To evaluate the accuracy of the ankle brachial index (ABI) measured with the SCVL® (“screening cardiovascular lab”; GenNov, Paris, France), an automated device with synchronized arm and ankle cuffs with an automatic ABI calculation.
Patients were consecutively included in a cardiovascular prevention unit if they presented with at least two cardiovascular risk factors. ABI measurements were made using the SCVL, following a synchronized assessment of brachial and ankle systolic pressure. These values were compared to the ABI obtained with the usual Doppler-assisted method.
We included 157 patients. Mean age was 59.1 years, 56.8% had hypertension, 22.3% had diabetes mellitus, and 17.6% were current smokers. An abnormal ABI was observed in 17.2% with the SCVL and in 16.2% with the Doppler. The prevalence rates of an abnormal ABI by patient measured with each device, ie, 15.7% (confidence interval [CI] 0.95: [11.8; 20.4]) or 14.3% (CI 0.95: [10.7; 18.9]), did not differ. The coefficient of variation of Doppler and SCVL measures was 15.8% and 15.1%, respectively. The regression line between the two measurement methods was statistically significant. The value-to-value comparison also shows a difference of mean equal to 0.010 (CI 0.95: [−0.272; 0.291]) (r = −0.055). Reproducibility of ABI measurements with the SCVL showed a difference of mean equal to 0.009 (CI 0.95: [−0.203; 0.222]), without heteroscedasticity (r = −0.003).
The SCVL is a fast and easy to use automated oscillometric device for the determination of ABI. The use of this two-synchronized-cuff device correlates well with the gold standard Doppler ultrasound method and is reproducible. The SCVL may ease the screening for peripheral arterial disease in routine medical practice.
ankle brachial index; automated device; peripheral arterial disease screening
Peripheral arterial disease (PAD) is a prognostic marker in cardiovascular disease. The use of Doppler-measured ankle-brachial pressure index (Dop-ABI) for PAD diagnosis is limited because of time, required training, and costs. We assessed automated oscillometric measurement of the ankle-brachial pressure index (Osc-ABI) by nurses and clinical staff.
RESEARCH DESIGN AND METHODS
Clinical staff obtained Osc-ABI with an automated oscillometric device in 146 patients (83 with diabetes) at the time of Dop-ABI measurement and ultrasound evaluation.
Measurements were obtained in most legs (Dop-ABI 98%; Osc-ABI 95.5%). Dop- and Osc-ABI were significantly related in diabetic and nondiabetic patients with good agreement over a wide range of values. When Dop-ABI ≤0.90 was used as the gold standard for PAD, receiver operating characteristic curve analysis showed that PAD was accurately diagnosed with Osc-ABI in diabetic patients. When ultrasound was used to define PAD, Dop-ABI had better diagnostic performance than Osc-ABI in the whole population and in diabetic patients (P = 0.026). Both methods gave similar results in nondiabetic patients. The cutoff values for the highest sensitivity and specificity for PAD screening were between 1.0 and 1.1. Estimation of cost with the French medical care system fees showed a potential reduction by three of the screening procedures.
PAD screening could be improved by using Osc-ABI measured by clinical staff with the benefit of greater cost-effectiveness but at the risk of lower diagnostic performance in diabetic patients.
The authors aimed to determine differences in the prevalence of peripheral arterial disease (PAD) and its associations with cardiovascular disease (CVD) risk factors, using different methods of calculating the ankle-brachial index (ABI). Using measurements taken in the bilateral brachial, dorsalis pedis, and posterior tibial arteries, the authors calculated ABI in 3 ways: 1) with the lowest ankle pressure (dorsalis pedis artery or posterior tibial artery) (“ABI-LO”), 2) with the highest ankle pressure (“ABI-HI”), and 3) with the mean of the ankle pressures (“ABI-MN”). For all 3 methods, the index ABI was the lower of the ABIs calculated from the left and right legs. PAD was defined as an ABI less than 0.90. Among 6,590 subjects from a multiethnic cohort (baseline examination: 2000–2002), in comparison with ABI-HI, the relative prevalence of PAD was 3.95 times higher in women and 2.74 times higher in men when ABI-LO was used. The relative magnitudes of the associations were largest between PAD and both subclinical atherosclerosis and CVD risk factors when ABI-HI was used, except when risk estimates for PAD were less than 1.0, where the largest relative magnitudes of association were found using ABI-LO. PAD prevalence and its associations with CVD risk factors and subclinical atherosclerosis measures depend on the ankle pressure used to compute the ABI.
