Changes in ankle brachial index in symptomatic and asymptomatic subjects in the general population

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.

The ankle-brachial index for assessing the prevalence of peripheral artery disease and cardiovascular risk in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Type 2 diabetes mellitus (T2DM) is an important risk factor for peripheral artery disease (PAD). Ankle-Brachial Index (ABI) was found associated with a higher cardiovascular (CV) risk and mortality. The main goals of this study were to establish the prevalence of PAD in a T2DM population, and assess the relationship between PAD and the CV risk calculated with the CUORE Project score (CPS) (https://www.cuore.iss.it/). The association between the ABI, the main risk factors for PAD and T2DM complications was also investigated.

METHODS AND RESULTS

Two hundred patients were consecutively enrolled. The prevalence of PAD in this population was 17%. The CV risk tended to be higher (p = 0.0712) in the group with a pathological ABI than in the group with a normal ABI. Glycated hemoglobin (r = -0.1591; p = 0.0244), total cholesterol (r = -0.1958; p = 0.0054), LDL cholesterol (r = -0.1708; p = 0.0156) and systolic blood pressure (r = -0.1523; p = 0.0313) correlated significantly and inversely with the left ABI. The frequency of diabetic retinopathy was significantly higher in the group with a pathological ABI (p = 0.0316).

CONCLUSIONS

The data reveal a high prevalence of PAD in patients with T2DM. The CPS confirmed that patients with a pathological ABI have tendency to a higher CV risk. The results point to the importance of an accurate CV assessment - also measuring individuals' ABI and calculating their CPS - to better pinpoint those at high risk of PAD, especially among patients with T2DM.

Ankle-Brachial Index and Energy Production in People Without Peripheral Artery Disease: The BLSA

Background Lower ankle-brachial index (ABI) values within the 0.90 to 1.40 range are associated with poorer mitochondrial oxidative capacity of thigh muscles in cross-sectional analyses. Whether ABI decline is associated with greater declines in thigh muscle oxidative capacity with aging is unknown. Method and Results We analyzed data from 228 participants (100 men) of the BLSA (Baltimore Longitudinal Study of Aging), aged 39 to 97 years, with an ABI between 0.9 and 1.40 at baseline and at follow-up (mean follow-up period of 2.8 years). We examined mitochondrial oxidative capacity of the left thigh muscle, by measuring the postexercise phosphocreatine recovery rate constant (kPCr) from phosphorus-31 magnetic resonance spectroscopy. Greater kPCr indicated higher mitochondrial oxidative capacity. Although kPCr was available on the left leg only, ABI was measured in both legs. Longitudinal rates of change (Change) of left and right ABI and kPCr of the left thigh muscle were estimated using linear mixed effects models, and their association was analyzed by standardized multiple linear regressions. In multivariate analysis including sex, age, baseline kPCr, both left and right baseline ABI, and ABI change in both legs, (kPCr)Change was directly associated with ipsilateral (left) (ABI)Change (standardized [STD]-β=0.14; P=0.0168) but not with contralateral (right) (ABI)Change (P=0.22). Adjusting for traditional cardiovascular risk factors, this association remained significant (STD-β=0.18; P=0.0051). (kPCr)Change was steeper in White race participants (STD-β=0.16; P=0.0122) and body mass index (STD-β=0.13; P=0.0479). There was no significant association with current smoking status (P=0.63), fasting glucose (P=0.28), heart rate (P=0.67), mean blood pressure (P=0.78), and low-density lipoprotein (P=0.75), high-density lipoprotein (P=0.82), or triglycerides (P=0.15). Conclusions In people without peripheral arterial disease, greater decline in ABI over time, but not baseline ABI, was associated with faster decline in thigh mitochondrial oxidative capacity in the ipsilateral leg. Further studies are needed to examine whether early interventions that improve lower extremity muscle perfusion can improve and prevent the decline of muscle energetics.

Sex as a Key Determinant of Peripheral Artery Disease – Epidemiology, Differential Outcomes, and Proposed Biological Mechanisms

Atherosclerotic peripheral artery disease (PAD) is associated with functional limitations and an increased risk of poor cardiovascular outcomes. Although men are traditionally viewed at higher risk of PAD than women, the true prevalence and incidence is inconsistent among available reports. Some of this variability is due to differences in PAD-related symptoms among women as well as sex-based differences in diagnostic tests, such as the ankle-brachial index, and it is critical for future epidemiologic studies to account for these differences. Generally, women with PAD experience greater functional impairment and decline then men and are less likely to receive guideline-directed medical therapy. In some settings, women are also more likely to present at later stages of disease and more often undergo lower limb amputation than men. Animal data exploring the biological underpinnings of these sex differences are limited, but several mechanisms have been postulated, including differential plaque morphology, alterations in the immune response, and hormonal variation and protection. Epidemiologic data suggest a link between inflammation and PAD and also reveal sex differences in lipid profiles associated with risk of PAD. In this review, we discuss available data on sex differences in PAD with additional focus on potential biological explanations for these differences. We also emphasize important knowledge gaps in this area, including under-representation of women in PAD clinical trials, to help guide future investigations and eliminate sex disparities in PAD.

Supervised walking exercise therapy improves gait biomechanics in patients with peripheral artery disease

OBJECTIVE

In patients with peripheral artery disease (PAD), supervised exercise therapy is a first line of treatment because it increases maximum walking distances comparable with surgical revascularization therapy. Little is known regarding gait biomechanics after supervised exercise therapy. This study characterized the effects of supervised exercise therapy on gait biomechanics and walking distances in claudicating patients with PAD.

METHODS

Forty-seven claudicating patients with PAD underwent gait analysis before and immediately after 6 months of supervised exercise therapy. Exercise sessions consisted of a 5-minute warmup of mild walking and stretching of upper and lower leg muscles, 50 minutes of intermittent treadmill walking, and 5 minutes of cooldown (similar to warmup) three times per week. Measurements included self-perceived ambulatory limitations measured by questionnaire, the ankle-brachial index (ABI), walking distance measures, maximal plantar flexor strength measured by isometric dynamometry, and overground gait biomechanics trials performed before and after the onset of claudication pain. Paired t-tests were used to test for differences in quality of life, walking distances, ABI, and maximal strength. A two-factor repeated measures analysis of variance determined differences for intervention and condition for gait biomechanics dependent variables.

RESULTS

After supervised exercise therapy, quality of life, walking distances, and maximal plantar flexor strength improved, although the ABI did not significantly change. Several gait biomechanics parameters improved after the intervention, including torque and power generation at the ankle and hip. Similar to previous studies, the onset of claudication pain led to a worsening gait or a gait that was less like healthy individuals with a pain-free gait.

CONCLUSIONS

Six months of supervised exercise therapy produced increases in walking distances and quality of life that are consistent with concurrent improvements in muscle strength and gait biomechanics. These improvements occurred even though the ABI did not improve. Future work should examine the benefits of supervised exercise therapy used in combination with other available treatments for PAD.

The progression rate of peripheral arterial disease in patients with intermittent claudication: a systematic review

Background

Intermittent claudication (IC) is the most common symptom of peripheral arterial disease and is generally treated conservatively due to limited prognostic evidence to support early revascularisation in the individual patient. This approach may lead to the possible loss of opportunity of early revascularisation in patients who are more likely to deteriorate to critical limb ischaemia. The aim of this review is to evaluate the available literature related to the progression rate of symptomatic peripheral arterial disease.

