Five-year outcomes of the GORE VIABAHN Endoprosthesis for the treatment of complex femoropopliteal lesions from a Japanese postmarket surveillance study.

Introduction: The safety and effectiveness of the GORE VIABAHN Endoprosthesis for treatment of symptomatic patients with peripheral artery disease (PAD) and complex femoropopliteal (FP) lesions was assessed in a real-world Japanese practice setting. Methods: A prospective, multicenter, postmarket surveillance study was conducted from 2016 to 2017 at 64 sites in Japan. Symptomatic patients with PAD and FP lesions ⩾ 10 cm and reference vessel diameters ranging from 4.0 to 7.5 mm were eligible for enrollment. Outcome measures evaluated at 5 years were primary patency (PP), primary-assisted patency (PAP), secondary patency (SP), freedom from target lesion revascularization (fTLR), occurrence of device- or procedure-related serious adverse events (SAEs), and stent fractures. Results: A total of 321 patients were enrolled and were a mean age of 73.9 ± 8.7 years; 77.3% were men and 26.5% had chronic limb-threatening ischemia (CLTI). The mean lesion length was 23.6 ± 6.6 cm and the frequency with TASC II C/D lesions and chronic total occlusions was 86.6% and 70.4%, respectively. The Kaplan-Meier estimated PP, PAP, SP, and fTLR at 5 years was 62.4%, 74.1%, 82.3%, and 75.9%, respectively. The mean ankle-brachial index was 0.92 ± 0.15 and the mean improvement in Rutherford class was 2.3 ± 1.4, which was maintained through 5 years. The rate of cumulative device- or procedure-related SAEs through 5 years was 19.9% with only 9.3% of those occurring after the first year. No stent fractures were observed through 5 years by x-ray evaluation. Conclusion: The 5-year safety and efficacy outcomes of the endoprosthesis were clinically acceptable for treating complex FP lesions in a real-world cohort of Japanese patients with PAD. (ClinicalTrials.gov Identifier: NCT04706273).

Accuracy of maximal acceleration time of pedal arteries to diagnose critical limb-threatening ischemia.

INTRODUCTION: Maximal acceleration time of distal arteries of the foot (ATmax) is correlated to ankle-brachial index (ABI) and toe-brachial index (TBI), and seems very promising in diagnosing severe peripheral artery disease (PAD) and especially critical limb-threatening ischemia (CLTI). Our goal was to confirm the cut-off value of 215 ms to predict a toe pressure (TP) ⩽ 30 mmHg. METHODS: A 4-month retrospective study was conducted on patients addressed for suspicion of PAD. Demographic data, ABI, TBI, and Doppler ultrasound scanning parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded. RESULTS: A total of 137 patients with 258 lower limbs were included. ATmax was highly correlated to TBI (r = -0.89, p < 0.001). With the cut-off value of 215 ms, ATmax was effective to diagnose TP ⩽ 30 mmHg with a sensitivity of 93% [95% CI 77-99], a specificity of 96% [95% CI 92-98], a positive predictive value of 73% [95% CI 56-86], a negative predictive value of 99% [95% CI 97-100], and an area under the receiver operating characteristics curve of 0.99 [95% CI 0.98-1.00]. ATmax also showed promising results to rule out PAD in healthy patients. CONCLUSION: ATmax is a reliable diagnostic tool to diagnose low TP and could be a new easily performed hemodynamic criterion for diagnosis of CLTI.

How cognitive performance changes according to the ankle-brachial index score in an elderly cohort? Results from the Toledo Study of Healthy Ageing.

