Índice tobillo-brazo en la detección de arteriopatía periférica: estudio de validez y concordancia entre Doppler y método oscilométrico

Automated Measurements of Ankle-Brachial Index: A Narrative Review

Peripheral artery disease (PAD) is an atherosclerotic disease that causes obstruction in lower limb arteries. It increases cardiovascular risk even in asymptomatic patients. Accurate diagnostic tools for identification of affected individuals are needed. Recently, there have been attempts to establish a reliable method of automated ankle-brachial index (ABI) identification. A search of PubMed database to identify studies assessing automatic ABI measurements in agreement with standard PAD diagnosis methods was conducted in December 2020. A total of 57 studies were analyzed in the review. The majority of analyzed studies found ABI measured by automatic oscillometric devices to be potentially feasible for use. Some note that, even though the Doppler and oscillometric methods are not fully interchangeable, the oscillometric devices could be used in screening. Significantly fewer publications are available on automatic plethysmographic devices. For photoplethysmography, most studies reported either good or moderate agreement with reference standards. For air plethysmography, poorer agreement with Doppler ABI is suggested. It is noted that pulse volume recording (PVR) function may improve the diagnostic accuracy of the devices.

The accuracy of an oscillometric ankle-brachial index in the diagnosis of lower limb peripheral arterial disease: A systematic review and meta-analysis

INTRODUCTION

Peripheral arterial disease (PAD) remains underdiagnosed and undertreated, partly because of limitations in the Doppler ankle-brachial index (ABI), the non-invasive gold standard.

OBJECTIVE

This systematic review and meta-analysis aims to compare the diagnostic accuracy of the oscillometric ABI and the Doppler ABI, and to examine the influence of two approaches to analysis: legs vs subjects and inclusion of oscillometric errors as PAD equivalents vs exclusion.

METHODS

Systematic searches in EMBASE, MEDLINE, Web of Science and the Cochrane Library databases were performed, from inception to February 2017. Random-effects models were computed with the Moses-Littenberg constant. Hierarchical summary receiver operating characteristic curves (HSROC) were used to summarise the overall test performance.

RESULTS

Twenty studies (1263 subjects and 3695 legs) were included in the meta-analysis. The pooled diagnostic odds ratio (dOR) for the oscillometric ABI was 32.49 (95% CI: 19.6-53.8), with 65% sensitivity (95% CI: 57-74) and 96% specificity (95%CI: 93-99). In the subgroup analysis, the "per subjects" group showed a better performance than the "per legs" group (dOR 36.44 vs 29.03). Similarly, an analysis considering oscillometric errors as PAD equivalents improved diagnostic performance (dOR 31.48 vs 28.29). The time needed for the oscillometric ABI was significantly shorter than that required for the Doppler ABI (5.90 vs 10.06 minutes, respectively).

CONCLUSIONS AND RELEVANCE

The oscillometric ABI showed an acceptable diagnostic accuracy and feasibility, potentially making it a useful tool for PAD diagnosis. We recommend considering oscillometric errors as PAD equivalents, and a "per subject" instead of a "per leg" approach, in order to improve sensitivity. Borderline oscillometric ABI values in diabetic population should raise concern of PAD.

Validity and reliability of the ankle-brachial index by oscillometric blood pressure and automated ankle-brachial index

Background:

This study was conducted to assess the validity and reliability of ankle-brachial index (ABI) by oscillometric blood pressure (BP) measurement as compared with an automated ABI as a gold standard.

Materials and Methods:

This study was conducted at Golden Jubilee Medical Center, Thailand. All the data were collected from 303 patients at risk of peripheral arterial disease (PAD) who were 45 years of age or above and who underwent treatment at the outpatient medical clinic between June and December 2015. Patients who were followed up at the medical clinic had both oscillometric BP measurement (Terumo, ES-P600) and an automated ABI (oscillometric method) at the same time. Sensitivity, specificity, positive predictive value, and negative predictive value of the oscillometric BP measurements to predict an abnormal ABI (<0.90) were determined using the automated ABI as the gold standard.