Methods

We conducted a systematic review of the literature in PubMed and MEDLINE, Cochrane library, Elsevier, Web of Science, CINAHL and Opengrey using relevant search terms to identify the progression rate of peripheral arterial disease in patients with claudication. Outcomes of interest were progression rate in terms of haemodynamic measurement and time to development of adverse outcomes. Two independent reviewers determined study eligibility and extracted descriptive, methodologic, and outcome data. Quality of evidence was evaluated using the Cochrane recommendations for assessing risk of bias and was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

Seven prospective cohort studies and one retrospective cohort study were identified and included in this review with the number of participants in each study ranging from 38 to 1244. Progression rate reports varied from a yearly decrease of 0.01 in ankle-brachial pressure index (ABPI) to a yearly decrease ABPI of 0.014 in 21% of participants. Quality of evidence ranged from low to moderate mostly due to limited allocation concealment at recruitment and survival selection bias.

Conclusions

Progression of PAD in IC patients is probably underestimated in the literature due to study design issues. Predicting which patients with claudication are likely to deteriorate to critical limb ischaemia is difficult since there is a lack of evidence related to lower limb prognosis. Further research is required to enable early identification of patients at high risk of progressing to critical ischaemia and appropriate early revascularisation to reduce lower limb morbidity.

Subclinical Longitudinal Change in Ankle-Brachial Index With Aging in a Community-Dwelling Population Is Associated With Central Arterial Stiffening

Background Aging is associated with a modest decline in ankle-brachial index (ABI); however, the underpinnings of this decline are not fully understood. The greater systolic ankle than brachial blood pressure, a normal ABI implies, is partially attributed to lower central than peripheral arterial stiffness. Hence, we examined the hypothesis that the age-associated decline in ABI is associated with central arterial stiffening with aging, assessed by pulse wave velocity. Methods and Results We analyzed longitudinal data from 974 participants aged 27 to 95 years from the Baltimore Longitudinal Study of Aging who were free of clinically significant cardiovascular disease. Participants had an average of 4 visits with a 6.8-year average follow-up time. Linear mixed-effects models showed that the average ABI decline beyond the age of 70 years was 0.03 per decade. In multiple regression analysis, the ABI rate of change was inversely associated with initial age (standardized β=-0.0711, P=0.0282), independent of peripheral disease factors and baseline ABI. After adjustment, the pulse wave velocity rate of change was inversely associated with ABI rate of change (standardized β=-0.0993, P=0.0040), rendering the association of the latter with initial age nonsignificant (standardized β=-0.0265, P=0.5418). Conclusions A modest longitudinal decline in ABI beyond the age of 70 years was shown to be independent of traditional risk factors for peripheral arterial disease but was accounted for by an increase in pulse wave velocity. A modest decline in ABI with aging might be a manifestation of changes in central hemodynamics and not necessarily attributable to peripheral flow-limiting factors.

Comparison of different exercise ankle pressure indices in the diagnosis of peripheral artery disease

Although the resting ankle-brachial index (ABI) is commonly used as a tool to diagnose peripheral artery disease (PAD), several additional indices measured after exercise may have increased sensitivity for identifying PAD. The aim of this study was to determine the utility of resting ABI and three post-exercise physiological parameters for diagnosing PAD confirmed by arterial imaging studies. For each qualifying study, we assessed the performance measures for identifying PAD for resting ABI < 0.90, exercise ABI < 0.90, a decrease in ABI > 20% with exercise, and a decrease in ankle pressure > 30 mmHg with exercise. Of the 199 exams that met our inclusion criteria, imaging showed a > 75% stenotic lesion in at least one limb in 138 (69%) of patients. For stenoses > 75%, resting ABI < 0.90 had a sensitivity of 64% (95% CI: 56-72%) and exercise ABI < 0.90 had a sensitivity of 88% (95% CI: 82-93%). The sensitivity for a post-exercise ABI decrease > 20% was 67% (95% CI: 59-75%) and the sensitivity for a decrease in ankle pressure > 30 mmHg was 4% (95% CI: 2-9%). For individuals with a normal resting ABI but stenotic lesions > 75% confirmed by imaging (n=49), the addition of exercise ABI testing correctly identified an additional 25% of this population. Overall, exercise ABI < 0.90 exhibits a greater sensitivity for detecting PAD compared to resting ABI. Furthermore, exercise ABI < 0.90 had added clinical utility in patients with normal resting ABIs and was superior to other commonly used exercise indices.

Skin perfusion pressure as a predictor of ischemic wound healing potential

Skin perfusion pressure (SPP) is the blood pressure that is the requisite for the restoration of microcirculatory or capillary flow following controlled occlusion and subsequent flow return. The purpose of the current review was to evaluate the value of SPP for the prediction of wound healing in patients with limb ischemia. Articles published up to January 31, 2017 were searched in the PubMed database and Chinese database CNKI, using the keywords of 'skin perfusion pressure', 'limb ischemia' and 'wound healing'. Articles were obtained and reviewed to analyze the predictive value of SPP with regard to the healing potential of ischemia wounds on limbs. Three different types of techniques are currently used for the measurement of SPP, namely radioisotope clearance, photoplethysmography and laser Doppler, with laser Doppler as the most widely applied technique, due to its noninvasiveness and ease of operability. SPP may effectively assess wound healing potential in ischemic limbs with high sensitivity and specificity; however, its optimum cut-off point remains uncertain. Compared with other noninvasive microcirculatory assessment tools including ankle-brachial index, toe blood pressure and transcutaneous oxygen pressure, SPP has its advantages including that it is not affected by vascular calcification, anatomical structure or patient condition. In conclusion, SPP may be used as an index to accurately predict wound healing in patients with limb ischemia. However, it is difficult to determine the optimum cut-off of SPP due to the limitations of current data. Further study is necessary to confirm the optimum cut-off value of SPP in predicting wound healing potential.

Association of diabetes mellitus with decline in ankle-brachial index among patients on hemodialysis: A 6-year follow-up study

Peripheral artery occlusive disease is common among diabetes mellitus (DM) and end-stage renal disease patients, and tends to progress faster and lead to worse outcomes. This study compared the association of DM with the decline in ankle-brachial index (ABI) among patients on hemodialysis (HD). This was a longitudinal analysis of ABI in HD patients from 2009 to 2015. Medical records and yearly ABI values were obtained. A longitudinal mixed-model analysis was used to evaluate ABI changing trends while accounting for within-patients correlation. There were 296 patients on HD in the period of 2009-2015. In a 6-year follow-up, those with DM had a more rapid ABI decline compared to non-DM patients (slopes: -0.014 vs. 0.010 per year, interaction p < 0.001). In DM patients, female sex, high pulse pressure, high triglyceride, low creatinine, and high uric acid were associated with a decrease in ABI. In non-DM patients, old age, high pulse pressure, high low-density lipoprotein cholesterol, and high uric acid were associated with a decreased in ABI. There were 49.6% of patients with a normal ABI experienced a decrease at least 0.1 of ABI from baseline, and 35.3% had a final ABI < 0.9 in patients with a baseline ABI ≥ 0.9 (n = 232). In this study, DM patients on HD tend to develop a more rapid decline in ABI than non-DM patients on HD. Age, sex, pulse pressure, lipid profile, creatinine, and uric acid are associated with a decreased in ABI.

