• Introduction
• Pathophysiology
• Exercise Effectiveness
• Clinical Management
  • Medical/Surgical Treatment
  • Pharmacology
  • Exercise Prescription

Introduction

Approximately 7-12 million older adults in the US have peripheral vascular diseases. Adults under the age of 55 years old rarely exhibit peripheral vascular diseases. The prevalence for ages 55-74 years old is 5%; and 10 to 18% for older adults >70 years old.

Peripheral vascular disease can be divided into

• Peripheral artery diseases
• Peripheral venous disorders

Peripheral arterial disease is defined as atherosclerosis of the distal aorta and/or lower limb arteries causing arterial narrowing and disruption of blood flow to the legs.

Risk factors for peripheral arterial disease:

• Tobacco abuse (risk persists >5 years after cessation)
  • Cigarette smoking
    • 20 per day: 2.11 relative risk
    • 11-20 per day: 1.75 relative risk
• Diabetes Mellitus
• Systolic Hypertension
• Hypercholesterolemia
• Hyperhomocysteinemia
• Advanced age
• Increased Body Mass Index (Obesity)

Coronary Artery Disease and Cerebrovascular disease are usually comorbidities.

Signs & Symptoms:

• Exertional pain:
  • 70% arterial stenosis
• Nocturnal pain:
  • 70 to 90% arterial stenosis
• Ischemic rest pain:
  • 90% arterial stenosis
    

Similar to angina, ischemic pain occurs in the legs due to the atherosclerotic process. Claudication is the term used to describe this pain or discomfort.

Classic claudication is like angina, in that it increases with exertion and is relieved with rest.

When the pain becomes nocturnal, the disease has progressed.

Ischemic rest pain (pain at rest) reflects the most severe stage of peripheral arterial disease.

The location of the claudication can indicated the location of the atherosclerotic lesion:

• Iliofemoral Occlusive Disease
  • Buttock
• Femoropopliteal Occlusive Disease
  • Thigh and calf claudication
    

EXERCISE EFFECTIVENESS

The literature on exercise for prevention and treatment of peripheral arterial disease is limited. In fact, there is no epidemiological studies. Only clinical trials.

Girolami and colleagues conducted a meta-analysis on the existing exercise treatment in peripheral arterial disease. They found 49 articles, but only four had good scientific controls.

• Girolami, B. E Bernardi, MH Prins, J Wouter ten Cate, R Hettiarachichi, P Prandoni, A Girolami, and HR Buller. Treatment of intermittent claudication with physical training, smoking cessation, pentoxifylline or nafronyl. Archives of Internal Medicine 159:337-345, 1999.

One of the most common variables observed in exercise treatment studies is the pain-free walking distance. This distance represents the claudication threshold.

The four quality studies are summarized to the right. It is clear that all of these studies showed a longer pain-free walking distance in the exercise treatment groups than in the control group following the training programs. The training programs ranged from 3 to 6 months.

Hiatt and colleagues published a series of articles on a study where they randomized 29 patients into treadmill walking, resistance training, and control groups. Both treadmill walking and resistance training programs were three sessions per week for 60 minutes.

The walking program was designed to produce claudication after 3-5 min. As soon as the claudication was exhibited, the subject rested until the pain subsided then continued to walk at that workrate for the remaining 50 minutes.

The resistance program consisted of

• heel raises
• dorsiflexion
• leg extensions
• leg curls
• foot extension

Resistance was set at a load that produced fatigue in six contractions. Three sets were done on one limb at a time.

• Hiatt, WR, EE Wolfe, RH Meier, and JG Regensteiner. Superiority of treadmill walking exercise vs. strength training for patients with perpherial arterial disease: Implications for the mechanism of the training response. Circulation 90:1866-1874, 1994.
• Hiatt, WR, JG Regensteiner, EE Wolfel, MR Carry and EP Brass. Effect of exercise training on skeletal muscle histology and metabolism in peripheral arterial disease. Journal of Applied Physiology 81:780-788, 1996.
• Regensteiner, JG, JF Steiner and WR Hiatt. Exercise training improves functional status in patients with peripheral arterial disease. Journal of Vascular Surgery 23:104-115, 1996.