ankle brachial index; cardiovascular diseases; continental population groups; ethnic groups; peripheral vascular diseases
Lower extremity peripheral arterial disease (PAD) is a marker of widespread atherosclerosis. Individuals with PAD, most of whom do not show typical PAD symptoms ('asymptomatic' patients), are at increased risk of cardiovascular ischaemic events. American College of Cardiology/American Heart Association guidelines recommend that individuals with asymptomatic lower extremity PAD should be identified by measurement of ankle-brachial index (ABI). However, despite its associated risk, PAD remains under-recognised by clinicians and the general population and office-based ABI detection is still poorly-known and under-used in clinical practice. The Prevalence of peripheral Arterial disease in patients with a non-high cardiovascular disease risk, with No overt vascular Diseases nOR diAbetes mellitus (PANDORA) study has a primary aim of assessing the prevalence of lower extremity PAD through ABI measurement, in patients at non-high cardiovascular risk, with no overt cardiovascular diseases (including symptomatic PAD), or diabetes mellitus. Secondary objectives include documenting the prevalence and treatment of cardiovascular risk factors and the characteristics of both patients and physicians as possible determinants for PAD under-diagnosis.
PANDORA is a non-interventional, cross-sectional, pan-European study. It includes approximately 1,000 primary care participating sites, across six European countries (Belgium, France, Greece, Italy, The Netherlands, Switzerland). Investigator and patient questionnaires will be used to collect both right and left ABI values at rest, presence of cardiovascular disease risk factors, current pharmacological treatment, and determinants for PAD under-diagnosis.
The PANDORA study will provide important data to estimate the prevalence of asymptomatic PAD in a population otherwise classified at low or intermediate risk on the basis of current risk scores in a primary care setting.
Trial registration number
Clinical Trials.gov Identifier: NCT00689377.
The purpose of this study was to compare the success rate of successful arterial peak flow (APF) and ankle-brachial index (ABI) measurements in patients with suspected or known peripheral arterial disease (PAD).
Materials and Methods
183 patients with varying degrees of PAD were included. All subjects underwent ABI measurements and MR imaging of the popliteal artery to determine APF. Proportions of patients with successful APF and ABI measurements were compared and the discriminative capability was evaluated.
APF was successfully measured in 91% of the patients, whereas the ABI could be determined in 71% of the patients (p<0.01). Success rates of APF and ABI were significantly higher in patients with intermittent claudication (95% and 80%, respectively) than in patients with critical ischemia (87% and 62%, respectively).
Compared to the assessment of PAD severity with ABI, the success rate of MRI-based APF measurements in patients with a clinical indication for MRA is 20% higher, with similar discriminatory capacity for disease severity. Therefore, APF is an especially convenient and valuable measure to assess severity in PAD patients scheduled to undergo MR angiography to obtain additional functional information concerning the vascular status.
Background. The aim of present study is to observe the association between the levels of ankle-brachial index (ABI) and cardiovascular risk factors among people with type 2 diabetes mellitus in north India. A cross-sectional study was carried out at a centre for heart and diabetic clinic in the state of Punjab on 1121 subjects (671 males and 450 females) with type 2 diabetes mellitus. History of symptoms related to cardiovascular diseases was noted, and blood pressure and anthropometric measurements were recorded. Ankle-brachial index (ABI) was measured using ultrasonic Doppler flow detector. Subjects with ABI ≤0.9 and ≥1.30 were classified as having low and high ABI, respectively. Females had a higher BMI and brachial-ankle pulse wave velocity (P < 0.001). Whereas, males had higher diastolic blood pressure and duration of type 2 diabetes mellitus. The differences of systolic blood pressure and ankle-brachial index were not found significant between the sexes. The prevalence of low ABI (<0.9) was 4.47% in men and 4.67% in women and high ABI (≥1.30) was prevalent in 14% of men and 10.45% of women. Age, BMI, baPWV, and blood pressures were significantly associated with ABI value in both sexes. The results suggested that the ABI might be used as a strong indicator for cardiovascular risk factors in type 2 diabetic subjects.
Peripheral artery tonometry (PAT) is a novel method for assessing arterial stiffness of small digital arteries. Pulse pressure can be regarded as a surrogate of large artery stiffness. When ankle-brachial index (ABI) is calculated using the higher of the two ankle systolic pressures as denominator (ABI-higher), leg perfusion can be reliably estimated. However, using the lower of the ankle pressures to calculate ABI (ABI-lower) identifies more patients with isolated peripheral arterial disease (PAD) in ankle arteries. We aimed to compare the ability of PAT, pulse pressure, and different calculations of ABI to detect atherosclerotic disease in lower extremities. We examined PAT, pulse pressure, and ABI in 66 cardiovascular risk subjects in whom borderline PAD (ABI 0.91 to 1.00) was diagnosed 4 years earlier. Using ABI-lower to diagnose PAD yielded 2-fold higher prevalence of PAD than using ABI-higher. Endothelial dysfunction was diagnosed in 15/66 subjects (23%). In a bivariate correlation analysis, pulse pressure was negatively correlated with ABI-higher (r = −0.347, p = 0.004) and with ABI-lower (r = −0.424, p < 0.001). PAT hyperemic response was not significantly correlated with either ABI-higher (r = −0.148, p = 0.24) or with ABI-lower (r = −0.208, p = 0.095). Measurement of ABI using the lower of the two ankle pressures is an efficient method to identify patients with clinical or subclinical atherosclerosis and worth performing on subjects with pulse pressure above 65 mm Hg. The usefulness of PAT measurement in detecting PAD is vague.