Peripheral artery disease: epidemiology and global perspectives

Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.

Change in Ankle-Brachial Index Over Time in a Screened Japanese Cohort - The Okinawa Peripheral Arterial Disease Study

BACKGROUND

The temporal change in ankle-brachial index (ABI) in the general population, especially in those aged <40 years, remains unclear.

METHODS AND RESULTS

ABIs of 23,673 individuals were measured in 1-day health checkups between 2003 and 2010. Among them, 1,117 participants aged 28-76 years (mean 53±9 years) whose ABI was measured at least twice within an interval of ≥4 years (mean: 4.9 years) were selected for this study. Baseline ABI was the lowest at age <40 years and increased with age. ABI significantly increased in participants aged <40 and 40-49 years, but not in participants aged 50-59 and ≥60 years. ABI increased in participants with borderline-low baseline ABI (0.9<ABI<1.0, 0.09; P<0.001) and normal baseline ABI (1.0≤ABI<1.2, 0.006; P=0.017). ABI decreased in participants with high-normal baseline ABI (1.2≤ABI<1.4, -0.04; P<0.001). Stepwise multivariate analysis revealed that ABI change was independently associated with baseline ABI (β=-0.566), height (β=0.162), body mass index (β=0.093), and sex (women, β=-0.08).

CONCLUSIONS

ABI was lowest at age <40 years and increased with age. In participants aged <50 years, ABI significantly increased over the mean observation period of 4.9 years. (Circ J 2016; 80: 2004-2009).

Physical Activity Improves Borderline Ankle-Brachial Index Values in a Cardiovascular Risk Population

BACKGROUND

Peripheral arterial disease (PAD) is an underdiagnosed and undertreated disease because it remains asymptomatic for so long. The ankle-brachial index (ABI) is a valid method for detecting PAD in lower extremities. ABI ≤0.90 indicates incident PAD. Recent studies have found that subjects with borderline ABI values (0.91-1.00) have increased mortality rates. The objective of our 7-year follow-up study was to investigate the progression of PAD in borderline ABI subjects, who underwent a multifactorial cardiovascular intervention.

METHODS

A total of 193 subjects with borderline ABI were examined in 2005-2006. None of them had previously diagnosed diabetes, cardiovascular or renal disease or intermittent claudication. They were given conventional treatment for multiple risk factors of cardiovascular diseases (hypertension, hypercholesterolemia, elevated blood glucose, smoking, and overweight). Sixty-four percent of these subjects (n = 123) attended a follow-up visit in 2012.

RESULTS

Of the 123 subjects with borderline ABI (mean age 59.0 ± 6.5 years, 62% female) at baseline, 18 (15%, 95% confidence intervals [CI]: 9%-22%) developed incident PAD during the follow-up. The mean ABI was 0.97 ± 0.03 at baseline and 1.01 ± 0.12 at 7-year follow-up visit. The change in mean ABI was +0.04 (95% CI: 0.03-0.07), P < 0.001. ABI improved significantly in 25 (20%) subjects. In multivariate ordered logistic regression analyses high and even moderate leisure-time physical activity (LTPA; odds ratio 6.15; 95% CI: 1.99-19.1) predicted a rise in ABI in comparison to low LTPA.

CONCLUSIONS

Physical activity seems to improve significantly ABI values among men and women with borderline ABI (0.91-1.00).

Incidence of peripheral arterial disease in the ARTPER population cohort after 5 years of follow-up

Background

To know the epidemiology (prevalence, incidence, progression and morbidity and mortality associated) of peripheral artery disease in general population and the factors associated with this progression is essential to know the evolution of atherosclerosis and develop preventive strategies. The aim of the study was to determine the incidence of PAD after 5 years of follow-up population-based cohort ARTPER, and the evolution of Ankle brachial Index (ABI) in this period.

Methods

Peripheral artery disease incidence analysis after 5 years of follow-up of 3786 subjects > 50 years old. Peripheral artery disease incident when the second cross section Ankle brachial Index was <0.9 in any of the lower limbs, with normal baseline (0.9 to 1.4).

Results

Between 2012 and 2013 2762 individuals (77 % participation) were re-examined . Finally analyzed 2256 subjects (after excluding pathological Ankle brachial Index) followed for 4.9 years (range 3.8 to 5.8 years), totalling 11,106 person-years. Peripheral artery disease 95 new cases were detected, representing an incidence of 4.3 % at 5 years and 8.6 per 1000 person-years (95 % CI 6.9 to 10.5) being higher in men (10.2, 95 % CI 7.4 to 13.5) than in women (7.5, 95 % CI 5.5 to 9.9). Linear correlation between the baseline Ankle brachial Index and the second cross section was low (r = 0.23).

Conclusions

The incidence of peripheral artery disease in ARTPER cohort was 8.6 cases per 1000 person-years, being higher in men, especially <65 years. The correlation between two measures Ankle brachial Index after 5 years of follow-up was low. One might consider whether Ankle brachial Index repeated measures could improve the correlation.

Estudo comparativo do Índice Tornozelo-Braquial em diabéticos e não diabéticos com isquemia crítica

Resumo Contexto A calcificação da camada média arterial pode tornar o Índice Tornozelo-Braquial (ITB) falsamente elevado em diabéticos, dificultando a avaliação da doença arterial. Objetivo Comparar os valores do ITB de diabéticos e não diabéticos com isquemia crítica. Métodos Foram incluídos 140 pacientes (60% de diabéticos) acompanhados no Serviço de Cirurgia Vascular do Complexo Hospitalar Universitário Professor Edgard Santos com isquemia crítica por DAOP infra-inguinal. Comparou-se a média dos valores do ITB dos dois grupos de pacientes, correlacionando o ITB com a gravidade da isquemia, segundo a Classificação de Rutherford. A análise estatística foi realizada pelo EPI-INFO. Resultados A maioria dos 140 pacientes (77%) se encontrava na Categoria 5 da Classificação de Rutherford, 6% na 4 e 17% na 6. Nove diabéticos (11%) e um não diabético (2%) apresentaram ITB > 1,15 (p = 0,02), sendo excluídos da análise das médias do ITB. Considerando os 130 pacientes, os 75 doentes diabéticos apresentaram média do ITB na artéria tibial posterior de 0,26 versus 0,28 dos 55 doentes não diabéticos (p = 0,6); e no ITB da artéria pediosa aqueles apresentaram média de 0,32 versus 0,23 desses (p = 0,06). Estratificando os doentes nas categorias da Classificação de Rutherford, não houve diferença nas médias do ITB nas categorias 4 e 5. Apenas em relação à artéria pediosa e em pacientes na Categoria 6, a média do ITB foi significativamente maior em diabéticos (0,44 versus 0,16; p = 0,03). Conclusão Os diabéticos apresentaram maior prevalência de ITB falsamente elevado. Porém, excluindo-se esses casos, a média dos valores de ITB são semelhantes aos não diabéticos, exceto na artéria pediosa, nos pacientes com isquemia na categoria 6.

