Measure Of Peripheral Arterial Disease Research Articles

Machine Learning Model of Clinical Risk Factors and Peripheral Calcium Scoring on Computed Tomography for the Prediction of Amputation in Patients with Peripheral Arterial Disease

To date, there is no quantifiable evidence of the preferred measure of peripheral arterial disease (PAD) to best predict outcomes. Lower extremity calcium scoring is a novel tool that helps risk stratify patients with PAD. This study uses a machine learning (ML)-based approach to develop risk scores based on clinical variables and peripheral calcium scoring in an attempt to predict risk of major amputation in patients with PAD.

Degree of adiposity and obesity severity is associated with cutaneous microvascular dysfunction in type 2 diabetes

Backgrounds and aimsObesity and diabetes independently contribute to cutaneous microvascular dysfunction via pathological processes that are not fully understood. We sought to determine if obesity severity is associated with cutaneous microvascular dysfunction and measures of peripheral arterial disease in adults with type 2 diabetes in cross-sectional observational study design. Methods and resultsPrimary outcomes were post-occlusive reactive hyperaemia as determined by laser-Doppler fluxmetry (peak flux post-occlusion, time to peak flux post-occlusion, peak as a percentage of baseline, and area under the curve [AuC] index post-occlusion to pre-occlusion). Secondary outcomes were ankle- and toe-brachial indices (ABI and TBI) and systolic toe pressure. Thirty-six participants (20 men, 16 women) with mean age 55 ± 8 years, BMI of 36 ± 5 kg/m2 and duration of diabetes 8 ± 6 years underwent measurements. After adjusting for age and duration of diabetes, SAT and total percentage body fat were able to explain 29% (p = 0.001) and 20% (p = 0.01) of variance of AuC index models, as well as 29% (p = 0.02) and 18% (p = 0.02) of peak as a percentage of baseline models, respectively. Though TBI demonstrated moderate, significant correlations with SAT (r:0.37, p = 0.04) and total percentage body fat (r:0.39, p = 0.03), these were not upheld by regression analyses. Neither ABI nor systolic toe pressure significantly correlated with any measure of adiposity or obesity. ConclusionThese findings demonstrate impairment in cutaneous microvascular function related to adiposity and obesity severity in adults with type 2 diabetes, suggesting that obesity may pathologically effect cutaneous microvascular function in the absence of overt macrovascular disease, warranting further investigation.

Performance of prognostic markers in the prediction of wound healing or amputation among patients with foot ulcers in diabetes: A systematic review.

Clinical outcomes of patients with diabetes, foot ulceration, and peripheral artery disease (PAD) are difficult to predict. The prediction of important clinical outcomes, such as wound healing and major amputation, would be a valuable tool to help guide management and target interventions for limb salvage. Despite the existence of a number of classification tools, no consensus exists as to the most useful bedside tests with which to predict outcome. We here present an updated systematic review from the International Working Group of the Diabetic Foot, comprising 15 studies published between 1980 and 2018 describing almost 6800 patients with diabetes and foot ulceration. Clinical examination findings as well as six non-invasive bedside tests were evaluated for their ability to predict wound healing and amputation. The most useful tests to inform on the probability of healing were skin perfusion pressure ≥ 40 mmHg, toe pressure ≥ 30 mmHg, or TcPO2 ≥ 25 mmHg. With these thresholds, all of these tests increased the probability of healing by greater than 25% in at least one study. To predict major amputation, the most useful tests were ankle pressure < 50 mmHg, ABI < 0.5, toe pressure < 30 mmHg, and TcPO2 < 25 mmHg, which increased the probability of major amputation by greater than 25%. These indicative values may be used as a guide when deciding which patients are at highest risk for poor outcomes and should therefore be evaluated for revascularization at an early stage. However, this should always be considered within the wider context of important co-existing factors such as infection, wound characteristics, and other comorbidities.

