Ankle-brachial Index Research Articles

An association between the blood perfusion parameters in foot tissues and the severity of arterial occlusion and stenosis in the lower extremities

Rationale: Peripheral artery disease (PAD) is common among the elderly and increases the risk of cardiovascular events, disability and death. PAD course and outcomes depend not only on the condition of macrovasculature but also on the tissue perfusion. We have previously shown that Type 2 diabetic patients with lower extremity ischemia have significantly lower perfusion than healthy volunteers, and the ratio of basal perfusion in the arm and leg (BP1/BP3) measured by incoherent optical fluctuation flowmetry (IOFF) allows to identify hemodynamically significant stenoses. Aim: To analyze associations between perfusion parameters registered by IOFF and the severity of vascular involvement in PAD patients. Methods: This single center cross-sectional study included 38 PAD patients admitted to the Department of Vascular Surgery and Coronary Artery Disease. The arteries were assessed with duplex Doppler ultrasonography (DDU), according to the results of which the PAD severity score and ankle-brachial index (ABI) were calculated. Skin microhemodynamic parameters were recorded by IOFF. The basal perfusion on the arm (BP1), the dorsal foot surface and the toe (BP2 and BP3), the ratio BP1/BP3, local thermal hyperemia (LTH2 and LTH3) and an increase in perfusion after heating on two leg zones (LTH2-BP2, LTH3-BP3) were evaluated and expressed in perfusion units (PU). BP1, BP3, and BP1/BP3 values were additionally measured with laser Doppler flowmetry (LDF). The analysis was performed depending on the degree of arterial involvement determined by DDU for each limb separately (n = 73). There were ≥ 50% stenoses in 15 extremities (Group 1), occlusion of one of the major arteries in 42 (Group 2) and ≥ 2 occlusions in 16 lower extremities (Group 3). Results: In the groups 1, 2 and 3, the values of most parameters estimated by IOFF decreased with an increase in severity of limb lesions. As an example, the respective perfusion parameters for the big toe in the study groups were as follows: BP3 4.0 [2.0; 9.8], 2.2 [0.9; 3.7] and 1.1 [0.7; 2.6] PU (p = 0.007); LTH3 10.0 [6.4; 14.9], 5.0 [1.5; 7.8] and 2.5 [1.4; 4.5] PU (p 0.001), and LTH3-BP3 3.8 [2.6; 7.8], 2.4 [0.6; 4.3] and 1.2 [0.4; 1.5] PU (p = 0.001). The BP1/BP3 ratio in the above mentioned group increased: 1.8 [0.8; 7.7], 7.2 [3.4; 21.3] and 14.2 [6.6; 18.3] (p = 0.004), respectively. No similar trend was found for this parameter registered by LDF. There were significant correlations between the lower extremities perfusion parameters measured by IOFF and ABI, with the correlation coefficients ranging from 0.365 to 0.717 (p 0.05). Conclusion: The functional parameters of the skin microhemodynamics vary with different PAD severity. In addition, they correlate with clinical indicators of atherosclerosis. The IOFF technique can be promising as an additional quantitative method for assessment of microvascular blood flow in patients with PAD.

Association of erectile dysfunction and peripheral arterial disease in NHANES 2001-2004: a cross-sectional study

ObjectiveTo evaluate the association between Erectile dysfunction (ED) and peripheral arterial disease (PAD) in adult American males using a large database.MethodsThe relationship between ED and PAD prevalence among participants in the 2001-2004 National Health and Nutrition Examination Survey (NHANES) database was assessed using a series of statistical analyses. ED was evaluated based on a single-item measure of self-reported erection problems from the Massachusetts Male Aging Study. PAD was defined as ankle-brachial index (ABI) < 0.9 in at least one leg. Multifactorial logistic regression models were used to investigate the association between ED and PAD.ResultsA total of 2394 participants were enrolled, of whom 905 individuals (37.8%) were diagnosed with ED. After adjusting for confounding variables, the association between ED and PAD remained positive, with an odds ratio of 2.05 (95% confidence interval 1.24-3.39). Subgroup analysis revealed that the relationship between ED and PAD was significant in patients aged >50 years old, without hypertension, without diabetes, without cardiovascular disease, without high cholesterol, former smokers, low physical activity levels, and a body mass index of 25-30 (P < 0.05). In addition, all subgroups analyzed were evaluated for any potential interaction, and no statistically significant association was discovered.ConclusionsIn a sample of US adults aged ≥40, this cross-sectional study found that ED is related to a higher occurrence of PAD. ED may be an independent predictor of PAD, and thus it should be considered in the treatment of patients with ED.