Low prevalence of peripheral arterial disease in a cross-sectional study of Danish HIV-infected patients

BACKGROUND

Patients infected with human immunodeficiency virus (HIV) appear to be at increased risk of cardiovascular disease (CVD). The ankle-brachial index (ABI) is a well-established screening tool for peripheral arterial disease (PAD) and future cardiovascular events in the general population. However, controversies exist on the prevalence of PAD among HIV-infected patients. In this study we aimed to measure the prevalence of PAD among HIV-infected patients and compare the ABI with carotid intima-media thickness (cIMT) and other known CVD risk predictors.

METHODS

We prospectively included HIV-infected patients from an outpatient clinic at the Department of Infectious Diseases, Hvidovre University Hospital, Denmark. We assessed the ABI pre- and post-exercise with a threshold for PAD defined as ABI ≤ 0.9. All patients had cIMT measured at the far wall of the distal common carotid artery.

RESULTS

Of 102 patients included (mean age 52 years, 75% male, 94% receiving antiretroviral therapy (ART), 33% active smokers), 1 had a pre-exercise ABI ≤ 0.9 and in addition 3 patients had a post-exercise ABI ≤ 0.9. We found a poor correlation between ABI and traditional CVD risk factors other than body mass index. In contrast, a strong correlation was found between cIMT and traditional risk factors. Values of post-exercise ABI and cIMT were not correlated. The current ART did not influence ABI values.

CONCLUSIONS

We found a low prevalence of PAD in HIV-infected patients. ABI did not correlate with CVD risk factors or cIMT. Based on these results ABI does not seem valuable as a screening tool for CVD among HIV-infected patients.

Time and reliability issues associated with automatic vs. manual measurements of Ankle to Brachial pressure Index (ABI) following heavy load exercise

OBJECTIVES

Ankle to brachial index after heavy load exercise is the most accurate way of diagnosing minor arterial lesions in athletes, such as endofibrosis. The reliability and practical aspects of ankle to brachial index measurements after heavy-load exercise have not been studied. The purpose of this study was to analyze the interest of oscillometric automatic vs. manual Doppler measurements, for the calculation of ankle to brachial index, after heavy-load exercise in athletes.

DESIGN

Prospective single-center study.

METHODS

Fifteen healthy trained athletes performed an incremental test twice. Ankle to brachial index measurements were performed at Rest, as soon as possible after exercise (Rec-0), and then started at the 3rd minute of recovery (Rec-3), by two operators using each one of the two ankle to brachial index measurement methods.

RESULTS

Mean times for automatic vs. manual ankle to brachial availability were 99 ± 18 s vs. 113 ± 25 s (p = 0.005) and 44 ± 25 s vs. 53 ± 12 s (p = 0.001) respectively at Rec-0 and Rec-3. Ankle to brachial index values from the two methods were highly correlated (r = 0.89). Mean absolute differences of automatic vs. manual ankle to brachial values from test-retest were 0.04 ± 0.05 vs. 0.08 ± 0.08 (p > 0.05) and 0.07 ± 0.05 vs. 0.09 ± 0.10 (p > 0.05) at Rest and Rec-0.

CONCLUSIONS

Automatic method allows obtaining faster and simultaneously post-exercise ankle to brachial index measurement compare to the manual Doppler. This time issue does not result in a significant change in absolute ankle to brachial index values, nor in the absolute differences of these in test-retest. Nevertheless, the test-retest variability of post-exercise ankle to brachial index results seems smaller with the automatic than the manual method.

ICAM-1 and SRD5A1 gene polymorphisms in symptomatic peripheral artery disease

The genotype distribution of two gene polymorphisms, previously associated with peripheral artery disease (PAD), has been evaluated in a population of diabetic (DPAD) and non-diabetic (NDPAD) patients affected by symptomatic PAD (stages II-IV). A decreased frequency of the AA genotype of rs5498 (ICAM-1) was observed in the PAD subjects compared to controls but this result did not reach statistical significance (p=0.06 by chi-squared test). On the contrary, a significant increase in the frequency of the GG homozygous genotype of rs248793 (SRD5A1) was observed in the PAD patient group in comparison to controls (p=0.01). These data confirm that the GG genotype of rs248793 in the SRD5A1 gene is significantly associated with symptomatic PAD and show a trend towards a stronger association with the non-diabetic status.

Current utility of the ankle-brachial index (ABI) in general practice: implications for its use in cardiovascular disease screening

Background

Peripheral arterial disease (PAD) is a marker of systemic atherosclerosis and associated with a three to six fold increased risk of death from cardiovascular causes. Furthermore, it is typically asymptomatic and under-diagnosed; this has resulted in escalating calls for the instigation of Primary Care PAD screening via Ankle Brachial Index (ABI) measurement. However, there is limited evidence regarding the feasibility of this and if the requisite core skills and knowledge for such a task already exist within primary care. This study aimed to determine the current utility of ABI measurement in general practices across Wales, with consideration of the implications for its use as a cardiovascular risk screening tool.

Method

A self-reporting questionnaire was distributed to all 478 General Practices within Wales, sent via their responsible Health Boards.

Results

The survey response rate was 20%. ABI measurement is primarily performed by nurses (93%) for the purpose of wound management (90%). It is infrequently (73% < 4 times per month) and often incorrectly used (42% out of compliance with current ABI guidance). Only 52% of general practitioners and 16% of nurses reported that patients with an ABI of ≤ 0.9 require aggressive cardiovascular disease risk factor modification (as recommended by current national and international guidelines).

Conclusion

ABI measurement is an under-utilised and often incorrectly performed procedure in the surveyed general practices. Prior to its potential adoption as a formalised screening tool for cardiovascular disease, there is a need for a robust training programme with standardised methodology in order to optimise accuracy and consistency of results. The significance of a diagnosis of PAD, in terms of associated increased cardiovascular risk and the necessary risk factor modification, needs to be highlighted.

Ankle-Brachial Index: Nurses Strategy To Cardiovascular Disease Risk Factors Identification

Elevated risk of fatal and non-fatal cardiovascular events is associated with high prevalence of peripheral arterial disease, with assessment through the ankle-brachial index (ABI). This study aimed to demonstrate that the ABI and the Edinburgh Claudication Questionnaire are tools to be used by nurses in prevention and/or treatment of CVD (cardiovascular disease). A cross-sectional study was carried out with patients from a cardiovascular clinic. The Edinburgh Claudication Questionnaire was applied and the ABI was measured with the formula (ABI= Blood Pressure Ankle/Blood Pressure Brachial). A total of 115 patients were included, most were females (57.4%), aged 60.6 ± 12.5 years. The most prevalent risk factors were hypertension (64.3%), physical inactivity (48.7%) and family history (58.3%). The study showed that abnormal ABI was frequently found and 42.6% of the patients with abnormal ABI showed intermittent claudication. The method to evaluate the ABI associated to the Edinburg Claudication Questionnaire, can be easily used by nurses in the clinical evaluation of asymptomatic and symptomatic CVD patients.

Impact of weight loss on ankle-brachial index and interartery blood pressures

OBJECTIVE

To assess whether weight loss improves markers of peripheral artery disease and vascular stenosis.