Carotenoid Intake and Status and Ankle Brachial Index (ABI) in Puerto Rican Adults (FS06-05-19)

ObjectivesTo observe the relationship between dietary intake and plasma concentration of carotenoids relative to ankle brachial index (ABI), a measure of peripheral artery disease and heart disease risk factor, in Puerto Rican adults. MethodsData were from 829 participants in the Boston Puerto Rican Health Study (aged 49–81 y at time of measurement). Risk of atherosclerosis was measured by ABI (systolic blood pressure at the ankle relative to at the brachial artery). Dietary intake of carotenoids was assessed by food frequency questionnaire and plasma total carotenoids with a colorimetric assay using a Beckman DU640 Spectrophotometer (CV 6%). SAS (version 9.4) was used to conduct analyses, including logistic regression. ResultsThe mean ABI was 0.99 +/– 0.09, mean plasma carotenoids (ug/dl), 94.6 +/– 41.7, and mean total dietary intake of carotenoids 9675 +/– 7494. 10% of participants had ABI < 0.9. Our measure of plasma carotenoids was significantly associated with low ABI (<0.9) in all models, including those adjusted for age, sex, BMI, plasma triglycerides, alcohol use, smoking, physical activity score, waist circumference, cholesterol, serum albumin, serum creatinine, diabetes, medications for lipids, medications for blood pressure, and poverty/income ratio (OR = 0.99; 95% CI = 0.98–1.00, P = 0.03). Associations between estimated dietary intake of total carotenoids and ABI were also statistically significant (OR = 0.61, 95% CI = 0.37–1.00, P = 0.05). Major sources of carotenoids in this population included tomato sauce, calabaza squash, carrots, plantains and root crops. ConclusionsTotal plasma carotenoid concentration and dietary intake of carotenoids were significantly associated with peripheral artery disease. Further research is needed to clarify the specific role of carotenoids in this relationship, and to identify if intake of individual (vs. total) dietary carotenoids provide a protective effect against arterial blockage in this high-risk population. Funding SourcesNIH-NHLBI. Supporting Tables, Images and/or Graphs▪

Ankle brachial index and cognitive function among Hispanics/Latinos: Results from the Hispanic Community Health Study/Study of Latinos

Background and aimsThe Ankle-Brachial index (ABI) is a well-accepted measure of peripheral artery disease (arterial stenosis and stiffness) and has been shown to be associated with cognitive function and disorders; however, these associations have not been examined in Hispanics/Latinos. Therefore, we sought to examine relationships between ABI and cognitive function among diverse middle-age and older Hispanics/Latinos. MethodsWe used cross-sectional data on n = 7991 participants aged 45–74 years, without stroke or coronary heart disease, from the Hispanic Community Health Study/Study of Latinos. Our primary outcome, global cognition (GC), was a continuous composite score of four cognitive domains (verbal learning and memory, verbal fluency, executive function, and mental status). Secondary outcomes were the individual tests representing these domains. The ABI was analyzed continuously and categorically with standard clinical cut-points. We tested associations using generalized survey regression models incrementally adjusting for confounding factors. Age, sex, hypertension, diabetes, and dyslipidemia moderations were examined through interactions with the primary exposure. ResultsIn age, sex, and education adjusted models, continuous ABI had an inverse u-shape association with worse GC. We found similar associations with measures of verbal learning and memory, verbal fluency, executive function, but not with low mental status. The associations were attenuated, but not completely explained, by accounting for the confounders and not modified by age, sex, education, and vascular disease risks. ConclusionsIn addition to being a robust indicator of arterial compromise, our study suggests that abnormal ABI readings may also be useful for early signaling of subtle cognitive deficits.

Popliteal Artery Entrapment Syndrome (PAES) and Ankle-Brachial Index (ABI), any association?

