The Validity, Reliability, Reproducibility and Extended Utility of Ankle to Brachial Pressure Index in Current Vascular Surgical Practice

Ankle-Brachial Index: Diagnostic Tool of Peripheral Arterial Disease and Predictor of Cardiovascular Risk-An Update of Current Knowledge

The ankle-brachial index (ABI) was introduced as a screening method for the diagnosis of lower extremity peripheral arterial disease (PAD). Later findings recognized ABI as a prognostic marker of adverse cardiovascular events due to its relation to atherosclerosis in other vascular territories. This narrative review aims to appraise the validity, reliability, and utility of ABI in the detection of PAD and the determination of global atherosclerotic cardiovascular risk. While the ABI value can be influenced by different physiological characteristics including age, sex, body position, and techniques used for ABI determination, it has high specificity and reproducibility in the assessment of vascular patients. In conclusion, when used correctly, the ABI remains a reliable and invaluable indicator of lower-limb perfusion and a useful tool for predicting the risk of future cardiovascular events. However, its underutilization in clinical settings is noteworthy.

Compression therapy for NHS inpatients with leg ulcers: a literature review

OBJECTIVE

Leg ulcers are common, distressing and painful for patients, and are a significant financial burden to healthcare providers. Compression therapy is the mainstay of treatment for venous leg ulceration. Several studies have evaluated leg ulcer management and compression therapy in the community. However, little is known about the prevalence of leg ulceration and use of compression therapy in acute hospitals. The aim of this study was to explore the published literature on the use of compression therapy for inpatients with leg ulcers in UK National Health Service hospital settings.

METHOD

A literature search was undertaken to identify published papers reporting on inpatient leg ulcer populations and the use of compression therapy in hospitals using the following databases: CINAHL, MEDLINE Complete, Embase and PubMed.

RESULTS

The literature review identified 364 articles, of which three met the eligibility criteria. These studies reported on the prevalence of leg ulceration, the number of Doppler assessments conducted for patients and the use of compression therapy.

CONCLUSION

This review confirmed a lack of information on the prevalence of hospital inpatients with leg ulcers, and identified the need to conduct prevalence audits, establish leg ulcer services to streamline inpatient leg ulcer care and provide staff and patient education programmes.

Hospital clinicians' perspectives of using compression therapy on venous leg ulcers: a systematic qualitative review

Venous leg ulcer treatment is frequently discontinued in hospitals in contravention of national guidance, significantly affecting patient outcomes and increasing NHS costs.

AIM

To identify, from the published literature, reasons for variable implementation.

METHOD

Systematic review with narrative synthesis, including full papers in English with empirical qualitative data. Synonyms for venous leg ulcer, compression therapy and secondary care were searched across a range of health-related databases. The Critical Appraisal Skills Programme (CASP) checklist determined study quality, and meta-ethnography was used for data synthesis.

RESULTS

7040 titles and abstracts and 41 full-text papers were screened with four papers selected. Three key themes were generated: educational needs surrounding implementation of compression therapy, patient factors regarding adherence and organisational resources including availability of appropriate equipment and trained staff.

CONCLUSION

Barriers at the ward level were identified. There is a need to better understand why hospitals are not addressing them.

Early identification and treatment for peripheral arterial disease in patients with ischemic cerebrovascular disease

Ischemic cerebrovascular disease (ICVD) is a major cause of mortality and disability worldwide and is often caused by atherosclerosis. As a systemic disease, atherosclerosis usually affects multiple vascular beds, mainly including cerebral, coronary, and peripheral arteries. Therefore, ICVD is easily complicated by lower-extremity peripheral arterial disease (PAD). ICVD patients with PAD have more serious symptoms and a worse prognosis, however, neurologists might neglect the evaluation and management of the coexistent PAD, and there is still a lack of consensuses about the diagnosis and treatment for such patients. By summarizing relevant research progresses, this review showed that duplex ultrasound had more advantages in the early screening and evaluation of PAD in ICVD patients among multiple methods to diagnose PAD. Furthermore, the current evidence seems to support that single-drug antiplatelet can be used as the basic treatment, and new antithrombotic strategies, such as ticagrelor only or aspirin combined with low-dose rivaroxaban are expected to further reduce the incidence of stroke for ICVD patients with PAD. More effective treatments would be explored by large-scale trials to guide the clinical management to prevent secondary stroke for such patients.

Outcomes following supervised exercise and home-based exercise for patients with intermittent claudication

INTRODUCTION

Intermittent claudication (IC) is the most common symptom of peripheral arterial disease (PAD) which presents as a consequence of muscle ischaemia resulting from the atherosclerotic obstruction to arterial flow. High-quality evidence (Lane et al., 2017) shows that exercise programmes provide important benefits compared with usual care in improving pain-free and maximum walking distance in people with IC, but do not improve ankle-brachial pressure index (ABPI).

METHODS

Retrospective data were analysed to examine walking and ABPI outcomes for participants who completed a 12-week course of supervised or home-based exercise. All participants had a history of IC.

RESULTS

46 participants (mean age 69±11 years; 76% male; 29% current smokers) referred for exercise were assessed, completed a 12-week course of exercise (home-based or supervised) and subsequently attended for re-assessment. Claudication onset distance (COD) increased by 363% (mean improvement 344.7 ± 265.1m; p < .001) and peak walking distance (PWD) by 324.4% in the supervised exercise group; COD increased by 30.6% (mean improvement 32.8 ± 57.2 m; p = 0.026) and PWD by 31.5% in the home-based exercise group. Resting ABPI for the total cohort significantly improved from 0.82 ± 0.25 at A1 to 0.88 ± 0.25 at A2 (p = 0.027).

DISCUSSION

A 12-week course of supervised exercise results in significantly greater walking distance outcomes (COD and PWD) than unmonitored home-based exercise. In contrast with previous findings (Lane et al. 2017), this retrospective study demonstrated a significant improvement in resting ABPI with both supervised exercise as well as home-based exercise.

CONCLUSION

A 12-week programme of exercise favourably influenced walking and ABPI outcomes for patients with IC. Both home-based exercise and supervised individualised exercise increased walking distances, but the magnitude of the improvement in walking outcomes was greater in individuals who attended supervised exercise therapy.

A point prevalence audit of inpatients with leg ulcers eligible for compression therapy in a large university NHS hospital

OBJECTIVE

Compression therapy is the mainstay of treatment for venous leg ulceration. Several studies have evaluated leg ulcer management and compression in the community. However, little is known about the leg ulcer population and use of compression therapy in the hospital setting, where it is not often part of inpatient care. This study aimed to evaluate the proportion of inpatients with leg ulceration eligible for compression therapy.

METHOD

A point prevalence audit was undertaken using three methods: patient electronic live report; a leg ulcer audit form; and an electronic record search. The following data were retrieved: patient age, sex, primary reason for admission, diabetes, mobility status, history of dementia, Clinical Frailty Scale score and presence of oedema. Ankle-brachial pressure index was measured to determine patients' eligibility for compression therapy.

RESULTS

The audit identified 80/931 (8.5%) inpatients as having confirmed, active leg ulceration. A total of 36/80 (45%) inpatients were assessed for eligibility for compression, of whom 25/36 (69.4%) were eligible for full compression, 2/36 (5.6%) reduced compression and 9/36 (25%) were not eligible for compression therapy.

