The bodyweight walking distance product and its relationship with clinical markers in patients with symptomatic peripheral artery disease.

PURPOSE: The six-minute walk test (6MWT) is extensively employed to evaluate gait impairment in patients with symptomatic peripheral artery disease (PAD) and has been associated with different health outcomes. However, various approaches exist for calculating and interpreting the six-minute test in order to address the needs of patients more effectively. Therefore, we investigated how these different approaches correlate with functional capacity and cardiovascular health in patients with symptomatic PAD. METHODS: In total, 227 PAD patients [65.2% men and 67 (13) y.o.] were included in this cross-sectional study. The 6MWT was performed along a 30-meter corridor and the distance was expressed in three ways: absolute (described as the meters walked during the test), relativized (based on the results of the 6MWT in healthy individuals), and DW (multiplying the body weight in kilograms by the absolute distance in the 6MWT). A functional capacity z-score was calculated using the results of the handgrip strength test, 4-meter walking test, and sit-and-stand test. A cardiovascular parameter z-score was calculated with data on brachial and central blood pressure, the low-frequency component/high-frequency component ratio, and carotid-femoral pulse wave velocity. RESULTS: The absolute (b = 0.30, 95%CI: 18-0.43, R² = 0.11, p < 0.001) and DW (b = 0.40, 95%CI: 27-0.53, R² = 0.17, p < 0.001) measures were related to functional capacity, independently of sex, age, and the ankle-arm index of the patients. Neither absolute nor DW were related to cardiovascular health. The relativized measure was not associated with either functional capacity or cardiovascular health. CONCLUSION: In patients with symptomatic PAD, absolute and DW measures are related to functional capacity, but not cardiovascular function.

Perfusion increase in foot angiosomes: Comparison between direct and indirect revascularization of crural arteries.

BACKGROUND AND AIMS: In retrospective studies, wound healing and leg salvage have been better if revascularization is targeted to the crural artery supplying arterial flow to the wound angiosome. No data exist on how revascularization changes the blood flow in foot angiosomes. The aim of this study was to evaluate the change in perfusion after infrapopliteal artery revascularization in all foot angiosomes and to compare directly revascularized (DR) angiosomes to the indirectly revascularized (IR) angiosomes. METHODS: In this prospective study, foot perfusion was measured with indocyanine green fluorescence imaging (ICG-FI) before and after either surgical or endovascular below-knee revascularization. According to angiograms, we divided the foot angiosomes into DR and IR angiosomes. Furthermore, in a subanalysis, the IR angiosomes were graded as IR_Coll+ angiosomes if there were strong collaterals arising from the artery which was revascularized, and as IR_Coll- angiosomes if strong collaterals were not seen. RESULTS: A total of 72 feet (28 bypass, 44 endovascular revascularizations) and 282 angiosomes were analyzed. Surgical and endovascular revascularization increased perfusion significantly in both DR and IR angiosomes. After bypass surgery, the increase in DR angiosomes was 55 U and 53 U in IR angiosomes; there were no significant difference in the perfusion increase between IR and DR angiosomes. After endovascular revascularization, perfusion increased significantly more, 40 U, in DR angiosomes compared to 26 U in IR angiosomes (p < 0.05). In the subanalysis of IR angiosomes, perfusion increased significantly after surgical bypass regardless of whether strong collaterals were present or not. After endovascular revascularization, however, a significant perfusion increase was noted in the IR_Coll+ but not in the IR_Coll- subgroup. CONCLUSION: Open revascularization increased perfusion equally in DR and IR angiosomes, whereas endovascular revascularization increased perfusion significantly more in DR than in IR angiosomes. Strong collateral network may help increase perfusion in IR angiosomes.

Feasibility of performing treadmill walking test for patients with peripheral arterial occlusive disease by the advanced practice nurses.

