Ankle/brachial blood pressure in men >70 years of age and the risk of coronary heart disease

Associations Between Systolic Interarm Differences in Blood Pressure and Cardiovascular Disease Outcomes and Mortality: Individual Participant Data Meta-Analysis, Development and Validation of a Prognostic Algorithm: The INTERPRESS-IPD Collaboration

Systolic interarm differences in blood pressure have been associated with all-cause mortality and cardiovascular disease. We undertook individual participant data meta-analyses to (1) quantify independent associations of systolic interarm difference with mortality and cardiovascular events; (2) develop and validate prognostic models incorporating interarm difference, and (3) determine whether interarm difference remains associated with risk after adjustment for common cardiovascular risk scores. We searched for studies recording bilateral blood pressure and outcomes, established agreements with collaborating authors, and created a single international dataset: the Inter-arm Blood Pressure Difference - Individual Participant Data (INTERPRESS-IPD) Collaboration. Data were merged from 24 studies (53 827 participants). Systolic interarm difference was associated with all-cause and cardiovascular mortality: continuous hazard ratios 1.05 (95% CI, 1.02-1.08) and 1.06 (95% CI, 1.02-1.11), respectively, per 5 mm Hg systolic interarm difference. Hazard ratios for all-cause mortality increased with interarm difference magnitude from a ≥5 mm Hg threshold (hazard ratio, 1.07 [95% CI, 1.01-1.14]). Systolic interarm differences per 5 mm Hg were associated with cardiovascular events in people without preexisting disease, after adjustment for Atherosclerotic Cardiovascular Disease (hazard ratio, 1.04 [95% CI, 1.00-1.08]), Framingham (hazard ratio, 1.04 [95% CI, 1.01-1.08]), or QRISK cardiovascular disease risk algorithm version 2 (QRISK2) (hazard ratio, 1.12 [95% CI, 1.06-1.18]) cardiovascular risk scores. Our findings confirm that systolic interarm difference is associated with increased all-cause mortality, cardiovascular mortality, and cardiovascular events. Blood pressure should be measured in both arms during cardiovascular assessment. A systolic interarm difference of 10 mm Hg is proposed as the upper limit of normal. Registration: URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42015031227.

Invasive screening for lower extremity peripheral artery disease: Killing two birds with one stone?

Objectives

There is substantial evidence that the majority of cases of lower extremity peripheral artery disease are undetected. As a result, there is great interest in the detection of lower extremity peripheral artery disease through routine screening. However, routine screening of lower extremity peripheral artery disease is still debated.

Methods

In our cross-sectional study, we included 200 consecutive patients with symptoms suggestive of angina who were undergoing coronary angiography. Irrespective of intermittent claudication, we subsequently performed peripheral angiography to detect lower extremity peripheral artery disease. The predictors of lower extremity peripheral artery disease were analyzed, and the diagnostic utility of these predictors and their combinations were determined. Additionally, the determinants of the amount of radio-opaque material used and peripheral fluoroscopy time were investigated.

Results

The overall prevalence of lower extremity peripheral disease was 16%. Being older than 65 years, having coronary artery disease and smoking history remained significant predictors after adjusting for other well-known parameters. Having the combination of age  ≥65 and smoking was associated with a positive predictive value of 50% (likelihood ratio 5.06), and having all of the predictors was associated with a positive predictive value of 100% (likelihood ratio >1000).

Conclusions

Routine screening for lower extremity peripheral disease patients undergoing coronary angiography may be useful in selected patients.

The Potential Role of Biomarkers Associated with ASCVD Risk: Risk-Enhancing Biomarkers

Serum cholesterol is major risk factor and contributor to atherosclerotic cardiovascular disease (ASCVD). Therapeutic cholesterol-lowering drugs, especially statin, revealed that reduction in low-density lipoprotein cholesterol (LDL-C) produces marked reduction of ASCVD events. In the preventive scope, lower LDL-C is generally accepted as better in proven ASCVD patients and high-risk patient groups. However, in patients with low to intermediate risk without ASCVD, risk assessment is clinically guided by traditional major risk factors. In this group, the complement approach to detailed risk assessment about traditional major risk factors is needed. These non-traditional risk factors include ankle-brachial index (ABI), high-sensitivity C-reactive protein (hsCRP) level, lipoprotein(a) (Lp[a]), apolipoprotein B (apoB), or coronary artery calcium (CAC) score. CAC measurements have an additive role in the decision to use statin therapy in non-diabetic patients 40–75 years old with intermediate risk in primary prevention. This review comprises ASCVD lipid/biomarkers other than CAC. The 2013 and 2018 American College of Cardiology/American Heart Association (ACC/AHA) guidelines suggest these factors as risk-enhancing factors to help health care providers better determine individualized risk and treatment options especially regarding abnormal biomarkers. The recent 2018 Korean guidelines for management of dyslipidemia did not include these biomarkers in clinical decision making. The current review describes the current roles of hsCRP, ABI, LP(a), and apoB in personal modulation and management of health based on the 2018 ACC/AHA guideline on the management of blood cholesterol.