CONCLUSION

The audit demonstrated that a significant proportion of hospital inpatients with leg ulcers were eligible for compression therapy and that this patient population were heterogenous in terms of comorbidity profile, mobility, frailty and dementia, among other factors. Further research is required to explore the most feasible and effective compression options for inpatients with leg ulcers.

Association of ankle-brachial index with cognitive decline in patients with lacunar infarction

Atherosclerosis is an important risk factor for cognitive decline. This study aimed to investigate the relationship of ankle-brachial pressure index (ABI) and brachial-ankle pulse wave velocity (baPWV) with cognitive function in patients with lacunar infarction. We included records of consecutive patients with their first-ever acute stroke and a diagnosis of lacunar infarction through magnetic resonance imaging (MRI) from July 1, 2011 to December 31, 2018. We excluded patients diagnosed with dementia, including strategic single-infarct dementia, before or after stroke onset. Moreover, we excluded patients with one or more microbleeds, severe white matter lesions, or severe medial temporal atrophy on MRI. For ABI, we used the lower ankle side and divided the results into ABI < 1.0 and ABI ≥ 1.0. For baPWV, we used the higher ankle side and divided the results into two groups based on the median value of the participants. We analyzed 176 patients with stroke (age 72.5 ± 11.4 years, 67 females). The median score on the Mini-Mental State Examination (MMSE) was 27. The number of patients with ABI < 1.0 was 19 (10.8%). Univariate analysis revealed that the MMSE score was associated with age, body mass index, education, chronic kidney disease, periventricular hyperintensity, and ABI < 1.0 (p < 0.10), but not baPWV. Multivariate analysis revealed that body mass index (p = 0.039) and ABI < 1.0 (p = 0.015) were independently associated with the MMSE score. For patients with lacunar infarction, a lower ABI, but not a higher PWV, was associated with cognitive decline.

Diagnostic Performance of Ankle-Brachial Pressure Index in Lower Extremity Arterial Disease

Introduction  Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark.

Methods  In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard.

Results  Concomitant assessment was performed in 438 limbs (250 patients) over a 27-month period. The ABI was normal (0.9 to 1.4) in 196 limbs (44.9%) and abnormal in the remaining 241 limbs (55.1%). False-positive results occurred in 83 out of 241 limbs (34.4%), and false-negative results occurred in 54 limbs out of 196 (27.5%). True-positive results were 158 out of 241 limbs (65.6%), whereas true-negative results were 142 out of 196 limbs (72.4%). ABI using DUS as a benchmark identified a sensitivity for peripheral artery disease of 72.3% and a specificity of 69.3%. Concomitant CTA imaging was available in 200 limbs. The sensitivity and specificity of ABI correlated with CTA were 65.5 and 68.8%, respectively.

Conclusion  ABIs have a moderate predictive value in the diagnosis of LEAD. Normal range outcomes cannot be taken to infer the absence of LEAD and, as such, further arterial imaging in the form of DUS or angiography should be strongly considered in those with suspected underlying disease requiring intervention. Further noninvasive tests such as exercise studies or pulse volume waveforms should be considered, if diagnostic uncertainty exists, in those requiring nonoperative intervention and risk factor control.

The ankle brachial index in people with and without diabetes: intra-tester reliability

Background

The ankle-brachial index (ABI) is widely used for determining the presence and severity of peripheral arterial disease (PAD), and current guidelines suggest it should be used to monitor possible progression in affected individuals. It is therefore important that the technique demonstrates adequate reliability for repeated measurements. Existing studies suggest that the ABI is reliable in the general population however, there is a lack of evidence for the reliability of the ABI in people with diabetes. The aim of this study was to investigate the intra-tester reliability of the ABI in people with and without diabetes.

Methods

Eighty-five participants (40 with and 45 without diabetes) underwent ankle and brachial systolic blood pressure measurements by a single clinician during two testing sessions. Intraclass correlation coefficients (ICC), their 95% limits of agreement, standard error of measurement and minimal detectable change were determined.

Results

Intra-tester reliability of the ABI was found to be good (ICC: 0.80), however sub-group analysis of participants with and without diabetes found that ABI was slightly less reliable in people with diabetes (ICC: 0.78) than in those without (ICC: 0.82). The relatively large limits of agreement (− 0.16 to 0.16), standard error of measurement (0.03 overall, 0.04 for the diabetes group), and minimal detectable change (0.08 overall, 0.11 for the diabetes group) suggest that a large change in ABI is required for it to demonstrate a true change rather than the result of measurement variability. The minimal detectable change for the ABI was 0.08 overall, and 0.11 for the diabetes group.

Conclusions

The ABI demonstrated good reliability in all groups analysed. However, the wide limits of agreement and considerable standard error of measurement obtained support the use of multiple methods of vascular assessment for ongoing monitoring of lower limb vascular status.

Correlation Between Ankle Brachial Index and Lower Limbs Digital Pulse Oximetry: A Referral Center Experience, Prevalence Study

Objective

Ankle-brachial index (ABI) is widely recommended and used to evaluate peripheral arterial disease. The oxygen saturation (SpO₂) has been associated with ABI, showing a promising clinical practice utility; however, little literature regarding this matter has been reported. This study aims to assess the correlation between pulse oximetry and ABI. 

Methods

A cross-sectional study was conducted using ABI measuring devices, such as the MESI® Ankle Brachial Pressure Index (ABPI) (MESI, Ltd., Slovenia, EU) and pulse oximetry. We compared the SpO₂ distribution by using the Wilcoxon test and evaluated its correlation by using logistic regression. 

Results

From a total of 86 patients, 54 were males (62.8%) and the median age was 54 years old (interquartile range (IQR) = 37 - 65 yrs.). Regarding ABI measurements of the right lower limb (RLL), a total of 20 patients (22.3%) had an abnormal classification. On the other hand, a total of 21 patients (22.1%) had an abnormal classification of the left lower limb (LLL) ABI measurements. The distribution of SpO₂ in relation to ABI categories was not statistically different (RLL p = 0.2433; LLL p = 0.1242). The SpO₂ classification of ABI and abnormal pulse oximetry for the RLL was at 76.7% and at 77.9% in the LLL (Pearson’s goodness-of-fit test: RLL = p < 0.001 and LLL = p < 0.001). 

Conclusion

Although we didn’t observe any statistical differences in the SpO₂ distribution regarding ABI measurements, in their correlation, there seems to be a different tendency. The SpO₂ might be a useful non-invasive tool to assess asymptomatic patients with risk factors for peripheral arterial disease (PAD).