Popliteal Artery Entrapment Syndrome (PAES) is an uncommon pathology. Often, it affects young athletic males, with symptoms like calf claudication, weakness, numbness, pain, coldness of the foot, cramps, foot drop and paresthesia. The etiology of this syndrome is related to anatomical variations determining an altered relationship between popliteal artery and the surrounding structures. Based on described anatomical variations, PAES has been classified in several types (type I to V). In other cases, the compression of the popliteal artery may be caused by the hypertrophic gastrocnemius muscle, without anatomical variations, defining a “functional popliteal entrapment” (type VI). [1]. The Ankle-Brachial Index (ABI) is the ratio of the systolic blood pressure measured at the ankle to that measured at the brachial artery. It’s a non-invasive measure of peripheral artery disease and can serve as a prognostic marker for cardiovascular events and functional impairment [2]. The ABI score is often pathological in patients affected by PAES. Nevertheless, to define diagnosis and type of PAES are often needed imaging studies and invasive procedures. The aim of the present study is to systematically review the available literature to define if ABI score could be useful to predict a specific type of PAES. Electronic databases have been searched using specific Keywords. Articles have been screened and full-texts of relevant papers have been retrieved. Case reports and case series with indications of symptoms, type of PAES, ABI score have been included. Results about ABI score (dependent variable) have been pooled and compared among types of PAES (independent variable). No statistical significance has been noted (ANOVA: F=1.9, p=0.09). The use of ABI is insufficient to predict the type of PAES and its prognosis. Nevertheless, this non-invasive method could be useful to suspect PAES and as a tool in follow up in these patients.

Body composition and ankle-brachial index in Ghanaians with asymptomatic peripheral arterial disease in a tertiary hospital.

BackgroundAnkle-brachial index (ABI) and indices of obesity are both use to indicate cardiovascular risk. However, association between body composition indices and ABI, a measure of peripheral arterial disease, is inconsistent in various study reports. In this study, we investigated the relationship between ABI and general and central indices of obesity in Ghanaians without history of cardiovascular diseases.MethodIn a case–control design, ABI was measured in a total of 623 subjects and categorised into PAD (ABI ≤ 0.9, n = 261) and non-PAD (ABI > 0.9, n = 362) groups. Anthropometric indices, BMI, waist circumference (WC), waist-hip ratio (WHR) and waist-height ratio (WHtR) were also measured.ResultsPAD subjects had higher mean BMI (29.8 ± 8.7 vs. 26.5 ± 7.6 kg/m2, p = 0.043) and waist circumference (95 ± 15 vs. 92 ± 24 cm, p = 0.034) than non-PAD subjects. In multivariable logistic regression models, having BMI ≥ 30 kg/m2 increased the odds of both unilateral [OR (95 % CI): 2 (1.14–3.51), p < 0.01] and overall PAD [2 (1.22–3.27), p < 0.01].ConclusionIn indigenous Ghanaians in our study, PAD participants had higher BMI and waist circumference than non-PAD participants. Also, halving BMI ≥ 30 kg/m2 was associated with twofold increase in the odds of PAD.Electronic supplementary materialThe online version of this article (doi:10.1186/s40608-016-0107-3) contains supplementary material, which is available to authorized users.

Performance of prognostic markers in the prediction of wound healing or amputation among patients with foot ulcers in diabetes: a systematic review.

Prediction of wound healing and major amputation in patients with diabetic foot ulceration is clinically important to stratify risk and target interventions for limb salvage. No consensus exists as to which measure of peripheral artery disease (PAD) can best predict outcomes. To evaluate the prognostic utility of index PAD measures for the prediction of healing and/or major amputation among patients with active diabetic foot ulceration, two reviewers independently screened potential studies for inclusion. Two further reviewers independently extracted study data and performed an assessment of methodological quality using the Quality in Prognostic Studies instrument. Of 9476 citations reviewed, 11 studies reporting on 9 markers of PAD met the inclusion criteria. Annualized healing rates varied from 18% to 61%; corresponding major amputation rates varied from 3% to 19%. Among 10 studies, skin perfusion pressure ≥ 40 mmHg, toe pressure ≥ 30 mmHg (and ≥ 45 mmHg) and transcutaneous pressure of oxygen (TcPO2 ) ≥ 25 mmHg were associated with at least a 25% higher chance of healing. Four studies evaluated PAD measures for predicting major amputation. Ankle pressure < 70 mmHg and fluorescein toe slope < 18 units each increased the likelihood of major amputation by around 25%. The combined test of ankle pressure < 50 mmHg or an ankle brachial index (ABI) < 0.5 increased the likelihood of major amputation by approximately 40%. Among patients with diabetic foot ulceration, the measurement of skin perfusion pressures, toe pressures and TcPO2 appear to be more useful in predicting ulcer healing than ankle pressures or the ABI. Conversely, an ankle pressure of < 50 mmHg or an ABI < 0.5 is associated with a significant increase in the incidence of major amputation.

