Reducing Risk Factors in Peripheral Arterial Disease

BACKGROUND:

Patients with PAD have a 3- to 4-fold higher risk of cardiovascular morbidity and mortality compared to patients without PAD. Risk of future cardiovascular events is comparable between patients with PAD and coronary artery disease (CAD). While improved atherosclerotic risk factor treatment has reduced cardiovascular morbidity and mortality in patients with CAD, such treatment in patients with PAD remains suboptimal. Intensity of cholesterol-lowering therapy, specifically, is significantly poorer in patients with PAD as compared to CAD. Data show that fully 69 percent of patients with PAD from a non-invasive vascular laboratory in Chicago did not have the recommended LDL-C level of less than 100 mg/dl. Our data from a national survey indicate that physicians believe atherosclerotic risk factor treatment is less important for patients with PAD than for patients with CAD. Our data also show that many patients with PAD are unaware of their increased risk of cardiovascular events and under-appreciate the importance of risk factor treatment in PAD. These findings likely contribute to risk factor under-treatment in patients with PAD. Clinical trials such as this are needed to demonstrate whether PAD risk factors can be reduced. If effective, this clinical trial will also encourage clinicians to adopt the proven intervention to lower cardiovascular risks in patients with PAD

DESIGN NARRATIVE:

This randomized, controlled clinical trial will test the ability of a health-counselor mediated telephone counseling intervention as compared to usual care to reduce LDL-C levels in patients with PAD. The study involves patients with PAD who have LDL-C levels greater than 100 mg/dl at baseline identified from non-invasive vascular laboratories in Chicago, IL and Worcester, MA. For their primary specific aim, the investigators hypothesize that subjects randomized to the intervention condition will achieve a reduction in LDL-C of at least 11.1 mg/dl greater than the reduction in LDL-C for subjects randomized to the usual care condition at 12-month follow-up. In their secondary aim, they will determine whether the telephone counseling intervention increases the proportion of PAD patients with LDL-C less than 100 mg/dl as compared to the usual care condition at 12-month follow-up. To identify the mediators of the intervention, in their exploratory aims they will determine whether patients in the intervention condition achieve greater increases (improvement) in specific behavioral and knowledge and attitude mediators that will be targeted by the intervention, as compared to patients in the usual care condition.