In the ageing process, the vascular system undergoes morphological and functional changes that may condition brain functioning; for this reason, the aims of this study were to assess the effect of vascular function indirectly measured by ankle-brachial index (ABI) on both cognitive performance at baseline and change in cognitive performance at end of follow-up. We developed a prospective, population-based, cohort study with 1147 participants aged > 65 years obtained from the Toledo Study for Healthy Ageing who had cognitive assessment and measured ABI in the first wave (2006-2009) were selected for the cross-sectional analysis. Those participants who also performed the cognitive assessment in the second wave (2011-2013) were selected for the prospective analysis. Cognitive impairment diagnosis and symptoms and/or history of cardio/neurovascular disease were used as exclusion criteria. Multivariate segmented regression model was used to assess the associations between ABI and cognitive performance in both the cross-sectional and prospective analyses. As ABI score decreased from 1.4, the cross-sectional analysis showed a higher decrease in cognitive performance and the prospective analysis showed a higher degree of worsening in cognitive performance. Our findings suggest that the ABI, a widespread measure of vascular health in primary care, may be a useful tool for predicting cognitive performance and its evolution.

Ultrasound-detected tibial artery calcification as a marker of cardiovascular and lower-limb risk in asymptomatic patients with type-2 diabetes.

BACKGROUND: Medial arterial calcification (MAC) is a vascular disease distinct from atherosclerosis. Recently, several studies have demonstrated that MAC is an important marker of cardiovascular events. We aim to assess the presence of MAC during ultrasound screening of lower-limb vasculature and its association with both cardiovascular (CV) and lower-limb events in patients with type-2 diabetes. METHODS: A retrospective cohort study was conducted on 1119 patients with type-2 diabetes free from CV disease. A CV work-up, including vascular ultrasound, was performed for each patient. The presence of MAC was assessed on posterior tibial arteries and ankle-brachial index (ABI) was measured. Major acute CV events (MACEs) and lower-limb events (MALEs) were recorded as a composite endpoint for a 5-year period. RESULTS: We identified MAC among 212 (18.9%) patients. The independent determinants of MAC were age and diabetic retinopathy. Over a period of 5 years, 125 MACEs and 22 MALEs occurred. MAC was significantly associated with the composite outcome MACE + MALE (HR = 1.94; 95% CI: 1.23, 3.08, p = 0.005) or with MACE (HR = 1.85; 95% CI: 1.16, 2.95, p = 0.010). Adjusted for ABI and diabetic foot wound, MAC remained a determinant of MALE (HR = 5.49; 95% CI: 2.19, 13.76, p < 0.001). Considering each ABI group, MAC was associated with both MACE and MALE in the normal ABI group. CONCLUSIONS: Ultrasound-detected MAC on tibial arteries seems to be a determinant of both CV and lower-limb events, independent from ABI. MAC helps to refine the CV risk in patients with normal ABI.

Lower extremity symptoms and ankle-brachial index screening as predictors of cardiovascular outcomes in Black adults.

BACKGROUND: The prevalence of peripheral artery disease (PAD) and leg symptoms are higher in Black than White adults. We studied the effects of self-reported lower extremity symptoms and ankle-brachial indices (ABI) groups on outcomes. METHODS: Black participants in the Jackson Heart Study with baseline ABI and PAD symptom assessments (exertional leg pain by the San Diego Claudication questionnaire) were included. Abnormal ABI was < 0.90 or > 1.40. Participants were divided into (1) normal ABI, asymptomatic, (2) normal ABI, symptomatic, (3) abnormal ABI, asymptomatic, and (4) abnormal ABI, symptomatic to examine their associations with MACE (stroke, myocardial infarction, fatal coronary heart disease) and all-cause mortality, using Kaplan-Meier survival curves and stepwise Cox proportional hazard models adjusting for Framingham risk factors. RESULTS: Of 4586 participants, mean age was 54.6 ± 12.6 years, with 63% women. Compared with participants with normal ABI who were asymptomatic, participants with abnormal ABI and leg symptoms had highest risk of MACE (adjusted HR 2.28; 95% CI 1.62, 3.22) and mortality (aHR 1.82; 95% CI 1.32, 2.56). Participants with abnormal ABI without leg symptoms had higher risk for MACE (aHR 1.49; 95% CI 1.06, 2.11) and mortality (aHR 1.44; 95% CI 1.12, 1.99). Participants with normal ABI and no leg symptoms did not have higher risks. CONCLUSION: Among Black adults, the highest risk for adverse outcomes were in symptomatic participants with abnormal ABIs, followed by asymptomatic participants with abnormal ABIs. These findings underscore the need for further studies to screen for PAD and develop preventative approaches in Black adults with asymptomatic disease.

