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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. [ABSTRACT FROM AUTHOR]

Patients with end-stage renal disease undergoing kidney transplant often have diffuse atherosclerosis and high cardiovascular morbidity and mortality rates. We analyzed the correlation of peripheral arterial disease (PAD), here quantified by an abnormal ankle--brachial index (ABI) measured within the 5 years prior to kidney transplant, with graft failure and mortality rates (primary end points) after adjusting for known cardiovascular risk factors (age, sex, smoking history, hypertension, diabetes, stroke, known coronary artery disease or heart failure, years of dialysis). Of 1055 patients in our transplant population, 819 had arterial studies within the 5 years prior to transplant. Secondary end points included myocardial infarction; cerebrovascular accident; and limb ischemia, gangrene, or amputation. Low ABI was an independent and significant predictor of organ failure (OR, 2.77 (95% CI, 1.68-4.58), p<0.001), secondary end points (HR, 1.39 (95% CI, 0.97-1.99), p<0.076), and death (HR, 1.84 (95% CI, 1.26-2.68), p=0.002). PAD was common in this population: of 819 kidney transplant recipients, 46% had PAD. Low ABI was associated with a threefold greater risk of graft failure, a twofold greater risk of death after transplant, and a threefold greater risk of secondary end points. Screening for PAD is important in this patient population because of the potential impact on long-term outcomes. [ABSTRACT FROM AUTHOR]

Peripheral artery disease (PAD) is associated with poor health status (symptoms, functioning, quality of life (QOL)). Whether sex differences exist in PAD-specific health status is unknown. In patients presenting to a specialty clinic with new-onset or recent exacerbation of PAD, we examined sex differences as assessed by the Peripheral Artery Questionnaire (PAQ). The Patient-centered Outcomes Related to TReatment Practices in Peripheral Arterial Disease: Investigating Trajectories (PORTRAIT) study is a multicenter, international prospective study of patients with new or worsening PAD symptoms. Baseline characteristics and mean PAQ scores were compared among women (n=481) and men (n=793) before they underwent treatment. The independent association of sex with health status was assessed with multivariable linear regression. As compared with men, women were less often Caucasian, married and employed, and more often lacking health insurance, living alone (36.2% vs 23.6%, p<0.001), had depression and avoided care due to cost (17.0% vs 12.3%, p=0.018). Women and men were of a similar age and education level, and had similar ankle-brachial index (ABI) values (0.7 ± 0.2 in both groups, p=0.052). Female sex was independently associated with lower PAQ scores on all domains (physical functioning adjusted mean difference of -8.40, p<0.001; social functioning adjusted mean difference of -6.8, p<0.001; QOL adjusted mean difference of -6.7, p<0.001), although no differences were observed in treatment satisfaction (adjusted mean difference -0.20, p=0.904). Despite similar ABIs, women presenting with symptoms of PAD had poorer PAD-specific functioning as compared with men, impacting all major health status domains, independent of socio-economic and clinical characteristics. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine if galectin-3 levels were different between participants with peripheral artery disease (PAD) and controls, and to describe its relationship with markers of early atherosclerosis. Sixty participants were recruited into two groups: a PAD group (n=31), ankle–brachial index (ABI) ⩽0.90 and a normal ABI group (n=29), ABI 1.0–1.4. PAD participants were older (68.6 vs 61.8 years, p=0.037), more commonly men (68% vs 38%, p=0.02), and with more cardiovascular risk factors (p<0.001). Galectin-3 was 22% higher in PAD participants (mean±SD: 17.6±4.7 vs 14.4±4.1 ng/mL, p<0.01). The odds ratio for galectin-3 in PAD to be 1 ng/mL higher than the participants with normal ABI was 1.19, after adjusting by age and gender (p=0.014). High-sensitivity C-reactive protein (hs-CRP) and homeostatic model assessment (HOMA) were positively associated with galectin-3 in the age- and gender-adjusted model, while arterial elasticity and microalbuminuria were not. In conclusion, galectin-3 levels were higher in participants with PAD. [ABSTRACT FROM AUTHOR]