Serum Resistin Level and Progression of Atherosclerosis during Glucocorticoid Therapy for Systemic Autoimmune Diseases

Adipokines are important regulators of several processes, including inflammation and atherosclerosis. In patients with systemic autoimmune diseases, atherosclerosis is accelerated with higher cardiovascular morbidity and mortality. We prospectively investigated the association of adipokines and glucocorticoid therapy with progression of premature atherosclerosis in 38 patients starting glucocorticoid therapy for systemic autoimmune diseases. To detect premature atherosclerosis, carotid ultrasonography was performed at initiation of glucocorticoid therapy and after a mean three-year follow-up period. The ankle-brachial pressure index and cardio-ankle vascular index (CAVI) were measured. Serum adipokine levels were determined with enzyme-linked immunosorbent assay kits. Twenty-three patients (60.5%) had carotid artery plaque at baseline. The carotid artery intima-media thickness (IMT) increased significantly during follow-up. Glucocorticoids reduced the serum resistin level, while increasing serum leptin and high molecular weight-adiponectin. There was slower progression of atherosclerosis (carotid IMT and CAVI) at follow-up in patients with greater reduction of serum resistin and with higher cumulative prednisolone dose. In conclusion, progression of premature atherosclerosis occurred at an early stage of systemic autoimmune diseases before initiation of glucocorticoid therapy. Since resistin, an inflammation and atherosclerosis related adipokine, is reduced by glucocorticoids, glucocortidoid therapy may not accelerate atherosclerosis in patients with systemic autoimmune diseases.

Subclinical Atherosclerosis in Patients with Cushing Syndrome: Evaluation with Carotid Intima-Media Thickness and Ankle-Brachial Index

BACKGROUND

Cushing syndrome (CS) has been described as a killing disease due its cardiovascular complications. In fact, chronic cortisol excess leads to a constellation of complications, including hypertension, hyperglycemia, adiposity, and thromboembolism. The main vascular alteration associated with CS is atherosclerosis.

METHODS

Aim of this study was to analyze carotid intima-media thickness (cIMT) and ankle-brachial index (ABI), two surrogate markers of subclinical atherosclerosis in a consecutive series of CS patients, compared to patients with essential hypertension (EH) and health subjects (HS).

RESULTS

Patients with CS showed a significant increase (P<0.05) of cIMT (0.89±0.17 mm) compared to EH (0.81±0.16 mm) and HS (0.75±0.4 mm), with a high prevalence of plaque (23%; P<0.03). Moreover, CS patients showed a mean ABI values (1.07±0.02) significantly lower respect to HS (1.12±0.11; P<0.05), and a higher percentage (20%) of pathological values of ABI (≤0.9; P<0.03).

CONCLUSION

In conclusion, we confirmed and extended the data of cIMT in CS, and showed that the ABI represent another surrogate marker of subclinical atherosclerosis in this disease.

Relationship between the ankle-brachial index and the risk of coronary heart disease and stroke: the circulatory risk in communities study

AIM

Patients with peripheral artery disease (PAD) are at a high risk of cardiovascular disease (CVD) among Western populations. However, evidence for an elevated risk in Asian populations is limited.

METHODS

This prospective cohort study examined 939 Japanese men 60-74 years of age at the time of the baseline survey. A total of 115 cases of CVD were detected during a median 9.3 years of follow-up, and the ankle brachial blood pressure index (ABI) functioned as a surrogate measurement of PAD.

RESULTS

The age-adjusted risks of coronary heart disease, ischemic stroke and ischemic CVD (coronary heart disease and ischemic stroke) were higher among men in the lowest ABI tertile compared with that observed in the men in the highest tertile (<1.08 vs. >1.17). These associations did not change substantially after adjusting for cardiovascular risk factors. The respective multivariable hazard ratios (HRs, 95% CI) for the three conditions were as follows: 2.48 (1.08-5.71), p for trend=0.03; 1.95 (0.94-4.02), p for trend=0.04; and 2.16 (1.25-3.72), p for trend=0.004. These results did not vary based on a comparison of the three ABI categories: ≤0.90, 0.91-1.10 and >1.10. The multivariable HRs (95% CI) for an ABI ≤0.90 versus >1.10 were as follows: 2.04 (0.67-6.20), p for trend=0.14 for coronary heart disease; 3.39 (1.10-10.5), p for trend=0.006 for ischemic stroke; and 2.61 (1.19-5.76), p for trend=0.003 for ischemic CVD. There were no associations between the ABI and the risk of hemorrhagic stroke.

CONCLUSIONS

A low ABI is associated with the risk of coronary heart disease, ischemic stroke and ischemic CVD in elderly Japanese men.

Simultaneously measured inter-arm and inter-leg systolic blood pressure differences and cardiovascular risk stratification: a systemic review and meta-analysis

Association of inter-arm systolic blood pressure difference (IASBPD) with cardiovascular (CV) morbidity and mortality remains controversial. We aimed to thoroughly examine all available evidence on inter-limb blood pressure (BP) difference and its association with CV risk and outcomes. We searched PubMed, EMBASE, CINAHL, Cochrane library, and Ovid for studies reporting bilateral simultaneous BP measurements in arms or legs and risk of peripheral arterial disease (PAD), coronary artery disease, cerebrovascular disease, subclavian stenosis, or mortality. Random-effect meta-analysis was performed to compare effect estimates. Twenty-seven studies met inclusion criteria, but only 17 studies (18 cohorts) were suitable for analysis. IASBPD of 10 mmHg or more was associated with PAD (risk ratios, 2.22; 1.41-3.5; P = .0006; sensitivity 16.6%; 6.7-35.4; specificity 91.9%; 83.1-96.3; 8 cohorts; 4774 subjects), left ventricular mass index (standardized mean difference 0.21; 0.03-0.39; P = .02; 2 cohort; 1604 subjects), and brachial-ankle pulse wave velocity (PWV) (one cohort). Association of PAD remained significant at cutoff of 15 mmHg (risk ratios, 1.91; 1.28-2.84; P = .001; 5 cohorts; 1914 subjects). We could not find statistically significant direct association of coronary artery disease, cerebrovascular disease, CV, and all-cause mortality in subjects with IASBPD of 10 mmHg or more, 15 mmHg or more, and inter-leg systolic BP difference of 15 mmHg or more. Inter-leg BP difference of 15 mmHg or more was strong predictor of PAD (P = .0001) and brachial-ankle PWV (P = .0001). Two invasive studies showed association of IASBPD and subclavian stenosis (estimates could not be combined). In conclusion, inter-arm and leg BP differences are strong predictors of PAD. IASBPD may be associated with subclavian stenosis, high left ventricular mass effect, and higher brachial-ankle PWVs. Inter-leg BP difference may also be associated with high left ventricular mass effect and higher brachial-ankle PWVs. Presence of inter-limb BP difference may indicate higher global CV risk.