Ankle-brachial index; peripheral arterial disease; hypertension
Ankle-brachial-Index (ABI) measured by manual Dopplersonography is an easily assessable marker of global cardiovascular risk. The aim of this study was to establish novel photo-plethysmography (PPG)-based ABI assessments in an epidemiologic context and to compare its results with those of Doppler.
Two devices for PPG-based ABI assessments (Vicorder, Vascular Explorer) were tested and compared against Doppler in 56 putatively healthy subjects. We determined acceptance, time requirements, agreement of repeat measurements, agreement with Doppler and intra- and inter-observer concordances for both devices and compared the results. Differences between cuff inflation- and deflation-based methods were also studied for Vascular Explorer.
Acceptance was similar for both devices but Vascular Explorer was more time consuming. Agreement of multiple measurements was moderate for both methods highlighting the importance of measurement replicates. Both automated devices showed significantly higher ABI compared to Doppler which can be traced back to higher brachial pressures (Vicorder) or higher ankle pressures (Vascular Explorer). This effect is more pronounced for Vascular Explorer but can be ameliorated using the deflation method of measurement. Intra-observer concordances were similar. Inter-observer concordance was non-significantly better for Vicorder.
Both devices proved to be feasible in epidemiologic studies, but compared to Doppler, do not constitute an advantage regarding time requirement and accuracy of ABI assessment. Since PPG-based ABI values are inflated compared to Doppler, it will be necessary to adjust Doppler-based cut-offs for risk stratification.
Ankle-brachial index; Feasibility; Vascular explorer; Vicorder
If a validated questionnaire, when applied to patients reporting with symptoms of intermittent claudication, could adequately discriminate between those with and without peripheral arterial disease, GPs could avoid the diagnostic measurement of the ankle brachial index.
To investigate the Edinburgh Claudication Questionnaire (ECQ) in general practice and to develop a clinical decision rule based on risk factors to enable GPs to easily assess the likelihood of peripheral arterial disease.
Design of study
An observational study.
General practice in The Netherlands.
This observational study included patients of ≥55 years visiting their GP for symptoms suggestive of intermittent claudication or with one risk factor. The ECQ and the ankle brachial index were performed. The prevalence of peripheral arterial disease, defined as an ankle brachial index <0.9, was related to risk factors using logistic regression analyses, on which a clinical decision rule was developed and related to the presence of peripheral arterial disease.
Of the 4790 included patients visiting their GP with symptoms suggestive of intermittent claudication, 4527 were eligible for analyses. The prevalence of peripheral arterial disease in this group was 48.3%. The sensitivity of the ECQ was only 56.2%. The prevalence of peripheral arterial disease in a clinical decision rule that included age, male sex, smoking, hypertension, hypercholesterolemia, and a positive ECQ, increased from 14% in the lowest to 76% in the highest category.
This study indicates that the ECQ alone has an inadequate diagnostic value in detecting patients with peripheral arterial disease. The ankle brachial index should be performed to diagnose peripheral arterial disease in patients with complaints suggestive of intermittent claudication, although our clinical decision rule could help to differentiate between extremely high and lower prevalence of peripheral arterial disease.
ankle brachial index; atheroscelerosis; clinical decision rule; Edinburgh Claudication Questionnaire; intermittent claudication; peripheral vascular disease
The current study aims to determine the relation between ankle–brachial index (ABI) and angiographic findings and major cardiovascular risk factors in patients with suspected coronary artery diseases (CAD) in Isfahan.
In this cross-sectional descriptive-analytic research, patients with suspected CAD were studied. Characteristics of studied subjects including demographics, familial history, past medical history and atherosclerotic risk factors such as diabetes mellitus, hypertension, hyperlipidemia and smoking were obtained using a standard questionnaire. ABI was measured in all studied patients. ABI≤0.9 (ABI+) was considered as peripheral vessel disease and ABI>0.9 (ABI-) was considered as normal. Then, all studied patients underwent coronary artery angiography. The results of the questionnaire and angiographic findings were compared in ABI+ and ABI- groups. Data were analyzed by SPSS 15 using ANOVA, t-test, Spearman's rank correlation coefficient, and discriminant analysis.
