Ankle-brachial Index Measurement Research Articles

Pressions intramusculaires : pour qui et comment ?

The diagnosis of chronic exertional compartment syndrome is usually carried out by the increasement of intramuscular pressures, more often in the lower limb after an exercise. This technique, initially described by Whitesides, has been significantly improved in recent years, and is currently carried out using a digital display pressure monitor. Measurements are performed within the pain compartment, at rest, and after physical exercise to reproduce the maximum pain felt by the patient. The most used threshold values are those using the Pedowitz criteria. However, these measurements have to be associated with other complementary examinations (MRI, dynamic Doppler, Ankle Brachial Index measurement..) in order to eliminate a differential diagnosis (most often popliteal artery entrapment syndrome). In addition, measures can sometimes be false negative, and must therefore be confronted with medical history and a thorough and rigorous clinical examination.

Quantitative evaluation of postintervention foot blood supply in patients with peripheral artery disease by computed tomography perfusion

ObjectiveThe aim of this study was to quantitatively evaluate the changes of the foot's blood supply after endovascular treatment in patients with peripheral artery disease (PAD) using foot computed tomography (CT) perfusion. MethodsNineteen patients who underwent endovascular treatment for PAD between January 2018 and November 2018 were included in the study. Perfusion CT scanning was performed before and after intervention with the measurement of ankle-brachial index. Regions of interest were selected from two arteries and four different tissues per foot. Perfusion maps of blood volume, blood flow, permeability surface area product, time to peak (TTP), mean transit time (MTT), mean slope of increase (MSI), Tmax, and impulse response function (IRFt0) were constructed and calculated by the perfusion analysis software. Wilcoxon signed rank test was performed on the eight parameter pairs of the limbs on the treated and untreated sides before and after intervention in the 19 patients. ResultsDifferences in blood flow, MTT, TTP, Tmax, MSI, and IRFt0 on the treated side of the tissue perfusion group and statistical difference in blood flow, MTT, and MSI on the treated side of the arterial perfusion group were observed (all P < .05). Ankle-brachial index improved from 0.41 ± 0.11 to 0.76 ± 0.10 (P < .001). For the untreated side, TTP of the tissue perfusion group was significantly shortened (by 7.71 seconds) after surgery (P = .006), whereas there were no differences in the other parameters. In addition, no significant differences in parameters were observed on the untreated side of the arterial perfusion group. The average radiation dose per phase of perfusion scan was 0.00097 mSv. Moreover, the hyperperfusion zone in the plantar dermis and periosteum reappeared after revascularization. ConclusionsPerfusion CT is a feasible and repeatable approach for quantifying blood supply in patients with PAD. The increase of blood flow, MSI, and MTT shortening suggest blood supply improvement after revascularization in both arterial perfusion and tissue perfusion. In addition, TTP may be a sensitive indicator of blood supply changes in tissue perfusion.

Evaluation of a comprehensive diabetic foot ulcer care quality model

AimsDiabetes-related amputations are typically preceded by a diabetic foot ulcer (DFU) but models to assess the quality of care are lacking. We investigated a model to measure inpatient and outpatient quality. MethodsCohort study among adults hospitalized with a DFU to a safety-net hospital during 2016. We measured adherence to DFU-related quality metrics based on guidelines during and 12 months following hospitalization. Inpatient metrics included ankle-brachial index measurement during or 6 months prior to hospitalization, receiving diabetes education and a wound offloading device prior to discharge. Outpatient metrics included wound care ≤30 days of discharge, in addition to hemoglobin A1c (HbA1c) ≤8%, tobacco cessation, and retention in care (≥2 clinic visits ≥90 days apart) 12 months following discharge. Results323 patients were included. Regarding inpatient metrics, 8% had an ankle brachial index measurement, 37% received diabetes education, and 20% received offloading prior to discharge. Regarding outpatient metrics, 33% received wound care ≤30 days of discharge. Twelve months following discharge, 34% achieved a HbA1c ≤8%, 13% quit tobacco, and 52% were retained in care. Twelve-month amputation-free survival was 71%. ConclusionsOur model demonstrated large gaps in DFU guideline-adherent care. Implementing measures to close these gaps could prevent amputations.

Peripheral Artery Disease in Type 2 Diabetes Mellitus: Survival Analysis of an Ecuadorian Population in Primary Care.