Peripheral arterial disease screening and diagnostic practice: A scoping review

Early reliable, valid screening, diagnosis, and treatment improve peripheral arterial disease outcomes, yet screening and diagnostic practices vary across settings and specialties. A scoping literature review described reliability and validity of peripheral ischaemia diagnosis or screening tools. Clinical studies in the PUBMED database January 1, 1970, to August 13, 2018, were reviewed summarising ranges of reliability and validity of peripheral ischaemia diagnostic and screening tools for patients with non-neuropathic lower leg ischaemia. Peripheral ischaemia screening and diagnostic practices varied in parameters measured such as timing, frequency, setting, ordering clinicians, degree of invasiveness, costs, definitions, and cut-off points informing clinical and referral decisions. Traditional ankle/brachial systolic blood pressure index <0.9 was a reliable, valid lower leg ischaemia screening test to trigger specialist referral for detailed diagnosis. For patients with advanced peripheral ischaemia or calcified arteries, toe-brachial index, claudication, or invasive angiographic imaging techniques that can have complications were reliable, valid screening, and diagnostic tools to inform management decisions. Ankle/brachial index testing is sufficiently reliable and valid for use during routine examinations to improve timing and consistency of peripheral ischaemia screening, triggering prompt specialist referral for more reliable, accurate Doppler, or other diagnosis to inform treatment decisions.

Assessment of Flow after Lower Extremity Endovascular Revascularisation: A Feasibility Study Using Time Attenuation Curve Analysis of Digital Subtraction Angiography

Objectives

Endovascular revascularisation is the mainstay of the treatment of lower extremity peripheral arterial disease. Improvement in perfusion after treatment is often quantified by a corresponding increment in ankle or toe brachial indices. These measurements are difficult to obtain in patients with foot wounds, and have to be performed at a separate time and setting after revascularisation. This preliminary study aimed to evaluate the use of parametric colour coding and analysis of time attenuation curves as a real time quantitative measure of perfusion after endovascular revascularisation.

Methods

Forty-seven consecutive patients with critical limb ischaemia were retrospectively enrolled and analysed. Parametric colour coding and generation of time attenuation curves in the main pedal vessel was performed for pre- and post-intervention digital subtraction angiograms of each patient. The change in time attenuation curve parameters was compared with the change in ankle or toe brachial indices before and after intervention.

Results

Comparing before and after lower extremity endovascular intervention, there were significant changes in the washout parameters derived from the time attenuation curve. The percentage of contrast decay 4 seconds after peak (I _4s) demonstrated the strongest correlation (R = .482) with the change in ankle or toe brachial indices.

Conclusions

Parametric colour coding and time attenuation curve analysis might be a helpful tool that can provide real time intra-procedural quantitative data on pedal perfusion which can improve clinical outcomes.

Ankle Brachial Pressure Index: An update for the vascular specialist and general practitioner

Objectives

Ankle brachial pressure index (ABPI) is an invaluable tool for assessing the severity of peripheral arterial disease. In addition, it can be used as an independent marker of cardiovascular risk, with a predictive ability similar to the Framingham criteria. Identification of an abnormal ABPI should therefore trigger aggressive cardiac risk factor modulation for a patient. Unfortunately, the significance of abnormal ABPIs is poorly understood within the general medical community. This is compounded by the influence of various comorbidities on accurate measurement of ABPI, potentially leading to a wide variability in readings that need to be considered before interpretation in these patient populations. We aim to address these issues by revealing several common misunderstandings and pitfalls in ABPI measurement, describing accurate methodology, and highlighting patient cohorts in whom additional or alternative approaches may be required.

Methods

We present a narrative review of the role of ABPI in both the community and hospital setting. We have performed a literature review, exploring the validity and reproducibility of methodology for obtaining ABPI, alongside the utility of ABPI in different clinical scenarios.

Results

The measurement of ABPI is often performed incorrectly. Common pitfalls include inadequate patient preparation, failure to obtain the blood pressure from the correct lower limb artery in patients with tibial disease, failure to account for differences in brachial blood pressure between the arms, inappropriately chosen equipment and patient factors such as highly calcified arteries. Standardisation of methodology greatly improves reliability of the test. Exercise ABPI can identify significant peripheral arterial disease in patients with normal resting ABPI. In addition to its role in peripheral arterial disease, ABPI measurement has a role in assessing venous ulcers, entrapment syndromes and injured extremities; conversely, it has a more limited utility in the diabetic population.

Conclusions

A thorough understanding of the correct technique and associated limitations of ABPI measurement is essential in accurately generating and interpreting the data it provides. With this knowledge, the ABPI is an invaluable tool to help manage patients with peripheral arterial disease. Perhaps more importantly, ABPI can be used to identify and risk stratify patients with asymptomatic peripheral arterial disease, itself a major indicator of significant underlying cardiovascular disease. With the emergence of best medical therapy, targeted pharmacotherapy and lifestyle changes can reduce the risk of major cardiovascular events in high-risk patients by approximately 30%, particularly in diabetic patients. Therefore, the utility of ABPI transgresses vascular surgery, with an essential role in general practice and public health.

ABPI reporting and compression recommendations in global clinical practice guidelines on venous leg ulcer management: A scoping review

Clinical practice guidelines (CPGs) for venous leg ulcer (VLU) management recommend below-knee compression to improve healing outcomes after calculating the ankle-brachial pressure index (ABPI) to rule out significant arterial disease. This systematic scoping review aimed to complete a qualitative and quantitative content analysis of international CPGs for VLU management to determine if consensus existed in relation to recommendations for compression application based on an ABPI reading and clinical assessment. Our review shows that there is a lack of consensus across 13 VLU CPGs and a lack of clear guidance in relation to the specific ABPI range of compression therapy that can be safely applied. An area of uncertainty and disagreement exists in relation to an ABPI between 0.6 and 0.8, with some guidelines advocating that compression is contraindicated and others that there should be reduced compression. This has implications in clinical practice, including when it is safe to apply compression. In addition, the inconsistency in the levels of evidence and the grades of recommendation makes it difficult to compare across various guidelines.

Temporal (in)stability of suboptimal toe-brachial indices

OBJECTIVE

To be effective in screening, prognostic, and monitoring contexts, the toe-brachial index (TBI) should not be susceptible to large sporadic fluctuations from one time to another. In order to identify whether those fluctuations exist in people who have suboptimal TBIs, the temporal stability of their TBIs was examined in detail across 6 months.

METHODS

TBI readings from SysToe and Omron automated devices were taken from 21 participants at baseline and at 2- and 6-month timepoints subsequently. The primary inclusion criterion was that participants had at least one of three baseline TBIs on either foot ≤0.65 if a standard 25-mm wide occlusion cuff was used, or ≤0.85 if a 15-mm occlusion cuff was used.

RESULTS

After excluding five participants because of their extremely high TBI fluctuations, TBI stability within the remaining 16 participants was examined. Ipsilateral TBIs changed by ≥0.10 on at least one foot for 11 participants across the initial 2-month timespan (maximum difference 0.26) and for same number of participants across the full 6-month timespan (maximum difference 0.36), with the composition of the 11-person groups differing slightly for the two timespans. Contralateral differences were ≥0.10 for five participants across the 2-month timespan (maximum difference 0.26) and for nine participants across the 6-month timespan (maximum difference 0.42), again with some group overlap. The foot with the higher TBI at baseline remained so across the 6 months.

CONCLUSIONS

For many people with suboptimal TBIs there might be inherent ipsilateral and contralateral inconsistency among TBI readings. This threatens the effectiveness of TBIs for screening, prognostic, and monitoring purposes. In order to maximize the prospects of the TBI as a valuable metric, adherence to standard protocols should be observed and other prospects for the TBI to assess vascular supply to the foot more effectively should be considered.