Accuracy of the pedal acceleration time to diagnose limb ischemia in patients with and without diabetes using the WIfI classification.

INTRODUCTION: Evaluation of limb hemodynamics using the ankle-brachial index (ABI) may be difficult due to skin lesions, extensive necrosis, and obesity, such as commonly present in patients with diabetes with chronic limb-threatening ischemia (CLTI). We hypothesized that the pedal acceleration time (PAT) correlates with ABI and Wound, Ischemia, and foot Infection (WIfI) scores in patients with diabetes to serve as a new modality to accurately stage CLTI. METHODS: A single-center, cross-sectional study included patients with and without diabetes > 18 years with CLTI. Limbs were categorized in three grades of ischemia based on the ABI (ABI < 0.8, < 0.6, and < 0.4) and in two classes based on WIfI stages of amputation risk. Receiver operator characteristic (ROC) curves were used to determine PAT sensitivity, specificity, and accuracy to predict lower-limb ischemia. RESULTS: A total of 141 patients (67 nondiabetic and 74 diabetic) and 198 lower limbs (94 nondiabetic and 104 diabetic) met the inclusion criteria. In patients without diabetes, the accuracy of PAT for detecting an ABI < 0.8 was 85%; for detecting an ABI < 0.6 was 85%; and for detecting an ABI < 0.4 was 87%. In patients with diabetes, the accuracy of PAT in detecting an ABI < 0.8 was 91%; for detecting an ABI < 0.6 was 79%; and for detecting an ABI < 0.4 was 88%. In patients without diabetes, the accuracy for detecting WIfI stages of moderate and high amputation risk was 77% and for patients with diabetes was also 77%. CONCLUSIONS: PAT shows high correlation with the ABI as well as with the WIfI stages of amputation risk and the grades of ischemia, with high accuracy.

Safety and efficiency of femoral artery access closure using QuikClot Combat Gauze in patients with severe arterial calcification of access sites.

Background: In order to achieve better hemostasis of puncture holes in the femoral artery (FA) after an endovascular procedure, this study evaluated the effect and safety of manual compression (MC) with QuikClot Combat Gauze (QIC) and with mechanical compression (using a C-clamp) of the common access site, the FA, in patients with peripheral arterial occlusive disease (PAOD) combined with anterior femoral artery calcification (AFAC). Methods: We prospectively reviewed 100 patients receiving either MC with QIC or mechanical compression (control group) after endovascular intervention for PAOD plus AFAC from February 2014 to September 2018 in a single unit, which was assessed using computerized tomography angiography (CTA). Results: The mean time to completion of hemostasis was 30±0 minutes in the control group and 18±2.20 minutes in the QIC group (P<0.001). The time to ambulation of the QIC and control groups was 4.38±0.46 and 4.86±0.30 hours (P<0.001), respectively. Eight (16%) patients in the control group had hematoma, as compared with one patient (2%) in the QIC group (P=0.031), while sixteen (32%) patients in the control group had ecchymosis, as compared with four (8%) in the QIC group (P=0.005). Use of QIC and coronary artery disease (CAD) were identified as independent factors correlated with an increased risk of minor complications. Conclusions: QIC facilitated effective and safe hemostasis in patients with PAOD and AFAC.

Risk of Frailty According to the Values of the Ankle-Brachial Index in the Toledo Study for Healthy Aging.

