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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]

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]

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]