BackgroundPeripheral artery disease (PAD) is associated with cardiovascular risk in type 2 diabetes mellitus (DM). The ankle-brachial index (ABI) is used for diagnosis of PAD.ObjectivesEstablish the prevalence and incidence rate for PAD and determine the associated factors and survival time for the development of PAD.MethodsRetrospective cross-sectional cohort study (follow up: 10 years) in 578 DM patients with at least 1 ABI measurement in a primary level of care diabetes clinic. Data was collected from clinical records. Sociodemographic and laboratory variables were analyzed determining its association (mean difference and bivariate logistic regression). Survival was calculated through life tables and Kaplan-Meier analysis.ResultsThe prevalence of PAD was 13.98%. The incidence rate through the time of follow up was 23.38 per 1000 person-year (95% CI: 19.91-27.26). The group that developed PAD showed higher glycated hemoglobin levels (P = .025), more years of DM (P < .001) and lower glomerular filtration rate (GFR, P = .003). The median time for developing PAD was 26.97 years (95% CI: 26.89-27.05). The risk for PAD was higher in females (95% CI: 1.51-4.38), GFR <60 mL/min/m2 (95% CI: 1.05-2.22) and use of metformin plus insulin (95% CI: 1.10-2.35).ConclusionHalf of a DM patient’s population in primary level of care will develop PAD in the third decade of disease. There are identifiable risk factors for PAD development in DM in the primary level of care such as low GFR, female sex, and use of metformin plus insulin.

2D perfusion-angiography during endovascular intervention for critical limb threatening ischemia - A feasibility study.

PurposeTwo-dimensional perfusion angiography is a new method to quantify and evaluate tissue perfusion during endovascular intervention. The aim was to evaluate time-patterns and dynamics of contrast arrival and distribution before and after endovascular intervention in patients with critical limb threatening ischemia.MethodsData were collected from 37 patients with critical limb threatening ischemia due to infra-inguinal occlusive disease having a successful endovascular procedure. two-dimensional perfusion angiography was used as a post-processing software with analysis of numeric parameters related to arrival and distribution patterns of contrast.ResultsThirty-three patients were successfully analysed whereas four patients were excluded due to motion artefacts. All patients were successfully treated with recanalization of the superficial femoral, popliteal, below the knee-vessels or a combination. Short-term improvement at 30-day follow-up was noted both clinically and by ankle-brachial index and toe pressure measurements. A significant reduction in contrast arrival time between pre-and post-angioplasty runs was noted as measured by arrival time median 3.2 and interquartile range (2.5–4.2) vs. 2.6 (1.6–3.4) and time-to-peak 4.1 (3.6–5.0) vs. 3.1 (2.3–3.9) p = 0.009. An increased wash-in rate was also observed 18.3 (12.6–21) vs. 30.1 (22–30.5) p = 0.001 between pre-and post-angioplasty runs.ConclusionsThe use of perfusion angiography for evaluation of foot-circulation during endovascular interventions provides new information regarding quantitative assessment of contrast inflow before and after endovascular intervention without the need for extra contrast or runs. No selective catheterisation is necessary. The technique is easily adopted in a clinical setting. Further studies are necessary to create robust clinical endpoints.

Health-related quality of life after vascular surgery and endovascular treatment in subjects with critical limb ischemia.

Background & Objective:Revascularization of the target vessel and restoration of distal flow is critical not only to reduce mortality and morbidity but also improve health-related quality of life (HRQoL) in patients with critical limb ischemia. However, data concerning the impact of surgical bypass and percutaneous transluminal angioplasty (PTA) on HRQoL is limited. This study aimed to compare the impact of surgical bypass and PTA on HRQoL in subjects undergoing superficial femoral artery (SFA) or popliteal artery revascularization.Methods:Seventy-one subjects who underwent successful revascularization of the SFA or popliteal artery either with surgical revascularization or PTA were enrolled in this study. Three months after revascularization, all subjects underwent ankle-brachial index (ABI) measurement, 6-minute walking test and completed the Nottingham Health Profile (NHP) questionnaire. The NHP score differences (measured at the post-procedural 3rd month) between subjects undergoing surgical or endovascular (PTA) revascularization subjects was the primary outcome measure of the study.Results:Both groups experienced significant improvements in ABI and 6-minute walking distance at post-procedure three months. NHP total scores of Part I and Part II at post-procedural six months were similar in the two groups. However, social isolation [77.98 (0 - 85) vs. 22.53 (0 - 100), p=0.002] and physical abilities [78.7 (30.31 - 87.7) vs. 54.47 (0 - 100), P=0.014] domain scores of the surgical revascularization group were significantly higher than that of the endovascular treatment group.Conclusion:This study shows that total scores obtained from the NHP questionnaire applied three months after revascularization of SFA stenosis are similar in subjects undergoing surgical revascularization or PTA. However, the social isolation and physical abilities domains of the NHP are significantly higher in subjects receiving surgical revascularization compared to those receiving PTA.