METHODS

The Action for Health in Diabetes randomized clinical trial compared intensive lifestyle intervention (ILI) for weight loss to a control condition of diabetes support and education (DSE) in overweight or obese adults with type 2 diabetes. Annual ankle and brachial blood pressures over four years were used to compute ankle-brachial indices (ABIs) and to assess interartery blood pressure differences in 5018 participants.

RESULTS

ILI, compared to DSE, produced 7.8% (Year 1) to 3.6% (Year 4) greater weight losses. These did not affect prevalence of low (<0.90) ABI (3.60% in DSE versus 3.14% in ILI; P = 0.20) or elevated (>1.40) ABI (7.52% in DSE versus 7.59% in ILI: P = 0.90), but produced smaller mean (SE) maximum interartery systolic blood pressure differences among ankle sites [19.7 (0.2) mmHg for ILI versus 20.6 (0.2) mmHg for DSE (P < 0.001)] and between arms [5.8 (0.1) mmHg for ILI versus 6.1 (0.1) mmHg for DSE (P = 0.01)].

CONCLUSIONS

Four years of intensive behavioral weight loss intervention did not significantly alter prevalence of abnormal ABI, however, it did reduce differences in systolic blood pressures among arterial sites.

Effects of the ankle-brachial blood pressure index and skin perfusion pressure on mortality in hemodialysis patients

OBJECTIVE

Clinically, the ankle-brachial blood pressure index (ABI) and skin perfusion pressure (SPP) are used to screen for subclinical peripheral artery disease. However, the association between the SPP and mortality in hemodialysis patients has not been previously reported. We investigated these factors and compared the ABI and SPP in patients receiving hemodialysis.

METHODS

A total of 102 patients receiving maintenance hemodialysis were enrolled in this study. The ABI was determined using an ABI-form (Colin, Japan). The SPP was measured using a SensiLase(TM) PAD3000 (Kaneka, Osaka, Japan).

RESULTS

The mean follow-up period was 3.2 ± 1.4 years. A multivariate Cox analysis identified a low ABI (p=0.019) and a low SPP (p=0.047) as being independent predictors of mortality. A receiver operating characteristic (ROC) analysis of the ABI revealed a cutoff point of 1.1 and an area under the curve (AUC) of 0.79, with a sensitivity of 90% and a specificity of 62%. A ROC analysis of the SPP revealed a cutoff point of 54.0 mmHg and an AUC of 0.71, with a sensitivity of 55% and a specificity of 84%.

CONCLUSION

Both low ABI and SPP values were found to be independent risk factors for mortality among hemodialysis patients. The cutoff point for ABI as a predictor of mortality was 1.1, while that for SPP was 54.0 mmHg.

Predictors of decrease in ankle-brachial index among patients with diabetes mellitus

AIM

Screening for peripheral arterial disease, a complication among patients with diabetes, is performed by periodic assessment of ankle-brachial index. We aimed to study the degree of ankle-brachial index change over time and factors associated with significant change.

METHOD

We assessed difference between two ankle-brachial index measurements over time in a consecutive series of 82 patients with Type 2 diabetes. All patients had ankle-brachial index > 0.9 but ≤ 1.3 for the first measurement, and significant ankle-brachial index decrease was defined as a decrease of > 0.1 in the follow-up measurement compared with the baseline.

RESULTS

The mean follow-up duration was 27.6 (median 30.0) months. Significant ankle-brachial index decrease was seen in 20.7% of patients, including 5% with follow-up ankle-brachial index of ≤ 0.9, consistent with the diagnosis of peripheral arterial disease. After adjusting for age and gender, higher baseline HbA(1c) and serum creatinine levels, increase in follow-up serum LDL cholesterol levels compared with baseline and history of retinopathy were predictors of significant ankle-brachial index decrease.

CONCLUSIONS

Our study suggests that, within two years, one in five patients with diabetes and a normal ankle-brachial index may have significant progression of peripheral arterial disease. Annual ankle-brachial index assessment and better control of hyperlipidaemia may thus be required for at-risk patients with poor glycaemic control, renal impairment and retinopathy.

Automated photoplethysmography-based determination of ankle-brachial index: a validation study against Doppler sonography

INTRODUCTION

Determination of ankle-brachial-index (ABI) by manual Doppler is well established to screen for lower extremity arterial disease (LEAD) and to predict cardiovascular risk. A new generation of digital-controlled devices promises automated ABI determination. The aim of this study was to determine comparability of automated photoplethysmography (PPG)-derived ABI calculation with the Doppler-ABI algorithm commonly used in cohort studies.

METHODS

Automated PPG-based ABI measurements [Vascular Explorer (VE) and Vicorder (VI)] were recorded from 112 limbs of healthy subjects and 22 limbs of patients with confirmed LEAD. Validity was evaluated on the basis of receiver-operating characteristic (ROC) analysis of clinical status and concordance with Doppler-ABI. Differences between cuff inflation [inf]- and deflation [def]-based method were studied in VE.

RESULTS

PPG-based ABI values were higher compared to Doppler-ABI (VI +0.06, VEinf +0.15, VEdef +0.09, p < 0.001, respectively). The difference was pronounced in pathological (<0.9), borderline (0.9-0.99) and low normal (1.0-1.09) ABI, but less in ABI ≥1.1. However, ROC analysis revealed excellent diagnostic value for LEAD (sensitivity/specificity) and comparable area under the curve at method-adapted ABI thresholds for all methods: Doppler (95/90 %, 0.95), VI (75/96 %, 0.91), VEinf (85/89 %, 0.93) and VEdef (80/98 %, 0.94).

CONCLUSIONS

Digital-controlled PPG-based ABI determination is a useful diagnostic application for LEAD. However, the systematic higher ABI in PPG-based measurement compared to Doppler and remarkable differences between the deflationary and inflationary method are critical for the interpretation of borderline and low normal ABI values where precise reading is essential to detect mild LEAD and subclinical disease and to predict cardiovascular risk.

Borderline peripheral arterial disease

Peripheral arterial disease (PAD), along with coronary artery disease and cerebrovascular disease, is a manifestation of systemic atherosclerosis. These cardiovascular diseases (CVDs) are the leading cause of death in the world, representing 30% of all global deaths. Although population-based studies indicate that PAD has a relatively benign course in the legs, patients with PAD show more cardiovascular comorbidity and have at least twofold risk of fatal coronary artery disease and cerebrovascular accidents compared with the general population. These studies suggest that noninvasive testing using the ankle-brachial index (ABI) is also an accurate marker of subclinical CVD and thus may hold promise for early identification of individuals at the greatest risk for major CVD events.The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) defines a cutoff ABI value of 0.90 or less for diagnosing PAD at rest. This threshold value has been reported to be 95% sensitive in detecting angiogram-positive PAD and almost 100% specific in identifying apparently healthy individuals. In persons without PAD, arterial pressures increase with greater distance from the heart, resulting in higher systolic blood pressures at the ankle than at the the brachial arteries. Thus, persons without atherosclerosis typically have an ABI greater than 1.00. But what is the significance of ABI values between 0.91 to 1.00, which are conventionally regarded as 'no disease'? The present article gives an overview of current knowledge of borderline PAD (ie, an ABI of 0.91 to 1.00).