CRT-200 The Association of Serum Ferritin and 1-Year Mortality in Patients with Critical Limb Ischemia

Several studies have examined the association of biomarkers of iron metabolism with measures of peripheral arterial disease. Few studies, however, have evaluated the association between biomarkers of iron metabolism and mortality in critical limb ischemia (CLI). Serum ferritin, iron (Fe), and total

Relationship between ankle brachial index and ejection fraction in elderly Egyptians with ischemic heart disease

There is a high prevalence of combined peripheral and coronary artery disease, with increasing morbidity and decline in cardiac function. The aim of the present study was to find an association between ankle brachial index, a non-invasive measure of peripheral artery disease, and ejection fraction in elderly patients with severe coronary artery disease. A case-control study recruiting 200 elderly male and female ischemic patients in Ain Shams University hospitals was carried out. All participants had significant coronary artery disease lesions in coronary angiography carried out before the study. Cases and controls were divided according to ankle brachial index, with further subdivision of each group according to age. Measurements include: ankle brachial index using Bistos handheld vascular Doppler (BT 200V,8 MHz), electrocardiography and echocardiography showing left ventricular ejection fraction. Coronary artery disease severity was estimated using the number of diseased vessels. The mean age of our study group was 67 years. Although our participants had mild to moderate peripheral artery disease, ejection fraction statistically decreased with decreasing ankle brachial index, being the lowest in participants aged > 70 years (46.84 ± 9.82 years) and the highest in controls aged >70 years (53.02 ± 5.53 years; P = 0.009). Ejection fraction was positively correlated with ankle brachial index (P = 0.011, 0.006) for cases and controls, respectively. Ankle brachial index can correlate with ejection fraction in elderly ischemic Egyptians with more severe coronary artery disease.

Cadmium exposure and peripheral artery disease. A cohort study.

Background: Cadmium exposure has been found to be associated with atherosclerotic plaques in the carotid arteries. Aims: To examine if blood and urinary cadmium levels are associated with low ankle-brachial index as a measure of peripheral artery disease in a longitudinal study. Method: This is a prospective cohort study with a 5-year follow-up of 64-year old women (n=489) recruited by stratified sampling of similarly-sized groups with normal, impaired and diabetic glucose tolerance as assessed in a population-based screening examination. The primary outcome measure was ankle-brachial index (ABI - ratio of the systolic blood pressures in the tibial and brachial arteries ?0.9 in any artery). Exposure to cadmium was based on cadmium in blood (B-Cd) and urine (U-Cd) at baseline. Cadmium levels were determined by ICP-MS with relevant analytical quality control. Odds ratios (OR) were calculated using logistic regression models including cardiovascular risk factors at baseline (pack years of smoking, systolic blood pressure, HbA1c, and apolipoprotein B/A-I as measure of dyslipidemia) as well as statin treatment and serum ICAM-I. Results: High concentrations (tertile 3 vs. tertile 1) of blood (B-Cd) or creatinine-adjusted urinary cadmium (U-Cd) at baseline were found to predict low ankle-brachial index after adjustment for smoking and other cardiovascular risk factors at baseline. For U-Cd the OR was 2.5 (95% CI 1.1-5.8). After exclusion of participants with ultrasound-assessed femoral atherosclerosis at baseline the OR for U-Cd was unchanged, and for B-Cd it was 3.7 (95% CI 1.05-13.3). Inclusion of serum ICAM-1 levels did not affect the cadmium-related ORs in multivariate analyses. Conclusions: Cadmium exposure was associated with future peripheral artery disease, supporting the concept that cadmium exposure in the population has pro-atherogenic effects, although ICAM-1 mediated effects do not seem to be involved.

Thromboembolism or Atherothromboembolism in Atrial Fibrillation?