Towards Standardized, Safe, and Efficacious Screening Approaches to Patients with Lower Extremity Peripheral Arterial Disease in the Setting of Lower Extremity Arthroplasty

Introduction: Peripheral arterial disease (PAD) impedes the ability to recover from lower extremity arthroplasties (LEA) while simultaneously increasing risks of peri- and postoperative complications, morbidity, and mortality. Despite the known risks that PAD presents, there are currently no standards outlining how practitioners should screen patients prior to undergoing LEA. The purpose of this manuscript is to facilitate the improved diagnosis of PAD, leading to appropriate vascular surgery consultation prior to undergoing orthopedic surgeries. Recommendations for Preoperative Assessment: Screening begins with a succinct history and physical exam, looking for signs and symptoms of diminished vascular integrity. A heightened suspicion for PAD should prompt the immediate enactment of an ankle brachial index, or alternatively, a pressure volume recording or the skin perfusion pressure technique.

Improving peripheral artery disease screening and treatment: a screening, diagnosis, and treatment tool for use across multiple care settings.

Peripheral artery disease (PAD) is an atherosclerotic disease that contributes to significant morbidity and mortality, including loss of limb, myocardial infarction (MI), stroke, and death. Treatment options are often underutilized. A major limiting factor in PAD care is the ability to efficiently identify and screen at-risk patients. A PAD patient screening and clinician decision support tool was created to improve access to high-quality, evidence-based care to drive improved clinical outcomes. The tool identifies known PAD risk factors and presenting symptoms, in combination with objective data obtained via the ankle-brachial index (ABI). The tool utilizes this data to drive PAD diagnosis, risk assessment, and treatment, and it is adaptable across multiple care settings, by varied health professions. The implementation of a PAD screening and treatment toolkit enhances anticoagulation and PAD stewardship, and it has been integrated into use across various care settings.

Reported outcomes in studies of intermittent claudication - first step toward a core outcome set: systematic review.

This review aimed to compile an exhaustive list of all outcome measures and identify different characteristics of the outcomes reported in studies of intermittent claudication as the first step in developing a core outcome set for intermittent claudication. Medline and Embase were searched for all studies including individuals with intermittent claudication and reporting ≥1 outcome from January 2015 to August 2024. Abstract, full text screening and data extraction were performed by two investigators independently. All reported outcome measures were extracted verbatim and categorized by Dodd's domains (Core Outcome Measures in Effectiveness Trials registration: COMIC Study, 1590; https://www.comet-initiative.org/Studies/Details/1590). 4985 studies were screened and 408 were included. A total of 541 unique outcomes across 25 Dodd's domains were identified. Ankle-brachial pressure index was the most frequently reported outcome. Among the 541 unique outcomes, 386 outcomes were only reported once. Only 38.9% of the studies exclusively included patients with intermittent claudication. Patient-reported outcomes were reported in 36.2% of studies. There were wide variations in the definition of commonly used outcome measures (for example, major adverse limb event and primary patency) across different studies. There is substantial heterogeneity in reported outcomes in studies of intermittent claudication. Most reported outcomes are clinical/physiology oriented rather than patient centred. Development of a core outcome set for intermittent claudication is vital to improve and standardize reporting in future research.

Heel Raises and Calf Stretches Exercises Versus Medication Only in Ischemic Intermittent Claudication: A Randomized Controlled Trial.

Intermittent claudication is a primary symptom of peripheral artery disease (PAD). a chronic progressive disease caused primarily by atherosclerosis. It is usually characterized by leg pain, aches, cramps, or fatigue when walking, which improves with rest. Physical therapy, including a supervised exercise program, is often recommended as the first treatment for sprains. This study aims to evaluate the short-term effects of incorporating heel raise and calf stretch exercises with standard medical therapy compared to medical therapy alone in managing intermittent claudication. From May 2022 to November 2023, 160 patients with Stage II Fontaine PAD were randomly assigned to two equal groups. Group A (80 patients) received heel raise and calf stretch exercises in addition to medical treatment, while Group B (80 patients) received only medical treatment. Both groups underwent treadmill walking tests before and after three months to measure absolute walking distance (ACD), peak walking time (PWT), and Walking Impairment Questionnaire (WIQ) scores, including distance, speed, and symptom severity. At baseline, there were no significant differences between the groups in terms of ACD, peak walking time, ankle-brachial index, distance, speed, and symptoms. At follow-up, Group A showed significantly greater improvements in ACD (312.00 ± 45.43 m), peak walking time (8.54 ± 1.55 min), distance (29.46 ± 4.63 km), speed (20.01 ± 3.13 kph), and WIQ symptoms (22.10 ± 1.02) compared to Group B, which had ACD (276.55 ± 29.07 m), peak walking time (6.72 ± 1.70 min), distance (23.68 ± 3.89 km), speed (15.71 ± 2.71 kph), and WIQ symptoms (20.80 ± 1.47) (P < .001). The ankle-brachial index remained similar between the groups (P > .05). We concluded that integrating standard physical therapy exercises, such as calf raises and leg stretches, with medical therapy significantly enhances walking function in patients with ischemic intermittent claudication.