In this study, 125 patients were investigated. ABI≤0.9 was seen in 25 patients (20%). The prevalence of ABI+ among men and women was 25.9% and 7.5%, respectively (P=0.01). The prevalence of atherosclerotic risk factors was significantly higher in ABI+ patients than in ABI- ones (P<0.05). ABI+ patients had more significant stenosis than ABI- ones. The mean of occlusion was significantly higher in ABI+ patients with left main artery (LMA), right coronary artery (RCA), left anterior descending artery (LAD), diagonal artery 1 (D1) and left circumflex artery (LCX) involvements (P<0.05).
The findings of this research indicated that ABI could be a useful method in assessing both the atherosclerotic risk factors and the degree of coronary involvements in suspected patients. However, in order to make more accurate decisions for using this method in diagnosing and preventing CAD, we should plan further studies in large sample sizes of general population.
Ankle–Brachial Index; Angiography; Atherosclerotic Risk Factors.
Objective: The objective of this study was to use non-invasive
laser Doppler flowmeter to measure changes in blood flow in peripheral vessels
in the legs before and after stress induced by leg elevation stress test and
investigate correlations with the ankle-brachial pressure index (ABI).
Methods: Subjects included 28 patients over 20 years of age
(mean, 73 years) who reported chiefly of leg symptoms such as intermittent
claudication, numbness, chills, or cramps had been examined at the study
institution, and agreed to participate in the study. The ABI of both legs was
measured, and patients were divided into two groups: low ABI (ABI
≤0.9) and normal ABI (ABI ≥0.9). Blood flow in the big
toe was measured using a box-type laser Doppler flowmeter before, during, and
after leg-elevation stress. Amplitude of the recorded waveform and changes in
blood flow were compared.
Results: Average ABI was 1.09 ± 0.10 in the normal
ABI group (33 legs) and 0.68 ± 0.17 in the low ABI group (21 legs).
Amplitude before and during stress was significantly smaller in the low ABI
group than in the normal ABI group (p<0.01),
and there was a significant correlation with ABI before and during stresses
(r= 0.4606, r=
0.5048, respectively; p<0.05). Change in blood
flow during stress was significantly lower in the low ABI group than in the
normal ABI group (p<0.05). There was a
significant correlation between change in blood flow during stress and ABI in
both groups (r= 0.5073;
p<0.05). There was also a significant
correlation between change in blood flow and change in amplitude in both groups
Conclusion: Results of this study show, that comparing amplitude
and change in blood flow before and after leg extension and elevation stress,
there was a correlation between change in blood flow and amplitude, and ABI
during stress. A box-type laser Doppler flowmeter may provide a means of
screening for peripheral arterial disease.
peripheral arterial disease; ankle-brachial pressure index; laser Doppler flowmeter; intermittent claudication; lumbar spinal stenosis
Background: The ankle-brachial pressure index (ABI) is widely used as a standard screening method for arterial occlusive lesion above the knee. However, the sensitivity of ABI is low in hemodialysis (HD) patients. Exercise stress (Ex-ABI) may reduce the false negative results.
Patients and Methods: After measuring resting ABI and toe-brachial pressure index (TBI), ankle pressure and ABI immediately after walking (Post-AP, Post-ABI) were measured using one-minute treadmill walking in 52 lower limbs of 26 HD patients. The definition of peripheral arterial occlusive disease (PAD) required an ABI value of less than 0.90, TBI value of less than 0.60, and decrease of more than 15% of the Post-ABI value and 20 mmHg of Post-AP in Ex-ABI. Computed tomographic angiography (CTA) was performed in 32 lower limbs of 16 HD patients. PAD is defined as presence of stenosis of more than 75% in the case of lesions from an iliac artery to knee on CTA.
Results: The accuracy of Ex-ABI (Sensitivity, 85.7%; Specificity, 77.7%) was higher than those of ABI (Sensitivity, 42.9%; Specificity, 83.3%) or TBI (Sensitivity, 78.6%; Specificity, 61.1%).
Conclusion: Ex-ABI with one-minute treadmill walking is the most useful tool for the screening of arterial occlusive lesions above the knee in maintenance HD patients.
peripheral arterial disease; exercise; diagnosis; screening; hemodialysis
According to population-based cohort studies CT coronary calcium score (CTCS), carotid intima-media thickness (cIMT), high-sensitivity C- reactive protein (CRP), and ankle-brachial index (ABI) are promising novel risk markers for improving cardiovascular risk assessment. Their impact in the U.S. general population is however uncertain. Our aim was to estimate the predictive value of four novel cardiovascular risk markers for the U.S. general population.
