Ankle-brachial blood pressure in elderly men and the risk of stroke: the Honolulu Heart Program

Low Ankle-Brachial Index Relates to Alzheimer-Signature Cerebral Glucose Metabolism in Cognitively Impaired Older Adults

BACKGROUND

Ankle-brachial index (ABI), an indicator of atherosclerosis or arterial stiffness, has been associated with Alzheimer's disease (AD) dementia and related cognitive impairment. Nevertheless, only limited information is available regarding its contribution to brain alterations leading to cognitive decline in late-life.

OBJECTIVE

We aimed to investigate the relationship of ABI with in vivo AD pathologies and cerebrovascular injury in cognitively impaired older adults.

METHODS

Total 127 cognitively impaired (70 mild cognitive impairment and 57 AD dementia) individuals, who participated in an ongoing prospective cohort study, were included. All participants underwent comprehensive clinical and neuropsychological assessment, ABI measurement, apolipoprotein E (APOE) ɛ4 genotyping, and multi-modal brain imaging including [11C] Pittsburgh Compound B (PiB)-positron emission tomography (PET) and [18F] fludeoxyglucose (FDG)-PET, and MRI.

RESULTS

General linear model analysis showed significant relationship between ABI strata (low ABI: <1.00, normal ABI: 1.00-1.29, and high ABI: ≥1.30) and AD-signature region cerebral glucose metabolism (AD-CM), even after controlling age, sex, clinical dementia rating-sum of box, and APOE ɛ4 positivity (p = 0.029). Post hoc comparison revealed that low ABI had significantly lower AD-CM than middle and high ABI, while no difference of AD-CM was found between middle and high ABI. There was no significant difference of global Aβ deposition, AD-signature region cortical thickness, and white matter hyperintensity volume between the three ABI strata.

CONCLUSION

Our findings suggest that lower ABI, likely related to atherosclerosis, may contribute to the aggravation of AD-related regional neurodegeneration in cognitively impaired older adults.

Ankle-brachial index and subsequent risk of incident and recurrent cardiovascular events in older adults: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

The ankle-brachial index (ABI) is a diagnostic test for screening and detecting peripheral artery disease (PAD), as well as a risk enhancer in the AHA/ACC guidelines on the primary prevention of atherosclerotic cardiovascular disease (ASCVD). However, our understanding of the association between ABI and cardiovascular risk in contemporary older populations is limited. Additionally, the prognostic value of ABI among individuals with prior ASCVD is not well understood.

METHODS

Among 5,003 older adults at ARIC visit 5 (2011-2013) (4,160 without prior ASCVD [median age 74 years, 38% male], and 843 with ASCVD [median age 76 years, 65% male]), we quantified the association between ABI and the risk of heart failure (HF), and composite coronary heart disease and stroke (CHD/stroke) using multivariable Cox regression models.

RESULTS

Over a median follow-up of 5.5 years, we observed 400 CHD/stroke events and 338 HF cases (242 and 199 cases in those without prior ASCVD, respectively). In participants without a history of ASCVD, a low ABI ≤0.9 (relative to ABI 1.11-1.20) was associated with both CHD/stroke and HF (adjusted hazard ratios 2.40 [95% CI: 1.55-3.71] and 2.23 [1.40-3.56], respectively). In those with prior ASCVD, low ABI was not significantly associated with CHD/stroke, but was with HF (7.12 [2.47-20.50]). The ABI categories of 0.9-1.2 and > 1.3 were also independently associated with increased HF risk. Beyond traditional risk factors, ABI significantly improved the risk discrimination of CHD/stroke in those without ASCVD and HF, regardless of baseline ASCVD.

CONCLUSIONS

Low ABI was associated with CHD/stroke in those without prior ASCVD and higher risk of HF regardless of baseline ASCVD status. These results support ABI as a risk enhancer for guiding primary cardiovascular prevention and suggest its potential value in HF risk assessment for older adults.

Predictive value of ankle-brachial index for long-term events of ischemic stroke in hemodialysis patients

OBJECTIVES

The ankle-brachial index is a noninvasive modality to evaluate atherosclerosis and is a predictive role for future cardiovascular events and mortality. However, few studies have evaluated its relation to long-term future ischemic stroke in hemodialysis patients. Therefore, we examined the relationship between ankle-brachial index and ischemic stroke events among hemodialysis patients in a seven-year follow-up.

METHODS

A total of 84 patients were enrolled. Ankle-brachial index was assessed in January 2009. Primary outcomes included ischemic stroke. An ankle-brachial index < 0.9 was considered abnormal and 1.4 ≥ ankle-brachial index ≥ 0.9 to be normal ankle-brachial index.

RESULTS

Mean values for ankle-brachial index were 0.98 ± 0.21at study entrance. In addition, 28 patients encountered ischemic stroke in the seven-year follow-up. In univariate Cox regression analysis, old age (hazard ratio (HR): 1.065, 95% confidence interval (CI): 1.030-1.102, p < 0.001), low seven-year averaged serum phosphate levels (HR: 0.473, 95% CI: 0.306-0.730, p = 0.001), and abnormal ankle-brachial index (HR: 0.035, 95% CI: 0.009-0.145, p < 0.001) were risk factors for ischemic stroke. In multivariate Cox regression analysis for significant variables in univariate analysis, abnormal ankle-brachial index (HR: 0.058, 95% CI: 0.012-0.279, p < 0.001) and low seven-year averaged serum phosphate levels (HR: 0.625, 95% CI: 0.404-0.968, p = 0.035) remained the risk factors for ischemic stroke. The risk of ischemic stroke was 3.783-fold in patients with abnormal ankle-brachial index compared with patients with normal ankle-brachial index (HR: 3.783, 95% CI: 1.731-8.269, p = 0.001).

CONCLUSIONS

These findings suggest that ankle-brachial index is an impressive predictor of future ischemic stroke among hemodialysis patients.

The ankle-brachial index and risk of incident stroke in Chinese hypertensive population without atrial fibrillation: A cross-sectional study

We aimed to evaluate the relation of the ankle–brachial index (ABI) with the prevalence of stroke and to examine any possible effect modifiers among hypertensive patients without atrial fibrillation. A total of 10 750 subjects with hypertension aged 27‐96 years were included in the current study. The outcome was a stroke. Odds ratios of stroke concerning ABI were calculated using multivariate logistic regression models. Among 10 750 hypertensive participants, 690 (6.42%) had a stroke. Multivariate logistic analyses showed that ABI was negatively correlated with the prevalence of stroke (per SD increment; adjusted OR, 0.88; 95% CI, 0.82‐0.94). Compared with participants in Q 1, the odds ratios (95% CI) for those in the Q2 (1.05 to 1.10), Q3 (1.10 to 1.15), and Q4 (≥1.15) were 0.71 (0.56, 0.90), 0.87 (0.70, 1.08), and 0.81 (0.65, 1.01), respectively. However, compared with higher ABI value, lower ABI value (<1.05) would significantly increase the odds of stroke (OR: 1.26, 95% CI [1.05‐1.50]), especially in the elderly over 65 years old. A generalized additive model and a smooth curve fitting showed that there existed an L‐shaped association between ABI and the prevalence of stroke. Our results suggest that an L‐shaped association between ABI and the prevalence of stroke was found in general hypertensive patients, with a turning point at about 1.05. Compared with higher ABI value, lower ABI value (<1.05) would significantly increase the prevalence of stroke (OR: 1.26, 95% CI [1.05‐1.50]), especially in the elderly over 65 years old.