Progression of asymptomatic peripheral artery disease over 1 year

The pathophysiology and time course of an individual converting from asymptomatic peripheral artery disease (PAD) to symptomatic claudication is unclear. The objectives of this study were: (1) to characterize the extent of atherosclerotic disease in individuals with an abnormal ankle–brachial index (ABI), but without claudication; and over 1 year of follow-up to (2) evaluate the progression of PAD using ultrasound imaging, (3) determine changes in the ABI and leg pain symptoms, and (4) correlate PAD progression with changes in the ABI and leg symptoms. We hypothesized that PAD progression would be associated with the development of claudication and changes in the ABI, 6-minute walk distance (6-MWD), and walking quality of life. Individuals with a reduced ABI but without typical intermittent claudication noted on community screening were invited to undergo baseline and 1-year follow-up assessment, including duplex ultrasound. The initial and repeat evaluations included measurement of the ABI, lower extremity duplex arterial mapping, and assessment of leg pain and functional status. Of the 50 people studied, 44 (88%) had significant atherosclerotic lesions in the lower extremity arteries, affecting 80 legs. A total of 33 of 50 individuals (66%) returned for the 1-year follow-up visit. On ultrasound examination, two of 18 normal legs developed PAD, and in 48 legs with PAD at baseline, 17 legs (35%) developed new or progressive lesions. Thirteen legs developed new claudication. Overall, there was no significant worsening in the ABI, 6-MWD, or the Walking Impairment Questionnaire (WIQ). However, legs with new lesions or lesion progression were significantly more likely to develop claudication, and the 13 legs (seven subjects) developing claudication showed a significant decline in the 6-MWD. In conclusion, these data indicate that a significant number of people with asymptomatic PAD show progression over 1 year, that such individuals are more likely to develop claudication, and that those developing claudication have a significant decrease in their 6-MWD.

Association of peripheral artery disease and long-term mortality in hemodialysis patients

BACKGROUND

Peripheral artery disease (PAD) is a common complication in hemodialysis patients. The ankle-brachial blood pressure index (ABI) has been widely used to screen for subclinical PAD. In the present study, we investigated the association between ABI and long-term (up to 8.8 years) mortality among hemodialysis patients.

METHODS

A total of 86 consecutive patients receiving maintenance hemodialysis who underwent an ABI examination between 2001 and 2003 were retrospectively enrolled in this study. Patients with an ABI of less than 0.9 were considered as having PAD; those with an ABI of more than 0.9 in both legs were considered as being free from PAD. We examined the relationship between mortality and several risk factors.

RESULTS

During the follow-up period, 43 deaths were recorded. In the univariate regression analysis, the mortality hazard ratio (HR) of patients with PAD was 1.67 (95% confidence interval [CI], 1.18-2.28). Other predictive variables for mortality included male gender, age, and diabetes mellitus (P = 0.006, P = 0.024, and P = 0.023, respectively). A multivariate Cox analysis identified PAD and male gender as independent predictors of mortality (P = 0.033 and P = 0.028, respectively). The impact of age and diabetes mellitus on mortality was no longer significant in the multivariate analysis.

CONCLUSION

After a relatively long-term observation period, a multivariate analysis indicated that PAD acted independently of other risk factors, including advanced age and the presence of diabetes mellitus. ABI measurements can be used to identify high-risk hemodialysis patients requiring intensive follow-up care.

Noninvasive assessment of lower extremity hemodynamics in individuals with diabetes mellitus

The timely and accurate noninvasive assessment of peripheral arterial disease (PAD) is a critical component of a limb preservation initiative in patients with diabetes mellitus. Noninvasive vascular studies (NIVS) can be useful in screening patients with diabetes for PAD. In patients with clinical signs or symptoms, NIVS provide crucial information on the presence, location, and severity of PAD, as well as an objective assessment of the potential for primary healing of an index wound or a surgical incision. Appropriately-selected NIVS are important in the decision-making process to determine whether and what type of intervention might be most appropriate, given the clinical circumstances. Hemodynamic monitoring is likewise very important following either an endovascular procedure or a surgical bypass. Surveillance studies, usually with a combination of physiologic testing and imaging with duplex ultrasound, accurately identify recurrent disease prior to the occurrence of thrombosis, allowing targeted reintervention. NIVS can be broadly grouped into three general categories: physiologic or hemodynamic measurements; anatomic imaging; and measurements of tissue perfusion. These types of tests and suggestions for their appropriate application in patients with diabetes are reviewed.

Ankle-Brachial Index Should Be Measured in Both the Posterior and the Anterior Tibial Arteries in Studies of Peripheral Arterial Disease

Lower extremity peripheral artery disease (PAD) is a powerful predictor of cardiovascular events and mortality. The ankle-brachial index (ABI) is an objective and standard diagnostic method to diagnose PAD (an ABI ≤ 0.9 is considered pathological). The American Heart Association (AHA) and the American College of Cardiology (ACC) recommend using both the posterior and anterior tibial arteries when assessing ABI. We investigated whether there was a difference in the diagnosis of PAD if the ABI was measured in the posterior or the anterior tibial arteries. The results showed that among participants with ABI ≤0.9, between 30% and 40% would not get a PAD diagnosis if the ABI was measured in only 1 of the arteries. In conclusion, this study emphasizes the importance of measuring the ABI in both the posterior tibial and the anterior tibial arteries when diagnosing PAD.

Pathophysiological changes in calf muscle predict mobility loss at 2-year follow-up in men and women with peripheral arterial disease

BACKGROUND

Associations of pathophysiological calf muscle characteristics with functional decline in people with lower extremity peripheral arterial disease are unknown.

METHODS AND RESULTS

Three hundred seventy participants with peripheral arterial disease underwent baseline measurement of calf muscle area, density, and percent fat with the use of computed tomography. Participants were followed up annually for 2 years. The outcome of mobility loss was defined as becoming unable to walk 1/4 mile or walk up and down 1 flight of stairs without assistance among those without baseline mobility limitations. Additional outcomes were > or =20% decline in 6-minute walk distance and becoming unable to walk for 6 minutes continuously among participants who walked continuously for 6 minutes at baseline. With adjustment for age, sex, race, body mass index, the ankle-brachial index, smoking, physical activity, relevant medications, and comorbidities, lower calf muscle density (P for trend <0.001) and lower calf muscle area (P for trend=0.039) were each associated with increased mobility loss rates. Compared with participants in the highest baseline tertiles, participants in the lowest tertile of calf muscle percent fat had a hazard ratio of 0.18 for incident mobility loss (95% confidence interval, 0.06 to 0.55; P=0.003), and participants in the lowest tertile of muscle density had a 3.50 hazard ratio for incident mobility loss (95% confidence interval, 1.28 to 9.57; P=0.015). No significant associations of calf muscle characteristics with 6-minute walk outcomes were observed.

CONCLUSIONS

Our findings suggest that interventions to prevent mobility loss in peripheral arterial disease should focus on reversing pathophysiological findings in calf muscle.