BACKGROUND: Vascular function (VF) is a general term used to describe the regulation of blood flow, arterial pressure, capillary recruitment, filtration and central venous pressure, it´s well known that age has direct effects on the VF, and this may affect the frailty status. OBJECTIVES: To analyse the association between Frailty Trait Scale 5 (FTS 5) with VF and its changes at values below and above a nadir. DESIGN: Prospective population-based cohort study. SETTING AND PARTICIPANTS: Data from 1.230 patients were taken from the first wave (2006-2009) of the Toledo Study for Healthy Aging. MEASUREMENTS: Frailty was evaluated using FTS 5, which evaluates 5 items: Body mass index, progressive Romberg, physical activity, usual gait speed and hand grip strength. VF was assessed using the ankle-brachial index (ABI) as an indirect measure of VF. Screening for cardiovascular and cerebrovascular disease was also performed by self-reporting and by searching medical records, and was used as exclusion criteria. RESULTS: The optimal ABI cut-off point that maximized the adjusted R2 was 1.071. We observed a statistically significant association for FTS 5 score above and below the ABI cut-off points. For every tenth that the ABI decreased below the cut-off point the patient had an increase in the FTS 5 score of 0.47 points and in every tenth that increased above the cut-off point the increase in the FTS 5 score was 0.41 points. Of all FTS 5 items, the gait speed was the only item that showed a significant association with an ABI changes 0.28 and 0.21 points for every tenth below and above the cut-off point, respectively. CONCLUSIONS: Frailty is highly associated with VF. In addition, FTS 5 and its gait speed criteria are useful to detect VF impairments, via changes in ABI.

Effects of ankle-brachial index and brachial-ankle pulse wave velocity on all-cause mortality in a community-based elderly population.

Background: Ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) are both important indicators of arterial stiffness and vascular injury. At present, most studies on the relationship between ABI and baPWV and all-cause mortality in community-based elderly are analyzing ABI or baPWV alone, and will focus on a single special population such as diabetes and stroke. The purpose of this study was to evaluate the relationship between ABI and baPWV in a Chinese community-based elderly population, and to analyze their impact on all-cause mortality in a community-based population through a follow-up of nearly 10 years. Methods: Participants were residents of the Wanshou Road community in Beijing, China. A total of 2,162 people in the community were included, with an average age of 71.48 years. During a mean follow-up period of 9.87 years, 1,826 subjects completed follow-up. Kaplan-Meier survival analysis and different Cox regression models were used to verify the association of ABI and baPWV with all-cause mortality. The selected subjects were divided into two groups according to ABI and baPWV, and ABI was divided into two groups with 0.90 as the cut-off point (group 1: 0.9 < ABI ≤ 1.3; group 2: ABI ≤ 0.9); according to the level of baPWV, they were divided into three groups (Tertile 1: baPWV <1761.5 cm/s; Tertile 2: 1761.5 ≤ baPWV <2121.5 cm/s; Tertile 3: baPWV ≥2121.5 cm/s). Results: 1,826 people were included in the statistical analysis, and the total mortality rate was 181.3/1000. The 10-year all-cause mortality rate of the abnormal ABI group (group 2) was 44.7%, and that of the normal ABI group (group 1) was 17.0%; The 10-year all-cause mortality rates from low to high in the baPWV tertile were 10.0%, 18.7%, and 26.4%. In the Cox proportional hazards model, after adjusting for possible confounders, the effect of baPWV on all-cause mortality was significant, with the 3rd tertile having a 1.647-fold higher risk of all-cause mortality than the 1st tertile (P = 0.014 ). Conclusions: ABI and baPWV are risk factors affecting all-cause mortality in the elderly community population, and baPWV is an independent predictor of all-cause mortality in the elderly community population.

Artificial intelligence for the evaluation of peripheral artery disease using arterial Doppler waveforms to predict abnormal ankle-brachial index.