Results:

ABI values were similar between the two methods. The oscillometric BP method for determining an ABI (cutoff point <0.90) on the right side had a sensitivity of 88.89%, specificity of 99.32%, an accuracy of 99.01%, a positive predictive value of 80%, and a negative predictive value of 99.32% whereas ABI on the left side had a sensitivity of 69.23%, a specificity of 99.66%, an accuracy of 98.35%, a positive predictive value of 90%, and a negative predictive value of 98.63%. Reliability of the oscillometric BP method by Kappa statistics was 0.84 on the right side and 0.77 on the left side (P = 0.000).

Conclusion:

The oscillometric BP method is a reliable and useful alternative to conventional automated ABI determination in patients with no severe arterial occlusion for estimation of the prevalence and screening of PAD in primary health-care settings.

The Validity and Reliability between Automated Oscillometric Measurement of Ankle-Brachial Index and Standard Measurement by Eco-Doppler in Diabetic Patients with or without Diabetic Foot

OBJECTIVE

To evaluate the concordance between oscillometric ABI and standard Doppler ABI in diabetic Chinese patients with or without diabetic foot.

METHODS

230 consecutive diabetic patients (n = 459 limbs) were included. The right and left ABIs were determined with both devices by the same investigator. The concordance and agreement were assessed by kappa index and the Bland-Altman method.

RESULTS

The average Doppler ABI was 1.003 ± 0.286 on the right and 0.990 ± 0.287 on the left, while oscillometric ABI was 1.002 ± 0.332 and 0.993 ± 0.319, which had no significance. The average time for oscillometric ABI was 8.600 versus 16.980 minutes for Doppler ABI (p < 0.001). There was good agreement between the two measurements, with a kappa value of 0.869 on the right and 0.919 on the left. Regarding the Doppler ABI as the gold standard, the accuracy, sensitivity, specificity, +LR, and -LR of oscillometric ABI reached 95.22%, 94.34%, 95.48%, 20.873%, and 0.059% on the right. For the left, it was 96.94%, 96.43%, 97.11%, 33.364%, and 0.036%.

CONCLUSIONS

The oscillometric measurement is a reliable, convenient, and less time-consuming alternative to standard Doppler ABI in patients. It should be widely used for PAD detection.

Diagnostic Accuracy Study of an Oscillometric Ankle-Brachial Index in Peripheral Arterial Disease: The Influence of Oscillometric Errors and Calcified Legs

BACKGROUND

Peripheral arterial disease (PAD) is an indicator of widespread atherosclerosis. However, most individuals with PAD, in spite of being at high cardiovascular risk, are asymptomatic. This fact, together with the limitations of the Doppler ankle-brachial index (ABI), contributes to PAD underdiagnose. The aim of this study was to compare oscillometric ABI and Doppler ABI to diagnose peripheral arterial disease, and also to examine the influence of oscillometric errors and calcified legs on the PAD diagnoses.

METHODS AND FINDINGS

We measured the ankle-brachial indexes of 90 volunteers (n = 180 legs, age 70 ± 14 years, 43% diabetics) using both oscillometer OMRON-M3 and Doppler. For concordance analyses we used the Bland and Altman method, and also estimated the intraclass correlation coefficient. Receiver Operating Characteristic Curves were used to examine the diagnostic performance of both methods. The ABI means were 1.06 ± 0.14 and 1.04 ± 0.16 (p = 0.034) measured by oscillometer and Doppler ABIs respectively, with limits of agreement of ± 0.20 and intraclass correlation coefficient = 0.769. Oscillometer yielded 23 "error" measurements, and also overestimated the measurements in low ankle pressures. Using Doppler as gold standard, oscillometer performance for diagnosis of PAD showed an Area Under Curve = 0.944 (sensitivity: 66.7%, specificity: 96.8%). Moreover, when considered calcified legs and oscillometric "error" readings as arteriopathy equivalents, sensitivity rose to 78.2%, maintaining specificity in 96%. The best oscillometer cut-off point was 0.96 (sensitivity: 87%, specificity: 91%, positive likelihood ratio: 9.66 and negative likelihood ratio: 0.14).

