ABI Measurements Research Articles

Longitudinal Patterns of Ankle-Brachial Index and Their Association With Progression of CKD in Patients With Type 2 Diabetes and Elevated Body Mass Index

Rationale & ObjectiveAnkle-brachial index (ABI) is used to screen for vascular complications in the setting of diabetes. This study sought to examine the relationship of longitudinal ABI data and chronic kidney disease (CKD) progression in patients with type 2 diabetes (T2D) and elevated body mass index (BMI). Study DesignA post-hoc analysis of the Look AHEAD trial. Setting & ParticipantsThis study included 3,631 participants in the Look AHEAD trial with a baseline glomerular filtration rate (eGFR) >60 ml/min/1.73 m2. ExposuresAverage ABI and average annual change in ABI were calculated based on annual ABI measurements during the first 4 years of the study. OutcomeCKD progression, defined as kidney failure requiring maintenance dialysis or the occurrence of eGFR<60 ml/min/1.73 m2 with a drop of ≥30% at a follow-up visit relative to the first eGFR measurement. Analytical ApproachRestricted cubic spline and Cox proportional hazards models were fit to estimate associations and to explore non-linearity. ResultsOver a median follow-up of 10.1 years, 1,051 participants developed CKD progression. There was a reversed J-shaped relationship of CKD progression with average ABI (when ABI <1.17: HR (per SD decrement), 1.23; 95%CI, 1.06-1.42; when ABI ≥ 1.17: HR (per SD increment), 1.10; 95%CI, 1.00-1.22) and average annual change in ABI (when change in ABI <-0.007: HR (per SD decrement), 1.37; 95%CI, 1.12-1.66; when change in ABI ≥-0.007: HR (per SD increment), 1.13; 95%CI, 1.03-1.24). LimitationsObservational study, potential unmeasured confounding. ConclusionsLow and high average ABI, even at clinically normal values, as well as decreasing and increasing average annual ABI, were associated a higher risk of CKD progression in patients with T2D and elevated BMI. Monitoring ABI and its changes over time may facilitate CKD risk stratification in patients with T2D.

Deep Learning for Precipitation Retrievals Using ABI and GLM Measurements on the GOES-R Series

Deep Learning for Precipitation Retrievals Using ABI and GLM Measurements on the GOES-R Series

Low Ankle-Brachial Index Is Associated With Stroke Recurrence in Ischemic Stroke Patients With Atrial Fibrillation

Introduction: Cardioembolic stroke (CE) has poor outcomes and high recurrence rates. A low ankle-brachial index (ABI <0.9) is associated with atrial fibrillation (AF) and poor stroke outcomes. We investigated whether a low ABI is associated with stroke recurrence, major adverse cardiovascular events (MACE), and mortality in patients with CE and whether this association is affected by AF.Methods: We enrolled patients with CE who underwent ABI measurements during hospitalization. Recurrent stroke was defined based on newly developed neurologic symptoms with relevant lesions 7 days after the index stroke. MACE comprised stroke recurrence, myocardial infarction, or death.Results: Of 775 patients, 427 (55.1%) were AF patients and 348 (44.9%) were non-AF patients. Patients were followed up for a median of 33.6 (IQR, 18.0–51.6) months. In total, 194 (25.0%) patients experienced MACE, including 77 (9.9%) patients with stroke recurrence and 101 (13.0%) patients with mortality, during the study period. Multivariable Cox regression analysis showed that an ABI <0.9 was independently associated with MACE (AF patients: hazard ratio [HR] = 2.327, 95% confidence interval [CI] = 1.371–3.949, non-AF patients: HR = 3.116, 95% CI = 1.465–6.629) and mortality (AF patients: HR = 2.659, 95% CI = 1.483–4.767, non-AF patients: HR = 3.645, 95% CI = 1.623–8.187). Stroke recurrence was independently associated with an ABI <0.9 in AF patients (HR = 3.559, 95% CI = 1.570–8.066), but not in non-AF patients (HR = 1.186, 95% CI = 0.156–8.989).Conclusions: We found that a low ABI is associated with stroke recurrence, MACE, and mortality in patients with CE. In particular, the association between ABI and recurrent stroke is only present in AF patients. A low ABI may be a useful prognostic marker in patients with CE, especially in AF patients.

