A high ankle brachial index is associated with greater left ventricular mass MESA (Multi-Ethnic Study of Atherosclerosis)

High ankle-brachial index participants experienced similar long-term mortality as peripheral artery disease in a national sample of community-dwelling adults

BACKGROUND

Only a few small studies have shown the association between high ankle-brachial pressure index (ABI >1.4) and adverse cardiovascular (CV) events and mortality. Although there is abundant literature depicting the association between ABI and overall systemic atherosclerosis, it typically focuses on low ABI. Furthermore, historically, many studies focusing on peripheral artery disease have excluded high ABI participants. We aimed to study the mortality outcomes of persons with high ABI in the National Health and Nutrition Examination Survey (NHANES).

METHODS

We obtained ABI from participants aged ≥40 years for survey years 1999 to 2004. We defined low a ABI as ≤0.9, normal ABI as 0.9 to 1.4, and high ABI as >1.4 or if the ankle pressures were >245 mm Hg. Demographics, various comorbidities, and laboratory test results were obtained at the time of the survey interview. Multivariable adjusted hazard ratios (HRs) along with 95% confidence intervals (CIs) were calculated for CV and all-cause mortality via Cox proportional hazards regression. Mortality was linked to all NHANES participants for follow-up through December 31, 2019, by the Centers for Disease Control and Prevention.

RESULTS

We identified 7639 NHANES participants with available ABI. Of these, 6787 (89%) had a normal ABI, 646 (8%) had a low ABI, and 206 (3%) had elevated ABI. Of participants with high ABI, 50% were men, 15% were African Americans, 10% were current smokers, 56% had hypertension, 33% had diabetes, 15% had chronic kidney disease (CKD), and 18% had concomitant coronary artery disease (CAD). Diabetes (odds ratio [OR], 2.4; 95% CI, 1.7-3.2), CAD (OR, 1.6; 95% CI, 1.0-2.4), and CKD (OR, 1.5; 95% CI, 1.0-2.3) at baseline were associated with having a high ABI, respectively. A high ABI was associated independently with elevated CV (HR, 2.6; 95% CI, 2.1-3.1; P < .0001) and all-cause mortality (HR, 2.5; 95% CI, 2.2-2.8; P < .0001) after adjusting for covariates, including diabetes, CKD, CAD, current smoking, cancer, and hypertension.

CONCLUSIONS

A high ABI is associated with an elevated CV and all-cause mortality, similar to patients with PAD. High ABI participants should receive the same attention and aggressive medical therapies as patients with PAD.

Association of the severity of vascular damage with discordance between the fractional flow reserve and non-hyperemic pressure ratios

BACKGROUND

While there is a discordance between fractional flow reserve (FFR) and non-hyperemic pressure ratios (NHPRs) in some cases, the mechanisms underlying these discordances have not yet been fully clarified. We examined whether vascular damage as assessed by measurement of the brachial-ankle pulse wave velocity (baPWV), a marker of arterial stiffness, or ankle brachial pressure index (ABI), a marker of atherosclerotic arterial stenosis, might be associated with their discordances.

METHODS

FFR and NHPRs were measured in 283 consecutive patients (69 ± 10 years old). Based on previously established cut-off values of the two markers (i.e. +/- = FFR ≤/> 0.80 or =NHPRs ≤/> 0.89), the study participants were divided into four groups (the + and - signs denoting "predictive of significant stenosis" and "not predictive of significant stenosis," respectively): the FFR+/NHPRs+ group (n = 124), FFR-/NHPRs+ group (n = 16), FFR+/NHPRs- group(n = 65), and FFR-/NHPRs- group (n = 78). The baPWV and ABI were also measured in all the participants, and values of <2000 cm/s and ≥1.00 of the baPWV and ABI, respectively, were considered as representing relatively less advanced atherosclerotic systemic vascular damage.

RESULTS

The prevalence of subjects with ABI ≥1.00 was higher in the FFR+/NHPRs- group than in the FFR-/NHPRs- group (p < 0.05). When the study subjects were divided into 2 groups, namely, the FFR+/NHPRs- group and the combined group, the prevalence of ABI ≥1.00 and that of baPWV <2000 cm/s were higher in the FFR+/NHPRs- group as compared with those in the combined group (p < 0.05). The results of binary logistic regression analysis demonstrated that ABI ≥1.00 was associated with a significant odds ratio (2.34, p < 0.05) for the FFR+/NHPRs- discordance.

CONCLUSION

The FFR+/NHPRs- discordance appears to be observed in patients with relatively less advanced atherosclerotic systemic vascular damage. Thus, ABI ≥1.00 may be a marker of the presence of the FFR+/NHPRs- discordance.