Interrater Reliability of Spectral Doppler Waveform Analysis Among Podiatric Clinicians

BACKGROUND

Spectral Doppler ultrasound examination of pedal arteries is one of the most frequently used noninvasive assessment methods by health-care professionals for the diagnosis and ongoing monitoring of people at risk for or living with peripheral arterial disease. The aim of this study was to determine the interrater reliability of the interpretation of spectral Doppler waveform analysis.

METHODS

An interrater reliability study was conducted among five experienced podiatric physicians at the University of Malta Research Laboratory (Msida, Malta). A researcher who was not a rater in this study randomly selected 229 printed spectral Doppler waveforms from a database held at the University of Malta. Each rater independently rated the qualitative spectral waveforms.

RESULTS

Interrater reliability of the spectral Doppler waveform interpretation was excellent among the five experienced podiatric physicians (α = 0.98). The intraclass correlation coefficient showed a high degree of correlation in waveform interpretation across raters ( P < .001).

CONCLUSIONS

This study demonstrates high interrater reliability in visual spectral Doppler interpretation among experienced clinicians. The current foot screening guidelines do not refer to spectral Doppler waveform analysis in their recommendations, which has been shown in studies to be an important modality for the diagnosis of peripheral arterial disease when ankle-brachial pressure indexes are falsely elevated in calcified arteries. If interpreted correctly, the information obtained can provide an indication of the presence of peripheral arterial disease and facilitate early management of this condition.

Measurement of Toe-Brachial Indices in People with Subnormal Toe Pressures Complexities and Revelations

BACKGROUND

Insufficient information exists about the nature of toe-brachial indices (TBIs) and how best to obtain them, yet their validity may be particularly important for the identification and management of peripheral artery disease and cardiovascular disease risk. We explore ways in which valid TBI measurements might be obtained.

METHODS

The TBI data were recorded from 97 people with subnormal toe pressures. Most people provided three TBI readings from each foot on six different occasions over a 6-month period. The foot with the lower baseline TBI was noted.

RESULTS

For most people, only small inconsistencies existed among the three readings taken from each foot on a single occasion, and there were no consistent differences based on sequence. However, for some people there were noticeable and unsystematic differences among the measures. Selecting any specific one of the three readings based on its sequential position, or averaging specific readings, did not yield TBIs that were unequivocally typical for a person, and taking the lowest reading of each set seemed to offer the most expedient solution in this context. That permitted baseline descriptive statistics to be produced for both the higher and lower pressure feet, between which there was a statistically significant TBI difference.

CONCLUSIONS

Accurate and consistent TBI readings cannot be assumed for people with subnormal toe pressures, and taking only a single reading or indiscriminately averaging readings seems inadvisable. Two readings and, if they are discrepant, additional readings, are recommended for each foot, ideally on several occasions, and careful consideration should be given to determine the most representative reading for each foot. Cuff sizes and other sources of inaccuracy or distortion should not be ignored, and standardized protocols for obtaining TBIs are recommended.

Subjecting the ankle-brachial index to timely scrutiny: is it time to say goodbye to the ABI?

Although the ankle-brachial index (ABI) has been used as an indicator of peripheral artery disease and vascular supply to the foot for over 50 years, it is now associated with reservations and qualifying empirical evidence to the extent that the provocative step of abandoning it totally might be advisable. In this article, the results of three publications concerning the ABI are initially described in some depth and the results from eight additional publications are then summarized more briefly. Cumulatively, the research indicates that ABIs that seem to be normal, as well as those in the subnormal range, are often inflated by medial arterial calcification and can therefore produce a high proportion of false-negative screening test results for arterial disease as well as a misleadingly high impression of vascular sufficiency to the lower extremity. The toe-brachial index is suggested as being likely to overcome the problems associated with the ABI, and other alternatives to the ABI and TBI are acknowledged.

Twenty-Year Predictors of Peripheral Arterial Disease Compared With Coronary Heart Disease in the Scottish Heart Health Extended Cohort (SHHEC)

BACKGROUND

Coronary heart disease and peripheral arterial disease (PAD) affect different vascular territories. Supplementing baseline findings with assays from stored serum, we compared their 20-year predictors.

METHODS AND RESULTS

We randomly recruited 15 737 disease-free men and women aged 30 to 75 years across Scotland between 1984 and 1995 and followed them through 2009 for death and hospital diagnoses. Of these, 3098 developed coronary heart disease (19.7%), and 499 PAD (3.2%). Hazard ratios for 45 variables in the Cox model were adjusted for age and sex and for factors in the 2007 ASSIGN cardiovascular risk score. Forty-four of them were entered into parsimonious predictive models, tested by c-statistics and net reclassification improvements. Many hazard ratios diminished with adjustment and parsimonious modeling, leaving significant survivors. The hazard ratios were mostly higher in PAD. New parsimonious models increased the c-statistic and net reclassification improvements over ASSIGN variables alone but varied in their components and ranking. Coronary heart disease and PAD shared 7 of the 9 factors from ASSIGN: age, sex, family history, socioeconomic status, diabetes mellitus, tobacco smoking, and systolic blood pressure (but neither total nor high-density lipoprotein cholesterol); plus 4 new ones: NT-pro-BNP, cotinine, high-sensitivity C-reactive protein, and cystatin-C. The highest ranked hazard ratios for continuous factors in coronary heart disease were those for age, total cholesterol, high-sensitivity troponin, NT-pro-BNP, cotinine, apolipoprotein A, and waist circumference (plus 10 more); in PAD they were age, high-sensitivity C-reactive protein, systolic blood pressure, expired carbon monoxide, cotinine, socioeconomic status, and lipoprotein (a) (plus 5 more).

CONCLUSIONS

The mixture of shared with disparate determinants for arterial disease in the heart and the legs implies nonidentical pathogenesis: cholesterol dominant in the former, and inflammation (high-sensitivity C-reactive protein, diabetes mellitus, smoking) in the latter.

Lower limb arterial calcification (LLAC) scores in patients with symptomatic peripheral arterial disease are associated with increased cardiac mortality and morbidity

AIMS

The association of coronary arterial calcification with cardiovascular morbidity and mortality is well-recognized. Lower limb arterial calcification (LLAC) is common in PAD but its impact on subsequent health is poorly described. We aimed to determine the association between a LLAC score and subsequent cardiovascular events in patients with symptomatic peripheral arterial disease (PAD).

METHODS

LLAC scoring, and the established Bollinger score, were derived from a database of unenhanced CT scans, from patients presenting with symptomatic PAD. We determined the association between these scores outcomes. The primary outcome was combined cardiac mortality and morbidity (CM/M) with a secondary outcome of all-cause mortality.

RESULTS

220 patients (66% male; median age 69 years) were included with follow-up for a median 46 [IQR 31-64] months. Median total LLAC scores were higher in those patients suffering a primary outcome (6831 vs. 1652; p = 0.012). Diabetes mellitus (p = 0.039), ischaemic heart disease (p = 0.028), chronic kidney disease (p = 0.026) and all-cause mortality (p = 0.012) were more common in patients in the highest quartile of LLAC scores. The area under the curve of the receiver operator curve for the LLAC score was greater (0.929: 95% CI [0.884-0.974]) than for the Bollinger score (0.824: 95% CI [0.758-0.890]) for the primary outcome. A LLAC score ≥ 4400 had the best diagnostic accuracy to determine the outcome measure.