Epidemiology of peripheral artery disease

New data on the epidemiology of peripheral artery disease (PAD) are available, and they should be integrated with previous data. We provide an updated, integrated overview of the epidemiology of PAD, a focused literature review was conducted on the epidemiology of PAD. The PAD results were grouped into symptoms, diagnosis, prevalence, and incidence both in the United States and globally, risk factors, progression, coprevalence with other atherosclerotic disease, and association with incident cardiovascular morbidity and mortality. The most common symptom of PAD is intermittent claudication, but noninvasive measures, such as the ankle-brachial index, show that asymptomatic PAD is several times more common in the population than intermittent claudication. PAD prevalence and incidence are both sharply age-related, rising >10% among patients in their 60s and 70s. With aging of the global population, it seems likely that PAD will be increasingly common in the future. Prevalence seems to be higher among men than women for more severe or symptomatic disease. The major risk factors for PAD are similar to those for coronary and cerebrovascular disease, with some differences in the relative importance of factors. Smoking is a particularly strong risk factor for PAD, as is diabetes mellitus, and several newer risk markers have shown independent associations with PAD. PAD is strongly associated with concomitant coronary and cerebrovascular diseases. After adjustment for known cardiovascular disease risk factors, PAD is associated with an increased risk of incident coronary and cerebrovascular disease morbidity and mortality.

Screening tests: a review with examples

Screening tests are widely used in medicine to assess the likelihood that members of a defined population have a particular disease. This article presents an overview of such tests including the definitions of key technical (sensitivity and specificity) and population characteristics necessary to assess the benefits and limitations of such tests. Several examples are used to illustrate calculations, including the characteristics of low dose computed tomography as a lung cancer screen, choice of an optimal PSA cutoff and selection of the population to undergo mammography. The importance of careful consideration of the consequences of both false positives and negatives is highlighted. Receiver operating characteristic curves are explained as is the need to carefully select the population group to be tested.

Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events

BACKGROUND

The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS.

DESIGN

An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events.

METHODS

Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events.

RESULTS

In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women.

CONCLUSIONS

An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

Sex differences in the prevalence and clinical outcomes of subclinical peripheral artery disease in the Health, Aging, and Body Composition (Health ABC) study

The objective of the study was to determine if there are sex-based differences in the prevalence and clinical outcomes of subclinical peripheral artery disease (PAD). We evaluated the sex-specific associations of ankle-brachial index (ABI) with clinical cardiovascular disease outcomes in 2797 participants without prevalent clinical PAD and with a baseline ABI measurement in the Health, Aging, and Body Composition study. The mean age was 74 years, 40% were black, and 52% were women. Median follow-up was 9.37 years. Women had a similar prevalence of ABI < 0.9 (12% women versus 11% men; P = 0.44), but a higher prevalence of ABI 0.9-1.0 (15% versus 10%, respectively; P < 0.001). In a fully adjusted model, ABI < 0.9 was significantly associated with higher coronary heart disease (CHD) mortality, incident clinical PAD and incident myocardial infarction in both women and men. ABI < 0.9 was significantly associated with incident stroke only in women. ABI 0.9-1.0 was significantly associated with CHD death in both women (hazard ratio 4.84, 1.53-15.31) and men (3.49, 1.39-8.72). However, ABI 0.9-1.0 was significantly associated with incident clinical PAD (3.33, 1.44-7.70) and incident stroke (2.45, 1.38-4.35) only in women. Subclinical PAD was strongly associated with adverse CV events in both women and men, but women had a higher prevalence of subclinical PAD.

Diagnosis and management of peripheral artery disease in women

Peripheral artery disease (PAD) is a significant cause of morbidity and mortality in the USA. Not only is it a major cause of functional impairment and limb loss, but it is also strongly associated with an increased risk of myocardial infarction, stroke, and death. Large population studies have demonstrated high rates of PAD in women, but this is not widely recognized by the public or by clinicians. One potential reason for this is that women with PAD are more likely than men to be asymptomatic or have atypical symptoms. In addition, women with PAD experience higher rates of functional decline and may have poorer outcomes after surgical treatment for PAD compared with men. Currently, it is not known if there are sex-specific differences in risk factors for the onset, progression, and surgical outcomes of PAD. This review will focus on the diagnosis and management of PAD in women and examine sex-specific differences in the prevalence, risk factors, presentation, and outcomes of this disease.

Determining the optimal cut-off value of the urinary albumin-to-creatinine ratio to detect atherosclerotic vascular diseases

BACKGROUND

We examined whether low-grade albuminuria, below the conventional cut-off value for microalbuminuria, was associated with atherosclerotic vascular diseases in 8897 community-dwelling Koreans aged ≥50 years.