The toe–brachial index (TBI) is used as an adjunct to the ankle–brachial index (ABI) for non-invasive lower limb vascular screening. With increasing evidence suggesting limitations of the ABI for diagnosis of vascular complications, particularly in specific populations including diabetes cohorts, the TBI is being used more widely. The aim of this review was to determine the sensitivity and specificity of the TBI for detecting peripheral artery disease (PAD) in populations at risk of this disease. A database search was conducted to identify current work relating to the sensitivity and specificity of toe–brachial indices up to July 2015. Only studies using valid diagnostic imaging as a reference standard were included. The QUADAS-2 tool was used to critically appraise included articles. Seven studies met the inclusion criteria. Sensitivity of the TBI for PAD was reported in all seven studies and ranged from 45% to 100%; specificity was reported by five studies only and ranged from 16% to 100%. In conclusion, this review suggests that the TBI has variable diagnostic accuracy for the presence of PAD in specific populations at risk of developing the disease. There was a notable lack of large-scale diagnostic accuracy studies determining the diagnostic accuracy of the TBI in detecting PAD in different at-risk cohorts. However, standardised normal values need to be established for the TBI to conclusively determine the diagnostic accuracy of this test. [ABSTRACT FROM AUTHOR]

We sought to evaluate whether case ascertainment using administrative health data would be a feasible way to identify peripheral artery disease (PAD) patients from the community. Subjects’ ankle–brachial index (ABI) scores from two previous prospective observational studies were linked with International Classification of Diseases (ICD) and Canadian Classification of Interventions (CCI) codes from three administrative databases from April 2002 to March 2012, including the Alberta Inpatient Hospital Database (ICD-10-CA/CCI), Ambulatory Care Database (ICD-10-CA/CCI), and the Practitioner Payments Database (ICD-9-CM). We calculated diagnostic statistics for putative case definitions of PAD consisting of individual code or sets of codes, using an ABI score ⩽ 0.90 as the gold standard. Multivariate logistic regression was performed to investigate additional predictive factors for PAD. Different combinations of diagnostic codes and predictive factors were explored to find out the best algorithms for identifying a PAD study cohort. A total of 1459 patients were included in our analysis. The average age was 63.5 years, 66% were male, and the prevalence of PAD was 8.1%. The highest sensitivity of 34.7% was obtained using the algorithm of at least one ICD diagnostic or procedure code, with specificity 91.9%, positive predictive value (PPV) 27.5% and negative predictive value (NPV) 94.1%. The algorithm achieving the highest PPV of 65% was age ⩾ 70 years and at least one code within 443.9 (ICD-9-CM), I73.9, I79.2 (ICD-10-CA/CCI), or all procedure codes, validated with ABI < 1.0 (sensitivity 5.56%, specificity 99.4% and NPV 84.6%). In conclusion, ascertaining PAD using administrative data scores was insensitive compared with the ABI, limiting the use of administrative data in the community setting. [ABSTRACT FROM AUTHOR]

We report recruitment strategies for an NIH-funded trial focused on African Americans with peripheral artery disease (PAD). We present complete recruitment efforts for this 1-year trial, 5-year study. Eligibility included the following: African American, a resting ankle–brachial index (ABI) ⩽ 0.99, a short physical performance battery (SPPB) score of 10 or lower, English speaking, telephone access, and absence of coronary ischemia during a submaximal treadmill test. Recruitment included mailings of brochures to zip codes in which more than 50% of residents were African American, advertisements, community events, and physician/clinic referrals. We telephone-screened 3511 persons, of whom 792 did not recall the method by which they learned about the study. We randomized 174 participants. Mailings yielded the highest percentage of randomized participants (n=60, 34.4%), followed by television advertisements (n=42, 24.1%), followed by community events (n=24, 13.8%). In conclusion, to recruit African Americans with PAD for a clinical trial, investigators should consider mailings of brochures, television advertisements, and community events. ClinicalTrials.gov Identifier: NCT01321086 [ABSTRACT FROM AUTHOR]

The article presents the author view over management of peripheral artery disease (PAD) among renal transplant. Topics discussed include recommendation of the American Society of Transplantation for adoption of angioplasty approaches; assessment of ankle–brachial index (ABI) for prediction of graft failure; and PAD may lead to claudication along with progression to critical limb ischemia (CLI).