BACKGROUND: Patients with peripheral artery disease (PAD) are at increased risk for major adverse limb and cardiac events including mortality. Developing screening tools capable of accurate PAD identification is a necessary first step for strategies of adverse outcome prevention. This study aimed to determine whether machine analysis of a resting Doppler waveform using deep neural networks can accurately identify patients with PAD. METHODS: Consecutive patients (4/8/2015 - 12/31/2020) undergoing rest and postexercise ankle-brachial index (ABI) testing were included. Patients were randomly allocated to training, validation, and testing subsets (70%/15%/15%). Deep neural networks were trained on resting posterior tibial arterial Doppler waveforms to predict normal (> 0.9) or PAD (⩽ 0.9) using rest and postexercise ABI. A separate dataset of 151 patients who underwent testing during a period after the model had been created and validated (1/1/2021 - 3/31/2021) was used for secondary validation. Area under the receiver operating characteristic curves (AUC) were constructed to evaluate test performance. RESULTS: Among 11,748 total patients, 3432 patients met study criteria: 1941 with PAD (mean age 69 ± 12 years) and 1491 without PAD (64 ± 14 years). The predictive model with highest performance identified PAD with an AUC 0.94 (CI = 0.92-0.96), sensitivity 0.83, specificity 0.88, accuracy 0.85, and positive predictive value (PPV) 0.90. Results were similar for the validation dataset: AUC 0.94 (CI = 0.91-0.98), sensitivity 0.91, specificity 0.85, accuracy 0.89, and PPV 0.89 (postexercise ABI comparison). CONCLUSION: An artificial intelligence-enabled analysis of a resting Doppler arterial waveform permits identification of PAD at a clinically relevant performance level.

Corrigendum: Ankle-Brachial Index Is Independently Associated With Cardiovascular Outcomes and Foot Ulcers in Asian Patients With Type 2 Diabetes Mellitus.

[This corrects the article DOI: 10.3389/fendo.2021.752995.].

Correlating Toe-Brachial Indices and Angiographically Confirmed Peripheral Artery Disease: A Retrospective Review.

In advanced peripheral arterial disease (PAD), medial arterial calcification is known to inflate the ankle-brachial index. An alternative method of evaluating symptomatic patients is toe-brachial indexes (TBI), where a ratio less than .7 indicates PAD and less than .4 indicates a severe form. The objective of this retrospective analysis was to investigate the association between TBIs less than .7 and angiographically verified PAD. Patients were required to have either a leg angiogram 13 months prior to or 12 months after a 6-minute walk test. Of the 174 included patients, the mean overall TBI was .450. The mean TBI by location was highest at iliac and infra-geniculate with .544 and lowest at supra-geniculate with .372. Infra-geniculate lesions were also the most frequent (n = 46). A TBI less than .4 was found in 47.7% of patients. TBIs greater than .7 were present in 36 patients; however, only 16 had significant angiographic stenosis. In conclusion, the majority of patients with angiographic PAD had a TBI less than .7, especially less than .4. Contrary to suspicion, infra-geniculate lesions were the most common and had the highest TBI.

Combination of Exercise Testing Criteria to Diagnose Lower Extremity Peripheral Artery Disease.