METHODS

The urinary albumin-to-creatinine ratio (UACR) was calculated using random spot urine. Common carotid artery (CCA) intimamedia thickness (IMT) and CCA internal diameter were measured using high-resolution B-mode ultrasonography, and carotid plaque was evaluated. Brachial-ankle pulse wave velocity (BaPWV) and the ankle-brachial index (ABI) were examined, and peripheral arterial disease was defined as ABI <0.9.

RESULTS

Youden's indices, predicting abnormal atherosclerotic conditions, were greatest at a UACR cut-off value of ∼15 mg/g, below the threshold conventionally used to define microalbuminuria. Compared with low normoalbuminuria (UACR <15.0 mg/g), CCA IMT, CCA diameter, and BaPWV were significantly greater in individuals with high normoalbuminuria (UACR 15.0-29.9 mg/g), who also had a significantly higher risk of carotid plaque than did those with low normoalbuminuria.

CONCLUSIONS

Subclinical atherosclerotic vascular diseases developed at lower UACRs, below the conventional classification of microalbuminuria. Further longitudinal studies are needed to investigate the relationship between microalbuminuria and the development of subclinical atherosclerosis.

An economic evaluation based on a randomized placebo-controlled trial of varenicline in smokers with cardiovascular disease: results for Belgium, Spain, Portugal, and Italy

BACKGROUND

An estimated 17.2% of patients continue to smoke following diagnosis of cardiovascular disease (CVD). To reduce the risk of further morbidity or mortality in cardiovascular patients, smoking cessation has been shown to reduce the risk of mortality by 36% and myocardial infarction by 32%. The objective of this study was to evaluate the long-term health and economic consequences of smoking cessation in patients with CVD.

DESIGN AND METHODS

Results of a randomized clinical trial comparing varenicline plus counselling vs. placebo plus counselling were extrapolated using a Markov model to simulate the lifetime costs and health consequences of smoking cessation in patients with stable CVD. For the base case, we considered a payer's perspective including direct costs attributed to the healthcare provider, measuring cumulative life years (LY) and quality adjusted life (QALY) years as outcome measures. Secondary analyses were conducted from a societal perspective, evaluating lost productivity due to premature mortality. Sensitivity and subgroup analyses were also undertaken. Results were analysed for Belgium, Spain, Portugal, and Italy.

RESULTS

Varenicline plus counselling was associated with a gain in LY and QALY across all countries; relative to placebo plus counselling. From a payer's perspective, incremental cost effectiveness ratios were € 6120 (Belgium), € 5151 (Spain), € 5357 (Portugal), and € 5433 (Italy) per QALY gained. From a societal perspective, varenicline in addition to counselling was less costly than placebo and counselling in all cases. Sensitivity analyses showed little sensitivity in outcomes to model assumptions or uncertainty in model parameters.

CONCLUSIONS

Varenicline in addition to counselling is cost-effective compared to placebo and counselling in smokers with CVD.

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.

Peripheral artery disease assessed by ankle-brachial index in patients with established cardiovascular disease or at least one risk factor for atherothrombosis--CAREFUL study: a national, multi-center, cross-sectional observational study

BACKGROUND

To investigate the presence of peripheral artery disease (PAD) via the ankle brachial index (ABI) in patients with known cardiovascular and/or cerebrovascular diseases or with at least one risk factor for atherothrombosis.

METHODS

Patients with a history of atherothrombotic events, or aged 50-69 years with at least one cardiovascular risk factor, or > = 70 years of age were included in this multicenter, cross-sectional, non-interventional study (DIREGL04074). Demographics, medical history, physical examination findings, and physician awareness of PAD were analyzed. The number of patients with low ABI (< = 0.90) was analyzed.

RESULTS

A total of 530 patients (mean age, 63.4 ± 8.7 years; 50.2% female) were enrolled. Hypertension and dyslipidemia were present in 88.7% and 65.5% of patients, respectively. PAD-related symptoms were evident in about one-third of the patients, and at least one of the pedal pulses was negative in 6.5% of patients. The frequency of low ABI was 20.0% in the whole study population and 30% for patients older than 70 years. Older age, greater number of total risk factors, and presence of PAD-related physical findings were associated with increased likelihood of low ABI (p < 0.001). There was no gender difference in the prevalence of low ABI, PAD symptoms, or total number of risk factors. Exercise (33.6%) was the most common non-pharmacological option recommended by physicians, and acetylsalicylic acid (ASA) (45.4%) was the most frequently prescribed medication for PAD.

CONCLUSION

Our results indicate that advanced age, greater number of total risk factors and presence of PAD-related physical findings were associated with increased likelihood of low ABI. These findings are similar to those reported in similar studies of different populations, and document a fairly high prevalence of PAD in a Mediterranean country.