Peripheral arterial disease and clinical risks in Taiwanese hemodialysis patients

Peripheral arterial disease (PAD) is associated with significant morbidity and mortality and is an important marker of systemic atherosclerosis. However, little is known about the associated risk factors for PAD in patients on maintenance hemodialysis (HD). We collected the basic data and possible risk factors associated with PAD for 277 patients on maintenance HD. Furthermore, we measured ankle-brachial blood pressure index (ABI) in these patients. PAD was defined as an ABI value less than 0.90. The prevalence of PAD in our HD center was 22.8% (61/268). Advanced age (P = 0.006), longer history of HD (P < 0.001), diabetes (P = 0.002) and presence of PAD symptoms (P < 0.001) were independent predictors of PAD. PAD patients with diabetes had shorter history of HD (P = 0.001). 2-vessel PAD had higher serum cholesterol in HD patients (>or= 200 vs < 200 mg/dL; Odds ratio, 12.12, 95% confidence interval, 2.199-67.79; P < 0.004).

Subclinical Peripheral Artery Disease in Patients Undergoing Peritoneal Dialysis: Risk Factors and Outcome

Background

Peripheral artery disease (PAD) is highly prevalent among patients in end-stage renal disease. The ankle–brachial index (ABI) is believed to be highly correlated with the subclinical PAD of lower extremities but little is known about the associated risk factors and outcome for PAD and ABI in patients on peritoneal dialysis (PD).

Methods

We performed a cohort study of 153 patients from a single center receiving stable PD for more than 3 months. These patients were screened for subclinical PAD using the ABI measurement. The ABI was measured and a ratio of <0.9 was considered abnormal. Clinical outcomes included actuarial patient and technique survival in this study.

Results

30 patients were classified into a subclinical PAD group. The prevalence of PAD (subclinical and overt) in our PD center was 19.61% (30/153). Advanced age, preexisting diabetes, preexisting cardiovascular and/or cerebrovascular disease (CVD), lower renal Kt/V urea, lower renal creatinine clearance (WCrCl), lower serum albumin level, and higher serum triglyceride level were risk factors for PAD in our PD center. Bivariate analysis showed that ABI was positively correlated with residual renal Kt/V urea and WCrCl, but was not correlated with peritoneal Kt/V urea and WCrCl. Patient and technique survival rates were significantly lower in the low ABI group than in the normal ABI group.

Conclusions

ABI is highly correlated with advanced age, preexisting diabetes, preexisting CVD, serum albumin, serum triglyceride, and residual renal clearance in PD patients. Also, lower ABI is independently associated with a high risk of patient mortality and PD technique failure.

Percutaneous treatment of peripheral vascular disease: the role of diabetes and inflammation

Peripheral arterial disease (PAD) is a growing health problem for many Americans and often occurs along with other cardiovascular risk factors, including diabetes mellitus (DM), low-grade inflammation, hypertension, and lipid disorders. Intermittent claudication (IC), an early manifestation of PAD, commonly leads to reduced quality of life for patients who are limited in their ambulation. While recent wide adoption of percutaneous peripheral interventional (PPI) techniques has increased the number patients being aggressively treated for IC, the overall effectiveness of PPI for the treatment of IC is not well known, especially for DM patients who have both hemodynamic and functional obstacles to treatment success. This review is designed to illustrate how treatment outcomes for IC can be measured by different modalities and how diabetes and inflammation can influence those outcomes. In the setting of greater concern for health care resources and clinical accountability, better understanding of treatment outcomes and efficacy will help us manage these complex challenges.

The prevalence of atherosclerosis in cirrhotic patients: assessment of two aspects of atherosis and sclerosis

AIM

In general, cirrhotic patients are known to have a low prevalence of cardiovascular disease. Cirrhosis is often accompanied by diabetes mellitus, while blood pressure and serum cholesterol levels are low in liver cirrhosis. We examined the atherosclerosis of patients with chronic liver disease by two phases of atherosis "lipid deposition" and sclerosis "arterial fibrosis."

METHODS

Atherosis was assessed by carotid intima-media thickness and the ratio of the systolic blood pressure at the ankle to the average systolic blood pressure at the right arm (ankle brachial pressure index), while sclerosis was evaluated by brachial ankle pulse wave velocity.

RESULTS

There were no significant differences in intima-media thickness and ankle brachial index among grades of cirrhosis. Brachial ankle pulse wave velocity decreased closely as the severity of cirrhosis progressed (F = 4.90, P < 0.05). In univariate analysis, brachial ankle pulse wave velocity was correlated with systolic blood pressure, age, total bilirubin, albumin, prothrombin time, retention rate of indocyanine green at 15 min, blood ammonia, branched chain amino acids/tyrosine molar rate and fasting blood sugar. Multiple regression analysis showed that systolic blood pressure and total bilirubin were independent factors for the inhibition of vascular sclerosis progression.

CONCLUSION

Although no difference in atherosis between cirrhotic patients and healthy controls was found, vascular sclerosis was decreased with the severity of cirrhosis through hypotension and hyperbilirubinemia.

Retrograde rotablator in limb salvage: a new technique using an open approach

Conventional vascular surgery and balloon angioplasty have poor results in severe and diffuse atherosclerotic disease of the infrapopliteal arteries. High-speed rotational atherectomy (Auth Rotablator) has not succeeded either, because of poor long-term patency and the non-reflow phenomenon. We report a case of limb salvage with long occlusion of the three infrapopliteal vessels. The anterior tibial artery was treated with retrograde Auth Rotablator atherectomy by an open approach through the pedal artery, resulting in full patency of the anterior tibial artery and healing of the skin lesions. The microparticulate debris from the ablation was drained out through the pedal arteriotomy, avoiding the complications associated with conventional antegrade high-speed rotational atherectomy.

Risk factors for progression of peripheral arterial disease in large and small vessels

BACKGROUND

Data on the natural history of peripheral arterial disease (PAD) are scarce and are focused primarily on clinical symptoms. Using noninvasive tests, we assessed the role of traditional and novel risk factors on PAD progression. We hypothesized that the risk factors for large-vessel PAD (LV-PAD) progression might differ from small-vessel PAD (SV-PAD).

METHODS AND RESULTS

Between 1990 and 1994, patients seen during the prior 10 years in our vascular laboratories were invited for a new vascular examination. The first assessment provided baseline data, with follow-up data obtained at this study. The highest decile of decline was considered major progression, which was a -0.30 ankle brachial index decrease for LV-PAD and a -0.27 toe brachial index decrease for SV-PAD progression. In addition to traditional risk factors, the roles of high-sensitivity C-reactive protein, serum amyloid-A, lipoprotein(a), and homocysteine were assessed. Over the average follow-up interval of 4.6+/-2.5 years, the 403 patients showed a significant ankle brachial index and toe brachial index deterioration. In multivariable analysis, current smoking, ratio of total to HDL cholesterol, lipoprotein(a), and high-sensitivity C-reactive protein were related to LV-PAD progression, whereas only diabetes was associated with SV-PAD progression.

CONCLUSIONS

Risk factors contribute differentially to the progression of LV-PAD and SV-PAD. Cigarette smoking, lipids, and inflammation contribute to LV-PAD progression, whereas diabetes was the only significant predictor of SV-PAD progression.