Independent ischemic stroke risk factors in older Americans: a systematic review

The Framingham Stroke Risk Profile (FSRP) is a validated model for predicting 10-year ischemic stroke risk in middle-aged adults, yet has not been demonstrated to consistently translate in older populations. This is a systematic review of independent risk factors measured among > 65 year olds, with subsequent first ischemic stroke, using PRISMA guidelines. We appraised peer-reviewed publications that included participants > 65 years old at risk assessment. Combined with other criteria, results were abstracted from 28 papers reporting six types of stroke risk factors: Serologic/Diagnostic, Conventional, Psychosocial, Genetic, Cognitive, and Antibiotic use. These studies demonstrated levels of serum androgens, C-reactive protein, and advanced glycation endproducts; thrombin generation; left ventricular mass; depressive symptoms; phosphodiesterase 4D single nucleotide polymorphisms; coagulation factor XII gene; peak thrombus generation; and lower cognitive functioning were independent risk factors for ischemic stroke in older adults. Plasma adipokines, free fatty acids and antibiotic use did not predict ischemic stroke. Purpose in life and APOEε2 allele were protective for ischemic stroke. This systematic review provides evidence of risk and protective factors for ischemic stroke in older cohorts that are not included in the FSRP. Further studies are needed to understand whether these factors are important enough to comprise a risk score.

Pulse Waves in the Lower Extremities as a Diagnostic Tool of Peripheral Arterial Disease and Predictor of Mortality in Elderly Chinese

Patients with peripheral arterial disease may have elongated upstroke time in pulse waves in the lower extremities. We investigated upstroke time as a diagnostic tool of peripheral arterial disease and predictor of mortality in an elderly (≥60 years) Chinese population. We recorded pulse waves at the left and right ankles by pneumoplethysmography and calculated the percentage of upstroke time per cardiac cycle. Diagnostic accuracy was compared with the conventional ankle-brachial index method (n=4055) and computed tomographic angiography (34 lower extremities in 17 subjects). Upstroke time per cardiac cycle at baseline (mean±SD, 16.4%±3.1%) was significantly ( P <0.0001) associated with ankle-brachial index in men (n=1803; r =−0.44) and women (n=2252; r =−0.32) and had an overall sensitivity and specificity of 86% and 80%, respectively, for the diagnosis of peripheral arterial disease (upstroke time per cardiac cycle, ≥21.7%) in comparison with computed tomographic angiography. During 5.9 years (median) of follow-up, all-cause and cardiovascular deaths occurred in 366 and 183 subjects, respectively. In adjusted Cox regression analyses, an upstroke time per cardiac cycle ≥21.7% (n=219; 5.4%) significantly ( P <0.0001) predicted total and cardiovascular mortality. The corresponding hazard ratios were 1.98 (95% confidence interval, 1.48–2.65) and 2.29 (1.58–3.32), respectively, when compared with that of 2.10 (1.48–3.00) and 2.44 (1.57–3.79), respectively, associated with an ankle-brachial index of ≤0.90 (n=115; 2.8%). In conclusion, pulse waves in the lower extremities may behave as an accurate and ease of use diagnostic tool of peripheral arterial disease and predictor of mortality in the elderly.

Co-existence of vascular disease in different arterial beds: Peripheral artery disease and carotid artery stenosis--Data from Life Line Screening(®)

BACKGROUND

Atherosclerosis is a systemic vascular disorder, involving multiple arterial territories. This project sought to investigate the relationship between lower extremity peripheral artery disease (PAD) and carotid artery stenosis (CAS) in a large self-referred population.

METHODS

Data from the ankle brachial index (ABI) and carotid duplex ultrasound were analyzed from 3.67 million US subjects in the Life Line Screening program between 2004 and 2008. PAD was defined by ABI<0.9 and CAS was defined by greater than 50% stenosis. Multivariate logistic regression analysis was used to estimate odds of CAS by PAD status and severity.

RESULTS

Mean age of the population was 63.7 ± 10.6 years and 64% were women. The prevalence of PAD and CAS was 4.1% and 3.9%, respectively. Subjects with PAD had a higher prevalence of CAS than those without PAD (18.8% vs. 3.3%, P < 0.0001). In multivariate analysis, PAD was associated with greater odds of CAS (OR 3.28, 95% CI 3.22-3.34). Both symptomatic (OR 3.66, 95% CI 3.58-3.75) and asymptomatic PAD (OR 2.91, 95% CI 2.84-2.98) was associated with CAS. Increasing severity of PAD was associated with greater odds of CAS (OR 2.32, 3.61, 4.19, 5.14, and 7.59 for ABI categories 0.81-0.90, 0.71-0.80, 0.61-0.70, 0.41-0.60, ≤0.40, respectively).

CONCLUSION

Presence and severity of PAD was associated with prevalence of CAS in the large self-referred and self-paying Life Line cohort, regardless of lower extremity symptoms.

Ankle-brachial index long-term outcome after first-ever ischaemic stroke

BACKGROUND AND PURPOSE

Ankle-brachial blood pressure index (ABI) is a clinical tool to identify the presence of peripheral artery disease. There is a scarcity of data associating ABI with long-term outcome in patients with IS. The association between ABI and long-term outcome in patients with first-ever acute IS was assessed.

METHODS

Ankle-brachial blood pressure index was assessed in all consecutive patients with a first-ever acute IS admitted at Alexandra University hospital (Athens, Greece) between January 2005 and December 2010. ABI was considered normal when > 0.90 and ≤ 1.30. The Kaplan-Meier product limit method was used to estimate the probability of 5-year composite cardiovascular event-free (defined as recurrent stroke, myocardial infarction or cardiovascular death) and overall survival. A multivariate analysis was performed to assess whether ABI is an independent predictor of 5-year mortality and dependence.

RESULTS

Amongst 653 patients, 129 (19.8%) with ABI ≤ 0.9 were identified. Five-year cumulative composite cardiovascular event-free and overall survival rates were better in normal ABI stroke patients (log-rank test: 7.22, P = 0.007 and 23.40, P < 0.001, respectively). There was no difference in 5-year risk of stroke recurrence between low and normal ABI groups (hazard ratio, HR = 1.23, 95% CI 0.68-2.23). In multivariate Cox regression analysis, independent predictors of 5-year mortality included age (HR = 2.55 per 10 years, 95% CI 1.86-3.48, P < 0.001), the National Institutes of Health Stroke Scale (per point increase HR = 1.12, 95% CI 1.08-1.16, P < 0.001), and low ABI (HR = 2.22, 95% CI 1.22-4.03, P = 0.009). Age (HR = 1.21 per 10 years, 95% CI 1.01-1.45, P = 0.04) and low ABI (HR = 1.72, 95% CI 1.11-2.67, P = 0.01) were independent predictors of the composite cardiovascular end-point.

CONCLUSIONS

Low ABI in patients with acute IS is associated with increased 5-year cardiovascular event risk and mortality. However, ABI does not appear to predict long-term stroke recurrence.

Risk factors related to low ankle-brachial index measured by traditional and modified definition in hypertensive elderly patients

Peripheral arterial disease (PAD) increases with age and ankle-brachial index (ABI) ≤ 0.9 is a noninvasive marker of PAD. The purpose of this study was to identify risk factors related to a low ABI in the elderly using two different methods of ABI calculation (traditional and modified definition using lower instead of higher ankle pressure). A cross-sectional study was carried out with 65 hypertensive patients aged 65 years or older. PAD was present in 18% of individuals by current ABI definition and in 32% by modified method. Diabetes, cardiovascular diseases, metabolic syndrome, higher levels of systolic blood pressure and pulse pressure, elevated risk by Framingham Risk Score (FRS), and a higher number of total and antihypertensive drugs in use were associated with low ABI by both definitions. Smoking and LDL-cholesterol were associated with low ABI only by the modified definition. Low ABI by the modified definition detected 9 new cases of PAD but cardiovascular risk had not been considered high in 3 patients when calculated by FRS. In conclusion, given that a simple modification of ABI calculation would be able to identify more patients at high risk, it should be considered for cardiovascular risk prediction in all elderly hypertensive outpatients.