Efficacy of oscillometric method for screening periferic arterial disease in primary care.

In primary care, measurement of the ankle-brachial index (ABI) by using hand Doppler is recommended for screening of peripheral arterial disease. Despite being relatively a simple procedure, the ABI is rarely measured in primary care due to unpracticality of the hand Doppler method. Oscillometry is an accessible, reliable, and an easy to use method for the measurement of ABI. With a little training, it can be used by anybody. Aim: The aim of the study is to compare the oscillometric method with a reference test (i.e. hand Doppler) for the screening of peripheral arterial disease (PAD) and arterial stiffness (AS) in primary care. A prospective observational diagnostic study was designed. Participants were 45 years of age or older. A survey including demographic data, risk factors, and symptoms of the peripheral arterial disease was applied to the participants besides measuring ABI both by Doppler and oscillometric methods. Three hundred and forty participants included in our study with 59.78 ± 9.8 mean age. 60.9% of the participants were men. Even though the results of the oscillometric calculations were higher, a strong correlation was observed between the measurements of two methods. Using the Doppler-derived ABI, as the gold standard, and 0, 9 as a cutoff point, the sensitivity and specificity of the oscillometric method was 74.4% and 100%, respectively, with an area under the curve of 0.98 (95% CI: 0.96-0.99). Oscillometry seemed to be a reliable screening method in primary care both for peripheral arterial disease and AS.

Effect of Foot Exercise and Care on Peripheral Vascular Status in Patients with Diabetes Mellitus

Introduction: Diabetes mellitus is a cause of health problems which occurs in most countries. Approximately 13 - 15% of all patients with diabetes mellitus will experience peripheral circulatory disorders. Foot exercise and foot care are interventions that can be implemented to prevent foot ulcers.Methods: This study employed a pre-post-test quasi-experimental design with a control group. The sample consisted of 94 patients with diabetes mellitus who were assigned to the intervention group (n=47) and the control group (n=47) respectively. Consecutive sampling was used to recruit the samples. The instruments used to collect the data included 10-g monofilament for the diabetic neuropathy test, a HbA1c test and a sphygmomanometer. The collected data was analyzed using a paired t-test.Results: The results of this study showed there to be significant effects from foot exercise and foot care on the HbA1c test, in relation to the frequency of the dorsalis pedis artery and diabetic neuropathy with a significance value of 0.00 (p&lt;0.05). However, in the ankle-brachial index measurement, there were no significant differences between the intervention and control groups with a significance value of 0.26 (p&gt;0.05).Conclusion: Foot exercise and foot care can be one of the independent nursing interventions used to prevent the complications of diabetes mellitus, as they have been proven to improve the peripheral vascular status of patients with diabetes mellitus by 70-80%.

A Targeted Literature Review of the Disease Burden in Patients With Symptomatic Peripheral Artery Disease.

Patients with peripheral artery disease (PAD) have an increased risk of cardiovascular (CV) and limb events, but the disease is frequently underdiagnosed and treatment options are limited. This review examines the disease burden of symptomatic PAD as well as key guideline recommendations. Publications were identified using the ProQuest portal to access the Medline, Medline In-Process, and Embase databases. Search terms for symptomatic PAD were combined with terms relevant to epidemiology, burden, treatment practice, and physiopathology. Articles in English published between January 2001 and September 2016 were screened according to the population, interventions, comparator, outcomes, and study design criteria. Relevant publications (n = 200) were identified. The reported incidence and prevalence of PAD varied depending on the definitions used and the study populations. Patients generally had a poor prognosis, with an increased risk of mortality, CV, and limb events and decreased quality of life. Guideline recommendations included ankle-brachial index measurements, exercise testing, and angiography for diagnosis and risk factor modification, antiplatelets, cilostazol, exercise therapy, or surgical interventions for treatment, depending on the patient profile. The clinical, humanistic, and economic burden of disease in patients with symptomatic PAD is substantial and needs to be reduced through improved PAD management.