Measurement, calculation, and normal range of the ankle-arm index: a bibliometric analysis and recommendation for standardization

Since its introduction in 1950, a variety of methods of measurement and calculation have been used to establish the ankle-arm index (AAI). This has resulted in variations of its normal range and difficulty in comparing study results. Hence, the objective of our study was to analyze the disparate methods used to assess AAI and its normal range and to recommend a standardized method to assess AAI based on that analysis. We made an inventory of the disparate AAI methods and its normal range reported in 100 randomly selected publications and recommend the means of such standardization. We recommend that an experienced observer assess AAI with the patient at rest in the supine position. The width of the sphygmometer cuffs should be 1.5 times that of the extremity to be measured, and brachial and crural pulses should be detected using a Doppler device. Systolic pressures should be measured at both arms and over the anterior and posterior arteries of both legs, with the cuff placed just proximally to the malleoli. The left arm pressure ought to be used as denominator and the mean of pressures of both crural arteries of each leg ought to be used for the numerator of the AAI for that leg. We advocate 0.90 as the cut-off value to distinguish patients who need further arterial assessment.

Reduced lung function in patients with abdominal aortic aneurysm is associated with activation of inflammation and hemostasis, not smoking or cardiovascular disease

OBJECTIVE

Abdominal aortic aneurysms often coexist with reduced lung function and chronic obstructive pulmonary disease (COPD). These conditions are each associated with cigarette smoking, cardiovascular disease, and evidence of increased inflammatory and hemostatic activity. The aim of this study was to determine if these factors accounted for the link between aneurysms and pulmonary disease.

METHODS

The design was a case-control study comparing patients with an asymptomatic abdominal aortic aneurysm with population-based controls without an aneurysm. Aneurysms were diagnosed by ultrasound scan, and pulmonary function was measured by respiratory questionnaire and spirometry. Activation of inflammation and hemostasis was measured by assay of plasma interleukin-6 (IL-6), fibrinogen, von Willebrand factor (vWF), tissue plasminogen activator (tPA) antigen, fibrin D-dimer, and plasmin antiplasmin complexes.

RESULTS

Cases with an abdominal aortic aneurysm (n = 89) had more COPD and worse expiratory lung function as measured by forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) than controls (n = 98) (FEV1, 1.9 vs 2.2 L, P < .01; FEV1/FVC, 0.67 vs 0.75, P < .001) and did not differ in restrictive function (FVC, 2.9 vs 3.0 L, P = .33). Cases also had higher levels of lifetime cigarette smoking (30 vs 24 pack-years, P < 0.01), cardiovascular disease (35% vs 18%, P = .01), plasma fibrinogen (3.5 vs 3.1 g/L, P = .02), IL-6 (2.8 vs 1.8, pg/mL, P < .001), plasmin antiplasmin complexes (596 vs 384 microg/L, P = .01), and D-dimer (442 vs 93 ng/mL, P < .001). On multiple logistic regression analysis of lung function and COPD on the risk of aneurysm, both cigarette smoking and cardiovascular disease had little effect on the relationships. For the markers of activated inflammation and hemostasis, plasmin antiplasmin complexes and D-dimer had the most important confounding effect on the odds ratios. All markers combined had a substantial effect: odds ratio of aneurysm for a one standard deviation decrease in FEV1 fell from 2.3 (95% confidence interval [CI], 1.5 to 3.5) (P < .01) to 1.3 (95% CI, 0.55 to 2.4) (P > or = .05).

CONCLUSION

The association between reduced respiratory function and abdominal aortic aneurysm was not accounted for by cigarette smoking or cardiovascular disease. We hypothesize that activation of inflammation and hemostasis in response to injury may be an important explanation of the association between aneurysm formation and reduced respiratory function. Further studies are required to test this hypothesis.

The physiological response of ankle systolic blood pressure and ankle to brachial index after maximal exercise in athletes is dependent on age

The development of sports activities in the over forties has increased the number of middle-aged patients performing heavy-load exercise. The normal response of ankle systolic blood pressure (ASBP) and ankle to brachial index (ABI) to intense exercise is known in young athletes, but little is known for other age groups. Three groups of 21 athletes: <20 (G1), 20-40 (G2), and >40 (G3) years old, respectively, were studied. ASBP and brachial systolic blood pressure (BSBP) were measured simultaneously before and after an incremental maximal cycle ergometer test. Rest ABI was higher in G3 compared to G1 (P<0.001: ANOVA, Bonferroni). Compared to respective resting values, BSBP, at 1 min of recovery, was increased for the three groups of age (P<0.001) whereas ASBP was unchanged for G1 and G2, and significantly increased for G3 (P<0.001). ASBP was significantly higher in G3 than in G1 and G2, ABI was lower in G1 and G2 compared to G3: 0.70+/-0.11, 0.76+/-0.09 and 0.91+/-0.14, respectively. This age-related ABI increase is consistent with the impaired vasodilator capacity observed in aging normal subjects but not with the decrease observed in ABI resting values in epidemiological studies. ABI is higher in older than in younger athletes at rest and after exercise. In aging athletes, aiming to detect mild to moderate arterial lesions, it is likely that normal limits defined in young athletes are not valid.

Distribution of the ankle-brachial index and associated cardiovascular risk factors in a population of middle-aged and elderly koreans

The Doppler ankle-brachial pressure index (ABI) is an objective and efficient tool that can be used to determine the presence and severity of peripheral arterial disease in the lower extremities. The ABI value is inversely associated with other cardiovascular risk factors. To date, there have been no studies of the distribution of ABI in Korea. We performed a cross-sectional study of 1,943 subjects (681 men and 1,262 women; 45-74 yr old) in Namwon, Korea. The prevalence of a low ABI (<0.90) was 2.2% in men and 1.8% in women, and a high ABI (>or=1.30) was prevalent in 3.1% of men and 0.8% of women. Age, smoking habits, waist circumference, hypertension, and blood pressure were associated with ABI values in both sexes. The presence of carotid plaques was associated with ABI values only in men, whereas pulse pressure was associated with ABI values only in women (p<0.05). Although the prevalence of a low ABI in the present study was lower than those reported previously for Western populations and Japanese men, our results suggest that the ABI might be used as an indicator of cardiovascular risk factors in adult Koreans.

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

BACKGROUND

Despite the increasing sophistication of vascular surgical practice, more than three decades after its introduction to clinical practice, the ankle to brachial pressure index (ABPI) remains the cornerstone of non-invasive assessment of the patient with symptomatic peripheral arterial disease (PAD).

AIM

To summarise what is known about ABPI and critically appraise its validity, reliability, reproducibility and extended utility.

METHODS

A MEDLINE (1966-2004) and Cochrane library search for articles relating to measurement of ABPI was undertaken; see text for further details.

RESULTS

There is considerable disagreement as to how ABPI should be measured. Furthermore, various factors, including the type of equipment used, and the experience of the operator, can result in significant inter- and intra-observer error. As such, care must be taken when interpreting data in the literature. ABPI is valuable in the assessment of patients with atypical symptoms, venous leg ulcers and after vascular and endovascular interventions. However, absolute pressures are probably more valuable in patients with critical limb ischaemia. ABPI is also useful in subjects with asymptomatic PAD where it correlates well with, and may be used in screening studies to quantify, cardiovascular risk.

CONCLUSIONS

While its apparent simplicity can beguile the unwary, ABPI will continue to have a key role in the assessment of symptomatic PAD. ABPI is also likely to have extended utility in health screening and institution of best medical therapy in asymptomatic subjects.