Rancang Bangun Alat Ukur Ankle Brachial Indeks Untuk Deteksi Peripheral Artery Disease

—ABI measurements are performed to detect PAD. ABI measurements are essential because, generally, patients are not aware of having PAD due to no significant signs and symptoms. Type 2 Diabetes Mellitus Patients tend to have PAD, which increases the risk of cardiovascular and mortality. Therefore, the measurement of ABI regularly is needed to prevent PAD. Early detection and regular monitoring of PAD by measuring ABI can avoid foot complications, such as injuries, gangrene, and amputation. The standard method to measure ABI is using Doppler. Unfortunately, not all health care providers have Doppler because it is an expensive instrument and relatively difficult to use. The purpose of this study is to design a simple and easy Prototype to measure ABI by using pressure sensors. Two pressure sensors measure the systole of blood pressure in the arm and leg to get the ABI. This study’s sample is 20 people consisting of 10 healthy people and ten diabetes mellitus patients. The result shows the ABI prototype has an error of 0.53% with an accuracy rate of 99.47%. It is indicated that the ABI prototype can be used for diagnosing PAD.

Value of the arterial stiffness index and ankle brachial index in subclinical atherosclerosis screening in healthy community-dwelling individuals

BackgroundCarotid intima media thickness (cIMT) and the carotid plaque score (cPS) are valid markers for detecting subclinical atherosclerosis. Evaluation of ASI and ABI for detection of atherosclerosis is assessed in this study. Finding a model to see which individual has a risk of having atherosclerosis, so those people can be further assessed by invasive but more accurate atherosclerosis detection methods like angiography is another objective of this study.MethodsData of 212 healthy community-dwelling subjects, consisting of carotid duplex records, ASI and ABI measurements, certain laboratory tests, and related cardiovascular disease (CVD) risks were analyzed for correlations.ResultsThe ABI was independently associated with high cPS. Age, hypertension and Waist circumference are determinants of subclinical atherosclerosis as in high cIMT and high cPS.ConclusionsThe use of the ASI cannot replace carotid ultrasound in detecting subclinical atherosclerosis because it is not independently associated with high cIMT and cPS while ABI can be used in detection of high cPS in healthy community-dwelling individuals. Public health policies to encourage weight reduction and treating hypertension can help prevention of subclinical atherosclerosis in healthy community-dwelling individuals. Models consist of age, body compositions like waist circumference and hypertension history can be used in further assessment of atherosclerosis.

Inflammatory Mediators Across the Spectrum of Ankle-Brachial Index.

Aim: Peripheral artery disease (PAD) is a manifestation of atherosclerosis with poor prognosis. It is generally complicated by vascular calcification, which is located either in the intima as patchy infiltrates; or circumferentially in the media, also known as medial arterial calcification (MAC). Obstructive PAD is reflected by low anklebrachial index (ABI ≤ 0.9), whereas MAC is revealed by high ABI (ABI > 1.4). Considering the increase in cardiovascular mortality at both ends of the ABI spectrum, this study aimed to explore the underlying pathology through cytokines with established prognostic significance; namely pentraxin-3(PTX3), high sensitivity C-reactive protein (hsCRP), copeptin, soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), NT-proBNP, and neopterin.Methods: We categorized 180 patients with previous multivessel coronary artery bypass grafting surgery into three groups based on their ABI measurements; 60 patients with ABI ≤ 0.9, 60 patients with ABI within 0.91 and 1.4 (normal ABI), and 60 patients with ABI > 1.4 constituted the “PAD,” “normal,” “MAC” groups, respectively. The circulating levels of the biochemical markers were determined.Results: In the PAD group, the cytokine levels with predominantly proatherogenic actions such as PTX3, hsCRP, copeptin, and sTREM-1 were increased and these cytokine levels declined as the ABI increased. In the MAC group, the cytokine concentrations with pleiotropic actions such as NT-proBNP and neopterin increased and; NT-proBNP and neopterin concentrations decreased as ABI decreased. The linear regression analysis revealed that neopterin (β = 0.72), PTX3 (β = −0.32), and copeptin (β = −0.48) were independent predictors of ABI.Conclusions: These findings suggest that different inflammatory pathways influence the pathology at the opposing ends of the ABI spectrum. Consequently, we suggest that PTX3, copeptin, and neopterin are promising biomarkers for future research.