Ankle brachial index,a non invasive tool predicts cardiovascular events after acute myocardial infarction:a 3 year follow -up study

Abstract Background / Introduction The ankle-brachial index (ABI) is a non-invasive tool that was initially used for the diagnosis of lower-extremity peripheral artery disease (PAD). It has been proven that ABI is a marker of atherosclerosis in other vascular sites and can therefore be used to predict cardiovascular events regardless the presence or not of PAD symptoms. Purpose This study aims to examine the prognostic value of ABI in the setting of acute myocardial infarction (MI), as up till now there is not enough relevant evidence. Method We followed up 441 patients [79% male;mean age 62 years;67% hypertnesive; 30% with diabetes mellitus (DM); 52% current smokers] who were hospitalized because of MI for a period of three years. All patients underwent baseline estimation of clinical and laboratory parameters during theri hospitalization.The ABI was measured according to established methodology using a certified automated device and abnormal ABI defined as a value ≤ 0.9. The primary endpoint was a composite of all-cause and cardiovascular death, as well as major cardiovascular events including decompensated heart failure, new acute coronary syndrome, cerebrovascular event, malignant arrhythmia, PAD event and new onset renal dysfunction. All events were assessed both in-hospital and within 3 years of follow-up. Results Our study population had a mean ABI of 1.1 (IQR: 1.00 to 1.18). With the use of reduced multivariate regression models ABI was proven to be a prognostic indicator for the in-hospital composite endpoint. Patients with an abnormal ABI had a threefold risk of in-hospital events [HR 2.93, 95% CI: 1.48-5.81, p=0.002]. After conducting multivariate analysis ABI maintained its predictive power of all-cause mortality [HR 2.88, 95% CI: 1.53 – 5.42, p=0.001], regardless of hypertension DM, LDL levels and smoking status of the study population in 3 years follow-up. Conclusion An impaired ABI is associated with greater risk of in-hospital events in patients with acute MI. Moreover, ABI emerges as an independent predictor of long-term all-cause mortality in those patients.The findings of this study suggest that subclinical and clinical PAD are associated with poor outcomes among patients with acute MI; thus, routine ABI tests enhance risk stratification and might carry important prognostic significance in these patients regardless of PAD symptoms.

Developing a multi-center registry of peripheral artery disease using natural language processing: unlocking the power of the electronic health record

Abstract Background Although peripheral artery disease (PAD) is common and associated with a high risk of mortality, contemporary PAD research remains limited due to poor accuracy of diagnosis codes in the electronic health record (EHR). We previously developed and validated a novel natural language processing (NLP) algorithm that can extract ankle brachial index (ABI) and toe-brachial index (TBI) values from clinical documents and identify patients with PAD with high accuracy (positive predictive value 92.4%). Purpose Scale the NLP system for developing a nationwide registry of PAD in the Veterans Health Administration (VHA), the largest integrated health system in the U.S. that provides care to ~9 million Veterans across 130 sites. Describe the baseline characteristics and mortality outcomes among participants and identify predictors of long-term mortality. Methods A total of 1,182,025 documents from vascular and radiology procedures during 2013-2020 were processed by the NLP system. After excluding non-ABI vascular studies, patients with a known diagnosis of PAD prior to 2015, patients younger than 40 years of age, and those who do not regularly follow-up in the VHA, we identified 107,711 patients with newly diagnosed PAD during 2015-2020. Patients were followed longitudinally using the VA’s electronic health record data. The primary outcome was all-cause mortality. We used Cox proportional hazards regression to examine predictors of long-term mortality. Results The mean age was 70.5 years; 97.3% were males, and 18.5% were of Black race. The mean ABI value was 0.78 (SD: 0.26) and the mean TBI value was 0.51 (SD: 0.19). There was a high prevalence of hypertension (83.6%), heart failure (20.8%), diabetes (53.6%), renal failure (22.1%) and chronic obstructive pulmonary disease (32.4%, Table 1). At 1-year, 9.6% of patients had died and this proportion increased to 25.4% at 3 years. Although nearly all patient variables were significantly associated with mortality, older age, severe PAD at diagnosis, diabetes, heart failure, renal failure and COPD were the strongest predictors of long-term mortality. Black race was associated with lower hazard of long-term mortality. Conclusions Using a previously validated novel NLP algorithm that extracts ABI and TBI values from clinical documents, we have successfully developed a registry of newly diagnosed PAD in the VHA. Ongoing studies from our cohort will yield important insights into the association between clinical management of PAD and clinical outcomes, with the goal of identifying opportunities for improving care.