AIM: The treadmill walking test with post-exercise pressure measurement can be used as a diagnostic test and could classify peripheral arterial disease of the lower limbs. It can also exclude the diagnosis allowing to raise the possibility of differential diagnoses. In this study, we assessed the feasibility of performing treadmill test by advanced practice nurse to assess suspected lower extremity peripheral artery disease patients. DESIGN AND METHOD: This is a longitudinal monocentric study to assess the feasibility of a treadmill walking test performed by an advanced practice nurse. The primary endpoint was the number of tests performed during this period. The secondary objectives were to evaluate the reasons for requesting the test, the main results obtained in terms of the test's contribution and diagnoses, and patients' clinical characteristics. RESULTS: From February to May 2023, amongst 31 patients who underwent the treadmill walking test, 4 tests were able to rule out peripheral arterial disease and to detect differential diagnoses. For the remaining 27 patients, 4 had stage IIa of the Leriche classification, 23 had stage IIb, 2 of which were associated with a narrow lumbar spine. In contrast to the usual report, the APN's report on the walking test included an identification of cardiovascular risk factors, as well as a possible medical reorientation linked to the correction of a detected cardiovascular risk factor. CONCLUSION: The treadmill walking test can be performed by an advanced practice nurse. He/She added a comprehensive/global patient management, with the detection of cardiovascular risk factors. This new profession led to an increase in the number of tests performed of more than 50% over the period and reduced the time to access the test.

Pedal Acceleration Time An Alternative Tool To Ankle-Brachial Index In Peripheral Arterial Disease.

INTRODUCTION: Ankle-Brachial Index (ABI) is a well-established diagnostic tool for evaluating peripheral arterial disease (PAD). Limitations in its application led to the development of alternative diagnostic methods, including Toe-Brachial Index (TBI) and Transcutaneous Pressure of Oxygen (TcPO2), yet these are not as widely available as ABI. Recently, Pedal Acceleration Time (PAT), has gained popularity as a new tool to assess PAD, requiring only an ultrasound. This study seeks to further establish the correlation between ABI and PAT, determining whether PAT can be a reliable alternative for diagnosing and assessing the severity of PAD. METHODS: ABI and PAT were measured in patients attending our consult with no history of vascular or endovascular surgery. Limbs with unmeasurable ABI were excluded. Patients were categorized into groups based on their PAD stage according to the Fontaine classification. Patient demographics, comorbidities and respective ABI and PAT were analysed. RESULTS: Sixty-nine patients (114 limbs) were included in the study. Mean age 68 ± 11.7 years, 78.3% male and 33.3% diabetic patients. Fifty-three claudicant limbs (46.5%) and 26 limbs (22.8%) with chronic limb threatening ischemia. Pearson correlation coefficient between ABI and PAT, showed a strong negative correlation (r= -0.78; p<0.01). Mean ABI and PAT for limbs in Fontaine stage I were 0.94 ± 0.17 and 82.0 ± 27.4 ms; Fontaine stage IIa 0.69 ± 0.21 and 141.3 ± 57.8 ms; Fontaine stage IIb 0.54 ± 0.14 and 173.4 ± 65.1 ms; Fontaine stage III 0.43 ± 0.15 and 216 ± 33.2 ms; Fontaine stage IV 0.49 ± 0.17 and 206.7 ± 78.1 ms, respectively. CONCLUSION: Our study suggests an inverse correlation between ABI and PAT, in accordance with the findings published in the literature, thus supporting the use of PAT as an easily reproducible and efficient alternative to ABI for evaluating the severity of PAD.

Randomized Trial Comparing a Stent-Avoiding With a Stent-Preferred Strategy in Complex Femoropopliteal Lesions.

BACKGROUND: Limited comparative data exist on different interventional strategies for endovascular revascularization of complex femoropopliteal interventions. OBJECTIVES: In this study, the authors aimed to compare a stent-avoiding (SA) vs a stent-preferred (SP) strategy, promoting optimal lesion preparation and the use of drug-eluting technologies in both arms. METHODS: Within a prospective, multicenter, pilot study, 120 patients with symptomatic complex femoropopliteal lesions (Rutherford classification 2-4, mean lesion length 187.7 ± 78.3 mm, 79.2% total occlusions) were randomly assigned in a 1:1 fashion to endovascular treatment with either paclitaxel-coated balloons or polymer-coated, paclitaxel-eluting stents. Lesion preparation including the use of devices for plaque modification and/or removal was at the operators' discretion in both treatment arms. RESULTS: In the SA group, lesion preparation was more frequently performed (71.7% SA [43/60] vs 51.7% [31/60] SP; P = 0.038) with a high provisional stenting rate (48.3% [29/60]). At the 12-month follow-up, primary patency was 78.2% (43/55) in the SA group and 78.6% (44/56) in the SP group (P = 1.0; relative risk: 0.995; 95% CI: 0.818-1.210). Freedom from major adverse events was determined in 93.1% (54/58) in the SA group and in 94.9% (56/59) in the SP group (P = 0.717; relative risk: 0.981; 95% CI: 0.895-1.075), with all adverse events attributable to clinically driven target lesion revascularization. CONCLUSIONS: Both endovascular strategies promoting lesion preparation before the use of drug-eluting devices suggest promising efficacy and safety results in complex femoropopliteal procedures with a high proportion of total occlusions through 12 months. Ongoing follow-up will show whether different results emerge over time. (Best Endovascular Strategy for Complex Lesions of the Superficial Femoral Artery [BEST-SFA]; NCT03776799).