PP.06.37

Objective: To assess the agreement and reproducibility of the non-invasive measurement of baPWV and ABI with the (VP1000) proving its utility in 36 Mexican healthy individuals.Design and method: A cross-sectional study was carried out in thirty-six healthy subjects (20 men and 16 women) from Guadalajara, México. The measurement of the baPWV and ABI was performed with the device VP1000, all the values are expressed as an average ± SD; the correlation between the first and the second measurements was analyzed using Pearson's correlation coefficient and the Bland Altman method. All p values were two-tailed, and P < 0.05 was accepted as statistically significant. Results: The average age was 20.6 ± 1.6 years, with a BMI of 23.5 ± 3.5 and a waist circumference of 82.5 ± 9.3. The right and left baPWV showed a good correlation between the first and second measurements with statistical significance respectively (r2 Pearson = 0.810, p < 0.001, r2 Pearson = 0.831, p < 0.001). The arterial ABI showed good correlation between the first and the second measurement with statistical significance, (r2 Pearson = 0.730, p < 0.001, r2 Pearson = 0.599, p < 0.001). The Bland–Altman plot of the first and the second baPWV and ABI measurements, demonstrate good agreement (mean difference -4.3 ± 39.43 cm/s), (mean difference-0.0071 ± 0.43) respectively. (figure 1). Conclusions: The results obtained by the OMRON VP1000 device, demonstrate that there is a high and significant correlation as well as good agreement between the left and right baPWV arterial stiffness values, as well as right and left ABI.

What is the Potential for False Positive Results in Ankle Brachial Index Measurements Performed by Emergency Providers?

Introduction: The Ankle-Brachial Index measurement (ABI) is an easily performed bedside test used to screen for lower extremity arterial injury. It is possible that the ABI is not always correctly performed in the acute setting, depending on available equipment and provider familiarity with validated measurement techniques. We sought to determine the potential for false positive ABI results in healthy subjects if the ABI is performed incorrectly. We also sought to identify the method most likely to minimize false positive results. Materials and methods: Healthy volunteers and low acuity emergency department patients were enrolled. Exclusion criteria included a known history of documented peripheral arterial disease or extremity trauma. Subjects were examined by two investigators. “Most Accurate” (MA) ABI measurements used the higher of the two ankle readings and the higher of the two brachial readings to calculate the result. “Least Accurate” (LA) measurements used the lower of the two ankle readings and the higher of the two brachial readings. Results: 118 study subjects were enrolled: mean age 32.8 years (range 19 to 49), 50% female, none with known peripheral vascular disease or extremity trauma, and none with documented femoral artery bruit at the time of the study. When a single provider performed LA ABI’s, the false positive rate was 29%, while single provider MA ABI’s lowered the false positive rate to 2%. For two provider ABI’s, these rates were 4% and 0%, respectively. Conclusions: We identified an unacceptably high rate of false positive ABI results if the test is performed incorrectly. We recommend strict adherence to standardized ABI measurement protocols to minimize this error. Ideally, an ABI measurement of less than 0.9 in a patient with lower extremity trauma should be confirmed by a second provider in order to minimize the risk of inappropriately implementing invasive diagnostic procedures.

Peripheral arterial disease in rheumatoid arthritis patients at the Kenyatta National Hospital, Kenya

Objective: To determine the magnitude of the rosclerotic arterial disease in Rheumatoid Arthritis(RA) patients at Kenyatta National Hospital. Design: hospital based cross-sectional study. Setting: Kenyatta National Hospital Rheumatology outpatient clinic. Subjects: Rheumatoid Arthritis patients. Results: We obtained ABI measurements in 90 RA patients, among them 23(25.5% 95% CI 17.2-36.1) had obstructed lower limb arteries. Among the 23, 21(91.3%) had mild PAD, two (8.7%) had moderate PAD; none had severe PAD nor incompressible vessels. The obstruction of vessels was independent of diabetes, hypertension, dyslipidemia and cigarette smoking though these factors increased the likelihood of having PAD. Risk age( ≥45 males, ≥55 females), Established RA(> 5 year duration) and severe RA were found to be significantly associated with the likelihood of having PAD. These trends remained significant after multivariable adjustment for potential confounders. twenty five (27.7%) of the study subjects exhibited symptoms of intermittent claudication, 13(52%) of them had PAD on ABI measurements, The Edinburgh claudication questionnaire was found to have 56.5% sensitivity and 82% specificity in detection of PAD in RA patients. Conclusion: There seems to be an association between PAD in RA with chronicity and severity of the RA. This association may support the pathogenic role of accumulated systemic inflammation in atherosclerosis. Clinicians should be alert to the possibility of impared arterial function and thus subsequent cardiovascular morbidity and mortality in this group of patients.