Racial-ethnic disparities in stroke care: the American experience: a statement for healthcare professionals from the American Heart Association/American Stroke Association

PURPOSE

Our goal is to describe the effect of race and ethnicity on stroke epidemiology, personal beliefs, access to care, response to treatment, and participation in clinical research. In addition, we seek to determine the state of knowledge on the main factors that may explain disparities in stroke care, with the goal of identifying gaps in knowledge to guide future research. The intended audience includes physicians, nurses, other healthcare professionals, and policy makers.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council Scientific Statement Oversight Committee and represent different areas of expertise in relation to racial-ethnic disparities in stroke care. The writing group reviewed the relevant literature, with an emphasis on reports published since 1972. The statement was approved by the writing group; the statement underwent peer review, then was approved by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

There are limitations in the definitions of racial and ethnic categories currently in use. For the purpose of this statement, we used the racial categories defined by the US federal government: white, black or African American, Asian, American Indian/Alaskan Native, and Native Hawaiian/other Pacific Islander. There are 2 ethnic categories: people of Hispanic/Latino origin or not of Hispanic/Latino origin. There are differences in the distribution of the burden of risk factors, stroke incidence and prevalence, and stroke mortality among different racial and ethnic groups. In addition, there are disparities in stroke care between minority groups compared with whites. These disparities include lack of awareness of stroke symptoms and signs and lack of knowledge about the need for urgent treatment and the causal role of risk factors. There are also differences in attitudes, beliefs, and compliance among minorities compared with whites. Differences in socioeconomic status and insurance coverage, mistrust of the healthcare system, the relatively limited number of providers who are members of minority groups, and system limitations may contribute to disparities in access to or quality of care, which in turn might result in different rates of stroke morbidity and mortality. Cultural and language barriers probably also contribute to some of these disparities. Minorities use emergency medical services systems less, are often delayed in arriving at the emergency department, have longer waiting times in the emergency department, and are less likely to receive thrombolysis for acute ischemic stroke. Although unmeasured factors may play a role in these delays, the presence of bias in the delivery of care cannot be excluded. Minorities have equal access to rehabilitation services, although they experience longer stays and have poorer functional status than whites. Minorities are inadequately treated with both primary and secondary stroke prevention strategies compared with whites. Sparse data exist on racial-ethnic disparities in access to surgical care after intracerebral hemorrhage and subarachnoid hemorrhage. Participation of minorities in clinical research is limited. Barriers to participation in clinical research include beliefs, lack of trust, and limited awareness. Race is a contentious topic in biomedical research because race is not proven to be a surrogate for genetic constitution.

CONCLUSIONS

There are limitations in the current definitions of race and ethnicity. Nevertheless, racial and ethnic disparities in stroke exist and include differences in the biological determinants of disease and disparities throughout the continuum of care, including access to and quality of care. Access to and participation in research is also limited among minority groups. Acknowledging the presence of disparities and understanding the factors that contribute to them are necessary first steps. More research is required to understand these differences and find solutions.

Cumulative smoking exposure, duration of smoking cessation, and peripheral arterial disease in middle-aged and older Korean men

Background

We investigated the association of cumulative smoking exposure and duration of smoking cessation with peripheral arterial disease (PAD).

Methods

The study population consisted of 2517 community-dwelling Korean men aged 50 years and older. Information on smoking characteristics such as smoking status, pack-years of smoking, and years since quitting smoking was collected using a standardized questionnaire. PAD was defined as an ankle-brachial index (ABI) less than 0.90 in either leg.

Results

The odds ratio (OR, 95% confidence interval) of PAD was 2.31 (1.20-4.42) for former smokers and 4.30 (2.13-8.66) for current smokers, after adjusting for other cardiovascular risk factors. There was a significant dose-response relationship between pack-years of smoking and PAD. Compared with those who had never smoked, the multivariate-adjusted ORs of PAD for smokers of 0.1-20.0, 20.1-40.0, and >40.0 pack-years were 2.15 (1.06-4.38), 2.24 (1.08-4.65), and 2.93 (1.41-6.09), respectively. There was a significant decrease in PAD risk as the years since quitting smoking increased. The multivariate-adjusted ORs of PAD for 11-20 and ≥21 years smoking cessation were 0.41 (0.19-0.86) and 0.49 (0.24-0.98), compared with current smokers.

Conclusions

Cumulative smoking exposure and duration of smoking cessation were significantly associated with PAD in middle aged and older Korean men.

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index

BACKGROUND

Blood pressure (BP) variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM). We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI).

METHODS AND RESULTS

In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time), standard deviation (SD) of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (≤ 0.90 or ≥ 1.40) was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007). In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04). In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P < 0.01). None of the other indexes of BP variability were associated with ABI in univariate and multivariate analyses.

CONCLUSION

Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.

Comparison of the Automated Oscillometric Method With the Gold Standard Doppler Ultrasound Method to Access the Ankle-Brachial Pressure Index

Objective: Despite its screening interest, the ankle-brachial pressure index (ABPI) remains uncommon in general practice, because it needs training and specific devices as Doppler. Easier methods such as the use of automated oscillometric devices may facilitate the peripheral arterial diseases (PADs) screening. We wanted to assess the reliability of the automated oscillometric measurement of the ABPI, compared with the gold standard Doppler ultrasound measurement. Patients and Method: In 287 patients aged 65 years or older without diagnosed PAD, we performed ABPI measurements with oscillometric and Doppler devices. Reproducibility was assessed by the intraclass correlation coefficient of agreement (R) and the Bland and Altman method. Results: The intermethod reliability was bad (R = .346, 95% CI = (0.268-0.420)), with a large confidence interval of the individual differences between the 2 methods: 95% CI = (—0.183-0.346). Conclusion: Automatic oscillometric devices cannot be recommended as reliable methods for ABPI measurement.

Update on peripheral arterial disease and claudication rehabilitation

The prevalence of peripheral arterial disease is high and will continue to grow with our aging population. It is often under diagnosed and under treated due to a general lack of awareness on the part of the patient and the practitioner. The evidence-base is growing for the optimal medical management of the patient with peripheral arterial disease; in parallel, endovascular revascularization options continue to improve. Exercise training for claudication rehabilitation plays a critical role. Comprehensive care of the peripheral arterial disease patient focuses on the ultimate goals of improving quality of life and reducing cardiovascular morbidity and mortality.

The role of ankle-brachial index as a screening test for coronary artery disease in the Hispanic population

OBJECTIVES

This study evaluated the role of ankle-brachial index (ABI) as an effective screening test of coronary artery disease (CAD) in the Hispanic population.

METHODS

This was an observational cross-sectional study, based on a retrospective review of the medical management of the study patients using already available data. The study comprised 155 patients, aged 50 to 70 years with metabolic syndrome but no known CAD, presenting in El Paso, Texas between February 2004 and November 2006. An ABI test had been performed on all the patients in this study. Also, myocardial nuclear perfusion imaging using single photon emission computed tomography and electrocardiogram gating tests had been performed on these patients, because they all had multiple traditional risk factors for CAD.

RESULTS

Sensitivity of low ABI in screening for CAD was 82.61%, while the specificity was 77.27%.

CONCLUSION

ABI is an effective and cost-efficient screening test for CAD.

Predictive value of the Essen Stroke Risk Score and Ankle Brachial Index in acute ischaemic stroke patients from 85 German stroke units

BACKGROUND

Risk stratification can contribute to individualised optimal secondary prevention in patients with cerebrovascular disease.