Vascular assessment in venous leg ulcer diagnostics and management in Australian primary care: Clinician experiences

AimIn this article, we focus on primary health clinicians’ experiences of vascular assessment in venous leg ulcer (VLU) diagnostics and management, including ankle brachial pressure index (ABPI) measurements using Doppler ultrasonography. MethodsWe conducted semi-structured face-to-face and telephone interviews with general practitioners [15] and practice nurses [20] from primary health care settings in Australia. Twenty-one participants were recruited from practices located in Melbourne metropolitan settings and 14 from rural Victoria. We used the theory driven thematic analysis as a method of data analysis. The Theoretical Domains Framework informed this analysis. ResultsFive domains were identified as relevant, including Environmental Context and Resources, Motivation and Goals, Skills, Knowledge, and Beliefs about Capabilities. Although the Australian and New Zealand clinical practice guideline for prevention and management of venous leg ulcers recommend that vascular assessment is conducted for all patients with suspected VLUs, findings from our study indicate vascular assessments are not routinely performed in many primary care settings. Our study also found that a lack of awareness of clinical practice guidelines among clinicians might be one of the main issues for not following the latest clinical recommendations for vascular assessment in venous leg ulcer diagnostics and wound management practice. ConclusionWe recommend development of theory-informed interventions for clinicians in primary health care settings to optimise VLU management and healing outcomes for patients with VLUs. Implementation and evaluation of these interventions have the potential to reduce the evidence-practice gap in VLU management and optimise healing outcomes.

Novel vascular laboratory technique in the assessment of peripheral artery occlusive disease

This paper highlights the need for a more accurate noninvasive test to measure perfusion in patients with peripheral artery disease and medial calcinosis from diabetes, age, or chronic kidney disease.1 Traditional ankle-brachial index measurements (ABIs) lack reliability in these patients, and even normal values can be misleading. Correlation with pulse volume recordings or Doppler waveforms can provide insight into an underlying arteriopathy with “normal” ABIs. The adjunctive use of toe pressures is sometimes helpful but is limited in patients with severe disease or in the setting of prior toe amputations.

Diagnostics and Treatment of Pad in Primary Health Care: Limited Adherence to a Dutch Guideline

Introduction - The Dutch general practitioner (GP) has a key role in the treatment of patients with peripheral arterial disease (PAD). The Dutch GPs guideline on PAD recommends measurement of the ankle-brachial index (ABI) and supervised exercise therapy (SET) for patients with intermittent claudication (IC). Antiplatelet drugs and statins should be prescribed as part of cardiovascular risk management (CVRM). Aim of this study was to evaluate the reliability of ABI measurements in primary health care and to determine the compliance to the national PAD guideline. Methods - All patients suspected of PAD referred to our vascular surgery outpatient clinic by GPs in 2015 were evaluated based on three criteria as recommended in the Dutch GPs guideline on PAD: ABI measurement, prescription of CVRM medication and referral for SET. Primary care ABI measurements were compared to values as measured in the vascular laboratory of our hospital and were depicted in a Bland-Altman plot. The leg with the lowest ABI was used for analysis. Results - In 2015, 476 patients suspected of PAD (259 men, 54%; age 70±12 years) were referred and 167 had a history of PAD. Of 309 de novo patients, just 58% (n=180) had indeed undergone an ABI measured by their GP. The primary care ABI was 0.73±0.23 compared to 0.79±0.28 as measured in the vascular laboratory (P=0.038). A large variation was observed between the two measurements. The Pearson correlation coefficient (r) was 0.64 (‘good’, r>0.75). Moreover, the intraclass correlation coefficient (ICC) was 0.62 (‘good’, ICC>0.75), whereas the coefficient of variation (CV) was 0.16 (‘good’, CV<0.15), see Fig. Just 56% (n=72) with an abnormal primary care ABI used antiplatelet drugs or coumarin derivatives whereas a mere 48% (n=61) used statins. Only 11 of the 113 (10%) de novo patients with IC symptoms and an abnormal primary care ABI were referred for SET by their GP. Conclusion - Dutch GPs do not sufficiently adhere to their PAD guideline. The technique of an ABI measurement as well as the decision-making process of prescribing CVRM medication and referring for SET need improvement. Collaboration between primary and secondary care should be optimized and a training program for GPs is necessary to enhance compliance to the national PAD guideline.