Validation of a New Ankle Brachial Index Measurement System Using Pulse Wave Velocity.

Peripheral artery disease (PAD) is a common circulatory disorder characterized by the accumulation of fats, cholesterol, and other substances in the arteries that restrict blood flow to the extremities, especially the legs. The ankle brachial index (ABI) is a highly reliable and valid non-invasive test for diagnosing PAD. However, the traditional method has limitations. These include the time required, the need for Doppler equipment, the training of clinical staff, and patient discomfort. PWV refers to the speed at which an arterial pressure wave propagates along the arteries, and this speed is conditioned by arterial elasticity and stiffness. To address these limitations, we have developed a system that uses electrocardiogram (ECG) and photoplethysmography (PPG) signals to calculate pulse wave velocity (PWV). We propose determining the ABI based on this calculation. Validation was performed on 22 diabetic patients, and the results demonstrate the accuracy of the system, maintaining a margin of ±0.1 compared with the traditional method. This confirms the correlation between PWV and ABI and positions this technique as a promising alternative to overcome some of the limitations of the conventional method.

Effects of acute hyperoxia on autonomic function and coronary tone in patients with peripheral artery disease.

Numerous studies have shown that oxidative stress plays an important role in peripheral artery disease (PAD). Prior reports suggested autonomic dysfunction in PAD. We hypothesized that responses of the autonomic nervous system and coronary tone would be impaired in patients with PAD during exposure to acute hyperoxia, an oxidative stressor. In 20 patients with PAD and 16 healthy, sex- and age-matched controls, beat-by-beat heart rate (HR, from ECG) and blood pressure (BP, with Finometer) were recorded for 10 min during room air breathing and 5 min of hyperoxia. Cardiovagal baroreflex sensitivity and HR variability (HRV) were evaluated as measures of autonomic function. Transthoracic coronary echocardiography was used to assess peak coronary blood flow velocity (CBV) in the left anterior descending coronary artery. Cardiovagal baroreflex sensitivity at rest was lower in PAD than in healthy controls. Hyperoxia raised BP solely in the patients with PAD, with no change observed in healthy controls. Hyperoxia induced an increase in cardiac parasympathetic activity assessed by the high-frequency component of HRV in healthy controls but not in PAD. Indices of parasympathetic activity were lower in PAD than in healthy controls throughout the trial as well as during hyperoxia. Hyperoxia induced coronary vasoconstriction in both groups, while the coronary perfusion time fraction was lower in PAD than in healthy controls. These results suggest that the response in parasympathetic activity to hyperoxia (i.e., oxidative stress) is blunted and the coronary perfusion time is shorter in patients with PAD.NEW & NOTEWORTHY Patients with peripheral artery disease (PAD) showed consistently lower parasympathetic activity and blunted cardiovagal baroreflex sensitivity compared with healthy individuals. Notably, hyperoxia, which normally boosts parasympathetic activity in healthy individuals, failed to induce this response in patients with PAD. These data suggest altered autonomic responses during hyperoxia in PAD.

Exercise Therapy for Peripheral Artery Disease.

PURPOSE OF REVIEW: To summarize evidence regarding exercise treatments for lower extremity peripheral artery disease (PAD). RECENT FINDINGS: Supervised walking exercise is recommended by practice guidelines for PAD. Supervised treadmill exercise improves treadmill walking distance by approximately 180 m and 6-min walk distance by 30-35 m, compared to control. The Centers for Medicaid and Medicare Services covers 12 weeks of supervised exercise, but most people with PAD do not participate. Home-based walking exercise may be more convenient and accessible than supervised exercise. In randomized clinical trials, home-based walking exercise interventions incorporating behavioral methods, such as accountability to a coach, goal-setting, and self-monitoring, improved 6-min walk distance by 40-54 m, compared to control. Arm and leg ergometry also improved walking endurance for people with PAD, but efficacy compared to walking exercise remains unclear. Walking exercise is first-line therapy for PAD-related walking impairment and can be effective in either a supervised or a structured home-based setting.

