How common is peripheral arterial disease, and should primary care physicians be screening for it? - POEMs

Journal of Family Practice, Dec, 2001 by Anne L Mounsey

Hirsch AT, Criqui MH, Treat-Jacobson D, et al. Peripheral arterial disease detection, awareness, and treatment in primary care. JAMA 2001; 286:1317-24

* BACKGROUND Peripheral arterial disease (PAD) is highly prevalent in the United States and associated with high rates of cardiovascular ischemic events. Failure to diagnose PAD may lead to underutilization of antiplatelet therapy and undertreatment of atherosclerosis risk factors. This study evaluated primary care physician awareness of PAD and the management of atherosclerosis risk factors in these patients.

* POPULATION STUDIED The survey population was identified from 27 primary care practices throughout the United States . A total of 6979 consecutive patients 70 years or older and those aged 50 through 69 years with a history of smoking or diabetes were screened for PAD. Patients were considered to have PAD if the ankle-brachial index (ABI) in either leg was 0.90 or less. The mean age of the population was 70 years with approximately equal proportions of men (48%) and women (52%).

* STUDY DESIGN AND VALIDITY This was a prospective cohort study. Subjects were divided into 4 clinical subgroups: those with no atherosclerosis, those with PAD only, those with cardiovascular disease (CVD) only, and those with both PAD and CVD. Patients with a history of coronary artery disease, cerebrovascular disease, or aortic aneurysm repair were diagnosed with CVD. The presence of atherosclerotic risk factors (smoking, diabetes, hyperlipidemia, hypertension and women's menopausal state) was also documented for each patient.

* OUTCOMES MEASURED Outcomes measured from examination of medical records included treatment for diabetes, hyperlipidemia, and hypertension; the use of hormone replacement therapy; referral to a smoking cessation program; and the use of antiplatelet medication. Patients with a previous diagnosis of PAD and their physicians were questioned as to their awareness of the diagnosis. All patients were assessed for the presence of leg pain.

* RESULTS Data collection was complete for 6417 (92%) of the enrolled patients, and PAD was detected in 1865 patients (29%). PAD only was newly diagnosed in 6.5% of the total subjects, and PAD with CVD was newly diagnosed in 5.2%. Of the 825 patients with PAD only, 457 (55%) were newly diagnosed, while of the 1040 patients with PAD and CVD only 35% were newly diagnosed. Thus, patients who did not already have a diagnosis of CVD were more likely to have undiagnosed PVD (P < .001). Patients with a new PAD diagnosis were less intensively treated for hyperlipidemia than were patients with a previous PAD diagnosis (P < .006). Prior PAD-only patients were less intensively treated for hyperlipidemia than the CVD-only group (P < .001). Hypertension was also treated more frequently in the atherosclerosis group than the reference group and more intensively treated in the CVD group than the new PAD or PAD-only groups. Patients who had CVD only were more likely to be on antiplatelet medication than those with previous PAD only. A total of 83% of the patients with prior PAD were aware of their diagnosis, but only 49% of their physicians had recognized their diagnosis. Only 8.7% of patients in the PAD-only group had classic symptoms of claudication.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Patients at risk for atherosclerotic disease frequently have undiagnosed and asymptomatic PAD. Also, patients with unknown PAD are less intensively treated for hyperlipidemia and hypertension and less likely to be taking antiplatelet therapy than patients already diagnosed with PAD or CVD.

This study does not provide evidence, however, that early detection of PAD will lead to behavioral changes on the part of either patients or physicians resulting in improved patient-oriented outcomes. Until further studies have been done that demonstrate improved outcomes as a result of early detection of PAD with the Doppler ABI, screening should not be routine.

Anne L Mounsey, MD
University of Virginia Health Sciences Center
Charlottesville

E-mail:alm2d@virginia.edu