CONCLUSION

Despite its limitations, oscillometric ABI could be a useful tool for the diagnosis of PAD, particularly when considering calcified legs and oscillometric "errors" readings as peripheral arterial disease equivalents.

Ankle brachial index for the diagnosis of lower limb peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) of the lower limb is common, with prevalence of both symptomatic and asymptomatic disease estimated at 13% in the over 50 age group. Symptomatic PAD affects about 5% of individuals in Western populations between the ages of 55 and 74 years. The most common initial symptom of PAD is muscle pain on exercise that is relieved by rest and is attributed to reduced lower limb blood flow due to atherosclerotic disease (intermittent claudication). The ankle brachial index (ABI) is widely used by a variety of healthcare professionals, including specialist nurses, physicians, surgeons and podiatrists working in primary and secondary care settings, to assess signs and symptoms of PAD. As the ABI test is non-invasive and inexpensive and is in widespread clinical use, a systematic review of its diagnostic accuracy in people presenting with leg pain suggestive of PAD is highly relevant to routine clinical practice.

OBJECTIVES

To estimate the diagnostic accuracy of the ankle brachial index (ABI) - also known as the ankle brachial pressure index (ABPI) - for the diagnosis of peripheral arterial disease in people who experience leg pain on walking that is alleviated by rest.

SEARCH METHODS

We carried out searches of the following databases in August 2013: MEDLINE (Ovid SP),Embase (Ovid SP), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO), Latin American and Caribbean Health Sciences (LILACS) (Bireme), Database of Abstracts of Reviews of Effects and the Health Technology Assessment Database in The Cochrane Library, the Institute for Scientific Information (ISI) Conference Proceedings Citation Index - Science, the British Library Zetoc Conference search and Medion.

SELECTION CRITERIA

We included cross-sectional studies of ABI in which duplex ultrasonography or angiography was used as the reference standard. We also included cross-sectional or diagnostic test accuracy (DTA) cohort studies consisting of both prospective and retrospective studies.Participants were adults presenting with leg pain on walking that was relieved by rest, who were tested in primary care settings or secondary care settings (hospital outpatients only) and who did not have signs or symptoms of critical limb ischaemia (rest pain, ischaemic ulcers or gangrene).The index test was ABI, also called the ankle brachial pressure index (ABPI) or the Ankle Arm Index (AAI), which was performed with a hand-held doppler or oscillometry device to detect ankle vessels. We included data collected via sphygmomanometers (both manual and aneroid) and digital equipment.

DATA COLLECTION AND ANALYSIS

Two review authors independently replicated data extraction by using a standard form, which included an assessment of study quality, and resolved disagreements by discussion. Two review authors extracted participant-level data when available to populate 2×2 contingency tables (true positives, true negatives, false positives and false negatives).After a pilot phase involving two review authors working independently, we used the methodological quality assessment tool the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2), which incorporated our review question - along with a flow diagram to aid reviewers' understanding of the conduct of the study when necessary and an assessment of risk of bias and applicability judgements.