OBJECTIVE

To prospectively investigate the prediction of the Essen Stroke Risk Score (ESRS) and a pathological Ankle Brachial Index (ABI) in consecutive patients hospitalised with acute ischaemic stroke or transient ischaemic attack (TIA) in 85 neurological stroke units throughout Germany.

METHODS

852 patients were prospectively documented on standardised case report forms, including assessment of ESRS and ABI. After 17.5 months, recurrent cerebrovascular events, functional outcome or death could be assessed in 729 patients predominantly via central telephone interview.

RESULTS

After discharge from the documenting hospital, recurrent stroke occurred in 41 patients (5.6%) and recurrent TIA in 15 patients (2.1%). 52 patients (7.1%) had died, 33 (4.5%) from cardiovascular causes. Patients with an ESRS > or = 3 (vs <3) had a significantly higher risk of recurrent stroke or cardiovascular death (9.7% vs 5.1%; odds ratio (OR) 2.00, 95% confidence interval (CI) 1.08 to 3.70) and a higher recurrent stroke risk (6.9% vs 3.7%; OR 1.93, 95% CI 0.95 to 3.94). Patients with an ABI < or = 0.9 (vs > 0.9) had a significantly higher risk of recurrent stroke or cardiovascular death (10.4% vs 5.5%; OR 2.00, 95% CI 1.12 to 3.56) and a higher recurrent stroke risk (6.6% vs 4.6%; OR 1.47, 95% CI 0.76 to 2.83).

CONCLUSION

Our prospective follow-up study shows a significantly higher rate of recurrent stroke or cardiovascular death and a clear trend for a higher rate of recurrent stroke in patients with acute cerebrovascular events classified as high risk by an ESRS > or = 3 or a pathological ABI.

Association of ankle-brachial index level with stroke

BACKGROUND

There are conflicting data on the relationship between peripheral arterial disease (PAD) as defined by an ankle-brachial index (ABI) of <0.9 and stroke risk, and these prior data have largely focused on a single race or gender. Furthermore, the association between subsequent ABIs above the established 0.9 threshold for PAD vs. stroke has not been studied. This study assessed stroke occurrence across the full spectrum of ABI values among a broad cohort of stroke survivors.

METHODS

Data from the National Health and Nutrition Examination Survey from 1999-2004, a nationally representative sample of United States adults, were used to assess prevalence of PAD as evidenced by ABI of <0.9, and to simultaneously identify the independent associations of ABI levels (<0.90, 0.90-0.99, 1.00-1.09, >1.3) with stroke prevalence.

RESULTS

Among 6382 adults, 4602 (72%) had full and complete data of which 277 (6%) reported stroke occurrence. Stroke survivors were older and more likely to have diabetes, hypertension, coronary artery disease, elevated blood pressure and glycohemoglobin, than non-stroke respondents. More subjects with ABI <0.9 vs. > or =0.9 had experienced a stroke (12.7% vs. 5.4%, p<0.001). Within the full ABI range, stroke presence rose with decreasing ABI (p=0.0013). After adjustment for potential confounders, only ABI <0.9 (OR 1.9, 95% CI=1.2-3.1) and 0.9-0.99 (OR 2.3, 95% CI=1.4-3.6) compared with the referent group (1.10-1.29) were significantly associated with presence of stroke.

CONCLUSIONS

Data from this nationally representative cohort support an independent relationship between established PAD and stroke occurrence, but also indicate that even borderline PAD is strongly linked to stroke.

Self-reported peripheral arterial disease predicts future vascular events in a community-based cohort

BACKGROUND

Lower extremity peripheral arterial disease (PAD) is highly prevalent and strongly associated with cardiovascular morbidity and mortality. The ankle-brachial index used to screen for PAD is not routinely performed in primary care settings.

OBJECTIVE

To determine if self-reported PAD is an independent predictor of combined vascular events (myocardial infarction, ischemic stroke, and vascular death).

DESIGN

Ongoing population-based prospective cohort (the Northern Manhattan Study). Subjects enrolled between July 1993 and June 2001 with a mean follow-up time of 7.1 years.

PATIENTS

Subjects (n = 2,977), aged 40 years or older and free of prior stroke or myocardial infarction, were classified as having self-reported PAD if they answered affirmatively to one of two questions regarding exercise-induced leg pain or a prior diagnosis of PAD.

MAIN OUTCOME MEASURES

Combined vascular outcome defined as incident myocardial infarction, incident ischemic stroke, or vascular death.

RESULTS

The mean age of the cohort was 68.9 +/- 10.4 years; 64% were women; 54% Hispanic, 25% African-American, 21% Caucasian; 15% reported having PAD. After a mean follow-up of 7.1 years, self-reported PAD was significantly predictive of combined events (n = 484) in the univariate model (HR 1.5, 95% CI, 1.2-1.9) and after adjustment for traditional cardiovascular risk factors (HR 1.3, 95% CI, 1.0-1.7).

CONCLUSION

Self-reported PAD is an independent risk factor for future vascular events in this predominantly non-white cohort. The addition of two simple PAD questions to the routine medical history in general medicine settings could identify high-risk patients who would benefit from further vascular evaluation and risk factor modification.

Ankle-to-Brachial Index and Dementia

Background— Measurement of the ankle-to-brachial index (ABI) is a noninvasive test to assess peripheral arterial disease. A low ABI is a strong correlate of cardiovascular disease and subsequent mortality. Evidence indicates the existence of vascular components in the pathogenesis of dementia. Here, we examine the association of ABI with dementia and subtypes.

Methods and Results— Data are from the Honolulu-Asia Aging Study (HAAS), a prospective community-based study of 3734 Japanese American men 71 to 93 years of age at baseline in 1991 to 1993. The analysis included 2588 men who were free of dementia at the first assessment, had an ABI measure, and were examined up to 2 more times for dementia between 1994 and 1999. The sample included 240 incident cases of dementia (144 of Alzheimer’s disease, 46 of vascular dementia, and 50 of dementia of other causes). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from Cox proportional-hazards models with age as the time scale after adjustment for education, year of birth, high blood pressure, body mass index, diabetes mellitus, cholesterol concentration, smoking status, alcohol consumption, and apolipoprotein E ε4 allele. A low ABI was associated with an increased risk of dementia and vascular dementia (HR, 1.66; 95% CI, 1.16 to 2.37; and HR, 2.25; 95% CI, 1.07 to 4.73, respectively). ABI was weakly associated with Alzheimer’s disease (HR, 1.57; 95% CI, 0.98 to 2.53), particularly in the apolipoprotein E ε4 carriers (HR, 1.43; 95% CI, 1.02 to 1.96).

Conclusions— These results suggest that ABI, a measure of atherosclerosis, is associated with the incidence of total dementia, vascular dementia, and Alzheimer’s disease in carriers of the apolipoprotein E ε4 allele.