Quantitative Assessment of Indocyanine Green Angiography in the Follow-Up of Patients with Severe Chronic Limb Ischaemia

Introduction - An ischaemic wound heals slowly after revascularization, and repeated revascularizations are needed in many cases to avoid amputation. Therefore, a surveillance programme is recommended to ensure revascularization patency and to prevent the need for additional procedures using the ankle-brachial index (ABI) and the toes (TP). Indocyanine green fluorescence imaging (ICG-FI) is useful to evaluate the perfusion of an ischaemic foot. The aim of this study was to assess the feasibility of ICG-FI in the surveillance of patients who have undergone revascularization of severe chronic limb ischemia (SCLI). We sought to determine the sensitivity and specificity of ICG-FI in distinguishing possible revascularization failure after bypass or PTA, as compared to ABI and TP. Methods - In this prospective trial, 61 patients (62 limbs) with SCLI were examined with ABI, TP and ICG-FI at baseline, immediately after revascularization and at 3-month follow-up. Twenty-five patients (33%) underwent bypass, and 36 (67%) underwent a total of 37 PTAs. ICG-FI results were assessed with the SPY-Q software, which provides a time-intensity curve of the selected region of interest (ROI), showing the fluorescence intensity plotted against time in seconds. Three parameters were derived from the curve: maximum intensity, intensity rate (IU/S), and ICG10 (intensity achieved during the first 10 seconds). Two ROIs were selected: the dorsum of the foot and the plantar region. ICG-FI results were compared with ABI and TP. The clinical status of the foot was analysed as to whether the wound was healed, healing, similar or worse. Results - At 3-month follow-up, the clinical status was improved compared to the baseline in 39 legs (63%); the wound was completely healed or healing), but in 23 (37%), the wound status was unchanged or worse. The sensitivity and specificity of ICG-FI for the unchanged or deteriorated clinical status were 61% and 72%, respectively. In 23 cases, the clinical status had not improved and ultrasound examination revealed restenosis or occlusion in 20 (90%) patients, and a new revascularization was scheduled. In 100% of these cases, ICG-FI at follow-up showed worse results compared to the immediate postoperative ICG-FI. A reliable ABI was possible in 38 (61%) legs at the follow-up visit, and it was higher than the baseline ABI in 29 (76%) cases and unchanged/worse in 9 (24%). The sensitivity and specificity to detect a deteriorated situation were 91% and 47%, respectively. TP measurements were possible in 49 (79%) cases at the follow-up visit. For 34 (69%) cases, the TP had increased from the baseline, while 15 (31%) had worse or unchanged values. The sensitivity to detect unfavourable healing was 80%, with a specificity of 47%. In ROC, the areas under the curve (AUC) using ICG-FI, ABI and TP were 0.66 (95% CI 0.52-0.81, p=0.03), 0.69 (95% CI 0.51-0.87, p=0.05) and 0.64 (95% CI 0.47-0.80, p=0.11), respectively. ICG-FI correlated with the clinical status in 68% of the cases, as opposed to the 74% correlation achieved with ABI and 67% with TP when only cases with successful measurements were considered. However, when all patients were considered, the respective proportions for ABI and TP were only 45% and 53%, due to the fact that not all patients had ABI and TP measurements available. Conclusion - ICG-FI is useful and feasible in the surveillance of SCLI after revascularization. Unlike ABI and TP, it can be measured in all patients. ReferencesSettembre N et al. World J Surg 2017,6

Ankle Brachial Index in Different Types of Popliteal Artery Entrapment Syndrome: A Systematic Review of Case Reports.

Similar to other peripheral artery diseases, vessel narrowing in popliteal artery entrapment syndrome (PAES) reduces the ankle brachial index (ABI). Since the PAES is related to several anatomical or functional variations, we sought to determine if the ABI was correlated with the type of syndrome. Through a systematic review of literature, we identified case reports and series in which the diagnosis of PAES was accompanied by ABI measurement. Twenty-seven studies included in the qualitative synthesis described 87 limbs. The most common types of the syndrome were those caused by an abnormal medial head of the gastrocnemius (type II, n = 35, 40.23%) and aberrant course of the popliteal artery (type I, n = 20, 22.99%). The variation of plantaris muscle (n = 7, 8.05%) is currently not included in the classification system. The median value of ABI was 0.87 (interquartile range (IQR) = 0.6–1.0). There were no differences among types of syndrome (F = 0.13, p = 0.72). In conclusion, despite clinical recommendations, the ABI remains underused in PAES diagnosis. No correlation was detected between the index score and type of syndrome. The cases of PAES involving structures other than the gastrocnemius or popliteus muscle suggest the need to revisit the current clinical classification system.

