Abstract P085: Screening for Peripheral Artery Disease in Cardiac Rehabilitation
Background Exercise-based cardiac rehabilitation (CR) is proven to benefit patients with cardiovascular disease, and the benefits correlate with the exercise performance achieved. Many patients in CR exercise at levels less than optimal, without obvious cardiac limitations. We hypothesized that occult lower extremity PAD in this population may be a determinant of diminished exercise capacity and reduced benefit obtained from CR.
Study Design In this cross-sectional study of 76 consecutive subjects enrolled in phase II CR, we describe the prevalence of PAD, the utility of screening questionnaires, and the potential impact on improvement in CR.
Results Twenty percent of patients had a low ABI (<0.90) and 5% had a high ABI (>1.40). Thirteen subjects were referred for diagnoses other that coronary disease or myocardial infarction; of these, three had an abnormal ABI. The Edinburgh Claudication Questionnaire was specific but not sensitive for PAD (sensitivity 10.5%, specificity 93.0%, NPV 75.7%, PPV 33.3%). The Walking Impairment Questionnaire did not differentiate patients with or without PAD with regard to walking distance (70.6 vs. 66.0, p=0.66), speed (44.1 vs. 50.7, p=0.31) or symptoms (86.6 vs. 89.5, p=0.35). Importantly, a modified Gardner protocol (2 mph, 0% grade, max = 10’) was of limited sensitivity to detect PAD (sensitivity 10.5%, specificity 91.2%, NPV 75.4%, PPV 28.6%). Fifty subjects completed CR (35 with normal ABI). Exercise improvement was greater (+2.3 vs. +1.5 METS, p=0.044) in those with normal ABI vs. those with abnormal ABI.
Conclusions PAD is common in patients in phase II CR, and is seldom detected by standard screening questionnaires. In this population lower extremity PAD does not appear to impair low level activity but significantly impacts exercise improvement, preventing patients from getting the full benefit of their exercise prescriptions.
- © 2013 by American Heart Association, Inc.