Atrial fibrillation (AF) is associated with increased morbidity, mortality, and ischemic stroke,1 and these ischemic strokes are almost always severe.2 Thrombus formation in the left atrium with ensuing embolism in the cerebral circulation is deemed to be the cause.2 Article see p 1168 According to the Virchow’s triad, hypercoagulability, endothelial dysfunction, and venous stasis should be prerequisite for thrombus formation in the left atrium.3 Several markers of clotting and platelet activation have been detected in AF patients, including high-plasma levels of the prothrombin fragment F1+2, a marker of thrombin generation, and P-selectin, a marker of clotting activation.3 The existence of a prothrombotic state may predispose to vascular disease. In a prospective study performed in 231 AF patients, we showed that plasma levels of CD40L, a marker of platelet activation, was associated with and predicted vascular outcomes, such as ischemic stroke and myocardial infarction (MI), during a follow-up period of 2 years.4 Endothelial dysfunction has been documented by measuring von Willebrand factor, which has been found to be elevated in AF patients and associated with poor vascular outcomes.5 The rate of endothelial damage seems temporarily related to AF duration because the highest levels have been observed in patients with permanent compared with those with paroxysmal or persistent AF.5 Venous stasis is the third component; it is supposed to be related not only to arrhythmia but also to AF-induced atrium remodeling, which could further lower contractility via several mechanisms, including low Ca2+ mobilization and impaired myosin phosphorylation.3 Furthermore, AF-related remodeling of left atrium may have a negative impact on the cardiac circulation as it is associated with downregulation of atrial NO, a molecule with vasodilator and antiaggregating properties.6 It is still unclear, however, whether remodeling-related venous stasis per se is actually …

Haemostatic markers are associated with measures of vascular disease in adults with hypertension

Haemostatic markers have been implicated in the development and progression of vascular disease. We investigated the associations of several haemostatic markers (fibrinogen, D-dimer, FV, FVII, FVIII, von Willebrand factor (vWF) and antithrombin III) with two quantitative measures of vascular disease in adults with hypertension. Participants included 1051 African Americans (65+/-9 years, 72% women) and 894 non-Hispanic whites (61+/-9 years, 55% women) belonging to hypertensive sibships. Phenotypes of vascular disease included the ankle-brachial index (ABI), a measure of peripheral arterial disease, and urinary albumin/creatinine ratio (UACR), a surrogate of glomerular endothelial function. Generalized estimating equations were used to assess whether plasma levels of haemostatic markers were associated with measures of arteriosclerosis, after adjustment for conventional risk factors and medication (statin, aspirin and oestrogen) use. Higher fibrinogen and D-dimer were significantly associated with lower ABI in African Americans (P<0.001 and 0.004 respectively) and in non-Hispanic whites (P<0.001 and 0.010 respectively). Higher fibrinogen (P<0.001), D-dimer (P=0.003), FVIII (P<0.001) and vWF (P<0.001) were significantly associated with higher UACR in African Americans, whereas, in non-Hispanic whites, higher fibrinogen (P=0.020) and FVII (P=0.006) were significantly associated with higher UACR. Our findings indicate that in adults with essential hypertension, several markers in the haemostatic pathway are independently associated with ABI and UACR, two measures of vascular disease..

Association of Soluble Cell Adhesion Molecules with Ankle-Brachial Index in a Biethnic Cohort of Predominantly Hypertensive Individuals

Higher plasma concentrations of soluble adhesion molecules have been shown to be associated with increased risk of cardiovascular events. We investigated the association of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) with ankle-brachial index (ABI), a measure of peripheral arterial disease (PAD), in a biethnic cohort of adults without known coronary heart disease or stroke. Participants included 1102 blacks (mean age, 63 years; 74% women) and 1013 non-Hispanic whites (mean age, 58 years; 59% women) belonging to sibships ascertained on the basis of hypertension. We measured plasma concentrations of sICAM-1 and sVCAM-1 using high-sensitivity immunoassays and ABI using a standard protocol; PAD was defined as ABI <0.9. We used generalized estimating equations to assess whether sICAM-1 and sVCAM-1 were associated with ABI and PAD, independently of conventional risk factors. After adjustment for conventional risk factors, blacks with sICAM-1 and sVCAM-1 concentrations in the highest quartiles had lower ABIs than those in the lowest quartiles (mean ABI 1.02 vs 0.98, P = 0.007, vs 1.02 vs 0.99, P = 0.003, respectively). In multivariable logistic regression analysis, sICAM-1 and sVCAM-1 concentrations in the highest quartiles were each associated with a higher odds ratio of having PAD, compared with the lowest quartiles: odds ratio (95% CI): 5.2 (1.8-15.2) and 2.2 (1.0-4.8), respectively. In contrast, in non-Hispanic whites, sICAM-1 and sVCAM-1 concentrations were not associated with ABI or PAD. Higher sICAM-1 and sVCAM-1 concentrations were independently associated with lower ABI and PAD in blacks, but not in non-Hispanic whites.