Carotid plague formation is associated with ankle-brachial index in elderly people.

This study aimed at examining whether ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) were independently associated with carotid Intima-media thickness (CIMT) or carotid artery plaque (CAP) in elderly people. A cross-sectional analysis was performed in 155 individuals aged over 75years who underwent the measurements of ABI and baPWV. Low ABI was defined as ABI ≤ 1.0. High baPWV was defined as baPWV > 2000cm/s. The CIMT and CAP were measured with a B-mode tomographic ultrasound system. Neither ABI nor baPWV was associated with CIMT in this elderly population. The group with low ABI (≤ 1.0) was significantly associated with a higher prevalence of carotid plaque (P = 0.001), while the relationship between baPWV and prevalence of carotid plaque was not found. Linear regression analysis showed that the value of ABI was significantly associated with the thickness of carotid plaque. Even in the full adjusted model, each 0.01unit ABI decreasing still increased 0.1663mm of carotid plaque thickness (P = 0.004). Logistic Regression Analysis demonstrated that ABI lower than 1.0 had predictive value in the formation of carotid plaque with top quartile thickness (OR 2.834, 95% CI 1.131-7.099, P = 0.026). Furthermore, individuals with low ABI (≤ 1.0) were more likely to form hypoechoic carotid plaques according to ultrasonography. Low ABI but not high baPWV was associated with the formation of carotid plaque. Furthermore, ABI was significantly associated with the thickness and morphology of carotid plaque in elderly people.

Valvular calcification and risk of peripheral artery disease: the Multi-Ethnic Study of Atherosclerosis (MESA).

The detection of cardiac valvular calcification on routine imaging may provide an opportunity to identify individuals at increased risk for peripheral artery disease (PAD). We investigated the associations of aortic valvular calcification (AVC) and mitral annular calcification (MAC) with risk of developing clinical PAD or a low ankle-brachial index (ABI). AVC and MAC were measured on cardiac computed tomography in 6778 Multi-Ethnic Study of Atherosclerosis participants without baseline PAD between 2000 and 2002. Clinical PAD was ascertained through 2015. Incident low ABI, defined as ABI <0.9 and decline of ≥0.15, was assessed among 5762 individuals who had an ABI >0.9 at baseline and at least one follow-up ABI measurement 3-10 years later. Adjusted Cox proportional hazards and Poisson regression modelling were used to determine the association of valvular calcification with clinical PAD and low ABI, respectively. There were 117 clinical PAD and 198 low ABI events that occurred over a median follow-up of 14 years and 9.2 years, respectively. The presence of MAC was associated with an increased risk of clinical PAD [hazard ratio 1.79; 95% confidence interval (CI) 1.04-3.05] but not a low ABI (rate ratio 1.28; 95% CI 0.75-2.19). No significant associations were noted for the presence of AVC and risk of either clinical PAD. MAC is associated with an increased risk of developing clinical PAD. Future studies are needed to corroborate our findings and better understand whether MAC holds any predictive value as a risk marker for PAD.

Change over time of the ankle brachial index

Abstract Objective this study was designed to better understand the evolution of the ankle brachial Index (ABI) over time, so as to better inform clinical decision-making. Methods patient selection included consecutive patients with at least two documented ABI Indexes obtained at Emory Healthcare between April 2005 and April 2013. Retrospective chart reviews were conducted on consecutive patients to assess ABI Index values, time between ABIs and whether revascularization had occurred between the two ABI measures. Qualifying patients included 76 patients with two ABIs and without a surgical intervention between the two measures. Results the primary study outcome measure was the change in ABI per day. The average change in ABI per year was calculated as -0.012045. Extrapolating from these data, the estimated time in which meaningful deterioration (0.1) was found to be 8.3 years. Conclusion these data demonstrate a change in ABI that is minimal and thus suggest that without intervening medical treatments that would change the ABI, routinely repeating this test is not warranted.