MAIN RESULTS

We screened 17,055 records identified through searches of databases. We obtained 746 full-text articles and assessed them for relevance. We scrutinised 49 studies to establish their eligibility for inclusion in the review and excluded 48, primarily because participants were not patients presenting solely with exertional leg pain, investigators used no reference standard or investigators used neither angiography nor duplex ultrasonography as the reference standard. We excluded most studies for more than one reason.Only one study met the eligibility criteria and provided limb-level accuracy data from just 85 participants (158 legs). This prospective study compared the manual doppler method of obtaining an ABI (performed by untrained personnel) with the automated oscillometric method. Limb-level data, as reported by the study, indicated that the accuracy of the ABI in detecting significant arterial disease on angiography is superior when stenosis is present in the femoropopliteal vessels, with sensitivity of 97% (95% confidence interval (CI) 93% to 99%) and specificity of 89% (95% CI 67% to 95%) for oscillometric ABI, and sensitivity of 95% (95% CI 89% to 97%) and specificity of 56% (95% CI 33% to 70%) for doppler ABI. The ABI threshold was not reported. Investigators attributed the lower specificity for doppler to the fact that a tibial or dorsalis pedis pulse could not be detected by doppler in 12 of 27 legs with normal vessels or non-significant lesions. The superiority of the oscillometric (automated) method for obtaining an ABI reading over the manual method with a doppler probe used by inexperienced operators may be a clinically important finding.

AUTHORS' CONCLUSIONS

Evidence about the accuracy of the ankle brachial index for the diagnosis of PAD in people with leg pain on exercise that is alleviated by rest is sparse. The single study included in our review provided only limb-level data from a few participants. Well-designed cross-sectional studies are required to evaluate the accuracy of ABI in patients presenting with early symptoms of peripheral arterial disease in all healthcare settings. Another systematic review of existing studies assessing the use of ABI in alternative patient groups, including asymptomatic, high-risk patients, is required.

[Concordance between 3 methods of measurement the ankle-brachial index to diagnose peripheral artery disease]

BACKGROUND AND OBJECTIVES

To determine the concordance of the ankle-brachial index (ABI) determined by automatic measurements (sphygmomanometer Omron and the triple cuff device) using doppler as the gold-standard, computing as well as sensitivity and specificity.

PATIENTS AND METHODS

ARTPER population cohort subjects, classified as peripheral arterial disease (PAD) if ABI<0.9, calcified if ABI≥1.4 and healthy otherwise. To asses concordance we used kappa index using the 3 categories and the intraclass correlation coefficient (ICC) for ABI continuous values.

RESULTS

Eighty-eight participants, 52% women, 57-87 years. It was possible to calculate the ABI using doppler for 100%, 97% using Omron and 95% using triple. ABI means (standard deviation) were: doppler 1.089 (0.236), Omron 1.082 (0.110), triple 1.146 (0.134), with poor agreement (ICC doppler/Omron=0.27, doppler/triple=0.13, and triple/Omron=0.39). Categorizing ABI as PAD-healthy-calcified 13.6% (doppler), 6.8% (Omron) and 3.4% (triple) were PAD and 9.1% (doppler), 1.1% (Omron) and 9.1% (triple) were calcified. Kappa indexes were weak (doppler/Omron=0.22, doppler/triple=0.01, triple/Omron=0.17). Both triple and Omron were highly specific (97%) but had very low sensitivity (8 and 33%, respectively) compared to doppler.

CONCLUSIONS

Concordance of ABI automatic measurements as Omron and triple with doppler was poor, and they do not seem suitable for screening for PAD in primary care consultations.

Concordance between automated oscillometric measurement of ankle-brachial index and traditional measurement by eco-Doppler in patients without peripheral artery disease

AIM

To evaluate the concordance between automated oscillometric measurement (WatchBP® Office ABI) of the ankle- brachial index (ABI) and the traditional measurement by eco-Doppler in a Spanish population without peripheral artery disease attended in primary care.

METHODS

The ABI was determined by both methods in a general population aged ≥ 18 years, from the RICARTO study. The intraclass correlation coefficient was calculated to assess the concordance between both techniques and the Bland-Altman plot was determined to analyze the agreement between them.

RESULTS

A total of 322 subjects (mean age 47.7 ± 16.0 years; 54.3% women) were included in the study. With regard to cardiovascular risk factors, 70.5% of subjects had dyslipidemia, 26.7% hypertension, 24.8% obesity, 8.4% diabetes and 25.5% were smokers. Mean ABI measured by eco-Doppler and the automated method were 1.17 ± 0.1 and 1.2 ± 0.1, respectively (mean differences - 0.03 ± 0.09; p < 0.001). The Pearson correlation coefficient and the intraclass correlation coefficient were in both cases 0.70.