Investigating the complex genetic architecture of ankle-brachial index, a measure of peripheral arterial disease, in non-Hispanic whites

BackgroundAtherosclerotic peripheral arterial disease (PAD) affects 8–10 million people in the United States and is associated with a marked impairment in quality of life and an increased risk of cardiovascular events. Noninvasive assessment of PAD is performed by measuring the ankle-brachial index (ABI). Complex traits, such as ABI, are influenced by a large array of genetic and environmental factors and their interactions. We attempted to characterize the genetic architecture of ABI by examining the main and interactive effects of individual single nucleotide polymorphisms (SNPs) and conventional risk factors.MethodsWe applied linear regression analysis to investigate the association of 435 SNPs in 112 positional and biological candidate genes with ABI and related physiological and biochemical traits in 1046 non-Hispanic white, hypertensive participants from the Genetic Epidemiology Network of Arteriopathy (GENOA) study. The main effects of each SNP, as well as SNP-covariate and SNP-SNP interactions, were assessed to investigate how they contribute to the inter-individual variation in ABI. Multivariable linear regression models were then used to assess the joint contributions of the top SNP associations and interactions to ABI after adjustment for covariates. We reduced the chance of false positives by 1) correcting for multiple testing using the false discovery rate, 2) internal replication, and 3) four-fold cross-validation.ResultsWhen the results from these three procedures were combined, only two SNP main effects in NOS3, three SNP-covariate interactions (ADRB2 Gly 16 – lipoprotein(a) and SLC4A5 – diabetes interactions), and 25 SNP-SNP interactions (involving SNPs from 29 different genes) were significant, replicated, and cross-validated. Combining the top SNPs, risk factors, and their interactions into a model explained nearly 18% of variation in ABI in the sample. SNPs in six genes (ADD2, ATP6V1B1, PRKAR2B, SLC17A2, SLC22A3, and TGFB3) were also influencing triglycerides, C-reactive protein, homocysteine, and lipoprotein(a) levels.ConclusionWe found that candidate gene SNP main effects, SNP-covariate and SNP-SNP interactions contribute to the inter-individual variation in ABI, a marker of PAD. Our findings underscore the importance of conducting systematic investigations that consider context-dependent frameworks for developing a deeper understanding of the multidimensional genetic and environmental factors that contribute to complex diseases.

Aortic augmentation index is associated with the ankle-brachial index: A community-based study

Background Increased arterial stiffness has been associated with greater risk of cardiovascular events. We investigated whether aortic augmentation index (AIx), a measure of arterial stiffness and wave reflection, was associated with the ankle-brachial index (ABI), a measure of peripheral arterial disease (PAD). Method AIx and ABI were measured in a community-based sample of 475 adults without prior history of heart attack or stroke (mean age 59.3 years, 46.5% men). Radial artery pulse waveforms were obtained by applanation tonometry and an ascending aortic pressure waveform derived by a transfer function. AIx is the difference between the first and second systolic peak of the ascending aortic pressure waveform indexed to the central pulse pressure. ABI was measured using a standard protocol, and subjects with non-compressible vessels (ABI >1.5) were excluded from the analyses. Multivariable linear and logistic generalized estimating equations (GEE) analyses were used to assess whether AIx was associated with ABI and ABI <1.00, respectively, independent of conventional risk factors. Results Mean (±S.D.) values were: AIx, 29.3 ± 11.6%; ABI, 1.12 ± 0.13; 59 (12.4%) participants had an ABI <1.00. Variables associated with a lower ABI (and ABI <1.00) included older age, shorter height, female sex, higher total cholesterol, hypertension medication use, history of smoking, and higher AIx. After adjustment for mean arterial pressure and the above variables, higher AIx remained associated with a lower ABI ( P = 0.015) and ABI <1.00 ( P = 0.002). A significant interaction ( P = 0.007) was present between AIx and age in the prediction of ABI; the (inverse) association of AIx with ABI was stronger in older subjects (>65 years). Conclusion AIx, a measure of arterial stiffness and wave reflection, was independently associated with a lower ABI in asymptomatic subjects from the community, and this association was modified by age.