Relationship of ankle-brachial index with all-cause mortality and cardiovascular mortality after a 3-year follow-up: the China ankle-brachial index cohort study

This study aimed to investigate the relationship of ankle-brachial index (ABI) with all-cause mortality and cardiovascular (CV) mortality in Chinese inpatients after 3 years of follow-up. All the participants were inpatients at high risk of atherosclerosis and enrolled from July to November 2004. A total of 3210 patients were followed up until an end point was reached or until February 2008. The mean follow-up time was 37.65+/-1.54 months. Patients with ABI <or=0.4 were significantly older than other ABI categories (P<0.001) at baseline. The all-cause and CV disease (CVD) mortality were highest (37.7 and 27.5%, respectively) after a 3-year follow-up in patients with ABI <or=0.4. There was a significant increasing tendency in mortality with decreasing ABI levels (P<0.001). The Kaplan-Meier curves of survival showed a decreasing survival rate with the ABI decreasing, not only for all-cause mortality but also for CVD mortality (P<0.001). Adjusted for other risk factors, patients with ABI <or=0.4 were 3.105 times (95% CI 1.936-4.979) as likely to die as those with ABI in the range of 1.00-1.4; patients with ABI <or=0.4 were about five times (95% CI 2.740-8.388) as likely to die of CVD as those with ABI in the range of 1.00-1.4. Even patients with ABI in the range of 0.41-0.90 were more than 1.5 times as likely to die (relative risk=1.534, 95% CI 1.199-1.962), or die of CVD (relative risk=2.031, 95% CI 1.479-2.789) as those with ABI in the range of 1.00-1.4. Low ABI is related to a higher all-cause and CV mortality compared with normal ABI. ABI as a marker of atherosclerosis should be routinely evaluated to assess the risk of CV mortality in Chinese patients.

Frequency of a low ankle brachial index in the general population by age, sex and deprivation: cross-sectional survey of 28,980 men and women

OBJECTIVES

An increasing interest is observed in the use of the ankle brachial index (ABI, ratio of systolic blood pressure at the ankle to that in the arm) to assess cardiovascular risk. The aim of this study was to provide information on the distribution of ABI in a large healthy population, essential for planning implementation of ABI measurement in preventive strategies in the general population.

STUDY DESIGN AND SETTING

Cross-sectional survey of the ABI was conducted in 28,980 men and women aged over 50 years, living in central Scotland and free of clinical cardiovascular disease.

RESULTS

The ABI was approximately normally distributed in both men (mean 1.06, SD 0.13) and women (mean 1.01, SD 0.11). A total of 10.9% of participants had an ABI<or=0.90, the most common cutpoint used to indicate increased cardiovascular risk. This percentage was higher for women (13.6%) than for men (7.3%) and rose with increasing age and with increased deprivation (6.7% in most affluent and 14.4% in most deprived participants). Similar patterns were observed for various different ABI cutpoints (<or=0.85, <or=0.95 and <or=1.0), the use of which (as expected) had a major influence on the proportion of the population categorized as 'at risk'.

CONCLUSIONS

Careful consideration is required of any ABI cutpoint used to discriminate between participants at 'high' and 'low' risk of cardiovascular disease, in terms of the proportion of the population who might then qualify for preventive measures. It may also be necessary to consider different cutpoints for men and women and for different age categories.

Ankle brachial index combined with Framingham Risk Score to predict cardiovascular events and mortality: a meta-analysis

CONTEXT

Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction.

OBJECTIVE

To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction.

DATA SOURCES

Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies.

STUDY SELECTION

Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality.

DATA EXTRACTION

Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease.

RESULTS

Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women.

CONCLUSION

Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.

Risk assessment in the patient with established peripheral arterial disease

Office-based cardiovascular risk prediction continues to challenge practitioners in primary and secondary risk stratification settings. In patients with established peripheral arterial disease (PAD), the risk of cardiovascular events (i.e. death or morbidity due to coronary heart disease and/or cerebrovascular disease) is high, yet traditional risk factors and the ankle-brachial index (ABI) do not provide a complete secondary risk prediction. In this population, office-based cardiovascular risk stratification may be improved by surrogate markers of the systemic atherosclerotic burden, as well as markers of systemic inflammation. This review will evaluate the utility of the ABI, clinical stage of disease, and the emerging role of C-reactive protein (CRP) and other inflammatory markers in secondary risk prediction in PAD. Defining which patients are in the highest category of risk may direct health care providers to emphasize secondary preventive measures, and facilitate patient adherence to recommended medical therapies and smoking cessation.

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.

Platelet activation increases with the severity of peripheral arterial disease: Implications for clinical management

INTRODUCTION

Patients with peripheral arterial disease (PAD) have increased mortality from cardiovascular events compared with age and sex matched controls Platelets play a major role in atherosclerosis and thrombotic vascular events. Platelet reactivity is increased in patients with PAD compared with healthy controls. We aimed to determine the relationship, if any, between platelet activation and severity of disease.

METHODS AND RESULTS

One hundred eighty-two patients with intermittent claudication (IC) or subcritical limb ischemia (SLI), defined as the presence of rest pain or ulceration, had the following investigations performed: platelet P-selectin expression and bound fibrinogen by flow cytometric analysis and platelet aggregation using the rapid platelet function assay with arachidonic acid (AA) and thrombin receptor activation peptide (TRAP) as agonists. Patients with SLI compared with IC had significantly enhanced ADP stimulated P-selectin expression (median 42.45% [inter-quartile range 33.32% to 58.5%] vs 35.2% [26.07% to 46.32%], P = .002) and bound fibrinogen (73.7% [54.3% to 83.2%] vs 63.7% [43.8% to 76.5%], P = .001). TRAP stimulated aggregation was higher (207 [153 to 238] PAU vs 183[155 to 199] PAU, P = .04) but AA mediated aggregation was not significantly different. An ankle-brachial pressure index (ABPI) of less than 0.6 was associated with increased ADP stimulated P-selectin and bound fibrinogen (P < .05). ABPI correlated inversely with ADP stimulated P-selectin expression (r = -0.228, P = .003), ADP stimulated fibrinogen binding (r = -0.156, P = .043) and TRAP stimulated aggregation (r = -0.179, P = .04).