Objectives: Nothing is known about the interest of the combination of exercise tests to diagnose Lower-extremity Peripheral Artery Disease (LEPAD). The aim of this study was to assess if combining exercise testing criteria [post-exercise Ankle-Brachial Index (ABI) + exercise-oximetry (exercise-TcPO2)] improves the detection of lower limbs arterial stenoses as compared with post-exercise ABI using American Heart Association (AHA) criteria, or exercise-TcPO2 alone. Material and Methods: In a prospective monocentric study, consecutive patients with exertional-limb pain and normal resting-ABI referred to our vascular center (Rennes, France) were assessed from May 2016 to February 2018. All included patients had a computed tomography angiography (CTA), a resting-ABI, a post-exercise ABI and an exercise-TcPO2. AHA post-exercise criteria, new validated post-exercise criteria (post-exercise ABI decrease ≥18.5%, post-exercise ABI decrease <0.90), and Delta from Rest of Oxygen Pressure (Total-DROP) ≤-15mmHg (criterion for exercise-TcPO2) were used to diagnose arterial stenoses ≥50%. For the different combinations of exercise testing criteria, sensitivity or specificity or accuracies were compared with McNemar's test. Results: Fifty-six patients (mean age 62 ± 11 years old and 84% men) were included. The sensitivity of the combination of exercise testing criteria (post-exercise ABI decrease ≥18.5%, or post-exercise ABI decrease <0.90 or a Total-DROP ≤-15mmHg) was significantly higher (sensitivity = 81% [95% CI, 71-92]) than using only one exercise test (post-exercise AHA criteria (sensitivity = 57% [43-70]) or exercise-TcPO2 alone (sensitivity = 59% [45-72]). Conclusions: Combination of post-exercise ABI with Exercise-TcPO2 criteria shows better sensitivity to diagnose arterial stenoses compared with the AHA post-exercise criteria alone or Exercise-TcPO2 criteria used alone. A trend of a better accuracy of this combined strategy was observed but an external validation should be performed to confirm this diagnostic strategy.

Ankle-Brachial Index Is Independently Associated With Cardiovascular Outcomes and Foot Ulcers in Asian Patients With Type 2 Diabetes Mellitus.

Background and Aims: The ankle-brachial index (ABI) is an efficient tool for objectively documenting the presence of lower-extremity peripheral arterial disease (PAD). The predictive factors of cardiovascular events and diabetic foot ulcer were not clear from the ABI examination in Taiwanese patients with type 2 diabetes mellitus (DM). Methods: We enrolled 482 patients with type 2 DM who regularly visited the outpatient department of Chang Gung Memorial Hospital and received ABI as well as brachial-ankle pulse wave velocity (ba-PWV) examinations from 2010 to 2017. Age, gender, PAD symptoms, comorbidities, family history of chronic diseases, lifestyle (smoking, alcohol consumption, and exercise), height, weight, waist circumference, monofilament testing and foot ulcer status were studied. Results: There were 104 (22%) patients (mean age, 67.8 years) with the ABI <1.0. These patients with low ABI (ABI<1.0) had a significantly older age (p=0.001), higher delta PWV (p<0.001), higher rates of stroke (p=0.007), myocardial infarction (p=0.016), and foot ulcer (p=0.039). In a multivariable analysis model, the adjusted odds ratio (aOR) for myocardial infarction, stroke, and foot ulcers associated with low ABI were 1.219 (0.397-3.743, p=0.729), 1.204 (0.556-2.610, p=0.638), and 2.712 (1.199-6.133, p=0.017), respectively. The patients with low PWV (PWV<1400 cm/s) were significantly younger (p<0.001) and had a lower rate of hypertension (p<0.001), and higher percentages of stroke (p=0.027) and dialysis (p=0.041) family history. Conclusions: Low ABI was associated with cardiovascular events and diabetic foot ulcer independently in patients with type 2 DM.

Sustained physical activity in peripheral artery disease: Associations with disease severity, functional performance, health-related quality of life, and subsequent serious adverse events in the LITE randomized clinical trial.