Validation of automated oscillometric versus manual measurement of the ankle–brachial index

We validated automated oscillometric measurement of the ankle-to-arm ratio of systolic blood pressure (ankle-brachial blood pressure index, ABI) against the manual approach, which requires trained observers and has an intra-observer variability of approximately 10%. A single observer measured ABI in 105 subjects (age range, 20-80 years; women, 51.9%). The manual approach involved the auscultatory measurement of systolic pressure at the brachial artery and Doppler measurements of systolic pressure at the anterior and posterior tibial arteries. The automated oscillometric VP-2000 (Omron Healthcare, Kyoto, Japan) was used to measure systolic pressure at the arm and ankle simultaneously. We applied Bland and Altman's methods to study reproducibility. Ankle-brachial blood pressure index averaged (+/-s.d.) 1.13+/-0.07 units and 1.12+/-0.10 units on automated and manual measurements, respectively. The absolute and percentage differences (P=0.64) between the two ABI measurements were 0.005 units (95% confidence interval, -0.015 to 0.024) and 0.60 (-0.69 to 1.04), respectively. The intra-observer variability of repeat ABI measurements was smaller on automated than on manual measurement (0.17 versus -0.84%; P=0.04). Automated ABI measurement by an oscillometric technique requires little observer training, and significantly increases the reproducibility of ABI estimates compared with the manual approach.

The correlation between ankle brachial pressure index and cognitive impairment in a population over 65 years

Background: The frequency of cognitive impairment increases with age. It is known that coronary and periphery arterial atherosclerotic physio-pathological process begins 10–15 years before the one in the brain’s arterial territory. Purpose: To evaluate the severity of the cognitive impairment in elderly in relation to the peripheral artery disease’s (PAD) severity. Material and method: 50 patients, older than 65, were included in the study that were admitted in the Neurology Clinic of the Arad County Hospital during 2006 and 2007. To certify the presence/the extent of the PAD, a pulse volume recorder (Doppler) was used to calculate the ABI. The cognitive status was evaluated using the Mini Mental State Evaluation (MMSE). Results: Most of the admitted patients were men (65%). The average age was 67.8 years. After the MMSE and ABI measurements, the results showed:

Multi-channel electrical bioimpedance: a non-invasive method to simultaneously measure cardiac output and individual arterial limb flow in patients with cardiovascular disease

Cardiac output is the fundamental determinant of peripheral blood flow however; optimal regional tissue perfusion is ultimately dependant on the integrity of the arterial conduits that transport flow. A complete understanding of tissue perfusion requires knowledge of both cardiac and peripheral blood flow. Existing noninvasive devices do not simultaneously assess the cardiac and peripheral circulations. Multi-channel electrical bioimpedance (MEB) measures cardiac output and peripheral flow simultaneously. Assessment of the accuracy of MEB to measure cardiac output in patients with clinical heart failure (group 1) and to measure regional arterial limb flow in patients with exertional leg pain clinically thought to have peripheral arterial disease (group 2). Cardiac output was measured by MEB in 44 patients with moderate to severe clinical heart failure (group 1) and was compared to a cardiac output measured by 2D-Echo Doppler. Peripheral blood flow (regional ankle and arm flow) was measured by MEB in another group of 25 patients with exertional leg pain clinically thought to be claudication (group 2). The MEB ankle/arm flow ratio (AAI index) was then compared to a conventional ankle/brachial pressure ratio (ABI index). There was excellent correlation between the mean cardiac index by MEB (2.01 l/min/m(2)) and by 2D-Echo Doppler (2.06 l/min/m(2)) and bias and precision was 0.05 (2.4%) and +/-0.48 l/min/m(2) (+/-23%), respectively. The correlation was maintained for each measurement over a wide range of cardiac indices. There was good correlation between AAI and ABI measurements (P < 0.05). MEB accurately measures cardiac output in patients with moderate to severe clinical heart failure and accurately measures regional arterial limb flow in patients with peripheral arterial disease.