Validation and development of a scoring system for comprehensively evaluating arterial damage in the elderly chinese

Abstract Background and aims Existing assessments on arterial damage focus on specific segments of arterial system (e.g., carotid artery), lacking a comprehensive index to evaluate overall arterial health. We aimed to integrate existing assessments for arterial damage and develop a new score, named Arterial Damage Index (ADI), to comprehensively evaluate arterial health status of the whole-body arterial system. Methods A total of 3075 community-dwelling elderly Chinese (age ≥65 years) from the North Shanghai Study (2014–2022) were included. Assessments on arteries including ankle-brachial index (ABI), pulse wave velocity (PWV), carotid intima-media thickness (CIMT) and plaques, pulse pressure (PP), and inter-arm (IASBPD) and -leg (ILSBPD) systolic blood pressure difference were included for screening. Cox proportional hazards regressions of MACEs (non-fatal myocardial infarction, non-fatal stroke, and all-cause mortality) were conducted to acquire the ADI algorithm. Internal and external validation on ADI were also performed. Results Over a median follow-up period of 6.4 years, 316 individuals (10.3%) experienced an incident of MACE. After screening, PWV, ABI, PP, CIMT, and carotid plaque were included for ADI scoring system. Survival analysis revealed a significant difference in the rates of composite events across different ADI stratifications (p for trend &amp;lt; .05). ADI showed superior discriminative performance (C-index 0.65±0.02) compared to any individual arterial-related indicator. Calibration curve shows the predictive model showed that the predicted and actual probabilities were broadly consistent. Additionally, ADI provided better incremental value when added to the base model (net reclassification improvement, 36.2% [95% CI, 15.3%-52.1%]; p &amp;lt; .05, integrated discrimination improvement, 7.9% [95% CI, 4.9%-11.0%]; p &amp;lt; .05) compared to any individual arterial-related indicator. These findings were confirmed in internal validation sets (p for DeLong tests &amp;gt;0.05), and was externally validated in 2155 participants from a community-based cardiovascular disease cohort among residents in Beijing, China. Conclusion ADI can comprehensively assess arterial damage and provide a valuable tool for further assessment of future cardiovascular risk.central illustration

Predicting atrial fibrillation within 7 years follow-up using machine learning models

Abstract Background The prevalence of atrial fibrillation (AF), the most common type of cardiac arrhythmia, has increased globally. AF is also the leading cardiac factor for several cardiovascular and cerebrovascular events. Early prediction and treatment of AF prevents major cardiovascular and cerebrovascular events. Purpose Our objective is to predict AF risk within 7-years follow-up using only twelve basic factors and applying machine learning (ML) models. Methods Data from the German epidemiological trial on ankle brachial index (getABI) were utilized in this work. GetABI includes 6,457 patients with mean age of 72.53 years. 3,985 individuals were assessed for AF of which 393 patients suffered from AF at 7-years follow-up. The feature selection was initially done manually, ending up in 45 features. The 10 best features were extracted from this dataset according to the SHAP (SHapley Additive exPlanations) values. The final features were body mass index, sensitive CRP, cholesterol, LDL-cholesterol, troponin I, NT-pro-BNP, glomerular filtration rate, ratio of triglycerides and HDL-cholesterol, gamma-GT, heart rate, including age and sex as major factors. The handling of missing values was achieved by SimpleImputer, estimating the mean values. XGBoost and Random Forest predicted AF. Logistic Regression was also used as a baseline model. The data were split into training and test set and ML models were applied for 100 iterative runs, extracting results with mean values. Results XGBoost was the most accurate model, predicting the AF with 71.19 % mean accuracy, 66.37 % mean sensitivity and 75.61 % mean specificity. Figure 1 depicts the performance of all models. Additionally, Receiver Operating Characteristic Curve (ROC) and Area Under Curve (AUC) for each model are presented in Figure 2. XGBoost also outperformed all the others models, achieving the highest mean AUC value, equal to 70.99 %. Contrariwise, logistic regression had the lowest overall performance. Conclusion ML models, specifically XGBoost, achieved accurate AF prediction in 3,985 individuals utilizing only twelve clinical-routine data.Evaluation results of each used model.ROC curve and AUC value of each model.