Modelling lower-limb peripheral arterial disease using clinically available datasets: impact of inflow boundary conditions on hemodynamic indices for restenosis prediction.

BACKGROUND AND OBJECTIVES: The integration of hemodynamic markers as risk factors in restenosis prediction models for lower-limb peripheral arteries is hindered by fragmented clinical datasets. Computed tomography (CT) scans enable vessel geometry reconstruction and can be obtained at different times than the Doppler ultrasound (DUS) images, which provide information on blood flow velocity. Computational fluid dynamics (CFD) simulations allow the computation of near-wall hemodynamic indices, whose accuracy depends on the prescribed inlet boundary condition (BC), derived from the DUS images. This study aims to: (i) investigate the impact of different DUS-derived velocity waveforms on CFD results; (ii) test whether the same vessel areas, subjected to altered hemodynamics, can be detected independently of the applied inlet BC; (iii) suggest suitable DUS images to obtain reliable CFD results. METHODS: CFD simulations were conducted on three patients treated with bypass surgery, using patient-specific DUS-derived inlet BCs recorded at either the same or different time points than the CT scan. The impact of the chosen inflow condition on bypass hemodynamics was assessed in terms of wall shear stress (WSS)-derived quantities. Patient-specific critical thresholds for the hemodynamic indices were applied to identify critical luminal areas and compare the results with a reference obtained with a DUS image acquired in close temporal proximity to the CT scan. RESULTS: The main findings indicate that: (i) DUS-derived inlet velocity waveforms acquired at different time points than the CT scan led to statistically significantly different CFD results (p<0.001); (ii) the same luminal surface areas, exposed to low time-averaged WSS, could be identified independently of the applied inlet BCs; (iii) similar outcomes were observed for the other hemodynamic indices if the prescribed inlet velocity waveform had the same shape and comparable systolic acceleration time to the one recorded in close temporal proximity to the CT scan. CONCLUSIONS: Despite a lack of standardised data collection for diseased lower-limb peripheral arteries, an accurate estimation of luminal areas subjected to altered near-wall hemodynamics is possible independently of the applied inlet BC. This holds if the applied inlet waveform shares some characteristics - derivable from the DUS report - as one matching the acquisition time of the CT scan.

Retrospective Evaluation of the Effect of Lumbar Sympathetic Blockade on Pain Scores, Fontaine Classification, and Collateral Perfusion Status in Patients with Lower Extremity Peripheral Arterial Disease.

Background and Objectives: The aim of this retrospective study was to evaluate the effect of lumbar sympathetic block (LSB) on pain scores, Fontaine Classification, and collateral perfusion status in patients with lower extremity peripheral artery disease (PAD), in whom revascularization is impossible. Material and Methods: Medical records of 21 patients with PAD who underwent LSB with a combination of local anesthetics, steroids, and patient follow-up forms containing six-month follow-ups between January 2020 and March 2021 were retrospectively reviewed. Numeric Rating Scale (NRS), Pain Detect Questionnaire (PDQ) scores, Fontaine Classification Stages, and collateral perfusion status (collateral diameter and/or development of neovascularization) evaluated by arterial color Doppler Ultrasound (US) from the medical records and follow-up forms of the patients were reviewed. Results: NRS and PDQ scores were significantly lower, and regression of the Fontaine Classification Stages was significantly better after the procedure at the first, third, and sixth month than at the baseline values (p < 0.001). Only four patients (19%) had collaterals before the procedure. An increase in the collateral diameter after LSB was noted in three out of four patients. Before the procedure, 17 patients had no prominent collateral. However, in thirteen of these patients, after LSB, neovascularization was detected during the six-month follow-up period (three patients in the first month, seven patients in the third month, and thirteen patients in the sixth month). The number of patients evolving neovascularization after LSB was found to be statistically significant at the third and sixth months compared to the initial examination (p < 0.001). Conclusions: LSB with the use of local anesthetic and steroids in patients with lower extremity PAD not only led to lower NRS and PDQ scores, but also resulted in regressed Fontaine Classification Stages and better collateral perfusion status.