Pentraxin 3 (PTX3) is a novel inflammatory cytokine produced in atherosclerotic plaque. We hypothesized that this marker may be a better predictor of peripheral artery disease (PAD) than C-reactive protein (CRP) in hemodialysis (HD) patients. The ankle–brachial index (ABI) was measured in HD patients. PTX3 levels in 116 HD patients and 30 healthy blood donors were measured by ELISA. A total of 116 HD patients (age: 56.44 ± 14.08 years) were enrolled; 21 (18%) patients had PAD. PTX3 was significantly higher in PAD versus non-PAD patients (5.55 ± 2.63 vs 2.32 ± 1.29 ng/mL; p < 0.001). In a univariate analysis, ABI correlated significantly with age, blood glucose and triglycerides, and plasma PTX3 (r = -0.548, p < 0.001) and high-sensitivity (hs)CRP (r = -0.495, p < 0.001). Using ROC curve analysis for PAD, PTX3 (cut-off value 4.06 ng/mL, AUC 0.901, p < 0.0001) showed a significantly better positive predictive value than hsCRP (cut-off value 3.33 mg/L, AUC 0.640, p < 0.05). Logistic regression analysis further confirmed that PTX3 (OR = 9.755, p = 0.001) was an independent predictor of PAD. In conclusion, we demonstrated that PTX3 may be a better marker of PAD than hsCRP, and independently correlated with PAD in HD patients. [ABSTRACT FROM PUBLISHER]

We studied associations of the number and size of magnetic resonance angiography (MRA)-assessed lower extremity collateral vessels with the ankle–brachial index (ABI), severity of superficial femoral artery (SFA) plaque, and leg symptoms in participants with peripheral artery disease (PAD). A total of 303 participants with PAD underwent time-resolved MRA at the thigh station. Collaterals were categorized by number (Category 1: 0–3 collaterals; Category 2: 4–7 collaterals; Category 3: ≥ 8 collateral vessels) and size (Grade 1: ≤ 5 small collaterals; Grade 2: > 5 small vessels; Grade 3: ≤ 5 large collaterals; Grade 4: > 5 large collaterals). Adjusting for age, sex, race, comorbidities and other covariates, more numerous collateral vessels were associated with lower ABI values (Category 1: 0.79; Category 2: 0.67; Category 3: 0.60; p trend < 0.001). Similarly, larger collateral vessels were associated with lower ABI values (Grade 1: 0.75; Grade 2: 0.65; Grade 3: 0.62; Grade 4: 0.59; p trend < 0.001). More numerous (p < 0.001) and larger (p < 0.001) collateral vessels were associated with greater mean SFA plaque area (p trend < 0.001). More numerous (p trend = 0.007) and larger (p trend = 0.017) collateral vessels were associated with a lower prevalence of asymptomatic PAD. In conclusion, among participants with PAD, larger and more numerous collaterals, measured by MRA, were associated with lower ABI values, greater plaque area in the SFA, and a lower prevalence of asymptomatic PAD. Further study is needed to determine the role of collateral vessels in maintaining functional performance in PAD. [ABSTRACT FROM AUTHOR]

The pathophysiology and time course of an individual converting from asymptomatic peripheral artery disease (PAD) to symptomatic claudication is unclear. The objectives of this study were: (1) to characterize the extent of atherosclerotic disease in individuals with an abnormal ankle–brachial index (ABI), but without claudication; and over 1 year of follow-up to (2) evaluate the progression of PAD using ultrasound imaging, (3) determine changes in the ABI and leg pain symptoms, and (4) correlate PAD progression with changes in the ABI and leg symptoms. We hypothesized that PAD progression would be associated with the development of claudication and changes in the ABI, 6-minute walk distance (6-MWD), and walking quality of life. Individuals with a reduced ABI but without typical intermittent claudication noted on community screening were invited to undergo baseline and 1-year follow-up assessment, including duplex ultrasound. The initial and repeat evaluations included measurement of the ABI, lower extremity duplex arterial mapping, and assessment of leg pain and functional status. Of the 50 people studied, 44 (88%) had significant atherosclerotic lesions in the lower extremity arteries, affecting 80 legs. A total of 33 of 50 individuals (66%) returned for the 1-year follow-up visit. On ultrasound examination, two of 18 normal legs developed PAD, and in 48 legs with PAD at baseline, 17 legs (35%) developed new or progressive lesions. Thirteen legs developed new claudication. Overall, there was no significant worsening in the ABI, 6-MWD, or the Walking Impairment Questionnaire (WIQ). However, legs with new lesions or lesion progression were significantly more likely to develop claudication, and the 13 legs (seven subjects) developing claudication showed a significant decline in the 6-MWD. In conclusion, these data indicate that a significant number of people with asymptomatic PAD show progression over 1 year, that such individuals are more likely to develop claudication, and that those developing claudication have a significant decrease in their 6-MWD. [ABSTRACT FROM AUTHOR]

