Peripheral Artery Disease:Risk Factor Modification

Dr. Jose L. Raygada, MDMedical Director, Vascular Medicine and Infectious DiseaseVascular Health Clinics

DISCLOSURE

Author does not have any disclosures

PERIPHERAL ARTERY DISEASE

• What is PAD?• What causes PAD?

• Atherosclerosis• Other: inflammatory & non-inflammatory

• What is atherosclerosis?

J Am Coll Cardiol 2012; 59: 294

EPIDEMIOLOGY OF PAD

• Worldwide prevalence is between 3-12%

• In USA it is estimated that at least 8.5 million persons have PAD

Lancet 2013; 382: 1329

RISK FACTORS FOR PAD

• Smoking• Hypertension• Diabetes• Hyperlipidemia• Homocysteinemia• Metabolic syndrome• Other: age, gender, ethnicity,

low/middle income regions

Circulation 2004; 110: 738

SMOKING CESSATION

• Extremely difficult goal to accomplish - initial success rates are low

• The efficacy of physician advice is < 5%• AHA/ACC recommendations

• All patients should be strongly advised to stop smoking by their physicians

• All patient should be offered counseling and pharmacotherapy• Bupropion• Varenicline• Nicotine replacement therapy

• All patients who are smokers or former smokers should be asked about the status of tobacco use at every visit

J Am Coll Cardiol 2011;58: 2020

SMOKING CESSATION

Bupropion ER (Wellbutrin SR)

• 150 mg PO BID x 7-12 wk; start 150 PO qd x3 days

• Stop smoking after 5-7 days of treatment

SMOKING CESSATION

Varenicline (Chantix)• 1 mg PO bid x11 wk• Start 0.5 mg PO x3 days,

then 0.5 mg PO bid x4 days

• Stop smoking 8-35 days after starting drug if quit date unplanned

• Initial Tx = 12wk (1 start pack + 2 cont. pack); may cont. additional 12 wk if initial tx successful

BLOOD PRESSURE CONTROL

• BP control is an important component of CV risk reduction among patients with PAD - all pts with PAD should undergo BP assessment

• Beta-adrenergic blockers• ACE inhibitors

N Engl J Med 2015:373: 2103

CONTROL OF DIABETES MELLITUS

• Multiple epidemiological studies have established a strong association between DM and PAD

• The relative risk of PAD is up to 4x that of nondiabetic patients

• Therapeutic options include: insulin, sulfonylureas, metformin, the thiazolidinediones (“glitazones”), alpha-glucosidase inhibitors, others

• The standard target HbA1c of less than 7% stands as a recommendation for most patients.

TREATMENT OF HYPERHOMOCYSTEINEMIA

• This is a disorder associated with derangements of the metabolic pathway involved in the metabolism of the essential AA methionine

• Epidemiological studies have established an association between elevated plasma homocysteine levels and CAD and CVD but also PAD

• Vitamin supplementation (folate, B6, B12) is a therapeutic consideration

ANTIPLATELET THERAPY

• The role of antiplatelet therapy in the management of patients with PAD is well established

• The CLIPS study showed that the use of aspirin was associated with a 64% reduction in the relative risk of fatal and nonfatal vascular events and a 58% reduction in fatal and nonfatal vascular events and CLI

• All patients with PAD regardless of concomitant CAD or CVD should receive antiplatelet therapy

• Options: aspirin 81-325 mg PO daily, clopidogrel

• With exception of recent ACS or percutaneous interviention, there is insufficient evidence to support dual therapy

ANTICOAGULANT THERAPY

• Based on the lack of efficacy data for warfarin and the associated risk of bleeding, the routine use of anticoagulation is not recommended

• Anticoagulation therapy may be considered following an episode of acute limb ischemia that had been treated with thrombolytic Rx or may be warranted when there is a comorbid condition associated with increased risk for thromboembolism

VAODILATOR DRUGS

• Cilostazol• Prostaglandins• Calcium Channel Blockers• Pentoxifylline

STATINS

• Lipid lowering therapy with statins reduces the risk of adverse CV events in patients with atherosclerosis including those with PAD

• Several prospective studies found that statin therapy reduced the risk of new or worsening claudication

• Mechanisms: reduction in plaque size, improvement in vasomotor regulation of blood flow, promotion of angiogenesis, nd increased skeletal muscle metabolic function

MISCELLANEOUS PHARMACOLOGICALAGENTS

• L-arginine• Vitamin E• Ginkgo biloba• Disodium

Ethylenediaminetetracetic Acid (EDTA)

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