This study investigated cross-sectional associations of peripheral artery disease (PAD) severity (defined by the ankle-brachial index (ABI)) and amounts of daily sustained physical activity (PA) (defined as > 100 activity counts per minute lasting 5 consecutive minutes or more). This study also investigated associations of amounts of daily sustained PA with 6-minute walk (6MW) distance and the Short Form-36 physical functioning domain (SF-36 PF) score in cross-sectional analyses and with serious adverse events (SAEs) in longitudinal analyses of people with PAD. PA was measured continuously for 10 days using a tri-axial accelerometer at baseline in 277 participants with PAD randomized to the LITE clinical trial. In regression analyses, each 0.15 lower ABI value was associated with a 5.67% decrease in the number of daily bouts of sustained PA (95% CI: 3.85-6.54; p < 0.001). Every additional bout of sustained PA per day was associated with a 4.56-meter greater 6MW distance (95% CI: 2.67-6.46; p < 0.0001), and a 0.81-point improvement in SF-36 PF score (95% CI: 0.34-1.28; p < 0.001). Participants with values of daily bouts of sustained PA below the median had higher rates of SAEs during follow-up, compared to participants above the median (41% vs 24%; p = 0.002). In conclusion, among participants with PAD, lower ABI values were associated with fewer bouts of daily sustained PA. A greater number of bouts of daily sustained PA were associated with better 6MW performance and SF-36 PF score, and, in longitudinal analyses, lower rates of SAEs. Clinicaltrials.gov ID: NCT02538900.

Surrogate Markers of Subclinical Atherosclerosis and Its Associated Factors in Patients with ß-Thalassemia Major.

ß-Thalassemia major (ß-TM) is a severe genetic hemoglobin (Hb) disorder with cardiovascular complications such as atherosclerosis due to transfusion-dependent iron overload. We aimed to determine the associated factors with surrogate markers of subclinical atherosclerosis in these patients. Sixty subjects with ß-TM referred to the Thalassemia Clinic of the Iranian Blood Transfusion Organization (IBTO) were included in our study. The blood samples were collected for laboratory measurements. The carotid intima-media thickness (CIMT), was measured by ultrasonography, and ankle-brachial index (ABI) was calculated. The multivariate linear analysis was performed to determine the appropriate indicators of subclinical atherosclerosis in ß-TM. There was no significant difference in baseline characteristics between the study groups. In multivariate linear analysis, age and systolic blood pressure (SBP) were negatively associated with inverse-transformed CIMT [unstandardized ß coefficient (B): -0.024, 95% confidence interval (95% CI): -0.032- -0.010, p < 0.001; B: -0.009, 95% CI: -0.017- -0.001, p 0.031, respectively]. There was also a significant correlation between the serum level of high-density lipoprotein cholesterol (HDL-C) and insulin with higher ABI, after adjustment for confounding variables (B: 0.003; 95% CI: 0.000-0.005; p = 0.030, and B: 0.004, 95% CI: 0.000-0.009, p = 0.037, respectively). Our results show that advancing age and increased SBP, HDL-C and insulin, associated with higher CIMT or ABI, are appropriate indicators of subclinical atherosclerosis in ß-TM patients.

Pilot study of contrast-free MRI reveals significantly impaired calf skeletal muscle perfusion in diabetes with incompressible peripheral arteries.

Patients with diabetes mellitus (DM) are more likely to have densely calcified lesions in the below-the-knee tibial arteries. However, the relationship between peripheral arterial calcification and local skeletal muscle perfusion has not been explored. Thirty subjects were prospectively recruited into three groups in this pilot study: (1) Non-DM: 10 people without DM; (2) DM, ABI < 1.3: 10 people with DM and normal ankle-brachial index (ABI) (0.9-1.3); and (3) DM, ABI ⩾ 1.3: 10 people with DM and ABI ⩾ 1.3. All subjects underwent calf perfusion measurements at rest and during an isometric plantarflexion contraction exercise within the magnetic resonance imaging (MRI) system. The noncontrast MRI techniques were applied to quantitatively assess skeletal muscle blood flow (SMBF) and oxygen extraction fraction (SMOEF) in medial gastrocnemius and soleus muscles. Both SMBF and SMOEF reserves were calculated as the ratio of the exercise value to the resting value. Exercise SMBF and SMOEF values in the medial gastrocnemius muscle were lower in the two DM groups than in the non-DM group (p < 0.05). The SMBF reserve in medial gastrocnemius was significantly lower in the DM, ABI ⩾ 1.3 group compared to the DM, ABI < 1.3 group (p < 0.05). This study demonstrates that people with DM and calcified arteries had lower perfusion in gastrocnemius muscle compared to those without DM and those with DM and a normal ABI.