Methods and Findings
Risk profiles, CRP and ABI data of 3,736 asymptomatic subjects aged 40 or older from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 exam were used along with predicted CTCS and cIMT values. For each subject, we calculated 10-year cardiovascular risks with and without each risk marker. Event rates adjusted for competing risks were obtained by microsimulation. We assessed the impact of updated 10-year risk scores by reclassification and C-statistics. In the study population (mean age 56±11 years, 48% male), 70% (80%) were at low (<10%), 19% (14%) at intermediate (≥10–<20%), and 11% (6%) at high (≥20%) 10-year CVD (CHD) risk. Net reclassification improvement was highest after updating 10-year CVD risk with CTCS: 0.10 (95%CI 0.02–0.19). The C-statistic for 10-year CVD risk increased from 0.82 by 0.02 (95%CI 0.01–0.03) with CTCS. Reclassification occurred most often in those at intermediate risk: with CTCS, 36% (38%) moved to low and 22% (30%) to high CVD (CHD) risk. Improvements with other novel risk markers were limited.
Only CTCS appeared to have significant incremental predictive value in the U.S. general population, especially in those at intermediate risk. In future research, cost-effectiveness analyses should be considered for evaluating novel cardiovascular risk assessment strategies.
The diagnosis of peripheral arterial disease (PAD) can be made by measuring the ankle–brachial index (ABI). Traditionally ABI values > 1.00–1.40 have been considered normal and ABI ≤ 0.90 defines PAD. Recent studies, however, have shown that individuals with ABI values between 0.90–1.00 are also at risk of cardiovascular events. We studied this cardiovascular risk population subgroup in order to determine their endothelial function using peripheral arterial tonometry (PAT).
We selected 66 individuals with cardiovascular risk and borderline ABI. They all had hypertension, newly diagnosed glucose disorder, metabolic syndrome, obesity, or a ten year risk of cardiovascular disease death of 5% or more according to the Systematic Coronary Risk Evaluation System (SCORE). Subjects with previously diagnosed diabetes or cardiovascular disease were excluded. Endothelial function was assessed by measuring the reactive hyperemia index (RHI) from fingertips using an Endo-PAT device.
The mean ABI was 0.95 and mean RHI 2.11. Endothelial dysfunction, defined as RHI < 1.67, was detected in 15/66 (23%) of the subjects. There were no statistically significant differences in RHI values between subjects with different cardiovascular risk factors. The only exception was that subjects with impaired fasting glucose (IFG) had slightly lower RHI values (mean RHI 1.91) than subjects without IFG (mean RHI 2.24) (P = 0.02).
In a cardiovascular risk population with borderline ABI nearly every fourth subject had endothelial dysfunction, indicating an elevated risk of cardiovascular events. This might point out a subgroup of individuals in need of more aggressive treatment for their risk factors.
peripheral arterial disease; ankle–brachial index; cardiovascular risk; endothelial dysfunction
Peripheral Arterial Disease (PAD) remains the least recognized form of atherosclerosis. The Ankle-Brachial Index (ABI) has emerged as one of the potent markers of diffuse atherosclerosis, cardiovascular (CV) risk, and overall survival in general public, especially in diabetics. The important reason for the lack of early diagnosis is the non-availability of a test that is easy to perform and less expensive, with no training required.
To evaluate the osillometric method of performing ABI with regard to its usefulness in detecting PAD cases and to correlate the signs and symptoms with ABI.
Materials and Methods:
Two hundred diabetics of varying duration attending the clinic for a period of eight months, from August 2006 to April 2007, were evaluated for signs, symptoms, and risk factors. ABI was performed using the oscillometric method. The positives were confirmed by Doppler evaluation. An equal number of age- and sex-matched controls, which were ABI negative, were also assessed by Doppler. Sensitivity and Specificity were determined.
There were 120 males and 80 females. Twelve males (10%) and six females (7.5%) were ABI positive. On Doppler, eleven males (91.5%) and three females (50%) were true positives. There were six false negatives from the controls (three each). The Sensitivity was 70% and Specificity was 75%. Symptoms and signs correlated well with ABI positives. Hypertension was the most important risk factor.
In spite of the limitations, the oscillometric method of performing ABI is a simple procedure, easy to perform, does not require training and can be performed as an outpatient procedure not only by doctors, but also by the paramedical staff to detect more PAD cases.
Ankle-Brachial Index; oscillometric method; PAD; risk factors; sensitivity; specificity
The ankle brachial index (ABI) is a valid and reliable measurement of lower extremity circulation and can be used as a screening tool for peripheral arterial disease (PAD), but the usage pattern in physical therapy practice is virtually unknown.
This study was performed to describe the phenomenon of using the ABI in outpatient physical therapy practice.
Nine participants from 3 different outpatient physical therapy clinics were provided with a hand held Doppler and education on how to accurately perform an ABI. Over a 3-month period, participants performed the ABI on any patient presenting with age > 50 with at least two risk factors for PAD. Immediately following the 3-month data collection period, two focus group interviews were performed to examine the therapist's experience using the ABI. Transcripts were analyzed to identify facilitators and barriers to implementation.