CONCLUSION

We have demonstrated for the first time that progression of severity of PAD is not only reflected by symptoms, signs, and ABPI but also by increased platelet activity as assessed by both flow cytometry and aggregation. As patients with more severe PAD have increased cardiovascular mortality, our findings suggest that new strategies for platelet inhibitory therapy are indicated in these patients.

Completing the Audit Cycle: Comparison of Cardiac Risk Factor Management in Patients with Intermittent Claudication in Two Time Periods

AIM

The first line treatment of patients with intermittent claudication (IC) is to prolong life via cardiac risk factor management. We aimed to compare current standards of secondary prevention with those in a previously published audit.

METHODS

Risk factor data was prospectively collated on 304 consecutive new referrals attending the claudication clinic over a 1-year period (2004/2005) and compared to the 104 patients assessed in 2000.

RESULTS

In 2004/5 30%, (n=91) of patients did not have a diagnosis of IC confirmed (p<0.01). The use of antiplatelet therapy remained static at 73%. Statin therapy increased in 2004/5 (62% versus 38%, p<0.01) but blood pressure control remained poor with 65% failing to achieve the target levels. Smoking cessation therapy continues to be offered to a minority of patients and 17% of patients have previously undiagnosed diabetes in 2004/2005 (p-value 0.353). The number of patients who have been advised to increase physical activity significantly has fallen from 15% to 2% in the 2004/5 (p<0.01).

CONCLUSIONS

Difficulties exist in diagnosing intermittent claudication in primary care and cardiac risk factor management continues to be sub-optimally managed.

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.

The association of the ankle-brachial index with incident coronary heart disease: the Atherosclerosis Risk In Communities (ARIC) study, 1987-2001

BACKGROUND

Peripheral arterial disease (PAD), defined by a low ankle-brachial index (ABI), is associated with an increased risk of cardiovascular events, but the risk of coronary heart disease (CHD) over the range of the ABI is not well characterized, nor described for African Americans.

METHODS

The ABI was measured in 12186 white and African American men and women in the Atherosclerosis Risk in Communities Study in 1987-89. Fatal and non-fatal CHD events were ascertained through annual telephone contacts, surveys of hospital discharge lists and death certificate data, and clinical examinations, including electrocardiograms, every 3 years. Participants were followed for a median of 13.1 years. Age- and field-center-adjusted hazard ratios (HRs) were estimated using Cox regression models.

RESULTS

Over a median 13.1 years follow-up, 964 fatal or non-fatal CHD events accrued. In whites, the age- and field-center-adjusted CHD hazard ratio (HR, 95% CI) for PAD (ABI<0.90) was 2.81 (1.77-4.45) for men and 2.05 (1.20-3.53) for women. In African Americans, the HR for men was 4.86 (2.76-8.47) and for women was 2.34 (1.26-4.35). The CHD risk increased exponentially with decreasing ABI as a continuous function, and continued to decline at ABI values > 1.0, in all race-gender subgroups. The association between the ABI and CHD relative risk was similar for men and women in both race groups. A 0.10 lower ABI increased the CHD hazard by 25% (95% CI 17-34%) in white men, by 20% (8-33%) in white women, by 34% (19-50%) in African American men, and by 32% (17-50%) in African American women.

CONCLUSION

African American members of the ARIC cohort had higher prevalences of PAD and greater risk of CHD associated with ABI-defined PAD than did white participants. Unlike in other cohorts, in ARIC the CHD risk failed to increase at high (>1.3) ABI values. We conclude that at this time high ABI values should not be routinely considered a marker for increased CVD risk in the general population. Further research is needed on the value of the ABI at specific cutpoints for risk stratification in the context of traditional risk factors.

[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.

Heritability of the ankle-brachial index: the Framingham Offspring study

The ankle-brachial blood pressure index (ABI) is a widely utilized measure for detecting peripheral arterial disease. Genetic contributions to variation in ABI are largely unknown. The authors sought to estimate ABI heritability in a community-based sample. From 1995 to 1998, ABI was measured in 1,097 men and 1,189 women (mean age = 57 years; range, 29-85 years) from 999 families in the Framingham Offspring cohort. Correlation coefficients for sibling pairs were calculated using the family correlations (FCOR) procedure in S.A.G.E. (Case Western Reserve University, Cleveland, Ohio). The heritability of ABI was estimated using variance-components methods in SOLAR (Southwest Foundation for Biomedical Research, San Antonio, Texas). Analyses were performed on normalized crude ABI and on normalized residuals from multiple linear regression analyses in SAS (SAS Institute, Inc., Cary, North Carolina) that adjusted for age, sex, smoking, diabetes, hypertension, ratio of total cholesterol to high density lipoprotein cholesterol, log triglyceride level, and body mass index. The mean ABI was 1.1 (range, 0.4-1.4). The age- and sex-adjusted and multivariable-adjusted sibling-pair correlation coefficients for normalized ABI were 0.15 and 0.11, respectively, resulting in heritability estimates of 0.30 and 0.22. Crude, age- and sex-adjusted, and multivariable-adjusted heritabilities for normalized ABI estimated using variance-components analysis were 0.27 (standard error, 0.06), 0.30 (standard error, 0.06), and 0.21 (standard error, 0.06), respectively (all p values < 0.0001). A modest proportion of the variability in ABI is explained by genetic factors.

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.

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.