Relationship between objective measures of peripheral arterial disease severity to self-reported quality of life in older adults with intermittent claudication

The aim of this study was to determine the relation between functional measures of peripheral arterial disease (PAD) severity with both disease-specific and generic self-reported health-related quality-of-life (HR-QOL) measures, as well as the relation between the two types of HR-QOL measures. This was a cross-sectional observation of participants from the community and primary care or vascular surgery clinics in an academic Veterans Administration medical center. Eighty patients with symptomatic Fontaine stage II PAD provided physiologic measures and self-response questionnaires. Objective measures included the ankle-brachial index (ABI), time to maximum claudication pain on a graded exercise test, and a 6-minute floor-walking distance. Self-reports included the Walking Impairment Questionnaire (WIQ), a disease-specific HR-QOL measure and the Medical Outcomes Study (MOS) Short-Form 36 (SF-36), a generic HR-QOL measure. Patients (mean age 70 +/- 8 [+/- SD] and 85% men) exhibited moderate-to-severe PAD by objective measures of ABI (0.65 +/- 0.19) and time in minutes to maximal claudication on a graded exercise test (7:54 +/- 4:58). Significant correlations were found between these measures and the WIQ distance, MOS-Physical Function, and MOS-Role Limitations due to physical dysfunction. The SF-36 and the WIQ subscales were significantly correlated. In older PAD patients with intermittent claudication, objective measures of disease severity are correlated with a self-reported, disease-specific and generic HR-QOL.

Relationship of high and low ankle brachial index to all-cause and cardiovascular disease mortality: the Strong Heart Study.

The associations of low (<0.90) and high (>1.40) ankle brachial index (ABI) with risk of all-cause and cardiovascular disease (CVD) mortality have not been examined in a population-based setting. We examined all-cause and CVD mortality in relation to low and high ABI in 4393 American Indians in the Strong Heart Study. Participants had bilateral ABI measurements at baseline and were followed up for 8.3+/-2.2 years (36 589 person-years). Cox regression was used to quantify mortality rates among participants with high and low ABI relative to those with normal ABI (0.90 < or =ABI < or =1.40). Death from all causes occurred in 1022 participants (23.3%; 27.9 deaths per 1000 person-years), and of these, 272 (26.6%; 7.4 deaths per 1000 person-years) were attributable to CVD. Low ABI was present in 216 participants (4.9%), and high ABI occurred in 404 (9.2%). Diabetes, albuminuria, and hypertension occurred with greater frequency among persons with low (60.2%, 44.4%, and 50.1%) and high (67.8%, 49.9%, and 45.1%) ABI compared with those with normal ABI (44.4%, 26.9%, and 36.5%), respectively (P<0.0001). Adjusted risk estimates for all-cause mortality were 1.69 (1.34 to 2.14) for low and 1.77 (1.48 to 2.13) for high ABI, and estimates for CVD mortality were 2.52 (1.74 to 3.64) for low and 2.09 (1.49 to 2.94) for high ABI. The association between high ABI and mortality was similar to that of low ABI and mortality, highlighting a U-shaped association between this noninvasive measure of peripheral arterial disease and mortality risk. Our data suggest that the upper limit of normal ABI should not exceed 1.40.

