Interobserver variability of ankle–brachial index measurements at rest and post exercise in patients with intermittent claudication

Abstract

The ankle-brachial index (ABI) post exercise is claimed to play a complementary role in the diagnosis or exclusion of intermittent claudication (IC). The interobserver variability of ABI measurements at rest and post exercise in patients with typical symptoms of IC is the subject of this study with emphasis on ABI post exercise. ABI at rest and post exercise were measured in both legs of 20 patients with typical symptoms of IC. After 15 minutes of rest these measurements were repeated by another observer. Analysis according to Bland-Altman was performed on 40 paired leg measurements at rest and 40 paired leg measurements post exercise. The average ABI at rest for the first observer was 0.84 (standard deviation ±0.18) and for the second was 0.84 (±0.17). Post-exercise averages were 0.73 (±0.25) and 0.74 (±0.27), respectively. The standard deviation of the ABI difference between observers was 0.08 at rest and 0.15 post exercise. The interobserver variability of the ABI was 10% at rest and 21% post exercise. The interobserver variability post exercise is an important given when rules are defined about how the ABI post exercise translates into a more reliable and objective diagnosis of IC.

Magnetic Resonance Imaging in Peripheral Arterial Disease

“…32 However, the ankle-brachial index is a relatively crude parameter as it is not able to pinpoint the exact location of a stenosis, is unreliable in patients with an uncompressible vessel wall due to arterial calcifications, and shows a large interobserver variability. 33 Other known techniques to determine vascular function are Doppler-based flow measurements, plethysmography, skin perfusion pressure measurements, positron emission tomography (PET), contrastenhanced ultrasound (CEUS), and intra-arterial pressure and/or flow measurements. 34 -43 Unfortunately, these methods either lack the spatial resolution or coverage to directly measure the effect of vascular adaptations (eg, collateral vessel formation or changes in microcirculation), or are unfavorable for repeated measurements for instance in the context of therapy monitoring due to invasiveness, use of ionizing radiation, or large interobserver variability.…”

MRI of Arterial Flow Reserve in Patients with Intermittent Claudication: Feasibility and Initial Experience

“…This method, however, is limited for the peripheral arteries by a relatively large interobserver variability during reactive hyperemic conditions, which are needed to determine the flow reserve [16], [17]. Other techniques to measure blood flow are Laser Doppler flowmetry, contrast-enhanced ultrasound (CEUS) and intra-arterial catheter based flow measurements [1], [9], [10], [14], [18].…”

“…Other techniques to measure blood flow are Laser Doppler flowmetry, contrast-enhanced ultrasound (CEUS) and intra-arterial catheter based flow measurements [1], [9], [10], [14], [18]. Unfortunately, these methods either lack the ability to directly measure flow in large, non-superficial, conduit arteries, are prone to poor interobserver variability, or are not suitable for repeated measurements, as in the context of therapy monitoring [9], [14], [16]. A promising alternative method to measure flow in the peripheral arteries, is MRI-based quantitative cine phase-contrast imaging (PCI) [2], [3], [4], [19], [20].…”

Pulse pressure and michigan neuropathy screening instrument are independently associated with asymptomatic peripheral arterial disease among type 2 diabetes community residents: A community-based screening program in Taiwan

“…[6] ABI shows high sensitivity and specificity with little variability. [7,8] The American Heart Association guidelines suggest that the ABI should be used to screen patients with symptoms of PAD, those older than 70 years of age, and those with risk factors (including diabetes, smoking, hypertension, dyslipidemia, and hyperhomocysteinemia). [9] The guidelines also suggest that the ABI can be considered as an effective tool for cardiovascular risk assessment.…”