The Prevalence, Clinical Characteristics, and Functional Significance of Ankle Brachial Index Defined Peripheral Arterial Disease in Patients with Heart Failure

Abstract

Background The prevalence and impact of lower extremity peripheral arterial disease (PAD) in patients with heart failure (HF) remains unclear. The purpose of this study was to prospectively examine the prevalence and clinical characteristics associated with PAD defined by the ankle brachial index (ABI) in an outpatient cohort of HF patients. Methods Clinical history, laboratory, and echocardiographic data were collected prospectively. Subjects underwent ABI measurement with calculation of both the ABI-HI (highest pedal pressure/highest brachial pressure) and ABI-LO (lowest pedal pressure/highest brachial pressure). Subjects also underwent a 6-MWD, sit to stand test, and quality of life questionnaires (QoL). Results A total of 103 patients were included. Abnormal ABI-LO and ABI-HI were identified in 28 (27%) and 16 (16%) of the patients, respectively. The average 6MWD was 387mts. By ABI-LO 24(23%) subjects had an ABI≤0.9 and 4(4%) had an ABI>1.4. Using ABI-HI 9(9%) had an ABI≤0.9 and 7(7%) had an ABI>1.4 An ABI-HI≤0.9 was more common in those with claudication (16% v. 3%, p=0.02). After adjusting for age and gender, the presence of neuropathy(OR:3.55, 95%CI:1.23-10.22), cardiomyopathy (ischemic vs non-ischemic; OR:3.10,95%CI:1.03-9.28), and worse NYHA class (OR:2.41, 95%CI:1.21-4.80) were associated with an abnormal ABI-LO. Conversely, in a model adjusted for age and gender, eGFR(OR:0.96, 95%CI:0.94-0.99) and peripheral neuropathy (OR:6.70, 95%CI:1.76-25.48) were significantly associated with an abnormal ABI-HI. ABI-LO but not ABI-HI was correlated with 6MWD Conclusions PAD may be as high as 27% in the ambulatory HF population and vary by calculation method. Ischemia, worsening HF, and eGFR were commonly associated with abnormal ABIs. ABIs had a small but significant correlation with 6-MWD but not of quality of life scores.