Exercise for Elderly Peripheral Revascularized Patients

Principal Investigator: Andrew Gardner, Ph.D.

Abstract:

Although infrainguinal revascularization, either through lower extremity arterial bypass surgery or percutaneous transluminal angioplasty, improves peripheral circulation, the majority of the revascularized PAOD patients reported in the literature remain functionally disabled with intermittent claudication (Stage II PAOD using the Fontaine classification system)5 measured by an objective treadmill test.6-11  In fact, we find that ambulatory function of PAOD patients with critical limb-threatening ischemia (Fontaine Stages III and IV PAOD) does not improve following revascularization.12  In our preliminary studies, older revascularized PAOD patients were only able to ambulate 58 meters before the onset of claudication pain and covered less than one-third of the distance during a six-minute walk than healthy age-matched controls.  This finding is particularly surprising given that revascularization improved the ankle/brachial index (ABI) by 133% to a value that was 22% better than non-revascularized PAOD patients with intermittent claudication.12,13  The lack of functional improvement in revascularized patients may be due to extreme physical deconditioning secondary to their critical limb-threatening ischemia.  Although numerous exercise rehabilitation studies have been performed in patients with stable intermittent claudication,3 to date no clinical trials have examined the effects of exercise rehabilitation on functional performance and quality of life in older patients who have recently undergone infrainguinal revascularization for limb-threatening PAOD.  This proposed study represents a unique contribution to the management of PAOD, and is an extension of the work conducted on patients with intermittent claudication to an even more disabled older population.

Specific Aims:

Specific Aim 1: To determine whether a 6-month exercise rehabilitation program will improve ambulation, free-living daily physical activity, and health-related quality of life in older, revascularized patients with PAOD.

Specific Aim 2: To determine whether the primary mechanisms by which exercise rehabilitation affects the above functional outcomes are through alterations in walking economy, peripheral circulation, and cardiopulmonary function.

Participant Inclusion Criteria:

The inclusion criteria for the revascularized patients will consist of the following:

1. lower extremity arterial bypass 3 to 12 months prior to screening
2. infrainguinal percutaneous transluminal angioplasty (PTLA) 2 weeks to 12 months prior to screening

The exclusion criteria for the revascularized patients will consist of the following:

1. persistent rest pain due to PAOD (Fontaine Stage III for PAOD)
2. persistent tissue loss due to PAOD (Fontaine Stage IV for PAOD)
3. medical conditions that are contraindicative for exercise according to the American College of Sports Medicine (e.g., acute myocardial infarction, unstable angina, etc.)
4. cognitive dysfunction (mini-mental state examination score of < 24)

Participant Compensation: Yes or No

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