Ankle brachial pressure index usefulness as predictor factor for coronary heart disease in diabetic patients

Ankle brachial pressure index (ABPI) is a non-invasive marker of atherosclerosis, helpful to identify subjects at high-risk for coronary heart disease (CHD) among large populations with cardiovascular disease (CVD) risk factors. The diagnostic role of ABPI has been also recognized in patients with diabetes. In the present study, the role of an ABPI score < 0.90 in predicting CHD has been evaluated in a large series of patients with Type 2 diabetes mellitus and compared to other known CVD risk factors. Nine hundred and sixty-nine (mean age was 66.1 yr) consecutive patients with Type 2 diabetes mellitus were evaluated. The patients were followed-up for 18.3+/-5.2 months (range 12- 24) and all events of CHD, defined as myocardial infarction, unstable and resting angina or coronary atherosclerosis at the instrumental investigation (at the coronary angiography and/or perfusion stress testing) were recorded. A rate of 17.5% of CHD events were recorded in diabetic population during the follow-up period. The relative risk of CHD was significantly increased for male patients [odds ratio (OR): 1.6; 95% confidence interval (CI): 1.1-2.2], patients with age > or = 66 yr (OR: 1.8; 95% CI: 1.3-2.5), body mass index (BMI) > 30 (OR: 1.5; 95% CI: 1.1-2.1), waist circumference > 88 cm for females and 102 cm for males (OR: 1.5; 95% CI: 1.0-2.1), proteinuria > or = 30 microg per min (OR: 1.6; 95% CI: 1.1-2.3), LDL-cholesterol > or = 100 mg/dl (OR: 2.1; 95% CI: 1.5-3.0), glycated hemoglobin > 7% (OR: 1.6; 95% CI: 1.1-2.3), insulin therapy (OR: 1.9; 95% CI: 1.3-2.9), and ABPI < 0.90 (OR: 3.7; 95% CI: 2.2- 6.2). BMI was higher in patients with ABPI < 0.90 than in those with ABPI > or = 0.90 (p<0.05). At the multivariate analysis, ABPI < 0.90 was the best factor independently associated with CHD (p<0.001). APBI < 0.90 is strongly associated to CHD in Type 2 diabetic patients. We recommend to use ABPI in diabetic patients and to carefully monitor diabetic subjects with an ABPI lower than 0.90.

Ankle brachial index and intima media thickness predict cardiovascular events similarly and increased prediction when combined

OBJECTIVE

To compare the predictive value of the ankle brachial index (ABI) and carotid intima media thickness (IMT) for cardiovascular events.

STUDY DESIGN AND SETTING

Population-based cohort study. New cardiovascular events (myocardial infarction [MI], stroke, angina, and intermittent claudication) were ascertained over a 12-year period in 1,007 men and women aged 60-79 and free of MI or stroke.

RESULTS

The positive and negative predictive values for an ABI<or=0.9, an IMT>or=0.9mm and for both tests abnormal were not substantially different. However, event rates in subjects with one test normal were increased when the alternate test proved positive (in people with a normal ABI test, 20.8% with an abnormal IMT developed MI/stroke compared with only 10.3% with a normal IMT). The area under the receiver operator curves (AUC) increased significantly between a model containing only age and sex (AUC 0.60, 95% confidence interval [CI] 0.55, 0.65) and that with either ABI (AUC 0.63, 95% CI 0.58, 0.69, P=0.002) or IMT (AUC 0.62, 95% CI 0.57, 0.67, P=0.005) added. The AUC increased further when both tests were added simultaneously (AUC 0.65, 95% CI 0.60, 0.70, P<0.001).

CONCLUSION

The ability of the ABI to predict cardiovascular disease was similar to that of the IMT. Combination of the two tests may be advantageous when the second test is applied to people with a negative first test and/or when the results are used as continuous variables.

Prevalence of and risk factors for peripheral arterial disease in the patients with hypertension among Han Chinese

OBJECTIVES

Peripheral arterial disease (PAD) is associated with morbidity and mortality of coronary heart disease and stroke. Hypertension is an independent risk factor for peripheral arterial disease. However, the prevalence and risk factors of PAD in hypertensive patients have not been studied in China.

METHODS

In order to investigate the prevalence of PAD and its risk factors in China, a cross-sectional study was carried out. A total of 4716 patients with hypertension and 833 age-gender matched people without hypertension were recruited; age 40 to 75 years, from seven rural communities. PAD was defined as an ankle-brachial index (ABI) <or= 0.9 in either leg; hypertension was defined as systolic blood pressure >or=140 mm Hg, diastolic blood pressure >or=90 mm Hg, or history of antihypertensive drug use.

RESULTS

The prevalence of PAD is 8.7% (n = 408) in patients with hypertension (n = 4716), higher than in people without hypertension (5.0%, n = 833, P = .004). Hypertensive patients with PAD were older, (61 +/- 8.6 vs 58 +/- 8.6, P < .01), had more conventional cardiovascular risk factors including systolic blood pressure (170 +/- 22.6 vs 167 +/- 22.7, P < .01), pulse pressure (72 +/- 19.7 vs 68 +/- 18.9, P < .01), blood glucose (5.8 +/- 2.2 vs 5.6 +/- 1.7, P < .05), total cholesterol (5.7 +/- 1.3 vs 5.5 +/- 1.1, P < .05), and serum uric acid (355 +/- 98.0 vs 293 +/- 86.2, P < .05) than the hypertensive patients without PAD. After adjusting for gender, age, and other cardiovascular risk factors by using multiple logistical regression analysis, PAD was still associated with current smoking (odds ratio [OR] = 1.65, 95% confidence interval [CI] 1.18-2.29), history of stroke (OR = 1.50, 95% CI 1.12-2.00), serum uric acid (OR = 1.21, 95% CI 1.10-1.59), and total cholesterol (OR = 1.12, 95% CI 1.10-1.59).

CONCLUSION

This study reports, for the first time, the prevalence of PAD in Chinese patients with hypertension, which is quite different from that in westerners, and that PAD is independently associated with conventional cardiovascular risk factors.

Nuevas perspectivas en la medición del riesgo cardiovascular: exploraciones para detectar la aterosclerosis subclínica y marcadores de inflamación

Among the new technologies for the detection of subclinical atherosclerosis, ankle-brachial index, carotid ultrasonography, computed tomography detection of coronary calcifications and high-resolution nuclear magnetic resonance are those of greatest clinical usefulness. These explorations are especially useful for patients with an intermediate cardiovascular risk, or a 10-20% risk according to the National Cholesterol Education Program-Adult Treatment Panel III or 3-4% according to the SCORE project. This is because they allow the identification of high-risk patients who need a more intense treatment. In addition, high-sensitivity C-reactive protein concentrations may be considered as a new marker for the evaluation of cardiovascular risk. In this article, the current state of knowledge about these explorations and the guidelines of the main scientific societies are reviewed, and the practical conclusions of the working group are provided.

Association between serum uric acid level and peripheral arterial disease

BACKGROUND

Higher serum uric acid levels have been implicated in the development and progression of atherosclerotic cardiovascular disease. However, it is not clear whether serum uric acid levels are related to subclinical measures of cardiovascular disease, including peripheral arterial disease (PAD). We examined the association between increasing serum uric acid levels and PAD in the US general population.

METHODS

A cross-sectional study was conducted among 3987 National Health and Nutrition Examination Survey 1999-2002 participants aged > or =40 years, without clinical history of cardiovascular disease. Main outcome-of-interest was PAD defined as ankle-brachial index <0.9 (n=229).

RESULTS

Higher serum uric acid levels were positively associated with PAD, independent of smoking, body mass index (BMI), hypertension, diabetes, serum total cholesterol, serum creatinine, and other confounders. Multivariable odds ratio (OR) [95 percent confidence intervals (CI)] comparing serum uric acid levels > or =75th percentile (> or =380.8 micromol/L) to uric acid levels <50th percentile (<315.6 micromol/L) was 1.62 (1.08-2.44), p-trend=0.015. This association persisted in separate analysis among men and women. Further, the results were consistent in subgroup analyses by categories of age, current smoking, BMI, and diabetes mellitus.

CONCLUSIONS

Higher serum uric acid levels are associated with PAD in the US general population. These results suggest that PAD may be an important indicator of the reported association between higher serum uric acid levels and clinical cardiovascular disease. Future prospective studies are required to clarify the temporal nature of this relationship.