CONCLUSION

This is the largest study to investigate links between lower limb arterial calcification and cardiovascular events in symptomatic PAD. We describe a straightforward, reproducible, CT-derived measure of calcification-the LLAC score.

High alert! Alarming rise in the Prevalence of cardiovascular risk events among the students of medical profession in India

Cardiovascular disease (CVD) risk events increase at an alarming rate among student of medical profession (SMP) in India. By estimating the prevalence, awareness could be created and further consequences could be prevented at early stage. The prevalence of CVD risk events was found to be 12.4% among SMP in India. Because evidence suggests that at early stage pathophysiological process for CVD begins.

The Role of Hemodynamic Measurements in the Management of Venous and Ischemic Ulcers

There is a need for quantitative investigations in the vascular laboratory to manage lower extremity ulcers. The majority of leg ulcers are of venous (45%-60%) or arterial origin (10%-20%). Despite the increasing complexity of new devices used in vascular surgical practice, the anklebrachial pressure index (ABPI) remains the cornerstone for the differential diagnosis of ischemic ulcers. The toe-brachial pressure index and the pole test represent attractive alternative tests especially in patients with diabetes. Color flow Doppler imaging (CFDI) is advantageous over ABPI in cases in which wounds and ulcers prevent the use of a cuff by virtue of their size or location; additionally CFDI technology can detect nonflow limiting lesions, lesions to nonaxial arteries such as the deep femoral artery, or lesions limited to a single tibial artery. Continued improvements in the accuracy of CFDI have prompted some vascular surgeons to replace contrast arteriography in distal bypass procedures. Transcutaneous partial oxygen tension measurement (TcPO2) is another noninvasive method that is reliable to select the level of amputation and recommended to determine tissue viability in critically ischemic limbs and in the management of the diabetic foot. CFDI has revolutionized the diagnostic approach to venous disorders and it is considered the gold standard for the assessment of the venous system of the lower limb, causes minimal inconvenience to patients, and is easily repeatable, but it is considered highly operator dependent. Various plethysmography techniques are of limited application in ulcer investigations, because of their difficulty to calibrate signal, unless time measurements such as the postexercise refilling time are used.

ABPI against Colour Duplex Scan: A Screening Tool for Detection of Peripheral Arterial Disease in Low Resource Setting Approach to Validation

Background. In Sri Lanka the ABPI has not been used as a screening tool to detect peripheral arterial disease (PAD) in epidemiological studies. This study was conducted to determine the best cutoff value of ABPI to detect PAD in Sri Lankan population. Methods. The ABPI measured by arterial Doppler to detect PAD was validated against colour duplex scan as the criterion using 165 individuals referred to vascular laboratory, National Hospital Sri Lanka. In all selected individuals ABPI was measured and lower limb colour duplex scan was performed. Narrowing of luminal diameter of lower limb arteries 50% or more was considered as haemodynamically significant and having PAD. The discriminative performance of the ABPI was assessed using Receiver Operator Characteristic (ROC) curve and calculating the area under the curve (AUC). The sensitivity and specificity of different threshold levels of ABPI and the best cutoff value of ABPI to detect PAD were determined. Results. ABPI 0.89 was determined as the best cutoff value to identify individuals with PAD. At this level of ABPI high sensitivity (87%), specificity (99.1%), positive predictive value (98.9%), and negative predictive value (88.4%) were observed. Conclusion. ABPI ≤ 0.89 could be used as the best cut off value to detect PAD.

Vascular assessment techniques of podiatrists in Australia and New Zealand: a web-based survey

Background

Podiatrists play a central role in conducting non-invasive vascular assessment in the lower extremity. This involves screening for signs and symptoms of peripheral arterial disease (PAD) and ongoing monitoring of the condition. Podiatric vascular assessment practices in Australia and New Zealand are currently unclear. Determining the clinical habits of Podiatrists is essential in identifying if there is a need for further education or support in performing accurate vascular assessments.

Methods

A web-based, secure, anonymous questionnaire was conducted of registered Podiatrists in Australia and New Zealand between 1 April and 31 July 2013. The questions examined clinician’s regular practices in vascular assessment, clinical indicators to perform and barriers in completing vascular assessment. Nominal logistic regression was performed to further examine years of experience and practice setting on clinical indicators to perform vascular assessment and types of assessment performed.

Results

Four hundred forty-seven podiatrists participated in the survey. Clinical indicators for vascular assessment, along with barriers and available equipment were examined and the results varied depending on the podiatrists’ geographical location, practice setting, and experience. Palpation of pedal pulses was the most frequently reported assessment (97 %) along with Doppler assessment (74 %). Pressure measurement was the least frequently reported vascular assessment method, with only 34 % undertaking ankle-brachial indices and 19 % completing toe-brachial indices. Public podiatrists reported more varied and complete vascular assessment compared to those in private practice. Lack of time was identified as the most frequently reported barrier (66 %) in performing vascular assessment, followed by lack of equipment (28 %). In New Zealand podiatrists, lack of equipment was much more of an issue than in Australian podiatrists.

Conclusion

Large variations exist in vascular assessment methods amongst Australian and New Zealand podiatrists. Some assessments being undertaken are potentially inadequate for accurate screening for PAD. There is a need for continuing education in vascular assessment to address the deficiencies in technique reported by some Podiatrists. A podiatry-relevant summary of broad international guidelines for PAD screening may be of use to improve utilisation and accuracy of screening methods to improve patient management.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-015-0130-5) contains supplementary material, which is available to authorized users.

Intratester and Intertester Reliability of Toe Pressure Measurements in People with and Without Diabetes Performed by Podiatric Physicians

BACKGROUND

Toe pressures and the toe brachial index (TBI) represent possible screening tools for peripheral arterial disease; however, limited evidence is available regarding their reliability. The aim of this study was to determine intratester and intertester reliability of toe systolic pressure and the TBI in participants with and without diabetes performed by podiatric physicians.

METHODS

Two podiatric physicians performed toe and brachial pressure measurements on 80 participants, 40 with and 40 without diabetes, during two testing sessions using photoplethysmography and Doppler probe. Intraclass correlation coefficients (ICCs) and 95% limits of agreement were determined.

RESULTS

In people with diabetes, intratester reliability of toe pressure measurement was excellent for both testers (ICCs, 0.84 and 0.82). Reliability of the TBI was good (ICCs, 0.72 and 0.75) and brachial pressure fair (ICCs, 0.43 and 0.55). The intertester reliability of toe pressure (ICC, 0.82) and the TBI (ICC, 0.80) was excellent. Intertester reliability of brachial pressure was reduced in people with diabetes (ICC, 0.49). In age-matched participants, intratester reliability of toe pressure measurement was excellent for both testers (ICCs, 0.83 and 0.87), and reliability of the TBI (ICCs, 0.74 and 0.80) and brachial pressure (ICCs, 0.73 and 0.78) was good to excellent. Intertester reliability of toe pressure (ICC, 0.84), the TBI (ICC, 0.81), and brachial pressure (ICC, 0.77) was excellent.