Retrograde Popliteal Access and Balloon Dilatation of Chronic Total Occlusion of Superficial Femoral Arteries

The objective of the study was to evaluate the effectiveness of retrograde popliteal access in subjects with chronic total occlusion of the superficial femoral artery. A retrospective review of subjects who underwent balloon dilatation via retrograde popliteal access (RPA) is included. Age, gender, tobacco use, comorbid diseases, body mass index, ejection fraction, claudication distance (0 to 50meters, 50 to 100meters and 100 to 150meters), preoperative Rutherford scale, and Ankle-brachial index (ABI) are noted for each subject. A duplex ultrasound (DUS) was performed preoperatively. The localization side of the lesion (right-left), the length of the atherosclerotic segment, and the localization of the diseased segment (proximal superficial femoral artery [SFA], mid-SFA, distal SFA, popliteal-above the knee) were noted. Subjects were followed for at least one year after the procedure. Subjects were reevaluated in the first, 6th, and 12th months after the procedure. In control subjects, Rutherford class and ABI were noted. A DUS was performed to detect restenosis. The subjects' preoperative Rutherford class and ABI and restenosis degree were compared with their postoperative values. A total of 93 subjects (75.3% male, 24.7% female; mean age 68.57±8.70years old) were evaluated. In all 93 (100%) subjects, successful RPA was achieved. Overall, balloon dilatation via RPA was successful in 86 (92.47%) of the 93 subjects. The procedural success rate was 92.47%. The occluded segment was on the right side in 49.5% of the subjects (n=46) and on the left side in 50.5% (n=47) of the subjects. The mean length of the lesion was 10.77±2.21cm, and the average stenosis degree was 95.9±5.05%. The localization of the occluded segment was in the proximal SFA, mid SFA, distal SFA and popliteal above the knee in 45.2%, 50.5%, 25.8% and 10.8% of the patients, respectively.When comparing the successful and unsuccessful groups, target lesion length (10.48±2.01 vs. 14.43±0.79, P<0.001), mid-SFA localization (n=40 vs. n=7, P=0,012) and claudication distance in the first 50meters (P=0,003) were significantly higher in subjects with failed balloon dilatation via RPA. When the Rutherford scale was examined, the mild, moderate, and severe claudication ratios were 23.7%, 29%, and 47.3%, respectively. After the procedure, 61.3% of the cases were asymptomatic, and 38.7% had mild claudication. The change in the Rutherford scale was statistically significant (P<0,001). When the ABI measurements were examined before procedure, it increased from 0.63±0.08 before to 0.90±0.06 after the procedure, indicating a statistically significant difference (P<0,001). When Doppler findings were examined, in the successful RPA group, the no-stenosis percentages were 82.6%, 72.1%, and 65.1 at the first, 6th, and 12th month follow-up, respectively. The mean disease-free survival time was 9.80±0.39months. In the first year, subjects were divided according to stenosis degree. Subjects with less than 50% stenosis were compared with subjects with more than 50% stenosis to detect the preprocedural characteristics that affect the restenosis degree. Tobacco use, chronic obstructive pulmonary disease, hyperlipidemia, chronical renal insufficiency, and popliteal above the knee localization were significantly higher in subjects who had more than 50% stenosis 1year after the procedure (P=0.009, P=0.015, P=0.044, P=0.001, and P=0.017, respectively). RPA under DUS guidance is an effective method. RPA has high procedural success rate with low morbidity. Longer target lesion length, mid-SFA localization, and claudication distance in first 50meters found to be related factors with RPA balloon dilatation failure. Restenosis rates after 12months of follow-up is low and comparable with literature.

100EMF Ankle-Brachial Index Measured Using Pulse Oximeter Plethysmograph Waveform and Automated Blood Pressure Device to Assess Lower Extremity Vascular Integrity