Accuracy of Acceleration Time of Distal Arteries to Diagnose Severe Peripheral Arterial Disease.

CONTEXT: Ankle-brachial index (ABI) and toe-brachial index (TBI) are the recommended tests for the diagnosis of lower extremity peripheral artery disease (PAD) and the assessment of its severity, whereas Doppler ultrasound (DUS) is usually used to localize vascular lesions. However, the performance of DUS as an alternative to TBI and ABI measurement is unknown. OBJECTIVE: The goals were (i) to evaluate the correlation between DUS parameters of distal arteries of the lower extremities with TBI in patients with PAD; (ii) to evaluate the correlation between DUS parameters of distal arteries with ABI; and (iii) to assess the diagnostic accuracy of maximal acceleration time of pedal arteries to detect toe pressure ≤30 mmHg. METHODS: An observational retrospective study was conducted for 1 year on patients with the diagnosis of PAD on DUS. Demographic data, ABI, TBI, and DUS parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded. RESULTS: Seventy-seven patients with 88 limbs were included, aged 69 [interquartile range: 11 years] with 28.6% of diabetic patients. The highest acceleration time of either DPA or LPA (ATmax) was the most correlated to TBI on both univariate (r = -0.78, p < 0.0001) and multivariate analysis (p < 0.0001). DUS parameters had a weaker correlation with ABI. ATmax > 215 ms showed high diagnosis accuracy to a toe pressure of 30 mmHg or less [sensitivity of 86% [0.57-0.98] and negative predictive value of 97% [0.89-1.00]]. CONCLUSION: ATmax demonstrates a high correlation with TBI in patients with PAD, and high diagnostic accuracy for detection of critical limb ischemia. Based on these results, ATmax can represent the next step in evaluating PAD severity with DUS, in patients with advanced lower extremity PAD.

A cost-effective smartphone-based device for ankle-brachial index (ABI) detection.

BACKGROUND AND OBJECTIVE: Detectors of ankle-brachial index (ABI) are commonly used in cardiovascular patients who have high-risk levels of arteriosclerosis. Increased evidences suggest that patients with arteriosclerosis possess many risks of geriatric and chronic diseases. Meanwhile, new chronic treatments trend from the hospitals toward family and community health centers, but for arteriosclerosis cases have delivered benefits far below instrument costs. Compared to traditional devices based on cuff pressure, cuffless and non-invasive measures have wider application potential in home health care, especially in the case of physically-restricted or severely symptomatic patients. METHODS: In this study, we developed a simple smartphone-based device for non-invasive ABI monitoring, which consists of four wireless cuffless limbs blood sensors. By identifying and tracking blood flow waveform, a multiparameter fusion (MPF) algorithm is used to estimate blood pressure and generate ABI value. An ARM-based chip STM32 has been adopted as the microcontroller. The ABI calculating program is embedded in C++ and executed by the processor. After generating data, ABI information can be delivered to the smartphone by using Bluetooth. Relying on mobile apps to visualize the data and display on the screen, doctors can monitor cardiovascular patients in real time and analyze the risk levels of arteriosclerosis online. RESULTS: In this paper, the detection conducted by the classical Doppler equipment and prototype were recorded respectively. A statistical evaluation of the verification results obtained from 29 patients and 7 sub-health volunteers is given, which shows that our device can achieve 91.80% and 93.84% accuracy for patients and sub-health volunteers, respectively. In addition, the prototype can be performed stably for a continuous long time monitoring. CONCLUSIONS: According to our studies, the accuracy of our device is sufficient for home medical and chronic disease monitoring within a certain time interval. The smartphone-based ABI device has several apparent advantages over traditional devices, such as portability, cost-effectiveness and energy-efficiency.