CONCLUSIONS

Toe pressures and the TBI demonstrated excellent reliability in people with and without diabetes and can be an effective component of lower-extremity vascular screening. However, wide limits of agreement relative to blood pressure values for both cohorts indicate that results should be interpreted with caution.

High Ankle-Brachial Index Indicates Cardiovascular and Peripheral Arterial Disease in Patients With Type 2 Diabetes

We assessed the association between high ankle-brachial index (ABI) and cardiovascular disease (CVD) and peripheral arterial disease (PAD) in Chinese patients with type 2 diabetes mellitus (T2DM). The ABI was measured, and foot inspection was performed in 2080 outpatients with T2DM. The clinical characters in different ABI levels were analyzed, and the diagnostic value of high ABI to CVD and PAD was determined. Compared with the normal ABI group, the high ABI (>1.3) group had a higher prevalence of CVD and PAD but less than the low ABI (≤0.9) group. High ABI was an independent risk factor for the development of CVD and PAD. Receiver-operating characteristic curve analysis showed that the optimal cutoff of high ABI to predict CVD and PAD was 1.43 and 1.45, respectively. The odds ratio of high ABI for CVD and PAD was 2.25 and 6.97, respectively, after adjusting for other confounding risk factors. In conclusion, high ABI indicated the risk of CVD and PAD in Chinese populations with T2DM.

Saving the Limb in Diabetic Patients With Ischemic Foot Lesions Complicated by Acute Infection

Ischemia and infection are the most important factors affecting the prognosis of foot ulcerations in diabetic patients. To improve the outcome of these patients, it is necessary to aggressively treat 2 important pathologies—namely, occlusive arterial disease affecting the tibial and femoral arteries and infection of the ischemic diabetic foot. Each of these 2 conditions may lead to major limb amputation, and the presence of both critical limb ischemia (CLI) and acute deep infection is a major risk factor for lower-extremity amputation. Thus, the management of diabetic foot ulcers requires specific therapeutic approaches that vary significantly depending on whether foot lesions are complicated by infection and/or ischemia. A multidisciplinary team approach is the key to successful treatment of a diabetic foot ulcer: ischemic diabetic foot ulcers complicated by acute deep infection pose serious treatment challenges because high levels of skill, organization, accuracy, and timing of intervention are required to maximize the chances of limb salvage: these complex issues are better managed by a multidisciplinary clinical group.

The relationship between childhood BMI and adult serum cholesterol, LDL, and ankle brachial index

OBJECTIVE

Effects of childhood overweight may persist into adulthood. We assessed the effect of childhood overweight on cardiovascular disease high risk factor levels in the same participants as adults, after controlling for adult body mass index (BMI) status.

DESIGN

A subset of participants in an observational study (Heartwatch) were contacted approximately 26-27 years after initial enrollment to participate in a follow-up study on the long-term effects of childhood overweight. During follow-up, BMI, waist:hip circumference (WHC), blood pressure (BP), serum lipids, and ankle brachial index (ABI) were measured; additional BMI measures throughout childhood were obtained as available from the electronic medical record. Primary outcomes were ABI and serum low density lipoprotein (LDL).

SETTING

The 1982 Heartwatch study was conducted with children participants living in Marshfield, Wisconsin; follow-up included original participants who were re-contacted and agreed to be enrolled.

PARTICIPANTS

Participants were a stratified random sample of eligible participants in the original 1982 Heartwatch study. Of the original 3106 participants, 647 adult participants completed follow-up exams.

RESULTS

Among males with 1982 BMI ≥ 85(th) percentile, adult BMI, WHC, (both P ≤ 0.001), ABI (P = 0.001), total cholesterol (P = 0.01), LDL (P = 0.003) and BP (P < 0.02) were higher in 2008-2009 as compared to males with 1982 BMI < 85(th) percentile. Among females, BMI, BP and WHC (all P < 0.001) were higher in 2008-2009. BMI in 1982 and 2008-2009 were correlated [r = 0.56 (males); 0.58 (females), P < 0.001]. 2008-2009 BMI was more strongly correlated with 2008-2009 measures of ABI (r = 0.16, P = 0.006, males) and high LDL [r = 0.18, P = 0.002 (males); r = 0.11, P = 0.046 (females)]. 1982 BMI was not independently associated with ABI or LDL after adjusting for adult BMI.

CONCLUSION

In a cohort studying childhood and adult overweight, childhood BMI was associated with health outcomes relating to cardiovascular disease in adulthood. However, childhood BMI was not independently related to LDL-C or ABI levels in adulthood after accounting for adult BMI. Longitudinal measurements of BMI and other health risk factors were not found to improve accuracy of models for high cardiovascular disease risk factor levels.

A practical approach to interpreting lower extremity noninvasive physiologic studies

Peripheral arterial disease (PAD) is an important manifestation of atherosclerosis, with an estimated age-adjusted prevalence of approximately 13% in people older than 50 years. Noninvasive vascular laboratory physiologic studies are indispensable tools in the initial evaluation and workup and postintervention follow-up. In this review, we describe a practical approach to the technique, interpretation, pitfalls, and limitations of these physiologic studies. We also provide an algorithmic approach for using these studies in the initial workup of patients with suspected PAD. Noninvasive techniques that primarily provide anatomic information have not been included in this review.

The Queensland high risk foot form (QHRFF) - is it a reliable and valid clinical research tool for foot disease?

BACKGROUND

Foot disease complications, such as foot ulcers and infection, contribute to considerable morbidity and mortality. These complications are typically precipitated by "high-risk factors", such as peripheral neuropathy and peripheral arterial disease. High-risk factors are more prevalent in specific "at risk" populations such as diabetes, kidney disease and cardiovascular disease. To the best of the authors' knowledge a tool capturing multiple high-risk factors and foot disease complications in multiple at risk populations has yet to be tested. This study aimed to develop and test the validity and reliability of a Queensland High Risk Foot Form (QHRFF) tool.

METHODS

The study was conducted in two phases. Phase one developed a QHRFF using an existing diabetes foot disease tool, literature searches, stakeholder groups and expert panel. Phase two tested the QHRFF for validity and reliability. Four clinicians, representing different levels of expertise, were recruited to test validity and reliability. Three cohorts of patients were recruited; one tested criterion measure reliability (n = 32), another tested criterion validity and inter-rater reliability (n = 43), and another tested intra-rater reliability (n = 19). Validity was determined using sensitivity, specificity and positive predictive values (PPV). Reliability was determined using Kappa, weighted Kappa and intra-class correlation (ICC) statistics.

RESULTS

A QHRFF tool containing 46 items across seven domains was developed. Criterion measure reliability of at least moderate categories of agreement (Kappa > 0.4; ICC > 0.75) was seen in 91% (29 of 32) tested items. Criterion validity of at least moderate categories (PPV > 0.7) was seen in 83% (60 of 72) tested items. Inter- and intra-rater reliability of at least moderate categories (Kappa > 0.4; ICC > 0.75) was seen in 88% (84 of 96) and 87% (20 of 23) tested items respectively.

