolving with development of less-invasive

techniques.

Gardner AW and Poehlman ET. JAMA (1995)  274:975-980.Patel PD and Thompson PD. ACC Current Journal Review (2004) 13: 16-20.

42 yr old lady referred for evaluation of non-STEMI. Complains of > 1 year of bilateral calf pain with walking <2 blocks. At cardiac cath found to have right common iliac occlusion and severe left iliac stenosis.

PMH: diabetes, dyslipidemia, CAD s/p LAD stent, continued tobacco abuse.

Meds: aspirin, lopressor, Avandamet, Altace.

Exam: Normal cardiac exam. 2+ carotid pulses without bruit, femoral pulses trace bilaterally with no bruits, popliteal pulses not palpable, DP and PTs Dopplerable bilaterally.

Labs: creatinine 1.3, Hct 41, INR 1.0

Aortoiliac Disease

• Who to revascularize:– Limb-threatening ischemia and life-style

limiting claudication. – Relatively low threshold to treat.

• How to revascularize:– Consider comorbidities, anatomic factors.– In general, endovascular therapy is

preferred.

Revascularization Options for Aortoiliac DiseaseAorto-bifemoral bypass

Fem-fem bypass

Angioplasty +/- stenting

Aortoiliac disease

Stenting: – 5 year efficacy: 71% primary patency, 81% primary-

assisted patency. – <0.5% operative mortality– Usually done as outpatient procedure.

Surgery (aortobifemoral bypass): – 5 year patency: 90% – 2-4% operative mortality– Substantial post-operative morbidity

Back MR et al. Ann Vasc Surg. 2003; 17: 596-603. Murphy TP et al. Radiology. 2004; 231: 243-249.Rutherford et al. Semin Vasc Surgery. 1994; 7: 11.TASC-2.

2 weeks post:

•Walking 2 miles/day without claudication.•Able to participate in cardiac rehab.•Stopped smoking.

4 years later: Continued patency.

Carotid Artery Disease

0 10 20 30 40

2y s

troke

rate

by

% s

teno

sis string sign

90-99%

80-89%

70-79%

0 5 10 15

2y s

troke

rate

by

% s

teno

sis 90-99%

80-89%

70-79%

60-69%

0-59%

11%

34%

28%

20%

10%

7%

3%

3%

3%

Symptomatic Asymptomatic

2y Event Risk

Data from NASCET and Chambers; NEJM ’86;315:860-5.

Risk of Stroke Depends Upon:1. Symptomatic Status

2. Stenosis Severity

CEA in Symptomatic Patients:Consistent Benefit

n Follow-up (months)

RR (%) p

NASCET 658 18 26 0.001

ECST 778 36 17 0.0001

VA Cooperative 193 12 19 0.01

For stenosis >70%: NNT=6.350-69%: NNT =16.1

More Than 80% of Strokes are Unheralded

Revascularization for Asymptomatic Carotid Stenosis

5.1

11

6.4

11.8

0

4

8

12

ACAS ACST

CEA

Medical tx

5 year CVA

JAMA 1995; 273: 1421.Lancet 2004; 363:1491.

(p<0.0001)(p=0.004)

• ACAS: – >60% stenosis (n=1662)– Perioperative death/stroke: 2.3%

• ACST:– >70% stenosis (n=3120)– Perioperative stroke: 3.1%

Indications for Screening

• Cervical bruit• Symptoms - Amaurosis fugax or

TIA/Stroke• Syncope (if vertibrobasilar insufficiency or

bilateral carotid disease is suspected – a very rare cause of syncope)

• Known subclavian stenosis• Previous CEA• Pre-operative evaluation for CABG

Carotid Stenting

Sapphire:

0

2

4

6

8

10

%

MAE Death MajorIpsi CVA

MinorIpsi CVA

MI

StentCEA

Yadav et al. NEJM 2004: 351:1493.

So I need revascularization, stent or CEA?

Currently, only patients at high risk for CEA:

Patient factors:

•CHF: NYHA ¾•EF <30•MI <24 hours and <4 weeks•Active unstable angina•Planned cardiac surgery w/in 6 weeks•Severe pulmonary disease

•Chronic O2

•FEV1 or DLCO <50%•Contralateral laryngeal palsy

Anatomic features:

•CEA restenosis•Contralateral carotid occlusion•Prior cervical XRT•Diffucult surgical access

(high or low lesion)_

Carotid Revascularization

Who to revascularize:– Symptomatic: >60% stenosis.

– Asymptomatic: >80% stenosis.

How to revascularize:– Consider comorbidities, anatomic factors.

– Stenting currently reserved for patients at high risk for CEA.

– Trials currently evaluating carotid stenting vs. CEA for all patients.

Where should I refer my carotid disease?

• Trials of CEA have a peri-operative stroke rate of ≤3%.

• Medicare data shows national peri-op stroke rate of 6%.

• Know the stroke rate of the program that you send your patients to.

• Refer to programs where both carotid stenting and CEA are done commonly.

Take Home Points:

• PAD is a coronary risk equivalent– Ask about symptoms– Feel for pulses– Low threshold to check ABI

• Stroke is devastating and revascularization works– Check carotid duplex in symptomatic patients.– Get carotid revascularization done where results are

excellent.