Lipid-associated GWAS loci as important markers of the risk, severity, and clinical course of peripheral artery disease

ABSTRACT Background This study investigated the relationship between lipid-associated loci identified through genome-wide association studies (GWAS) and the risk of peripheral artery disease (PAD), its severity, as well as clinical and laboratory features. Research design and methods A study included 1263 unrelated Russian subjects, consisting of 620 patients diagnosed with PAD and 643 healthy controls. Thirteen single nucleotide polymorphisms (SNP) were genotyped using the MassArray-4 system. Results Polymorphisms rs1689800, rs55730499 and rs881844 were found to be associated with an increased risk of PAD, whereas SNPs rs1883025, rs3136441, rs3764261 and rs6065906 showed protective effects against disease (Pperm ≤ 0.05). SNPs rs1689800, rs217406, rs1883025, and rs3136441 exhibited combined effects with cigarette smoking on the PAD risk (Pperm ≤ 0.05). Polymorphisms rs55730499 (beta = 0.124, Pperm = 0.04), rs9987289 (beta = 0.558, Pperm = 0.03), and rs881844 beta = −0.171, Pperm = 0.03) correlated with the ankle-brachial index. Multiple associations have been found between the SNPs and clinically significant characteristics, including disease severity, risk of gangrene, early disease onset, plasma procoagulant and atherogenic lipid changes (Pperm ≤ 0.05). Conclusions We identified novel genetic markers associated with PAD susceptibility and disease-related clinical and laboratory features. The identified biomarkers enhance the potential for predictive genetic testing related to the risk and progression of PAD, facilitating the integration of molecular diagnostics into clinical decision-making processes.

Foot Sole Temperature Correlates with Ankle–Brachial Index, Pulse Wave Velocity, and Arterial Age in Diabetic Patients Without Diagnosis of Peripheral Arterial Disease

Background/Objectives: Some vascular alterations such as peripheral arterial disease (PAD) or arterial stiffness can alter perfusion of the limbs, so we wondered if this is reflected in the temperature of the soles of the feet of diabetic patients who did not have a diagnosis of peripheral arterial disease. Foot sole temperature was correlated with the ankle–brachial index (ABI), carotid—femoral pulse wave velocity (cfPWV), brachial–ankle pulse wave velocity (baPWV), and arterial age. Methods: A total of 175 patients with type 2 diabetes mellitus, without a previous diagnosis of PAD, were recruited. Comorbidities, anthropometry, biochemical analysis results, temperature, ABI, cfPWV, baPWV, and arterial age were recorded. Forty-two temperature records were obtained from the sole of the foot with an FLIR T865 thermal imaging camera. ABI, cfPWV, baPWV, and arterial age were obtained using plethysmographic and oscillometric methods. Statistical analysis was performed with SPSS v.29.0 (correlations and multiple linear regression models). Results: All temperature points analyzed correlated negatively with ABI (p &lt; 0.001) and rho values ranged from −0.168 to −0.210. Likewise, cfPWV, baPWV, and arterial age had similar results, since most temperature records showed low rho values and a negative correlation with these parameters. Four models were developed to explain the variables of interest. Temperature was involved in all of them. The temperature of the first toe was included in the prediction of cfPWV, baPWV, and arterial age. Conclusions: There is an inversely proportional relationship between temperature and ABI, cfPWV, baPWV, and arterial age in diabetic patients without a previous diagnosis of arterial disease. Temperature can be a predictor of these hemodynamic variables.

Plasma Lipidomic Profiles Improve upon Traditional Risk Factors for the Prediction of Arterial Stiffness Among Patients with Type 2 Diabetes Mellitum: A Randomized, Placebo-Controlled Trial