CONCLUSIONS

The QHRFF had acceptable validity and reliability across the majority of items; particularly items identifying relevant co-morbidities, high-risk factors and foot disease complications. Recommendations have been made to improve or remove identified weaker items for future QHRFF versions. Overall, the QHRFF possesses suitable practicality, validity and reliability to assess and capture relevant foot disease items across multiple at risk populations.

Bicycle testing as an alternative diagnostic tool in patients suspected of intermittent claudication

BACKGROUND

The ankle-brachial index (ABI) obtained after a treadmill challenge is often used to confirm the diagnosis of intermittent claudication (IC). However, some patients fail treadmill testing due to (temporary) orthopedic or neurologic comorbidity or fear of falling. The aim of this study was to evaluate the role of bicycle testing as an alternative for treadmill testing. It was hypothesized that ABIs obtained after bicycle tests were not different compared with values after standard treadmill testing.

METHODS

In this validation study, newly diagnosed IC patients (Rutherford 1-3) underwent a standard treadmill test (TT, "gold standard") and two bicycle protocols, one with a continuous resistance submaximal character (submaximal bicycle test, SBT) and a second with an incremental ramp form having a maximal character (maximal bicycle test, MBT). ABIs of both legs were obtained before and twice after each of these three different exercise tests. Healthy individuals matched for age and gender served as controls.

RESULTS

The study population consisted of 32 patients (68 ± 11 years, 21 men). ABIs of each leg (n = 64) obtained after TT correlated significantly with values obtained after either bicycle test (TT vs. SBT: r = 0.90, P < 0.001; TT vs. MBT: r = 0.88, P < 0.001). Drops in ABI after both types of exercise were significantly correlated (TT vs. SBT: r = 0.66, P < 0.001; TT vs. MBT: r = 0.32, P < 0.01). A 98% sensitivity and 86% specificity for diagnosis of IC was observed after the SBT. After the MBT, these values were 98% and 43%, respectively. Healthy controls (n = 13) demonstrated ABI values >0.9 after cycling in all tests.

CONCLUSIONS

Both submaximal and a maximal bicycle tests may serve as alternative noninvasive tools for detecting intermittent claudication. Bicycle tests can potentially be used for patients unable to perform a treadmill test.

A comparison of the Doppler ultrasound interpretation by student and registered podiatrists

BACKGROUND

Hand held Doppler ultrasound machines are routinely used by podiatrists to assess the arterial perfusion of the lower limb. They are practical, painless and effective as a screening tool, and the available general evidence would suggest that interpretation by practitioners is reliable. This study compared the abilities of student and Health and Care Professions Council (HCPC) registered podiatrists to identify correctly Doppler ultrasound outputs.

METHOD

A prospective single blind comparative study design was utilised. Fifteen Doppler recordings of the blood flow in the posterior tibial artery, five each of monophasic, biphasic and triphasic blood flow, were used to compare the interpretation abilities of 30 undergraduate podiatry students and 30 HCPC registered podiatrists. Chi-squared analysis of the results was undertaken.

RESULTS

Chi-squared analysis found that there was no statistically significant difference between the overall abilities of student podiatrists and HCPC registered podiatrists to identify correctly Doppler ultrasound recordings (p = 0.285). No significant difference was found in their ability to identify Doppler ultrasound recordings of monophasic, biphasic or triphasic blood flow (p > 0.050).

CONCLUSION

The results of this relatively small study suggest that both student and HCPC registered podiatrists are in general able to identify the nature of blood flow based on the output of handheld Doppler ultrasound units. However, the results raise an issue regarding professional development of practitioners who might have been expected to have enhanced their skills of Doppler ultrasound sound identification since professional registration.

Ankle brachial pressure index of normal, healthy, younger adults

Doppler ultrasound and ankle brachial pressure index (ABPI) calculations are used in the assessment of lower limb vascularity, specifically to determine arterial deficiency. ABPI is important as it is used as an indicator when deciding management options for the treatment of leg ulceration. This study aimed to investigate the range of ABPI measurement, using Doppler ultrasound and sphygmomanometry in 36 young healthy adults aged 18-55 years. The findings show a mean ABPI in the left leg of 1.19 and a mean ABPI of 1.17 in the right leg which, while within the normal range, are consistently in the upper range and significantly higher than the acknowledged 'normal' midpoint of 1.0. It would appear that younger people will have ABPIs within the upper aspect of the normal range and well above the established norm of 1.0.

Training to Measure Ankle–Brachial Index at the Undergraduate Level

We examined the effectiveness of teaching ankle–brachial index (ABI) measurement to medical students. ABI was estimated in 28 lower limbs by an experienced vascular surgeon. After a 2-week training course, 5 fourth-year students repeated the estimations and their results were compared with that of the trainer’s. There was no difference in ABI values between trainees and trainer for subjects with mild-to-moderate peripheral arterial disease (PAD; 0.77 ± 0.22 vs 0.77 ± 0.19, respectively, P = .95). In the 4 normal limbs, ABI was 1.37 ± 0.12 and 1.16 ± 0.11, as measured by the trainer and the trainees, respectively ( P < .00001). In subjects with severe PAD, trainees tended to overestimate ABI ( P = .0002) in the beginning of the educational process, but this was no longer the case at a later stage of the training with no difference in ABI values between the 2 examiner groups ( P = .09). In conclusion, training of medical students in ABI measurement can be helpful toward accurate estimation of PAD and merits further practice.

A Study on the Relationship between Serum Beta 2-Microglobulin Levels, Underlying Chronic Kidney Disease, and Peripheral Arterial Disease in High-Vascular-Risk Patients

BACKGROUND

Serum beta 2-microglobulin (B2M) levels have been found to be increased in patients with peripheral arterial disease (PAD), yet it is still unknown whether B2M correlates with PAD intensity.

OBJECTIVES

We aim to evaluate the correlation between B2M and the ankle-brachial index (ABI) values in high-vascular-risk patients.

METHODS

This is a cross-sectional study of 63 high-vascular-risk patients admitted to the Cardiology Department or evaluated as outpatients in the Internal Medicine Department of our institution. Patients were classified into two groups according to their ABI: patients without PAD (n = 44, ABI values between 0.9 and 1.4) and patients with PAD (n = 19, ABI values lower than 0.9 or higher than 1.4). We performed univariate and multivariate analysis based on a multiple linear regression model.

RESULTS

Serum B2M levels were higher in patients with pathological ABI values than in those without PAD (2.36 ± 1.13 vs. 1.80 ± 0.65 mg/L; P<0.05). We found no correlation between B2M and ABI in our total population (r = -0.12) or in patients with PAD (r = -0.09; NS for both comparisons). Age, gender, arterial hypertension, estimated glomerular filtration rate (eGFR), uric acid, total cholesterol, and LDL-cholesterol correlated with B2M in the univariate analysis. In the final linear regression model, eGFR, uric acid and total cholesterol correlated independently with B2M (P<0.01).

CONCLUSION

We found no correlation between B2M levels and ABI values in high-vascular-risk patients that could usefully help in the subsequent diagnosis of PAD. However, we observed a significant correlation between B2M and eGFR, even when renal function was only slightly impaired.