Body surface area is positively associated with ankle-brachial index.

BACKGROUND: Ankle-brachial index (ABI) measurement is a widely used diagnostic test for lower extremity artery disease. Previously, a larger body surface area (BSA) has been associated with lower blood pressure and lower 2-h post-load glucose concentrations in the oral glucose tolerance test. Our aim was to evaluate whether BSA has an impact on ABI and the prevalence of lower ABI values. METHODS: ABI measurements were performed on 972 subjects aged 45 to 70 years at high cardiovascular disease (CVD) risk. Subjects with previously diagnosed kidney disease, CVD, and diabetes were excluded. Their BSA was calculated by the Mosteller formula. Study subjects were divided into five BSA levels corresponding to 12.5th, 25th, 25th, 25th, and 12.5th percentiles of the total distribution. Effect modification by BSA in ABI between sexes was derived from a four-knot restricted cubic splines regression model. RESULTS: After adjustments for age, sex, pulse pressure, glucose regulation, waist circumference, alcohol intake, smoking status, leisure-time physical activity and medication, BSA level had a positive linear relationship with ABI (p for linearity <0.001). When BSA was less than 2.0 m2, there was no difference between the sexes, but when BSA was higher than 2.0 m2, men had higher ABI. CONCLUSION: BSA shows a positive linear relationship with ABI in CVD risk subjects without manifested CVD. The difference in ABI between men and women is modified by BSA and is appreciable when BSA is larger than 2.0 m2.

Temporal changes in toe-brachial index results in haemodialysis patients.

INTRODUCTION: Toe brachial index (TBI), the ratio of toe pressure to systolic blood pressure (SBP), helps predict peripheral arterial disease. In patients with kidney failure this may be performed during haemodialysis for convenience. Until recently there has been little evaluation of the impact of haemodialysis in limb and systemic perfusion on these values. We aimed to determine if the values of TBI would change during and after dialysis compared to pre-dialysis assessments. METHODS: Using a repeated measures study, TBIs and toe pressures were measured using the Hadeco Smartop Vascular Ultrasound Doppler in 31 patients undergoing haemodialysis. TBI assessments were completed pre-dialysis and compared to values obtained at 1 hour, 2 hours, 3 hours, and post-dialysis to monitor change in TBI results. Comparison of values for each patient were tested for differences using paired t-tests. Linear mixed-effects models were used to test for the effect of patient and clinical factors on change in outcome measures. RESULTS: Mean TBI decreased from pre-dialysis at 1 hour (0.72 to 0.63, p = 0.01) and remained lower at 2 hours and 3 hours, before returning to pre-dialysis levels at post-dialysis. Mean systolic blood pressure also declined during dialysis. Mean TBI results were lower in those with a history of lower limb ulceration and in females. Sixteen patients (51.6%) had a normal TBI at baseline, 14 (45.2%) had a mildly low TBI, and one (3.2%) had a severely low TBI. Between baseline and 1 h, five patient's results moved from normal to mildly abnormal and one from mildly abnormal to severely abnormal. As haemodialysis concluded (post-dialysis) there were 17 (56.7%) 'normal' TBIs, with no severely abnormal TBIs (p = 0.73). 0.30). CONCLUSION: TBI and toe pressures are impacted significantly by dialysis. TBI and toe pressure assessments should be conducted before haemodialysis begins, or between dialysis sessions to avoid variability.

Alginate-Encapsulated Mesenchymal Stromal Cells Improve Hind Limb Ischemia in a Translational Swine Model.