Background: Exercise or vitamin D intervention can reduce the risk of arterial stiffness; however, the underlying mechanisms of lipid metabolism remain unexplored. To examine the effects of a 12-week moderate and vigorous exercise program (65–80% maximal heart rate, 60 min/time, 2~3 times/week) with or without vitamin D supplementation (1000 IU/day) on the reduction in arterial stiffness and further explore whether the effects of interventions could be associated with the basal lipidome among patients with Type 2 diabetes mellitum (T2DM). Method: 61 patients with T2DM were randomly assigned to the following groups: control (CON, n = 15), exercise (EX, n = 14), vitamin D (VD, n = 16), and exercise + vitamin D (EX + VD, n = 16). Arterial stiffness risk factors (ankle–brachial index (ABI); brachial–ankle pulse wave velocity (baPWV), systolic blood pressure (SBP), and diastolic blood pressure (DBP)) were evaluated before and after the intervention. The plasma lipidome was determined using ultra-performance liquid chromatography coupled with tandem mass spectrometry. Machine learning was applied to establish prediction models for the responsiveness to arterial stiffness. Result: Vitamin D supplementation could inhibit the decrease in the ankle–brachial index (mean ± SD: EX + VD and VD, −0.001 ± 0.058; EX + CON, −0.047 ± −0.089; p = 0.03). We observed high inter-individual variability in the arterial stiffness risk factors in response to the interventions. We also found that optimally selecting the lipid predictors at baseline, such as SM d44:6, LPE 18:2, and Hex2Cer 29:0, could enhance the predictive power by 100% for arm SBP changes in the exercise group. Basal levels of Cer (33:1) and GM3 (44:4) could enhance the predictive power by 100% for changes in baPWV in the vitamin D group. Conclusions: A 12-week vitamin D supplementation was beneficial in preventing arterial stiffness. Compared with traditional clinical risk factors, specific lipids at baseline could significantly improve the ability to predict intervention-induced changes in the reduction of arterial stiffness.

The use of a novel toe-thumb pressure index for assessing arterial status in the lower limb. A reliability and validity study.

This study explored the reliability, validity and perceived comfort of a novel thumb pressure measure and calculation of a toe-thumb index to identify their suitability as an adjunct or alternatives to ankle-brachial and toe-brachial indices. Repeated manual thumb and toe systolic blood pressures were conducted using two raters, over two time points, on 34 healthy participants. Concurrent automated toe, thumb and brachial systolic blood pressures as well as comfort ratings for these measures (using a 10mm visual analogue scale) were captured once by a research assistant. Automated thumb and brachial measures showed fair correlation (ρ=0.36, p=0.03) and a toe-thumb index and toe-brachial index good correlation (ρ=0.62, p<0.01). Intraclass correlation coefficients (ICC) identified moderate intra-rater reliability for manual thumb pressures for Rater 1 and 2 (ICC 0.57, 95% CI [0.14, 0.79] and ICC 0.74, 95% CI [0.49, 0.87], respectively), while inter-rater reliability was poor (ICC=0.16, 95% CI [-0.85, 0.47]). Concurrent validity comparing manual and automated measures for thumb pressure was also poor (ICC -0.05, 95% CI [-1.06, 0.72] and ICC 0.42, 95% CI [-0.16, 0.72] Rater 1 and 2 respectively). Thumb measures were significantly more comfortable than brachial measures (5mm, p<0.00). Thumb systolic pressures are correlated with brachial systolic pressures, with reasonable intra-rater reliability, however, correlation is only fair and measurement error wider than clinically acceptable. Furthermore, manual measures are poorly correlated with automated units. Consequently, caution is required in applying these techniques. As thumb measures were perceived as significantly more comfortable than brachial measures and have an advantage where brachial pressures cannot, or should not, be obtained, further evaluation is warranted.

Technical aspects of the new BYCROSSTM atherectomy device - preliminary results after 28 patients.

Purpose: Technical aspects are crucial for the planning and performing of the atherectomy to treat peripheral arterial disease. This report illustrates the use of a novel atherectomy device and investigates the feasibility, efficacy, and safety procedures involved in performing the atherectomy on 28 patients. We performed a prospective analysis of patients who underwent an atherectomy with the BYCROSSTM Atherectomy device between August 2022 and September 2023 at a tertiary referral centre. Patients with a lesion below the aortic bifurcation (vessel diameter ≥ 3mm) having a de novo or restenotic (stent-included) present were recruited. Major adverse events (MAE) are defined as amputation, death, myocardial infarction, or angiographic distal embolization that require a separate intervention. Of the 28 patients treated with the BYCROSS device, 23 were men with a mean age of 65.6 ± 9,6 years and a mean BMI of 24,6 ± 3.9 kg/m2. Most patients had a typical atherogenic risk profile as well as multiple preexisting comorbidities. In all patients, a symptomatic peripheral arterial disease (PAD) was the main reason for an intervention. The most common Rutherford category was 5 (12/28). The most common lesion region was the femoropopliteal segment (25/28) with 23 de novo stenosis. Mean lesion length was 218,0 ± 93,7 mm. The mean PACCS Score was 3,0 ± 1,0. Stenosis grade was by mean 99,3 ± 3,7%. Ankle Brachial Index (ABI) increased significantly after BYCROSS atherectomy (pre- 0,44 ± 0,43 vs. post-procedure 0,84 ± 0,30 P<0,001. Target lesion/vessel revascularization (TLR/TVR) within the first 30 days was 3,6% (1/28). 30-day MAE rate was 14,3% (vessel perforation in 3/28 patients, embolism in 1/28). There were no deaths, index limb amputations, or myocardial infarctions. The BYCROSSTM atherectomy system is a new device with numerous advantages in treating high-grade, calcifying stenosis and occlusion processes in PAD. Based on the above findings, the BYCROSSTM Atherectomy device represents a feasible, safe, and effective method for endovascular treatment of peripheral arterial disease.