Abstract No. 227: Directional Atherectomy for In-Stent Restenosis of the Femoropopliteal Artery: Results of a Pilot Study

Initial results of a prospective non- randomized single center study to evaluate safety and effectiveness of directional atherectomy as a primary treatment modality for femoro-popliteal instent restenosis. 12 patients (70,8 ± 9,8 years) with restenosis following stent placement into the femoropopliteal artery were treated primarily with excisional atherectomy using the Silver Hawk™ device. Distal filter protection was not used. Primary objective is anatomical treatment success with residual stenosis < 30% or hemodynamically relevant dissection in the absence of complications. Secondary objective is target vessel patency at 6 and 12 months. Follow-up consists of clinical evaluation, ABI measurements and color coded duplex sonography. Angiography in performed in case of suspected restenosis. Most patients (11/12, 92%) were claudicants. Stents had been implanted for a mean period of 8,5 (± 8,2) months before the secondary procedure. Maximum grade of restenosis was 92,2% (±7,7), mean lesion length was 11,6 cm (±8,2). Length of stented vessel segments was 14,8 cm (±5,0) with one case of stent fracture. On intention-to-treat basis anatomical treatment success of excisional atherectomy alone was 67% (8/12). In half of the cases additional balloon angioplasty was performed for residual stenosis or proximal and distal de-novo lesions. Additional stents were implanted in 2/12 cases (16,7%). Overall treatment success of the revascularization procedure was 100%. Doppler index improved from 0,44 (±0,3) to 0,76 (±0,3). There was one case of distal embolization, managed by aspiration thrombectomy (1/12; 8,3%). One patient experienced reocclusion of the treated vessel before 30 days. Patency rates at 6 months are pending and will be presented. Directional atherectomy as a primary treatment modality for instent restenosis of the femoropopliteal artery is safe with promising initial success and low complication rates. If the theoretical advantage of removing neointimal tissue without repeated barotrauma also translates into a clinical benefit has to be proven by long-term follow-up.

Multi-Channel Electrical Bioimpedance: A New Noninvasive Method To Simultaneously Measure Cardiac And Peripheral Blood Flow

We sought to assess the ability of a new multi-channel electrical bioimpedance (MEB) methodology to accurately measure both cardiac blood flow and peripheral limb blood flow. Cardiac output is the primary determinant of peripheral blood flow; however, optimal regional tissue perfusion is ultimately dependent on the patency of the arterial conduits that transport that flow. A complete understanding of regional tissue perfusion requires knowledge of both cardiac and peripheral blood flow. Existing noninvasive devices do not simultaneously assess the cardiac and peripheral circulations. Cardiac blood flow (cardiac output) was measured by MEB in 30 healthy volunteers and was compared to a 2D-Echo Doppler cardiac output. Peripheral blood flow (regional ankle and arm flow) was measured by MEB in 15 healthy volunteers. The MEB ankle/arm flow ratio (AAI index) was then compared to a conventional ankle/brachial pressure ratio (ABI index). There was good correlation between the mean cardiac index by MEB (3.08 l/min/m2) and by Echo Doppler (3.13 l/min/m2) and bias and precision was 0.051 (1.6%) and +/-0.52 l/min/m2 (+/-17%), respectively. The close correlation was maintained for each measurement over a wide range of cardiac indices. There was good correlation between AAI and ABI measurements (p < 0.05) with a sensitivity of 100% and specificity of 100%. MEB methodology can precisely measure cardiac output and peripheral limb flow in healthy volunteers.

Intensive Treatment of Diabetes Is Associated With a Reduced Rate of Peripheral Arterial Calcification in The Diabetes Control and Complications Trial

Peripheral arterial disease (PAD) is a significant contributor to the morbidity and mortality of >2 million Americans (1). In addition to its own specific disease risks, PAD has been shown to be a predictor of cardiovascular mortality and coronary artery disease, as well as a general marker for the atherosclerotic disease process (2,3). PAD complications, especially in the lower limb, are significantly greater in individuals with diabetes compared with those without diabetes, and the risk imparted by diabetes is similar or greater in magnitude to that seen for ischemic heart disease and stroke (4,5). The aortofemoral arteries are prime sites for PAD; hence, determination of claudication and measurement of blood flow in the lower extremities are the most common assessments (6). A relatively low ankle systolic blood pressure (ankle-to-brachial ratio index [ABI]) has been found to be an indicator of atherosclerosis/occlusion in this region (5). Conversely, in diabetes, a high-pressure ABI due to medial wall arterial calcification and noncompressible vessels may also be associated with adverse outcomes, including diabetic kidney disease (7). Sex differences have been reported in ABI measurements in type 1 diabetes, with women having a greater frequency of low ABI and men having a higher frequency of high ABI (7). Here, we extend these analyses by examining the effect of previous intensive diabetes management on the development of abnormally high and low ABIs in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) cohort with the hypothesis that …