Physical work capacity increased in the treadmill group more than the resistance group.

Resistance changes were not measured in either group.

Claudication threshold was only increased in the treadmill walking group.

Resistance exercise did not improve claudication threshold even though muscle weakness is a characteristic of peripheral arterial disease.

Daily physical activity increased in the treadmill walking group.

Patients were able to increase other activities as their claudication threshold and physical work capacity increased.

Physical functioning was also assessed and increased the most in the treadmill walking group.

Muscle fiber typing and oxidative enzymes were also measured, but did not exhibit any changes for any groups.

Other studies have shown:

• Reduce Risk Factors
• Increase Physical Work Capacity
• Increase in leg blood flow
  • Favorable distribution of leg blood flow
  • Increase Collateral Circulation
• Increase oxygen capacity of muscle
• Decrease Claudication
  • Increase in claudication threshold

CLINICAL MANAGEMENT

Evaluation of the disease will be presented with clinical management. Evaluation is similar to coronary artery disease:

• Catheterization or angiography
• CT or MRI Scans
• Ultrasound

The CT scan of the arteries before and after treatment. Image A shows aneurysm in right popliteal artery and multiple stenoses in posterior tibial artery of the right leg. In addition, a long arterial occlusion of left superficial femoral artery.

Image B is normal blood flow after treatment.

The ankle-brachial index is tested to determine the severity of the disease based on blood flow to the foot. Blood flow to the foot will be decreased if the artery exhibits occlusion higher in the leg. Blood pressures at the ankle reflect blood flow to the foot.

Ankle-Bracial Index is the ratio of pulse magnitude between the brachial and tibial arteries. When the atherosclerotic plaque has blocked the artery significantly, the tibial pulse and ankle blood pressure will be reduced.

The formula for determining the Ankle/Brachial Index is summarized below

Fontaine Stage - rates the stage of Peripheral Arterial Disease

• Stage I: Asymptomatic
  • Ankle-Brachial Index < 0.9
  • Decreased distal pulses
• Stage II: Intermittent claudication
• Stage III: Daily rest pain
• Stage IV: Focal tissue necrosis
  • Ankle-Brachial Index < 0.3 (50% block)
    

MEDICAL/SURGICAL TREATMENTS

Patients with PAD may also be on additional meds to lower cholesterol and/or control diabetes. Smoking cessation is also a significant element of lifestyle treatments.

Surgical treatments are similar to coronary artery disease in that procedures attempt to increase blood supply.

An arterial bypass can also be completed on the blockage in the arteries of the legs. Veins are used for these bypasses.

Bypasses are also used on aneurysm of the arteries of the leg.

PHARMACOLOGY

Treatment of Peripheral Artery Disease includes reduction of risk factors such as smoking and cholesterol, diet, exercise and medications. Exercise is recommended to increase claudication threshold or pain free walking time. The objective of medications is to increase blood flow.

• antiplatelet drugs
  • aspirin
  • clopidogrel (Plavix)
  • cilostazol
• pentoxifylline

Both clopidlgrel and cilostazol are classified as antiplatelet meds. Pentoxifylline improves blood flow (via decreasing viscosity) and also acts as an antiinflammatory med.

There should be no precautions for exercise with these medications.

EXERCISE PRESCRIPTION

Exercise programs for PAD focus on relieving claudication and prevention of cardiovascular events.

• Walking
• Walk/cycle
• Stair Climbing

• Resistance

• 3-5/week

• 2/week

• Accumulate 30-60 min

• 1-2 sets
• 10-12 reps
• upper & lower body

• 40-60%
• to claudication of 3 (on a scale of 1-4)

• Be prepared for angina/angina equivalents as pt improves
• Cold weather may make symptoms worse - long slow warm-up in cold weather
• Consider comorbidities

• Smoking Cessation
• Diet/Nutrition

If the PAD patient needs an amputation, consideration is warranted regarding the energy expenditure of weight dependent work.

Energy expenditure is 24% higher for the longer leg prosthetic than the lower leg.

Ventilation is 14% higher for the longer leg prosthetic.