Facilitators identified include familiarity, ease of use, accuracy, and confidence with results. Barriers included flow and routine disruption, patient did not want/refused, and issues related to direct access.
Although some barriers to use of the ABI in an outpatient clinical setting need to be considered, most participants found the experience of using the ABI positive and feasible.
ankle brachial index; peripheral arterial disease; physical therapy
Myeloperoxidase (MPO) is an enzymatic mediator of several inflammatory cascades and higher serum levels have been associated with increased risk of adverse cardiovascular events. We investigated the association of serum MPO with the ankle-brachial index (ABI) and peripheral arterial disease (PAD), in a bi-ethnic cohort of African-Americans and non-Hispanic whites. Participants included 1324 African-Americans (64 y, 71% women) and 1237 non- Hispanic whites (59 y, 57% women) belonging to hypertensive sibships. Plasma levels of MPO were measured by solid phase sandwich immunoassay. ABI was measured using a standard protocol and PAD defined as ABI <0.90. Multivariable regression analysis using generalized estimating equations (GEE) were performed to assess whether serum MPO levels were associated with ABI and the presence of PAD. After adjustment for age and sex, higher MPO levels were significantly associated with lower ABI and presence of PAD in African-Americans (P=0.004 and P=0.005, respectively) and in non-Hispanic whites (P=0.001and P=0.021, respectively). After additional adjustment for conventional risk factors (diabetes, smoking status, total and HDL cholesterol, waist circumference, hypertension), prior history of myocardial infarction or stroke, and medication use (statins, aspirin, estrogen), higher MPO levels remained significantly associated with lower ABI and presence of PAD in both African- Americans (P=0.008 and P=0.012, respectively) and non-Hispanic whites (P=0.001and P=0.029, respectively). We conclude that higher MPO levels are associated with lower ABI and the presence of PAD in African-Americans and non-Hispanic whites.
peripheral arterial disease; inflammation; ankle-brachial index; myeloperoxidase
Peripheral arterial disease (PAD) of the lower limbs is a cardiovascular disease highly prevalent particularly in the asymptomatic form. Its prevalence starts to be a concern in low coronary risk countries like Spain. Few studies have analyzed the relationship between ankle-brachial index (ABI) and cardiovascular morbi-mortality in low cardiovascular risk countries like Spain where we observe significant low incidence of ischemic heart diseases together with high prevalence of cardiovascular risk factors. The objective of this study is to determine the relationship between pathological ABI and incidence of cardiovascular events (coronary disease, cerebrovascular disease, symptomatic aneurism of abdominal aorta, vascular surgery) and death in the >49 year population-based cohort in Spain (ARTPER).
Baseline ABI was measured in 3,786 randomly selected patients from 28 Primary Health Centers in Barcelona, distributed as: ABI<0.9 peripheral arterial disease (PAD), ABI ≥1.4 arterial calcification (AC), ABI 0.9-1.4 healthy; and followed during 4 years.
3,307 subjects were included after excluding those with previous vascular events. Subjects with abnormal ABI were older with higher proportion of men, smokers and diabetics. 260 people presented cardiovascular events (incidence 2,117/100,000 person-years) and 124 died from any cause (incidence 978/100,000 person-years). PAD had two-fold greater risk of coronary disease (adjusted hazard ratio (HR) = 2.0, 95% confidence interval (CI) 1.3-3.2) and increased risk of vascular surgery (HR = 5.6, 95%CI 2.8-11.5) and mortality (HR = 1.8, 95%CI 1.4-2.5). AC increased twice risk of cerebrovascular events (HR = 1.9, 95%CI 1.0-3.5) with no relationship with ischemic heart disease.
PAD increases coronary disease risk and AC cerebrovascular disease risk in low cardiovascular risk Mediterranean population. ABI could be a useful tool to detect patients at risk in Primary Health Care.
Peripheral arterial disease; Ankle-brachial index; Cardiovascular diseases; Incidence; Primary health care; Cohort studies
Peripheral arterial disease is a coronary risk equivalent; a low ankle-brachial index (ABI) is indicative of systemic vascular disease, and should place a patient in the high-risk category. Few physicians measure ABI because it is technically challenging and time consuming. Oscillometric blood pressure monitors are readily available and easy to use. The use of a simple method of documenting ABI was assessed and compared with the conventional method.
The oscillometric ABI (OABI) was measured for normal volunteers, patients attending a cardiovascular risk clinic (Cardiovascular Risk Factor Reduction Unit [CRFRU] at the University of Saskatchewan, Saskatoon) and patients referred to a vascular laboratory (vasc lab). The latter group had Doppler ABI (DABI) measurements and served to validate OABI. An Omron HEM 711C oscillometric system (Omron Canada Inc) with appropriate cuff size for arm and leg circumference was used.