Measurement, calculation, and normal range of the ankle-arm index: a bibliometric analysis and recommendation for standardization

Since its introduction in 1950, a variety of methods of measurement and calculation have been used to establish the ankle-arm index (AAI). This has resulted in variations of its normal range and difficulty in comparing study results. Hence, the objective of our study was to analyze the disparate methods used to assess AAI and its normal range and to recommend a standardized method to assess AAI based on that analysis. We made an inventory of the disparate AAI methods and its normal range reported in 100 randomly selected publications and recommend the means of such standardization. We recommend that an experienced observer assess AAI with the patient at rest in the supine position. The width of the sphygmometer cuffs should be 1.5 times that of the extremity to be measured, and brachial and crural pulses should be detected using a Doppler device. Systolic pressures should be measured at both arms and over the anterior and posterior arteries of both legs, with the cuff placed just proximally to the malleoli. The left arm pressure ought to be used as denominator and the mean of pressures of both crural arteries of each leg ought to be used for the numerator of the AAI for that leg. We advocate 0.90 as the cut-off value to distinguish patients who need further arterial assessment.

Mortality and cardiovascular risk across the ankle-arm index spectrum: results from the Cardiovascular Health Study

BACKGROUND

A low ankle-arm index (AAI) is a strong predictor of mortality and cardiovascular events. A high AAI also appears to be associated with higher mortality risk in select populations. However, mortality and cardiovascular risk across the AAI spectrum have not been described in a more broadly defined population.

METHODS AND RESULTS

We examined total and cardiovascular mortality and cardiovascular events across the AAI spectrum among 5748 participants in the Cardiovascular Health Study (CHS). The mean age of the sample population was 73+/-6 years, and the sample included 3289 women (57%) and 883 blacks (15%). The median duration of follow-up was 11.1 (0.1 to 12) years for mortality and 9.6 (0.1 to 12.1) years for cardiovascular events. There were 2311 deaths (953 of which were cardiovascular) and 1491 cardiovascular events during follow-up. After adjustment for potential confounders, AAI measurements < or =0.60 (hazard ratio [HR] 1.82, 95% CI 1.42 to 2.32), 0.61 to 0.7 (HR 2.08, 95% CI 1.61 to 2.69), 0.71 to 0.8 (HR 1.80, 95% CI 1.44 to 2.26), 0.81 to 0.9 (HR 1.73 95% CI 1.43 to 2.11), 0.91 to 1.0 (HR 1.40, 95% CI 1.20 to 1.63), and >1.40 (HR 1.57, 95% CI 1.07 to 2.31) were associated with higher mortality risk from all causes compared with the referent group (AAI 1.11 to 1.20). The pattern was similar for cardiovascular mortality. For cardiovascular events, risk was higher at all AAI levels <1 but not for AAI levels >1.4 (HR 1.00, 95% CI 0.57 to 1.74). The association of a high AAI with mortality was stronger in men than in women and in younger than in older cohort members.

CONCLUSIONS

In a cohort of community-dwelling elders, mortality risk was higher than the referent category of 1.11 to 1.2 among participants with AAI values above the traditional cutpoint of 0.9 (ie, 0.91 to 1.0 and >1.4), and the specific association of AAI with mortality varied by age and gender.

Post-moderate exercise testing and clinical predictive value of ankle arm index measurements

Since peripheral vascular disease (PVD) is the forerunner of coronary heart disease (CHD), it is vital to detect PVD at an early stage. In the past, the non-invasive ankle arm index (AAI) has been successfully used to predict the susceptibility of PVD/CHD. However, different authors have used different permutations (i.e. highest, average and lowest) of ankle (ASBP) and arm (HSBP) systolic blood pressures to calculate AAI. This study aims to investigate the validity and applicability of different permutations of AAI formulae to predict sub-clinical PVD/CHD in young individuals. The study also investigated whether the use of AAI post-moderate exercise would enhance the predictability of PVD or CHD at an early stage. Individuals from different ethnic background within the UK took part in this study. Following 5min moderate cycle exercise using 50% of heart reserve, the AAI was significantly reduced (P<0.05). It was found that not all the permutations of AAI were acceptable and some over/under estimated AAI compared to currently accepted methodologies. According to the statistical analysis (ANOVA and 95% limits of agreement) calculation of AAI using values of (1) highest ASBP divided by highest HSBP, (2) highest ASBP divided by average HSBP, (3) average ASBP divided by highest HSBP and (4) lowest ASBP divided by average HSBP were within acceptable agreement with the standard method of calculating AAI. Inclusion of these permutations together with the standard method, would give a better predictions of PVD/CHD at an early age.

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.

A new probe for ankle systolic pressure measurement using photoplethysmography (PPG)

An automated method for ankle systolic pressure measurement, less operator dependent than the standard continuous wave (CW) Doppler technique, would imply an advantage both in patient measurements and in epidemiological studies. We present a new photoplethysmographic (PPG) probe that uses near-infrared light (880 nm) to detect pulsatory blood flow underneath the distal end of a standard pneumatic cuff. The probe is adapted to the anatomical conditions at the ankle, permitting recording of pressures in both ankle arteries separately. The validity of the equipment was tested with CW Doppler-derived systolic pressures and invasive blood pressure measurements for reference. In 20 healthy subjects, visual analysis of the PPG curves revealed a mean difference between CW Doppler and PPG measurements of -0.5 mmHg (SD 6.9). Corresponding results for the anterior and posterior tibial arteries separately were -1.8 mmHg (SD 6.2) and 0.9 mmHg (SD 7.3), respectively. A correct probe position was essential for the results. In direct recordings from the dorsalis pedis artery in 10 intensive care patients, PPG underestimated systolic pressure in the anterior tibial artery by 4.5 mmHg (SD 12.1). With further development, the PPG probe, integrated in the pneumatic cuff, may simplify measurements of ankle systolic pressures.