[Peripheral artery disease of the lower limbs and morbidity/mortality in type 2 diabetics]

OBJECTIVE

To study the relationship between the presence of peripheral artery disease (PAD) and the morbidity and mortality at 6 years, and the ankle-brachial index (ABI) as a predictor of morbidity and mortality in type 2 diabetes mellitus.

DESIGN

Retrospective cohort study. Six years follow-up.

SETTING

Urban health centre.

PARTICIPANTS

A total of 269 type 2 diabetics, of which 63 had PAD in 1996: 20 were previously diagnosed and 43 had an ABI of < or =0.90.

PRINCIPAL MEASUREMENTS

An appointed was made with the patients to find out the incidence of fatal and non-fatal microvascular and macrovascular events and the histories were reviewed. Six patients were excluded as all their data were not available.

RESULTS

Thirty nine patients had died, of whom 19 had PAD in 1996 (30.1%) and 20 did not (9.7%) (P = .001). Sixteen patients died in the group with an ABI < or =0.9 (30.2%) and 21 (10.1%) in the group with normal ABI values (P = .001). 7 (13.2%) patients died due to a cardiovascular cause with a pathological ABI, and 8 (3.9%) with a normal value (P = .009). The presence of PAD has been associated with a higher probability of having a non-fatal episode of ischaemic cardiac disease (P = .04), a cerebrovascular accident (CVA) (P < .001) and ulcers (P = .006). A low ABI has been associated with a higher probability of presenting with a fatal or non-fatal cardiovascular event (P < .001). After the multivariate analysis an increase was observed in cardiovascular (odds ratio [OR] =2.81; 95% confidence interval [CI], 1.16-6.78), CVA (OR = 3.47; 95% CI, 1.19-10.07), and cardiac failure (OR = 6.75; 95% CI, 1.34-33.81), morbidity and mortality in diabetics with an ABI of < or = 0.90.

CONCLUSIONS

The type 2 diabetics with PAD present with a higher morbidity and mortality. The ABI is a good predictor of cardiovascular disease and heart failure morbidity and mortality.

Low ankle-brachial index predicts an adverse 1-year outcome after acute coronary and cerebrovascular events

BACKGROUND

Low ankle-brachial Index (ABI) identifies patients with symptomatic and asymptomatic peripheral arterial disease. The aim of this study was to correlate ABI value (normal or low) with 1-year clinical outcome in patients hospitalized for acute coronary syndromes or cerebrovascular diseases (CVD).

METHODS

ABI was measured in consecutive patients hospitalized because of acute myocardial infarction, unstable angina, stroke or transient ischemic attack (TIA). An ABI lower than or equal to 0.90 was considered abnormal. The primary outcome of the study was the composite of non-fatal acute myocardial infarction, non-fatal ischemic stroke, and death from any cause during the year following the index event.

RESULTS

An abnormal ABI was found in 27.2% of 1003 patients with acute coronary syndromes, and in 33.5% of 755 patients with acute CVD. After a median follow-up of 372 days, the frequency of the primary outcome was 10.8% (57/526) in patients with abnormal ABI and 5.9% (73/1232) in patients with normal ABI [odds ratio (OR) 1.96; 95% CI 1.36-2.81]. Death was more common in patients with abnormal ABI (OR 2.05; 95% CI 1.31-3.22). Cardiovascular mortality accounted for 81.7% of overall mortality. ABI was predictive of adverse outcome after adjustment for vascular risk factors in the logistic regression analysis (OR 1.93; 95% CI 1.24-3.01). The predictive value of ABI was mainly accounted for by patients hospitalized for acute coronary syndromes (adverse outcome: 12.8% in patients with abnormal ABI and 5.9% in patients with normal ABI, OR 2.35; 95% CI 1.47-3.76).

CONCLUSIONS

An abnormal ABI can be found in one-third of patients hospitalized for acute coronary or cerebrovascular events and is a predictor of an adverse 1-year outcome.

Relation of borderline peripheral arterial disease to cardiovascular disease risk

Peripheral arterial disease (PAD) is a well-established risk factor for clinical cardiovascular disease (CVD). The impact of a low ankle-brachial index (ABI), higher than the generally recognized 0.9 cutpoint for PAD, on CVD risk is not well characterized. We analyzed data from the 1999 to 2002 National Health and Nutrition Examination Survey (n = 4,895), a nationally representative sample of United States adults, to determine the prevalence of PAD (ABI <0.90), borderline PAD (ABI 0.90 to 0.99), a low-normal ABI (1.00 to 1.09), and a normal ABI (1.10 to 1.29), and the association of these ABI levels with CVD. The prevalence of PAD, borderline PAD, a low-normal ABI, and a normal ABI was 5.0%, 8.7%, 27.8%, and 54.8%, respectively. After age, race/ethnicity, and gender adjustment, the odds ratios of a 10-year coronary heart disease (CHD) risk of >or=20%, CHD, stroke, and CVD were higher at lower ABI levels (each p trend <0.01). After additional adjustment for potential confounders, the odds ratios associated with a low-normal ABI, borderline PAD, and PAD, compared with those with a normal ABI, were 1.24 (95% confidence interval [CI] 0.91 to 1.70), 1.34 (95% CI 0.99 to 1.83), and 1.87 (95% CI 1.29 to 2.73), respectively (p trend <0.001) for CVD and 1.20 (95% CI 0.82 to 1.77), 1.45 (95% CI 0.80 to 2.63), and 2.02 (95% CI 1.20 to 3.39), respectively (p trend = 0.015) for a 10-year risk of CHD of >or=20%. In contrast, a trend was not present for CHD and stroke after multivariate adjustment. In conclusion, subjects with a low-normal ABI or with borderline PAD need screening for CVD risk factors, and interventions may be appropriate to prevent cardiovascular events.

Risk of mortality and cardiovascular disease associated with the ankle-brachial index: Systematic review

OBJECTIVE

To determine the strength and consistency with which a low ankle brachial pressure index (ABI), measured in the general population, is associated with an increased risk of subsequent death and/or cardiovascular events.

DESIGN

Systematic review.

DATA SOURCES

Medline, Embase, reference lists and grey literature were searched; studies known to experts were also retrieved.

MAIN OUTCOME MEASURES

All cause mortality, fatal and non-fatal coronary heart disease and stroke.

REVIEW METHODS

Longitudinal studies in which participants were representative of the general population (all ages, either sex) and which used any standard method for measurement and calculation of the ABI. Studies in which participants were selected according to presence of pre-existing disease or were post intervention (e.g. angioplasty or peripheral arterial grafting) were excluded.

RESULTS

11 studies comprising 44,590 subjects from six different countries were included. Despite clinical heterogeneity between studies, the findings were remarkably consistent in demonstrating an increased risk of clinical cardiovascular disease associated with a low ABI. A low ABI (<0.9) was associated with an increased risk of subsequent all cause mortality (pooled RR 1.60, 95% CI 1.32-1.95), cardiovascular mortality (pooled RR 1.96, 95% CI 1.46-2.64), coronary heart disease (pooled RR 1.45, 95% CI 1.08-1.93) and stroke (pooled RR 1.35, 95% CI 1.10-1.65) after adjustment for age, sex, conventional cardiovascular risk factors and prevalent cardiovascular disease.

CONCLUSIONS

The ABI may help to identify asymptomatic individuals in the general population who are at increased risk of subsequent cardiovascular events. Evaluation is now required of the potential of incorporating ABI measurement into cardiovascular prevention programmes.