Temporary decrease in microvascular tissue saturation after transcatheter aortic valve implantation.

Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited. The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function. In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels. 26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels. Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Prognostic factors and outcomes of chronic limb threatening ischaemia in patients post kidney transplant: a systematic review

BackgroundKidney Transplantation (KT) is widely recognized as the optimal treatment for patients with End Stage Renal Disease (ESRD), improving not only life expectancy but also quality of life. Undetected peripheral arterial disease (PAD) in patients undergoing KT may lead to lower limb ischaemic ulceration and gangrene which is associated with an increased mortality rate. If undiagnosed and untreated this may lead to limb loss and graft failure. This review aims to evaluate the current evidence related to the prognosis of chronic limb-threatening ischemia (CLTI) in patients with a KT.MethodsWe conducted a systematic review of the literature in PubMed and MEDLINE, the Cochrane database of systematic reviews, Elsevier, Web of Science, and CINAHL using relevant search keywords to identify the prognosis and progression of CLTI in patients with a KT. Outcomes of interest were CLTI and progression rate in terms of haemodynamic measurement. This systematic review adhered to the guidelines set forth by the Cochrane Collaboration. The study design, population selection, and follow-up time frame were outlined in accordance with the PRISMA guidelines.ResultsStudies have shown a decline in the ankle-brachial index (ABI) post-KT, indicating vascular deterioration. Surgical interventions and amputations are more likely, particularly on the ipsilateral side of KT. The infrapopliteal artery is the most compromised in this cohort. A low ABI was found to be an independent predictor of graft failure, doubling the risk of mortality post-KT. Quality of evidence was observed to be low primarily due to confounding and selection bias.ConclusionsThe available evidence regarding the prognosis of CLTI in individuals with KT is limited to a small number of studies offering predominantly low-quality evidence and conflicting results pertaining to PAD and its progression into CLTI. Further research is required on CLTI prognosis and progression among KT recipients.

Leukotrienes E4 and B4 and vascular endothelium – New insight into the link between vascular inflammation and peripheral arterial

Leukotrienes are proinflammatory mediators that participate in the process of atherogenesis and contribute to the development of symptomatic peripheral arterial disease. The aim was to evaluate the relationship between leukotriene E4 (LTE4) and B4 (LTB4) with parameters reflecting endothelial vascular function in patients with chronic lower limb ischemia. This prospective observational study enrolled 50 consecutive patients undergoing endovascular treatment due to chronic lower limb ischemia (Rutherford 3). All participants were followed-up for one year (after 1, 3, 6 and 12 months), with a sequential assessment of urinary LTE4 and LTB4, as well as measures of endothelial and vascular function: Flow-Mediated Dilatation (FMD), Intima-Media Thickness (IMT), corrected Augmentation Index (AI75), Shear Rate (SR), Ankle-Brachial Index (ABI), Toe-Brachial Index (TBI). There was a significant relationship between LTE4 and measures of vascular function: FMD (R2 = 0.69, P < 0.001), IMT (R2 = 0.12, P < 0.01), AI75 (R2 = 0.43, P < 0.001), SR (R2 = 0.48, P < 0.001). Similar findings were noted for LTB4: FMD (R2 = 0.47, p < 0.001), IMT (R2 = 0.23, P < 0.001), AI75 (R2 = 0.61, P < 0.001) and SR (R2 = 0.33, P < 0.001). Alterations in parameters were significantly related: ΔLTE4 vs ΔFMD(R2 = 0.63, P < 0.001), ΔSR (R2 = 0.42, P < 0.001) and ΔLTB4 vs AI75(R2 = 0.40, P < 0.001), SR(R2 = 0. 29, P < 0.001). We conclude, that increasing concentrations of LTE4 and LTB4 are associated with impairment of vascular and endothelial function, which may lead to worse endovascular treatment clinical outcomes.

Impact of vascular biomarkers and supine hypertension on cardiovascular outcomes in hypertensive patients: first results from the Cardiovascular Prognostic COUPLING Study in Japan.