The effect of a 3-month supervised exercise programme on gait parameters of patients with peripheral arterial disease and intermittent claudication

BACKGROUND

The management of peripheral arterial disease with intermittent claudication includes angioplasty, pharmaceutical therapy, risk factor modification and exercise therapy. Supervised exercise programmes are used sporadically but may improve the distance that an individual with claudication can walk. The purpose of this study was to evaluate the effectiveness of a 3-month supervised exercise programme on improving gait parameters in patients with intermittent claudication.

METHODS

12 participants were recruited (mean (SD) - age: 67.3 (6.8) years, height: 1.67 (0.09) m, mass: 79.4 (14.0) kg, ankle brachial pressure index: 0.73 (0.17)) from the local vascular unit and enrolled in a supervised exercise programme. Kinematic and kinetic data were collected at the following time points: pain-free walking, initial claudication pain, absolute claudication pain and after a patient-defined rest period. Data were collected before and after the 3-month supervised exercise programme.

FINDINGS

No significant differences were found in any of the gait parameters post-intervention including pain-free walking speed (P=0.274), peak hip extension (P=0.125), peak ankle plantarflexion (P=0.254), or first vertical ground reaction force peak (P=0.654). No significant gait differences were found across different levels of pain pre- or post-intervention.

INTERPRETATION

The lack of improvement post-intervention observed suggests that the current exercise protocol was not tailored to elicit significant improvements in patients with intermittent claudication, specifically. The results indicate that exercise programmes may show improved results post-intervention if they are longer in duration and varied in intensity. Further research into more detailed muscle and biomechanical adaptations is needed to inform exercise programmes specific to this population.

Shockwave therapy in patients with peripheral artery disease

INTRODUCTION

Previous studies support the fact that extracorporeal shockwave (SW) induces angiogenesis and improves symptoms in patients affected by limb ischemia. The aim of this study was to evaluate the effects of SW therapy in patients with peripheral artery disease (PAD).

METHODS

Twenty-two patients were enrolled in this study and were randomly assigned into two groups: SW treatment (12 patients, 67 ± 9 years) and control (10 patients, 68 ± 12 years). The inclusion criteria were the following: age over 40 years, PAD diagnosis, optimal medical therapy, and ankle-brachial index less than 0.9. SW therapy was administered using the Minilith® SL1 litotriptor with an ultrasound guide able to detect the target area using a B-mode technique and a 7.5 MHz convex probe emitting 2,000 impulses with an energy flux density of 0.03 mJ/mm(2).

RESULTS

The variation in the degree of stenosis before and after treatment was statistically significant between the groups (-9% ± -10% vs. 0% ± 0%; P = 0.001). In addition, a significantly higher number of treated patients than controls showed a reduction in the Fontaine stage (12 [63%] vs. 0 [0%]; P < 0.001). This result was confirmed by analyzing the difference in patients' pain-free walking distance before and after SW therapy (76 ± 46 m vs. 0 ± 0 m for treated patients vs. controls; P < 0.001) and the difference in pain severity (measured on a pain scale; -1.4 ± 0.5 in the treated patients vs. -0.2 ± 0.4 in the controls; P < 0.001).

CONCLUSION

On the basis of these results the authors hypothesized a direct effect of SW on the ultrastructural composition of the vessel walls, inducing a reduction in artery stenosis. These data support the application of SW therapy as a new medical tool to improve the natural clinical course of PAD.

Perceptions of the ankle brachial index amongst podiatrists registered in Western Australia

Background

The ankle brachial index (ABI) is an objective diagnostic tool that is widely used for the diagnosis of peripheral arterial disease. Despite its usefulness, it is evident within the literature that many practitioners forgo using this screening tool due to limiting factors such as time. There is also no recommended technique for ABI measurement. The purpose of this study is to investigate the perceptions of the use of ABI clinically among Western Australian podiatrists.

Methods

This study was a cross sectional survey which evaluated the perceptions of the ABI amongst registered podiatrists in Western Australia. The study sample was obtained from the register of podiatrists listed with the Podiatrists Registration Board of Western Australia. Podiatrists were contacted by telephone and invited to participate in a telephone questionnaire. Chi-square tests were performed to determine if there was a statistically significant relationship between use of the ABI and podiatrists’ profile which included: sector of employment; geographical location; and length of time in practice.

Results

There is a statistically significant relationship (p=0.004) between podiatrists’ profile and the use of ABI, with higher usage in the tertiary hospital setting than in private practice. Length of time spent in practice had no significant impact on ABI usage (p=0.098). Time constraints and lack of equipment were key limiting factors to performing the ABI, and no preferred technique was indicated.

Conclusion

Western Australian podiatrists agree that the ABI is a useful tool for lower limb vascular assessment, however, various factors influence uptake in the clinical setting. This study suggests that a podiatrists’ profile has a significant influence on the use of the ABI, which may be attributed to different patient types across the various settings. The influence of time spent in practice on ABI usage may be attributed to differences in clinical training and awareness of lower limb pathology over time. The authors recommend publication of ‘best practice’ guidelines to ABI performance, as well as further education and financial rebates from health organizations to facilitate increased utility of the ABI based on the findings of this study.

Micro-lightguide spectrophotometry for tissue perfusion in ischemic limbs

OBJECTIVE

To validate micro-lightguide spectrophotometry (O2C) in patients with lower limb ischemia and to compare results with those obtained from toe blood pressure.

METHODS

We prospectively examined 59 patients, 24 of whom complained of claudication, 31 had critical ischemia, and four were asymptomatic. Diabetes was present in 19 (32%) patients. Saturation (SO(2)) and flow measured with O2C were determined with the limb in the horizontal position followed by a 55-cm elevation. Toe pressures were determined in the horizontal position only. In addition, 13 patients were examined before and, on average, 3 days after revascularization.

RESULTS

Median SO(2) was 62% (25%-75% percentile: 37%-75%) with the limb in the horizontal position and 16% (3%-41%) with the limb elevated. Comparing the individual toe pressures with SO(2) values measured in the horizontal position and elevated position revealed a significant correlation (r(s) = 0.40; P < .01 and r(s) = 0.56; P < .01, respectively). A low SO(2) (ie, <40% in the horizontal position and <20% in the elevated position) was highly predictive of a toe pressure of 40 mm Hg or less. In the horizontal position, the positive predictive value was 100%, whereas the negative predictive value was 47%. The similar figures in the elevated position were a positive predictive value of 97% and a negative predictive value of 68%. Postoperatively, SO(2) increased significantly from 27% (P25%-75%: 11%-75%) to 79% (68%-87%) in the horizontal position (P = .008) and from 14% (P25%-75%: 2%-39%) to 55% (30%-73%) in the elevated position (P = .011), respectively. Looking at the individual 13 cases in which revascularization was performed, three patients had a partial reconstruction (ie, superficial femoral artery occlusion distal to a central reconstruction or reconstruction to a popliteal blind segment). These patients had significantly lower postoperative SO(2) as well as toe pressure compared with the 10 patients with unobstructed flow to the foot.

CONCLUSIONS

O2C was easy to use, fast, and painless. The most useful finding was the high predictive value of a low saturation and the rise in O2C values after successful revascularization.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal–Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.