Methodology for measuring cerebrovascular disease burden

Biological aging of the brain is partly attributable to aging of the cerebrovascular circulation and the effects of these vascular changes on the brain. A variety of techniques ranging from simple, clinical scores to complex radiological techniques have been used in an attempt to understand, describe and quantify this process. Simultaneously attempts have been made to relate these changes to cognitive and physical changes and the risk of dementia and stroke associated with brain aging. The most frequently used clinical scores are the Framingham Stroke Risk Profile and the Hachinski Ischemic Score for vascular dementia. Radiological techniques to estimate cerebrovascular burden include many varieties of ultrasonographic, computerized tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine techniques. The radiological techniques evaluate the nature and extent of disease in the vessels supplying the brain and the pattern and extent of radiological evidence of damage to the brain both on static and dynamic imaging and are briefly outlined in this review. There are several studies using these techniques to study 'normal' aging populations, and the techniques used in the most widely known of these studies are briefly highlighted in this review.

Can we improve cardiovascular risk prediction beyond risk equations in the physician's office?

BACKGROUND AND OBJECTIVES

Beyond a global estimation of the cardiovascular risk through the assessment of major risk factors and their integration in dedicated risk scales or equations, the use of specific markers provides additive prognostic information at an individual level, including predisposing factors, which are not included in the risk equations as well as the individual susceptibility to their long-term exposure. However, the majority of these markers require specific devices and skills, which are not widely available in primary care.

METHODS

Some clinical and/or "low-cost" parameters are shown to be valuable risk markers, and their use could refine the risk estimation in a physician's office. Several epidemiologic studies suggest the heart rate, the pulse pressure and the ankle-brachial index are effective cardiovascular risk markers. The arms systolic pressure asymmetry could also be a useful marker of risk.

RESULTS AND CONCLUSIONS

Through a general review, the authors evaluate the potential of these clinical markers, including their use in combination for more accurate risk determination.

The ankle-brachial index is not related to mortality in elderly subjects living in nursing homes

Low ankle-brachial index (ABI) levels are associated with increased risk of all-cause and cardiovascular mortality in middle-aged and older adults. We evaluated the association between low ABI and all-cause and cardiovascular mortality in elderly patients living in nursing homes. In 632 subjects (mean age 82.1 +/-7.4 years, 137 men) living in 3 municipal nursing homes, ABI, prevalent cardiovascular diseases, and conventional risk factors were evaluated at baseline in 1998. After a 3-year follow-up the relation between a low ABI and mortality outcomes was evaluated by using multivariable Cox proportional hazards analysis. A low ABI (<0.90) was observed in 177 participants (28%). After 3 years, 304 subjects (48.1%) died; death occurred in 53.6% of those with low ABI and in 45.9% of those with normal ABI. No significant relation between low ABI and all-cause (hazard ratio [HR] 1.1, 95% confidence interval [CI] 0.7-2.0) or cardiovascular mortality (HR 1.3, 95% CI 0.8-2.1) was observed. Among elderly patients living in nursing homes, there is a high prevalence of low ABI, which is not related to all-cause and cardiovascular mortality.

Management of peripheral arterial disease in chronic kidney disease

PAD has been overlooked in many epidemiologic studies evaluating cardiovascular risk associated with renal disease. Conversely, CKD has not been evaluated as a potential risk factor in epidemiologic studies of PAD. PAD, however,seems to be more prevalent among patients with even moderate CKD than in the general population and is most common among chronic dialysis patients, one third or more of whom have a low ABI. Patients with CKD also seem to be at increased risk for developing claudication and for requiring surgical intervention for lower extremity PAD. Furthermore, even moderate CKD seems to be a risk factor for postoperative death and complications after both lower extremity amputation and revascularization procedures. Conversely, even asymptomatic PAD seems to be a risk factor for death among dialysis patients. In the general population, statins, antiplatelet agents (particularly clopidogrel), antihypertensive agents, and ACE inhibitors all have a proven benefit in reducing cardiovascular events in patients with PAD and in some instances may also reduce PAD events. Available evidence suggests that patients with CKD also experience cardio-vascular risk reduction with statin and ACE-inhibitor therapy, but these therapies have not been shown to reduce PAD events specifically in patients with CKD. Further studies are needed to identify interventions that can specifically reduce the incidence of PAD complications in patientswith CKD. Although it is clear that mortality and complication rates after both lower extremity amputation and revascularization are increased in patients with even moderate CKD, currently available observational studies do not provide clear guidance for surgical decision making in CKD patients with limb-threatening ischemia. Further studies are needed to evaluate the risksand benefits of amputation over revascularizationamong patients with CKD and to investigatereasons for the high mortality associated with these procedures in this patient group. Further studies are also needed to measure the impact of CKD on care processes for PAD with the goal of identifying target areas for improvement.

Lower extremity arterial disease assessed by ankle-brachial index in a middle-aged population of African Americans and whites: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Lower extremity arterial disease (LEAD) is one of the most common manifestations of atherosclerosis. Its epidemiologic characteristics have not been well described, particularly in African Americans. Our purpose was to estimate the prevalence of LEAD and its associations with cardiovascular risk factors in a biracial population of men and women aged 45 to 64 years.

METHODS

We examined 15,173 African-American and white men and women who participated in the baseline examination (1987-1989) of the Atherosclerosis Risk in Communities (ARIC) Study. LEAD was defined by a resting ankle-brachial index (ABI), the ratio of ankle systolic blood pressure to brachial systolic pressure, of < or = 0.90. Cross-sectional analyses were used to determine the association of LEAD with cardiovascular risk factors.

RESULTS

The age-adjusted prevalence of ABI < or = 0.90 was 3.1% in African-American men, 4.4% in African-American women, 2.3% in white men, and 3.2% in white women. Cigarette smoking was the single most important risk factor for prevalent LEAD. The odds ratio estimate for LEAD in ever smokers versus never smokers was 6.6 (95% confidence interval [CI]=2.0-21.5) in African-American men, 2.3 (95% CI=1.5-3.5) in African-American women, 10.4 (95% CI=3.8-28.3) in white men, and 1.9 (95% CI=1.4-2.6) in white women, after adjustment for age, LDL cholesterol, hypertension, and diabetes. Prevalent LEAD was also associated with hypertension, diabetes, and higher concentrations of total cholesterol, triglycerides, LDL-cholesterol, and fibrinogen, and lower concentrations of HDL cholesterol, but the associations were not always significant across race/ethnic and gender groups. The associations of LEAD with plasma lipids were generally stronger in African Americans than whites.

CONCLUSIONS

The prevalence of LEAD appears to be higher in African Americans than whites. Elevations in traditional cardiovascular risk factors are associated with a higher prevalence of LEAD across race/ethnic and gender groups.

Sensitivity and specificity of the ankle-brachial index to predict future cardiovascular outcomes: a systematic review

OBJECTIVE

The ankle-brachial index is the ratio of the ankle and the brachial systolic blood pressure and is used to assess individuals with peripheral arterial disease. An ankle-brachial index <0.90 suggests the presence of peripheral arterial disease and is a marker of cardiovascular risk. The objective of this review is to determine the sensitivity and specificity of an ankle-brachial index <0.90 to predict future cardiovascular events, including coronary heart disease, stroke, and death.

METHODS AND RESULTS

We conducted a systematic review of the literature and included studies that used an ankle-brachial index cutoff between 0.80 and 0.90 to classify patients with or without peripheral arterial disease, followed patients prospectively, and recorded cardiovascular outcomes (ie, myocardial infarction, stroke, or mortality). Data were combined using a random-effects model meta-analysis to determine the sensitivity, specificity, relative risks, and likelihood ratios of a low ankle-brachial index to predict future cardiovascular disease. A total of 22 studies were identified, 13 were excluded, and 9 studies were included in the meta-analysis. The sensitivity and specificity of a low ankle-brachial index to predict incident coronary heart diseases were 16.5% and 92.7%, for incident stroke were 16.0% and 92.2%, and for cardiovascular mortality were 41.0% and 87.9%, respectively. The corresponding positive likelihood ratios were 2.53 (95% CI, 1.45 to 4.40) for coronary heart disease, 2.45 (95% CI, 1.76 to 3.41) for stroke, and 5.61 (95% CI, 3.45 to 9.13) for cardiovascular death.