The prognostic impact of vascular biomarkers and supine blood pressure (BP) is not well understood. The multicenter, prospective Coupling study determined the prognostic impact of vascular biomarkers and supine BP in outpatients aged ≥30 years with ≥1 cardiovascular risk factor. Occurrence of major cardiovascular events during follow-up was recorded. The primary outcome was time to onset of a major cardiovascular event. Office and supine BP, the cardio-ankle vascular index (CAVI), and the ankle-brachial index (ABI) were determined annually. Of the 5109 participants in the Coupling study, 4716 were analyzed (51.9% male, mean age 68.5 ± 11.4 years); participants mostly had hypertension treated based on seated office/home BP according to relevant guidelines. During a median follow-up of 5.0 years (interquartile range 3.6-5.2), 231 major cardiovascular events occurred. After adjustment for age, sitting office systolic BP, and other covariates, a 1-unit increase in CAVI (hazard ratio [HR] 1.12, 95% confidence interval [CI] 1.01-1.24) and a 0.1-unit decrease in ABI (HR 1.41, 95% CI 1.18-1.68) were significantly associated with cardiovascular event risk; risk was greatest when CAVI was ≥8.0 and ABI was ≤1.10. Uncontrolled supine hypertension (≥140/90 mmHg) was also significantly associated with adjusted cardiovascular event risk (HR 1.36, 95% CI 1.02-1.81); seated office BP control was not significantly associated with cardiovascular event risk. Increased arterial stiffness, mildly lower ABI, and supine hypertension are risk factors for cardiovascular events during standard clinical practice. Supine evaluation of BP and vascular biomarkers has highlighted a blind spot in current hypertension management (Clinical trial registration: University Hospital Medical Information Network Clinical Trials Registry, UMIN000018474).

Associations of Circulating ANGPTL3, C-Terminal Domain-Containing ANGPTL4, and ANGPTL3/8 and ANGPTL4/8 Complexes with LPL Activity, Diabetes, Inflammation, and Cardiovascular Mortality.

ANGPTL3/4/8 (angiopoietin-like proteins 3, 4, and 8) are important regulators of LPL (lipoprotein lipase). ANGPTL8 forms complexes with ANGPTL3 and ANGPTL4. ANGPTL4/8 complex formation converts ANGPTL4 from a furin substrate to a plasmin substrate, and both cleavages generate similar C-terminal domain-containing (CD)-ANGPTL4 fragments. Whereas several studies have investigated associations of free ANGPTL proteins with cardiovascular risk, there are no data describing associations of the complexes and CD-ANGPTL4 with outcomes or describing the effects of the complexes on LPL bound to GPIHBP1 (glycosylphosphatidylinositol HDL-binding protein 1). Recombinant protein assays were used to study ANGPTL protein and complex effects on GPIHBP1-LPL activity. ANGPTL3/8, ANGPTL3, ANGPTL4/8, and CD-ANGPTL4 were measured with dedicated immunoassays in 2394 LURIC (Ludwigshafen Risk and Cardiovascular Health) study participants undergoing coronary angiography and 6188 getABI study (German Epidemiological Trial on Ankle Brachial Index) participants undergoing ankle brachial index measurement. There was a follow-up for cardiovascular death with a median (interquartile range) duration of 9.80 (8.75-10.40) years in the LURIC study and 7.06 (7.00-7.14) years in the getABI study. ANGPTL3/8 potently inhibited GPIHBP1-LPL activity and showed positive associations with LDL-C (low-density lipoprotein cholesterol) and triglycerides (both P<0.001). However, in neither study did ANGPTL3/8 correlate with cardiovascular death. Free ANGPTL3 was positively associated with cardiovascular death in the getABI study but not the LURIC study. ANGPTL4/8 and especially CD-ANGPTL4 were positively associated with the prevalence of diabetes, CRP (C-reactive protein; all P<0.001), and cardiovascular death in both studies. In the LURIC and getABI studies, respective hazard ratios for cardiovascular mortality comparing the third with the first ANGPTL4/8 tertile were 1.47 (1.15-1.88) and 1.68 (1.25-2.27) when adjusted for sex, age, body mass index, and diabetes. For CD-ANGPTL4, these hazard ratios were 2.44 (1.86-3.20) and 2.76 (2.00-3.82). ANGPTL3/8 potently inhibited GPIHBP1-LPL enzymatic activity, consistent with its positive association with serum lipids. However, ANGPTL3/8, LDL-C, and triglyceride levels were not associated with cardiovascular death in the LURIC and getABI cohorts. In contrast, concentrations of ANGPTL4/8 and particularly CD-ANGPTL4 were positively associated with inflammation, the prevalence of diabetes, and cardiovascular mortality.