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.

Metabolic Syndrome, Subclinical Coronary Atherosclerosis, and Cardiovascular Risk

The metabolic syndrome is a constellation of cardiovascular disease risk factors, and it is associated with the presence of advanced subclinical coronary atherosclerosis. The presence of the metabolic syndrome appears to provide incremental predictive value on top of the Framingham risk score in predicting future cardiovascular events. Traditional risk-prediction formulas fail to account for a significant portion of coronary heart disease morbidity and mortality. The metabolic syndrome may be particularly useful in predicting risk among individuals classified as low or intermediate risk by Framingham risk score.

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.

Improved Prediction of Fatal Myocardial Infarction Using the Ankle Brachial Index in Addition to Conventional Risk Factors

Background— Prediction of major cardiovascular and cerebrovascular events using conventional risk factor models is limited. Noninvasive measures of subclinical atherosclerosis such as the ankle brachial index (ABI) could improve risk prediction and provide more focused primary prevention strategies. We wished to determine the added value of a low ABI in the prediction of long-term risk of cardiovascular and cerebrovascular events and death.

Methods and Results— In 1988, 1592 men and women 55 to 74 years of age were randomly selected from the age-sex registers of 11 general practices in Edinburgh, Scotland, and followed up over a period of 12 years for incident events. After adjustment for age and sex, an ABI ≤0.9 was predictive of an increased risk of fatal myocardial infarction (MI), cardiovascular death, all-cause death, combined fatal and nonfatal MI, and total cardiovascular events. After further adjustment for prevalent cardiovascular disease, diabetes, and conventional risk factors, a low ABI was independently predictive of the risk of fatal MI. Addition of the ABI significantly ( P ≤0.01) increased the predictive value of the model for fatal MI compared with a model containing risk factors alone. Comparison of areas under receiver operator characteristic curves confirmed that a model including the ABI discriminated marginally better than one without.

Conclusions— Addition of the ABI significantly improved prediction of fatal MI over and above that of conventional risk factors. We recommend that the ABI be incorporated into routine cardiovascular screening and that the potential of its inclusion into cardiovascular scoring systems (with a view to improving their accuracy) now be examined.

Pulse wave velocity and ankle brachial index in patients with Kawasaki disease

BACKGROUND

Pulse wave velocity (PWV) and ankle brachial index (ABI) are a useful method to estimate atherosclerosis in adults, while a history of Kawasaki disease (KD) may be a risk factor for later atherosclerosis of systemic arteries. PWV and ABI in patients with a history of KD have not been reported.

METHOD

In total, 90 patients ranging in age from 4 to 25 years who had a history of KD previously, any time from 1 month to 19 years ago, were studied. As a control group, 119 patients with other trivial cardiovascular diseases such as a small ventricular, an atrial septal defect or mild arrhythmias, were also evaluated. A high value of PWV was determined as >/=120% of normal predicted value of PWV, while a low value of ABI was determined as </=0.9. Age, sex, height, weight, body mass index, blood pressure, ABI and PWV by t-test, and univariate and multivariate analyses of a logistic-regression model, were analyzed.

RESULTS

When a cut-off point was set as per cent of normal predicted PWV (%N PWV) >/= 120%, and ABI </= 0.9, patients with a history of KD had a higher PWV than the control group, while there was no significant difference in the ABI between the two groups. There was no significant difference in the PWV or the ABI between the KD patients with or without coronary aneurysms.

CONCLUSION

Patients with a history of KD may have increased aortic stiffness for their age.

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.

Changes in ankle brachial index in symptomatic and asymptomatic subjects in the general population

OBJECTIVE

To determine changes over time in the ankle brachial index (ABI) among subjects with and without intermittent claudication in the general population.

DESIGN OF STUDY

Population cohort study.

SETTING

General population in Edinburgh, Scotland.

SUBJECTS

A total of 1592 men and women aged 55 to 74 years selected at random from age-sex registers of 11 general practices and followed up over 12 years. Main outcome measures Changes in ABI for each leg recorded at baseline in 1988 and at subsequent 5-year and 12-year clinical examinations.

RESULTS

Overall, 695 subjects (348 men and 347 women) had valid ABI measurements on both legs at all three examinations. At baseline, the ABI was on average.03 higher in the right leg than the left (P < or =.001). Men had a mean ABI that was.07 higher than women (P < or =.001). Mean ABI in the worse leg showed little change over 12 years in both men and women. However, in the whole population, the ABI in the better leg showed a significant drop, 1.15 to 1.08 (P < or =.001). A total of 179 cases of intermittent claudication were identified during the 12-year follow-up. At baseline, ABI in the worse leg of the claudicants was significantly lower than in healthy subjects (.99 vs 1.08; P < or =.01). In claudicants, mean ABI in the worse leg fell by.04 over 5 years (P < or =.05) and in the better leg showed a highly significant drop of.09 (P < or =.001) to levels similar to those of the worse leg.

CONCLUSIONS

The mean ABI in the worse leg of study subjects showed little progression over 12 years. Individuals with intermittent claudication experienced a greater decline in both legs compared with those without claudication. Deterioration occurred more rapidly in the limb with a higher ABI at baseline, which possibly indicates a systemic tendency to atherosclerosis.