BACKGROUND: Cellular therapies have been investigated to improve blood flow and prevent amputation in peripheral artery disease with limited efficacy in clinical trials. Alginate-encapsulated mesenchymal stromal cells (eMSCs) demonstrated improved retention and survival and promoted vascular generation in murine hind limb ischemia through their secretome, but large animal evaluation is necessary for human applicability. We sought to determine the efficacy of eMSCs for peripheral artery disease-induced limb ischemia through assessment in our durable swine hind limb ischemia model. METHODS AND RESULTS: Autologous bone marrow eMSCs or empty alginate capsules were intramuscularly injected 2 weeks post-hind limb ischemia establishment (N=4/group). Improvements were quantified for 4 weeks through walkway gait analysis, contrast angiography, blood pressures, fluorescent microsphere perfusion, and muscle morphology and histology. Capsules remained intact with mesenchymal stromal cells retained for 4 weeks. Adenosine-induced perfusion deficits and muscle atrophy in ischemic limbs were significantly improved by eMSCs versus empty capsules (mean±SD, 1.07±0.19 versus 0.41±0.16, P=0.002 for perfusion ratios and 2.79±0.12 versus 1.90±0.62 g/kg, P=0.029 for ischemic muscle mass). Force- and temporal-associated walkway parameters normalized (ratio, 0.63±0.35 at week 3 versus 1.02±0.19 preligation; P=0.17), and compensatory footfall patterning was diminished in eMSC-administered swine (12.58±8.46% versus 34.85±15.26%; P=0.043). Delivery of eMSCs was associated with trending benefits in collateralization, local neovascularization, and muscle fibrosis. Hypoxia-cultured porcine mesenchymal stromal cells secreted vascular endothelial growth factor and tissue inhibitor of metalloproteinase 2. CONCLUSIONS: This study demonstrates the promise of the mesenchymal stromal cell secretome at improving peripheral artery disease outcomes and the potential for this novel swine model to serve as a component of the preclinical pipeline for advanced therapies.

Predicting Outcomes Following Lower Extremity Endovascular Revascularization Using Machine Learning.

BACKGROUND: Lower extremity endovascular revascularization for peripheral artery disease carries nonnegligible perioperative risks; however, outcome prediction tools remain limited. Using machine learning, we developed automated algorithms that predict 30-day outcomes following lower extremity endovascular revascularization. METHODS AND RESULTS: The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity endovascular revascularization (angioplasty, stent, or atherectomy) for peripheral artery disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day postprocedural major adverse limb event (composite of major reintervention, untreated loss of patency, or major amputation) or death. Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 machine learning models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Overall, 21 886 patients were included, and 30-day major adverse limb event/death occurred in 1964 (9.0%) individuals. The best performing model for predicting 30-day major adverse limb event/death was extreme gradient boosting, achieving an area under the receiver operating characteristic curve of 0.93 (95% CI, 0.92-0.94). In comparison, logistic regression had an area under the receiver operating characteristic curve of 0.72 (95% CI, 0.70-0.74). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.09. The top 3 predictive features in our algorithm were (1) chronic limb-threatening ischemia, (2) tibial intervention, and (3) congestive heart failure. CONCLUSIONS: Our machine learning models accurately predict 30-day outcomes following lower extremity endovascular revascularization using preoperative data with good discrimination and calibration. Prospective validation is warranted to assess for generalizability and external validity.

Convolutional Neural Networks to Study Contrast-Enhanced Magnetic Resonance Imaging-Based Skeletal Calf Muscle Perfusion in Peripheral Artery Disease.

Peripheral artery disease (PAD) is associated with impaired blood flow in the lower extremities and histopathologic changes of the skeletal calf muscles, resulting in abnormal microvascular perfusion. We studied the use of convolution neural networks (CNNs) to differentiate patients with PAD from matched controls using perfusion pattern features from contrast-enhanced magnetic resonance imaging (CE-MRI) of the skeletal calf muscles. We acquired CE-MRI based skeletal calf muscle perfusion in 56 patients (36 patients with PAD and 20 matched controls). Microvascular perfusion imaging was performed after reactive hyperemia at the midcalf level, with a temporal resolution of 409 ms. We analyzed perfusion scans up to 2 minutes indexed from the local precontrast arrival time frame. Skeletal calf muscles, including the anterior muscle, lateral muscle, deep posterior muscle group, and the soleus and gastrocnemius muscles, were segmented semiautomatically. Segmented muscles were represented as 3-dimensional Digital Imaging and Communications in Medicine stacks of CE-MRI perfusion scans for deep learning (DL) analysis. We tested several CNN models for the 3-dimensional CE-MRI perfusion stacks to classify patients with PAD from matched controls. A total of 2 of the best performing CNNs (resNet and divNet) were selected to develop the final classification model. A peak accuracy of 75% was obtained for resNet and divNet. Specificity was 80% and 94% for resNet and divNet, respectively. In conclusion, DL using CNNs and CE-MRI skeletal calf muscle perfusion can discriminate patients with PAD from matched controls. DL methods may be of interest for the study of PAD.