CONCLUSIONS

The automated oscillometric measurement of ABI is a reliable and useful alternative to conventional eco-Doppler determination in the general population without peripheral artery disease attended in primary care.

Measurement of the ankle brachial index with a non-mercury sphygmomanometer in diabetic patients: a concordance study

BACKGROUND

The removal of mercury sphygmomanometers from health centers requires the validation of other instruments to measure blood pressure in the limbs to calculate the ankle-brachial index (ABI).

METHODS

Descriptive cross-sectional study of agreement between two measurement methods in type 2 diabetes patients from three urban primary healthcare centres in the Barcelonès Nord i Maresme area (Catalonia, Spain).

RESULTS

211 patients were included, from these, 421 limbs were available for study. The mean age of the participants was 67 years (SD = 10), 51.7% were women.

CONCLUSION

The combination of a Doppler device with the hybrid sphygmomanometer is a simple and reliable method to measure ABI showing that hybrid sphygmomanometer is a good alternative to the use of mercury sphygmomanometers.

Automated oscillometric determination of the ankle-brachial index: a systematic review and meta-analysis

Measurement of the ankle-brachial index (ABI) using a Doppler device is widely used to identify subjects with peripheral artery disease (PAD), and those who are at high risk of cardiovascular disease. This paper presents a systematic review (Medline/PubMed, Embase and Cochrane) and meta-analysis of studies assessing the usefulness of automated oscillometric devices for ABI estimation and PAD detection compared with the conventional Doppler method. A total of 25 studies including 4186 subjects were analyzed. A random-effects model analysis showed that the average oscillometric ABI was similar to the Doppler ABI (mean difference ± s.e. 0.020 ± 0.018, P=0.3) but that the absolute differences were significant (0.048 ± 0.009, P<0.01). The pooled correlation coefficient (r) between the oscillometric and Doppler ABI was 0.71 ± 0.05. Simultaneous arm-leg measurements resulted in a smaller difference between the average oscillometric ABI value and the average Doppler ABI value than did sequential measurements (-0.012 ± 0.022 vs. 0.040 ± 0.026, respectively, P<0.01). The average sensitivity and specificity of the oscillometric ABI estimation in PAD diagnosis was 69 ± 6% and 96 ± 1%, respectively (with Doppler ABI taken as the reference). These data suggest that an automated ABI measurement obtained by oscillometric blood pressure monitors is a reliable and practical alternative to the conventional Doppler measurement for the detection of PAD. To increase the sensitivity of the PAD diagnosis based on an oscillometric ABI, a higher threshold of 1.0 might be preferable.

Sensitivity and specificity of the ankle—brachial index to diagnose peripheral artery disease: a structured review

The ankle—brachial index (ABI) is a simple, inexpensive diagnostic test for peripheral artery disease (PAD). However, it has shown variable accuracy for identification of significant stenosis. The authors performed a structured review of the sensitivity and specificity of ABI ≤ 0.90 for the diagnosis of PAD. MEDLINE, EMBASE, Cochrane databases, Science Citation Index database, and Biological Abstracts database were searched for studies of the sensitivity and specificity of using ABI ≤ 0.90 for the diagnosis of PAD. Eight studies comprising 2043 patients (or limbs) met the inclusion criteria. The result indicated that, although strict inclusion criteria on studies were formulated, different reference standards were found in these studies, and methods of ABI determination and characteristics of populations varied greatly. A high level of specificity (83.3—99.0%) and accuracy (72.1—89.2%) was reported for an ABI ≤ 0.90 in detecting ≥ 50% stenosis, but there were different levels of sensitivity (15—79%). Sensitivity was low, especially in elderly individuals and patients with diabetes. In conclusion, the test of ABI ≤ 0.90 can be a simple and useful tool to identify PAD with serious stenosis, and may be substituted for other non-invasive tests in clinical practice.