CONCLUSIONS

The specificity of a low ankle-brachial index to predict future cardiovascular outcomes is high, but its sensitivity is low. The ankle-brachial index should become part of the vascular risk assessment among selected individuals.

Excess 1-year cardiovascular risk in elderly primary care patients with a low ankle–brachial index (ABI) and high homocysteine level

Previous studies in selected patient samples suggested a high risk for total mortality and cardiovascular (CV) morbidity associated not only with symptomatic, but also with asymptomatic peripheral arterial disease (PAD). Our aim was to assess the 1-year risk of death and CV morbidity associated with PAD in primary care. Furthermore, we quantified the strength of association between low ankle-brachial index (ABI, as indicator for PAD), plasma homocysteine (HC) levels, and various accepted PAD risk factors, and death and outcomes. In a prospective cohort study, 6880 unselected patients > or =65 years were followed up by 344 primary care physicians in Germany. At 1 year, all-cause mortality was 2.8% in patients with PAD and 0.9% in patients without PAD (odds ratio [OR] adjusted for age and gender: 2.7 [95% confidence interval: 1.7; 4.2]; multivariate adjusted OR: 2.0 [1.3; 3.3]). Mortality due to CV events was 1.6 versus 0.4% (OR: 3.7 [2.0; 6.9], adjusted OR: 2.5 [1.3; 4.9]). Patients with PAD and high HC values (> or =fourth quintile) had a markedly increased risk of premature death: OR versus no PAD/low HC level (<first quintile): 9.8 [3.2, 29.9], adjusted OR 6.6 [2.1, 20.9]. Patients with a low ABI have a substantially increased risk of (short-term) all-cause mortality. The combination of a low ABI and high HC level is particularly useful for identifying patients at excess risk.

Combined use of brachial-ankle pulse wave velocity and ankle-brachial index for fast assessment of arteriosclerosis and atherosclerosis in a community

BACKGROUND

Pulse volume recordings and blood pressures at arms and ankles can be obtained automatically and simultaneously to allow fast measurements of the brachial-ankle pulse wave velocity and the ankle-brachial index. We applied this novel technique to assess the extent of arteriosclerosis and atherosclerosis in a community.

METHODS

A total of 1329 residents in Kinmen completed a health survey including interview, physical examination, blood test, and the measurements of brachial-ankle pulse wave velocity and ankle-brachial index in 10 working days.

RESULTS

Brachial-ankle pulse wave velocity was significantly related to age, systolic blood pressure, body mass index, waist circumference, ankle-brachial index, and fasting blood levels of glucose, triglyceride, high-density lipoprotein cholesterol, uric acid, and creatinine, and was significantly related to the 10-year risk of developing coronary heart disease estimated from the Framingham risk function. The prevalence of arteriosclerosis as defined by brachial-ankle pulse wave velocity values higher than the age and sex stratified references from the low risk subjects was 27.1% for men and 25.4% for women. The prevalence of atherosclerosis defined by ankle-brachial index <0.9 was 2.8% in men and 1.7% in women. In men but not in women, subjects with low ankle-brachial index had significantly greater risk for developing coronary artery disease than those with normal values.

CONCLUSIONS

Brachial-ankle pulse wave velocity and ankle-brachial index can be obtained simultaneously and quickly for the assessment of arteriosclerosis and atherosclerosis in a community.

C-reactive protein and peripheral artery disease among Japanese elderly: the Tsurugaya Project

We investigated the cross-sectional relationship between ankle brachial index and cardiovascular disease risk factors, including C-reactive protein (CRP), among Japanese elderly, a topic which has had little prior epidemiologic study. Our study population comprised 946 subjects aged at least 70 years in whom both CRP and ankle brachial index were measured. The participants were classified into a low (ankle brachial index<0.9) and normal ankle brachial index group. We found that current smoking, high-density lipoprotein cholesterol <40 mg/dl, a low body mass index (continuous variable), hypertension, diabetes and statin use were all significantly related to a lower ankle brachial index. Higher log-transformed CRP level was significantly related to a lower ankle brachial index after adjustment for the cardiovascular risk factors mentioned above (p <0.01). The odds ratios for low ankle brachial index compared to 0-1 risk factors were 5.79 (95% confidence interval [CI]: 2.99-11.20) for 2 risk factors and 17.45 (95% CI: 6.78-49.91) for 3 or more risk factors; independently of other risk factors, the odds ratio for CRP>1.0 mg/l was 2.10 (95% CI: 1.13-3.88) compared to lower CRP values. Thus, a high level of CRP is related to a low ankle brachial index among Japanese elderly as well as Western subjects. This is the first study to report the relationship between CRP and low ankle brachial index among Japanese elderly.

High density lipoprotein cholesterol and the risk of stroke in elderly men: the Honolulu heart program

High density lipoprotein (HDL) cholesterol has been inversely associated with coronary heart disease. Associations with stroke are less clear, particularly among the elderly. In this study, the authors examined the relation between HDL cholesterol levels and the risk of stroke in elderly men. Levels of HDL cholesterol were measured in 2,444 Honolulu Heart Program men aged 71-93 years at the 1991-1993 examinations. The participants, who were free of prevalent stroke, coronary heart disease, and cancer at baseline, were followed to the end of 1998 for thromboembolic and hemorrhagic stroke. While HDL cholesterol was unrelated to hemorrhagic events, incidence of thromboembolic stroke declined consistently with increasing HDL cholesterol level (p = 0.003). There was a nearly threefold excess of thromboembolic stroke in men with low HDL cholesterol levels (<1.0 mmol/liter (<40 mg/dl)) compared with men with high levels (> or =1.6 mmol/liter (> or =60 mg/dl)) (10.6/1,000 person-years vs. 3.6/1,000 person-years; p = 0.001). Adjustment for other risk factors had little effect on these findings, although associations appeared strongest in elderly men with "desirable" total cholesterol levels, hypertension, or diabetes mellitus. These findings suggest that HDL cholesterol level is inversely related to the risk of thromboembolic stroke in elderly men. Whether HDL cholesterol alters the effect of other factors on stroke risk in elderly men warrants further study.

Prevalence and associations of an abnormal ankle-brachial index in systemic lupus erythematosus: a pilot study

BACKGROUND

Accelerated atheroma is a well recognised complication of systemic lupus erythematosus (SLE). Its aetiology is multifactorial and several methods may be used to detect early signs of atheroma.

METHODS

Patients aged </=55 years were screened using the ankle-brachial index (ABI). Ninety one patients aged </=55 years and fulfilling the revised American College of Rheumatology criteria for SLE were studied. The ABI was measured using a contour wrapped 12 cm cuff attached to a mercury sphygmomanometer and an 8 MHz Doppler probe in the arms and legs; a ratio of <1 was considered abnormal.

RESULTS

The mean (SD) age of the patients was 39.0 (9.2) years. Of the 91 patients studied, 34 (37%) had an abnormal ABI. Only one patient was mildly symptomatic. Abnormal ABI correlated with age but not with disease duration, cumulative steroid dosage, ECLAM score, or any other traditional risk factors for atherosclerosis. In comparison with population studies, the prevalence of an ABI<1 in the patients with SLE with a mean age of 39 years was similar to that in adults aged over 80.

CONCLUSION

In this pilot study, patients with SLE with a mean age of 39 years had a high prevalence of an abnormal ABI. The ABI is a simple non-invasive tool for the early detection of accelerated atheroma in SLE.