Coronary calcification detected by electron-beam computed tomography and non-coronary measures of atherosclerosis:

0004 Coronary calcification as detected by electron-beam tomography (EBT) is a measure of coronary atherosclerosis. We investigated whether coronary artery calcium is associated with non-coronary measures of atherosclerosis, using data from the population-based Rotterdam Study. Participants in the third phase of the study were invited to undergo EBT scanning for detection of coronary calcifications. EBT scans were obtained from 2263 participants (47% men, mean age (SD), 71.3 (5.7)). Quantification of coronary calcifications was performed using Agatston’s method, and resulted in a calcium score. Calcium scores were available for 1874 subjects. Measures of non-coronary atherosclerosis included presence of aorta calcification detected by X-ray, presence of plaques in carotid arteries and intima-media thickness of the common carotid artery, both detected by ultrasonography, and ankle to brachial blood pressure index as a measure of peripheral arterial disease. Three calcium score categories were considered: 0 - 100, 101 - 500, and &gt;500. The calcium score showed a graded association with the measures of non-coronary atherosclerosis. Using logistic regression analysis, age and sex adjusted odds ratios for aorta calcification were 3.2 (95% confidence interval, 2.0 - 5.2) in subjects with calcium score 101 - 500 and 12.0 (7.6 - 18.9) in subjects with calcium score &gt; 500, when compared to subjects in the lowest calcium score category. The corresponding odds ratios for carotid plaques were 2.4 (1.6 - 3.5) and 5.8 (3.9 - 8.6). In a general linear model adjusted for age and sex, mean intima-media thickness increased with increasing calcium score category, while mean ankle to brachial blood pressure index decreased. These results indicate that known measures of non-coronary atherosclerosis are strongly related to coronary atherosclerosis, as measured by EBT calcium.

Effect of Diagnostic Criteria on the Prevalence of Peripheral Arterial Disease

The ankle/brachial systolic blood pressure index (ABI), a noninvasive measure of peripheral arterial disease (PAD), is widely used in epidemiological studies. However, the normal ranges of the ABI in healthy populations and ABI criteria for the diagnosis of PAD in large population studies have not been critically evaluated. The San Luis Valley Diabetes Study (SLVDS) was designed to evaluate the prevalence and complications of non-insulin-dependent diabetes mellitus (NIDDM) in a biethnic population. The present study was conducted as part of the SLVDS to assess the prevalence of vascular disease in 1280 nondiabetic control subjects and 430 patients with NIDDM. The ABI criteria for PAD were developed in 403 healthy individuals with a low risk for cardiovascular disease. In these low-risk subjects, the average resting ABI value was 0.07 lower in women than in men. In both sexes, the dorsalis pedis ABI was 0.04 lower than in the posterior tibial artery, and the left leg ABI was 0.02 lower than the right leg ABI (all differences, P < .05). In the low-risk subjects, ABI values were lower after exercise than at rest and had similar differences by sex and leg as observed at rest. Using specific abnormal cutoff points for the ABI, we evaluated three criteria for PAD in the overall population: two abnormal vessels in the same leg at rest (both dorsalis pedis and posterior tibial arteries), one abnormal vessel per leg at rest, and an ABI abnormality only after exercise. Subjects classified with PAD by the two-vessel criterion had a higher frequency of claudication and the physical finding of an absent pulse compared with subjects without PAD or patients with PAD defined by the one-vessel or exercise criterion. Use of the two-vessel criterion identified an increased risk of PAD with increasing age, NIDDM, smoking, hypertension, and elevated cholesterol levels. In contrast, the one-vessel PAD criterion was associated only with increasing age and smoking, and exercise-diagnosed PAD was not associated with any cardiovascular risk factor except for male sex. In low-risk subjects, the normal distribution and lower abnormal cutoff point values of the ABI differed by type of test, sex, ankle vessel, and leg. When these specific abnormal cutoff points were applied to the SLVDS population, the two-vessel abnormal criterion described patients with typical clinical characteristics of PAD and the expected associations of PAD with cardiovascular risk factors. These clinical characteristics and cardiovascular risk factor associations were less evident with PAD diagnosed by the one-vessel or exercise criterion. Therefore, an abnormal dorsalis pedis and posterior tibial ABI in the same leg at rest should be used for the diagnosis of PAD in epidemiological studies.