The mean ± SEM OABI was 1.13±0.08 in normal volunteers (n=26), 1.10±0.10 in CRFRU patients (n=11, P not significant) and 1.03±0.14 in vasc lab patients (n=57, P<0.05 compared with normal volunteers). No difference was found between sexes, and there was no correlation with age. In the vasc lab group, the correlation with DABI was 0.71 (P<0.05). The sensitivity of OABI to detect DABI of less than 0.9 was 0.71, and the specificity was 0.89. OABI was found to be less sensitive at detecting low values in patients with nonpalpable pulses on physical examination.
The OABI is feasible and operator-independent, but does not detect low ABI efficiently. If OABI is abnormal, low DABI is likely. The OABI is less likely to detect disease in patients with nonpalpable peripheral pulses. Such patients are better referred directly to a vascular laboratory for DABI testing.
Ankle-brachial index; Atherosclerosis; Diagnosis; Peripheral vascular disease; Risk factors
The reference standard for diagnosing peripheral arterial disease in primary care is the ankle brachial index (ABI). Various methods to measure ankle and brachial blood pressures and to calculate the index are described.
To compare the ABI measurements performed in primary care with those performed in the vascular laboratory. Furthermore, an inventory was made of methods used to determine the ABI in primary care.
Design of study
Primary care practice and outpatient clinic.
Consecutive patients suspected of peripheral arterial disease based on ABI assessment in primary care practices were included. The ABI measurements were repeated in the vascular laboratory. Referring GPs were interviewed about method of measurement and calculation of the index. From each patient the leg with the lower ABI was used for analysis.
Ninety-nine patients of 45 primary care practices with a mean ABI of 0.80 (standard deviation [SD] = 0.27) were included. The mean ABI as measured in the vascular laboratory was 0.82 (SD = 0.26). A Bland–Altman plot demonstrated great variability between ABI measurements in primary care practice and the vascular laboratory. Both method of blood pressure measurements and method of calculating the ABI differed greatly between primary care practices.
This study demonstrates that the ABI is often not correctly determined in primary care practice. This phenomenon seems to be due to inaccurate methods for both blood pressure measurements and calculation of the index. A guideline for determining the ABI with a hand-held Doppler, and a training programme seem necessary.
diagnosis; Doppler effect; intermittent claudication; peripheral vascular diseases; ultrasonography
An abnormally high ankle brachial index (ABI) is associated with increased all-cause and cardiovascular mortality. The relationship of obesity to incident high-ABI has not been characterized. We investigated the hypothesis that increased obesity—quantified by body weight, BMI, waist circumference, and waist-to-hip-ratio—is positively associated with a high-ABI (ABI ≥ 1.3) and with mean ABI increases over a four year follow-up. Prevalence and incidence ratios for a high-ABI were obtained for 6540 and 5045 participants respectively in the Multi-Ethnic Study of Atherosclerosis (MESA), using log-binomial regression models adjusted for demographic, cardiovascular, and inflammatory/novel risk factors. Linear regression was used to analyze mean ABI change. Both prevalence and incidence of a high-ABI were significantly higher for the highest versus the lowest quartile of every baseline measure of obesity, with weight and BMI demonstrating the highest incidence ratios (2.7 and 2.4, respectively). All prevalence and incidence ratios were positive and graded across obesity quartiles, and were persistent in the subpopulation without diabetes. Among those with normal baseline ABI values, one MESA-standard deviation increase in every baseline measure of obesity was associated with significant increases in mean ABI values. In conclusion, we observed an independent, positive and graded association of increasing obesity to both prevalent and incident high-ABI, and to mean increases in ABI values over time. Weight and BMI seemed to be at least as strongly, if not more strongly, associated with a high-ABI than were measures of abdominal obesity.
obesity; anthropometric measures; peripheral vascular disease; ankle-brachial index; epidemiology
Prognosis for patients with the human immunodeficiency virus (HIV) has improved with the introduction of highly active antiretroviral therapy (HAART). Evidence over recent years suggests that the incidence of cardiovascular disease is increasing in HIV patients. The ankle-brachial index (ABI) is a cheap and easy test that has been validated in the general population. Abnormal ABI values are associated with increased cardiovascular mortality. To date, six series of ABI values in persons with HIV have been published, but none was a prospective study. No agreement exists concerning the risk factors for an abnormal ABI, though its prevalence is clearly higher in these patients than in the general population. Whether this higher prevalence of an abnormal ABI is associated with a higher incidence of vascular events remains to be determined.
The deleterious nature of peripheral arterial disease (PAD) is compounded by a status of underdiagnosed and undertreated disease. We evaluated the prevalence and predictive factors of PAD in high-risk patients using the ankle-brachial index (ABI).