Functional performance influences quality of life in individuals with peripheral artery disease (PAD) and is also a powerful prognostic marker in these patients. The pathophysiology of impaired functional performance in patients with PAD is incompletely understood. The severity of atherosclerotic burden, non-invasively assessed by the ankle—brachial index (ABI), does not reliably predict the degree of functional impairment observed in PAD patients. We review associations of measures of arterial function (arterial stiffness and endothelial dysfunction) with functional performance in PAD patients, and also review potential therapies for arterial stiffness and endothelial dysfunction that could improve functional performance in PAD. Recent studies suggest that measures of arterial function, such as arterial stiffness and endothelial function, are associated with exercise performance in the setting of PAD. These studies have provided new insights into (1) the pathophysiology of functional impairment in PAD, (2) mechanisms of strategies known to be effective such as walking programs, and (3) potential new therapeutic interventions for improving functional performance. Thus, therapies aimed at arterial ‘de-stiffening’ and improving endothelial function (such as aerobic exercise, statins and angiotensin-converting enzyme inhibitors) may improve functional performance in patients with PAD; however, further investigations are needed. [ABSTRACT FROM AUTHOR]

The article presents the nature and scope of the clinical performance measures for adults with peripheral artery disease(PAD) which was developed by the Peripheral Artery Disease Performance Measures Writing Committee in the U.S. It says that the performance measures deal with lower extremity and aortic disease, as covered by the ACC/AHA 2005 guidelines for the patients with PAD. Mandatory sequential steps in the development of performance systems, PAD guidelines, and outcome measures are cited.

The purpose of this study was to investigate the association between chronic kidney disease (CKD) and peripheral arterial disease (PAD) and examine the combined effect of CKD and PAD on all-cause and cardiovascular disease (CVD) mortality. The Chinese Ankle Brachial Index Cohort consisted of 3732 adults aged 35 years or older enrolled in 2004 and followed-up in 2007. Complete baseline data were compiled on 3610 people which were examined in the final analysis. Mortality surveillance was completed from December 2007 to February 2008. Survival analysis was used to compare the survival rate in different CKD/PAD groups. The relative risks (RR) of death from all-cause and CVD were compared using a Cox regression model. It was found that the prevalence of PAD in patients with and without CKD was 41.9% and 22.3%, respectively (p < 0.001). The survival rate for the CKD and PAD group was significantly lower than that for any single disease, for both all-cause and CVD mortality (log-rank: p < 0.001). In conclusion, CKD is a risk factor for PAD. The combined CKD and PAD patients had the highest risk for all-cause and CVD mortality. Early recognition of risk can be made by taking an ankle-brachial index measurement of PAD; a corresponding laboratory assessment should be used as a measurement of renal function for PAD patients. [ABSTRACT FROM AUTHOR]

The ankle-brachial index (ABI) is the standard test used in clinical practice to detect peripheral artery disease (PAD) and is a powerful predictor of adverse cardiovascular outcomes. This study sought to measure the baseline knowledge of the ABI test among a sample of internal medicine residents and to examine the impact of an educational intervention on performance of the test. A total of 29 residents were asked to perform three tasks, with the performance of each task being assessed using a point-based scoring system: measure an ABI on a normal volunteer (15 points), calculate the ABI based on data from a hypothetical patient (3 points), and interpret a range of ABI values (6 points). A standardized educational intervention was then provided and post-education performance was assessed for each task using the same scoring system. At baseline, 4% of residents correctly measured the ABI, 10% correctly calculated the ABI, and 45% correctly interpreted the ABI. Baseline performance was unaffected by year of residency training. Following the educational intervention, 50% of residents correctly measured the ABI, 75% correctly calculated the ABI, and 88% correctly interpreted the ABI. The mean score for the tasks of ABI measurement, calculation and interpretation between baseline and post-education were 4.6 ± 3 and 13.9 ± 1.6 (p < 0.0001), 1 ± 0.9 and 2.3 ± 1.2 (p = 0.002), and 4.9 ± 1.6 and 5.9 ± 0.3 (p = 0.008), respectively. In conclusion, baseline knowledge of the ABI test was poor among a sample of internal medicine residents. These results suggest that instruction regarding the ABI test is deficient in medical school and residency programs and requires action by those responsible for the education of medical students and residents. [ABSTRACT FROM AUTHOR]

The author reflects on the study that investigates several issues related to peripheral artery disease (PAD) awareness among general practitioners (GPs) in Queensland. She contends that the study's response rate was low at 26%, however, it clearly highlights the importance of disseminating PAD guidelines and improving ankle-brachial index (ABI) awareness. She notes that the study distinguishes between PAD screening and PAD diagnosis.