The characteristics of arterial risk factors and ankle-brachial index in patients with lower extremity chronic venous diseases: results from the BEST study.

BACKGROUND: The aim of our study was to explore the characteristics of the arterial risk factors and ankle-brachial index (ABI) in patients with lower extremity chronic venous disease (LECVD). METHODS: A total of 2642 subjects were employed in our study. The lifestyle and clinical data were collected. The history of vascular diseases contained coronary artery disease, stroke, hypertension, and diabetes. ABI low than 0.9 was considered as lower extremity artery disease (LEAD). A series of blood indicators were measured. RESULTS: Patients with ABI low than 0.9 belonged to the group of LEAD. Age, smoking, drinking, hypertension, diabetes mellitus, lipid-lowering drug, antidiabetic, total protein, total protein, triglyceride, low-density lipoprotein cholesterol, glycosylated hemoglobin and homocysteine were the common risk factors shared by LEAD and LECVD (P<0.05). The prevalence of LEAD in patients with LECVD was higher than those without LECVD (P<0.05). In Pearson correlation analysis, LECVD was related to LEAD (P<0.05). Before and after adjusted shared factors, as the performance of the logistic regression models, LEAD was an independent risk factor for the prevalence of LECVD (OR=2.937, 95% CI: [1.956, 4.411], P<0.001). CONCLUSIONS: Our study demonstrated that an ABI lower than 0.9 is an independent risk factor for LECVD.

Association of endothelial dysfunction and peripheral arterial disease with sarcopenia in chronic kidney disease.

BACKGROUND: Endothelial dysfunction and peripheral arterial disease (PAD), which disturb skeletal muscle microperfusion, are highly prevalent in patients with chronic kidney disease (CKD). We evaluated the association of endothelial dysfunction and PAD with sarcopenia in patients with non-dialysis CKD. METHODS: This cross-sectional study included 420 patients with stages 3-5 non-dialysis CKD aged 69.0 ± 11.8 years. Skeletal muscle index (skeletal muscle mass/height2), handgrip strength, 6-m gait speed and strength of hip flexion and knee extension were measured. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019. Endothelial dysfunction and PAD were assessed using the vascular reactivity index (VRI) and ankle-brachial index (ABI), respectively. A VRI < 1.0 was classified as poor endothelial function, and an ABI < 0.9 was defined as PAD. Additionally, endothelial and inflammatory biomarkers, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), asymmetric dimethylarginine, endothelin-1 (ET-1) and interleukin-6, were measured in a subgroup of 262 patients. RESULTS: Among the participants, 103 (24.5%) were classified as having sarcopenia. Compared with patients without sarcopenia, those with sarcopenia had significantly lower ABI (1.04 ± 0.16 vs. 1.08 ± 0.15, P = 0.028 for the right ABI; 1.01 ± 0.16 vs. 1.06 ± 0.16, P = 0.002 for the left ABI) and VRI (0.83 ± 0.57 vs. 1.08 ± 0.56, P < 0.001) and had higher serum levels of ICAM-1 (P < 0.001), VCAM-1 (P = 0.003) and ET-1 (P = 0.037). Multivariate logistic regression revealed that, beyond age and body mass index, the average ABI (odds ratio [OR]: 0.81/0.1 increase; 95% confidence interval [CI]: 0.67-0.98; P = 0.032) and VRI (OR: 0.93/0.1 increase; 95% CI: 0.88-0.98; P = 0.010) were independently associated with sarcopenia. Among the endothelial biomarkers measured, ICAM-1 (OR: 2.47/1-SD increase; 95% CI: 1.62-3.75) and VCAM-1 (OR: 1.91/1-SD increase; 95% CI: 1.27-2.87) were independent predictors of sarcopenia. Group stratification based on the cut-offs of VRI and ABI showed that those with both poor VRI and ABI had the greatest risk for sarcopenia (OR: 4.22; 95% CI: 1.69-10.49), compared with those with normal VRI and ABI. CONCLUSIONS: Endothelial dysfunction and PAD are independently associated with sarcopenia in patients with stages 3-5 CKD, suggesting the dominant role of vascular dysfunction in sarcopenia.