There is no practical, readily available and accurate method to assess lower extremity vascular injuries in the emergency department (ED). The ankle-brachial index (ABI) assesses the integrity of the lower-extremity arterial vasculature and the need for emergent vascular imaging. However, ABI measurement requires careful auscultation by Doppler. This measurement is made more difficult by the noisy environment of the ED or during ambulance or helicopter transport. A critical knowledge gap is whether alternative methods of ABI measurement using the pulse oximeter plethysmograph waveform or automated oscillometric sphygmomanometer (Dynamap®) can be substituted for auscultation with Doppler interrogation of the pulse. We sought to test the hypothesis that the ABI measured using the pulse oximeter plethysmograph waveform and Dynamap® have high levels of agreement with measurement by Doppler, the criterion standard for this measurement. We also tested the hypothesis that each measurement technique has high intra-rater reliability. We conducted a cross-sectional study using a convenience sample of healthy adults age 18 or older. We measured systolic blood pressures in each participant’s right arm and right leg and calculated the ABI using three different methods: (1) Doppler and manual sphygmomanometer; (2) Pulse oximeter plethysmograph waveform (“plethysmograph”) and manual sphygmomanometer; and (3) Automated oscillometric sphygmomanometer (Dynamap®). We repeated each method three times and calculated the mean ABI obtained using each method. We used Bland-Altman plots to visually examine agreement of ABI measured using the Doppler and (1) the plethysmograph waveform and (2) the Dynamap®. We measured intraclass correlation coefficients (ICCs) for intra-rater reliability of the three measurements for each method using a two-way mixed effects model for absolute agreement. Among 58 participants enrolled to date, median age was 26 [24, 28] years, 24 (41.4%) were male, 4 (6.9%) Black, 46 (79.3%) White, and 5 (8.6%) Asian race, median BMI 24.08 [21.94, 38.36], and 0 smokers. Mean absolute difference between ABI measured using plethysmograph and Doppler was 0.01 [95% CI -0.12, +0.14] with limits of agreement -0.11 to 0.14. Mean absolute difference between ABI measured by Dynamap® and Doppler was 0.03 (95% CI -0.17, +0.23) with limits of agreement -0.16 to 0.22. The ICCs for intra-rater reliability were as follows: Doppler, 0.64 (95% CI 0.51, 0.76); plethysmograph, 0.67 (95% CI 0.54, 0.77); and Dynamap® 0.45 (95% CI 0.29, 0.60). ABI measured using the pulse oximeter plethysmograph waveform has a high level of agreement with measurement by Doppler. The Dynamap® and Doppler have good agreement but wider limits of agreement than plethysmograph measurement. The Doppler and plethysmograph measurements have good intra-rater reliability. ABI measured using the pulse oximeter plethysmograph waveform may be a valuable adjunct for assessing lower-extremity vascular integrity in noisy clinical environments.

P946Abnormal ankle brachial indices are associated with ischemic stroke: evidence from a large cohort study

Abstract Background Peripheral arterial disease is a marker of aggressive atherosclerosis. The ankle brachial index (ABI) is a simple and non-invasive tool to diagnose peripheral arterial disease (PAD). Patients with PAD are at increased risk for ischemic strokes and other cardiovascular diseases. Purpose To evaluate the association of abnormal ABI and poorly compressible vessels with ischemic stroke in a large patient cohort. Methods We analyzed lower extremity vascular studies of all patients with ABI measurements at a tertiary care hospital between January 1996 and August 2018. PAD is defined as ABI&lt;1.0, and poorly or non-compressible (PC/NC) arteries as ABI&gt;1.4 while ABI between 1.0–1.4 is normal. Association of these ABIs with new ischemic stroke events post ABI measurement were analyzed after adjusting for high risk confounders such as atrial fibrillation. Hazard ratios (HR) were calculated using multivariable Cox proportional regression with 95% confidence intervals. Results In total, 38,016 unique patients (mean age 66.1±14.8 years, female 42.3%) were included. Abnormal ABI was found to be more prevalent among elderly male patients compared to patients with normal ABI. In contrast to non-PAD patients, both PAD and PC/NC patients as defined by ABI had a statistically significant risk of ischemic stroke, with PAD conferring the greatest risk compared to PC/NC vessels. The data is summarized in Table 1. Table 1 Unadjusted HR p-value Adjusted HR p-value PAD vs. No PAD 2.77 (2.62, 2.92) &lt;0.001 2.10 (1.98, 2.22) &lt;0.001 PC/NC vs. No PAD 2.11 (1.95, 2.28) &lt;0.001 1.38 (1.26, 1.51) &lt;0.001 PAD vs. PC/NC 1.37 (1.28, 1.46) &lt;0.001 1.37 (1.28, 1.48) &lt;0.001 Adjusted and unadjusted hazard ratios with p-values. HR adjusted for age, sex, atrial fibrillation, ischemic stroke, transient ischemic attack, chronic heart failure, diabetes mellitus, hyperlipidemia, hypertension, and coronary artery disease. PAD = Peripheral artery disease and PC/NC = poorly compressible/non-compressible. Conclusion This study adds to the growing body of evidence that PAD and poorly-compressible vessels are independently associated with an increased risk of ischemic stroke. Given the associated risk of cerebrovascular disease, clinicians should aggressively treat to minimize risk factors in those with abnormal ABIs.