The ABI was measured by general practitioners in France (May 2005–February 2006) in 5679 adults aged 55 years or older and considered at high risk. The primary outcome was prevalence of PAD (ABI strictly below 0.90).
In all, 21.3% patients had signs or symptoms suggestive of PAD, 42.1% had previous history of atherothrombotic disease and 36.6% had two or more cardiovascular risk factors. Prevalence of PAD was 27.8% overall, ranging from 10.4% in patients with cardiovascular risk factors only to approximately 38% in each other subgroup. Prevalence differed depending on the localization of atherothrombotic events: it was 57.1–75.0% in patients with past history of symptomatic PAD; 24.6–31.1% in those who had experienced cerebrovascular and/or coronary events. Regarding the classical cardiovascular risk factors, PAD was more frequent when smoking and hypercholesterolemia history were reported. PAD prevalence was also higher in patients with history of abdominal aortic aneurysm, renal hypertension or atherothrombotic event. Intermittent claudication, lack of one pulse in the lower limbs, smoking, diabetes and renovascular hypertension were the main factors predictive of low ABI.
Given the elevated prevalence of PAD in high-risk patients and easiness of diagnosis using ABI in primary care, undoubtedly better awareness would help preserve individual cardiovascular health and achieve public health goals.
Background: Despite increased cardiovascular morbidity and mortality in rheumatoid arthritis, the peripheral arteries remain understudied.
Objective: To examine the lower limb arteries in age and sex matched, non-smoking subjects with and without rheumatoid arthritis.
Methods: The ankle-brachial index (ABI) was measured at the posterior tibial and dorsal pedal arteries. Arteries were classified as obstructed with ABI ⩽0.9, normal with ABI >0.9 but ⩽1.3, and incompressible with ABI >1.3. Multinomial logistic regression was used to estimate differences in ABI between patients and controls, adjusting for cardiovascular risk factors, rheumatoid arthritis manifestations, inflammation markers, and glucocorticoid dose.
Results: 234 patients with rheumatoid arthritis and 102 controls were studied. Among the rheumatoid patients, 66 of 931 arteries (7%) were incompressible and 30 (3%) were obstructed. Among the controls, three of 408 arteries (0.7%) were incompressible (p = 0.002) and four (1%) were obstructed (p = 0.06). At the person level, one or more abnormal arteries occurred among 45 rheumatoid patients (19%), v five controls (5%, p = 0.001). The greater frequency of arterial incompressibility and obstruction in rheumatoid arthritis was independent of age, sex, and cardiovascular risk factors. Adjustment for inflammation markers, joint damage, rheumatoid factor, and glucocorticoid use reduced rheumatoid arthritis v control differences. Most arterial impairments occurred in rheumatoid patients with 20 or more deformed joints. This subgroup had more incompressible (15%, p⩽0.001) and obstructed arteries (6%, p = 0.005) than the controls, independent of covariates.
Conclusions: Peripheral arterial incompressibility and obstruction are increased in rheumatoid arthritis. Their propensity for patients with advanced joint damage suggests shared pathogenic mechanisms.
Claudication is a typical symptom of peripheral arterial disease (PAD) and lumbar spinal stenosis (LSS). Differential diagnosis of PAD and LSS is often difficult due to the subjective natures of symptoms and atypical signs. The authors aimed to determine the usefulness of ankle-brachial index (ABI) measurement for the differential diagnosis of PAD and LSS when the etiology of claudication is uncertain.
Forty-two consecutive patients who had been referred by spine surgeons to a lower extremity vascular surgeon for atypical claudication were retrospectively analyzed. Atypical claudication was defined as claudication not caused by PAD, as determined by clinical manifestations, or by LSS, as determined by MR imaging. A final diagnosis of PAD was established by CT angiography (CTA) and of LSS by excluding PAD. Diagnostic validity of ABI for PAD in atypical presentation was assessed.
Sixty-two legs of 42 atypical claudication patients were analyzed. Mean patient age was 65.8 ± 8.2 years (38–85) and 29 (69.0%) had diabetes mellitus. Mean ABI was 0.73 ± 0.14 (0.53–0.94) in the PAD group and 0.92 ± 0.18 (0.52–1.10) in the LSS group (P < 0.001). Of the 33 legs with a low ABI (ABI < 0.9), 29 legs were diagnosed as true positives for PAD by CTA and 4 were false positives, and of the 29 legs with a high ABI, 5 were false negatives and 24 were true negatives. The sensitivity and specificity of ABI for the diagnosis of PAD in patients with atypical claudication were 85.3 and 85.7%, respectively, and its positive and negative predictive values were 87.9 and 82.8%.
ABI is a recommended screening test for the differential diagnosis of lower leg claudication when clinical symptoms are atypical.
Claudication; Peripheral arterial disease; Lumbar spinal stenosis; Ankle-brachial index; Validity