The high normal ankle brachial index is associated with left ventricular hypertrophy in hypertension patients among the Han Chinese

Left ventricular hypertrophy (LVH) is the most common target organs damage in the hypertension patients. Abnormal low (≤0.9) or high (≥1.40) ankle brachial index (ABI) are associated with an increased risk of cardiovascular events. However, the relationships between a high ABI in the normal range (0.9–1.4) and LVH in Han Chinese hypertension are not entirely elucidated. This study included 3953 hypertension patients aged 40–75 years among Han Chinese. Hypertension was defined as systolic blood pressure≥140 mm Hg, diastolic blood pressure≥90 mm Hg, or history of antihypertensive drug use. Left ventricular mass (LVM) was measured by transthoracic echocardiography. LVH was diagnosed by using the criteria of LVM ≥49.2 g/m^2.7 for men and 46.7 g/m^2.7 for women. Our study suggested that the ABI was higher in patients with LVH than in those without (1.13±0.11, 1.11±0.11, p < 0.001). The prevalence of LVH in patients with the lowest (0.9 < ABI≤1.03), second (1.04≤ABI≤1.11), the third (1.12≤ABI≤1.20), and the highest quartile (1.21≤ABI < 1.40) of ABI was 37.2%, 38.2%, 45.5%, 45.7%, respectively. Logistic regression analysis suggested that the highest and third quartile of ABI were significantly associated with increased LVH risk (multivariate‐adjusted OR of highest group:1.83; third group:1.61). The association of ABI at second quartile with LVH was nonsignificant. Similar results were observed in less than 60 years and without coronary heart disease or diabetes group. Our observations in Chinese patients with hypertension indicated high ABI may be an important risk factor for LVH in hypertension patients among Han Chinese, even in the normal range.

High ankle-brachial index predicts cardiovascular events and mortality in hemodialysis patients with severe secondary hyperparathyroidism

Introduction:

Vascular calcification related to severe secondary hyperparathyroidism (SHPT) is an important cause of cardiovascular and bone complications, leading to high morbidity and mortality in patients with chronic kidney disease (CKD) undergoing hemodialysis (HD). The present study aimed to analyze whether ankle-brachial index (ABI), a non-invasive diagnostic tool, is able to predict cardiovascular outcomes in this population.

Methods:

We selected 88 adult patients on HD for at least 6 months, with serum iPTH>1,000pg/mL. We collected clinical data, biochemical and hormonal parameters, and ABI (sonar-Doppler). Calcification was assessed by lateral radiography of the abdomen and by simple vascular calcification score (SVCS). This cohort was monitored prospectively between 2012 and 2019 for cardiovascular outcomes (death, myocardial infarction (MI), stroke, and calciphylaxis) to estimate the accuracy of ABI in this setting.

Results:

The baseline values were: iPTH: 1770±689pg/mL, P: 5.8±1.2 mg/dL, corrected Ca: 9.7±0.8mg/dL, 25(OH)vit D: 25.1±10.9ng/mL. Sixty-five percent of patients had ABI>1.3 (ranging from 0.6 to 3.2); 66% had SVCS≥3, and 45% aortic calcification (Kauppila≥8). The prospective evaluation (51.6±24.0 months), provided the following cardiovascular outcomes: 11% of deaths, 17% of nonfatal MI, one stroke, and 3% of calciphylaxis. After adjustments, patients with ABI≥1.6 had 8.9-fold higher risk of cardiovascular events (p=0.035), and ABI≥1.8 had 12.2-fold higher risk of cardiovascular mortality (p=0.019).

Conclusion:

The presence of vascular calcifications and arterial stiffness was highly prevalent in our population. We suggest that ABI, a simple and cost-effective diagnostic tool, could be used at an outpatient basis to predict cardiovascular events in patients with severe SHPT undergoing HD.

Levels of ankle-brachial index and the risk of diabetes mellitus complications

OBJECTIVE

We sought to compare the association of categorized ankle-brachial index (ABI) with mortality and complications of diabetes in persons with no symptoms of peripheral arterial disease (PAD) and in primary cardiovascular disease prevention.

RESEARCH DESIGN AND METHODS

This is a retrospective cohort study of persons with type 2 diabetes aged 35-85 years, from 2006 to 2011. Data were obtained from the Sistema d'Informació per al Desenvolupament de la Investigació en Atenció Primària (SIDIAP^Q). Participants had an ABI measurement that was classified into six categories. For each category of ABI, we assessed the incidence of mortality; macrovascular complications of diabetes: acute myocardial infarction (AMI), ischemic stroke, and a composite of these two; and microvascular complications of this metabolic condition: nephropathy, retinopathy, and neuropathy. We also estimated the HRs for these outcomes by ABI category using Cox proportional hazards models.

RESULTS

Data from 34 689 persons with type 2 diabetes were included. The mean age was 66.2; 51.5% were men; and the median follow-up was 6.0 years. The outcome with the highest incidence was nephropathy, with 24.4 cases per 1000 person-years in the reference category of 1.1≤ABI≤1.3. The incidences in this category for mortality and AMI were 15.4 and 4.1, respectively. In the Cox models, low ABI was associated with increased risk and was significant from ABI lower than 0.9; below this level, the risk kept increasing steeply. High ABI (over 1.3) was also associated with significant increased risk for most outcomes.

CONCLUSIONS

The studied categories of ABI were associated with different risks of type 2 diabetes complications in persons asymptomatic for PAD, who were in primary cardiovascular prevention. These findings could be useful to optimize preventive interventions according to the ABI category in this population.

Hypertension and high ankle brachial index: the overlooked combination

OBJECTIVE

Assessment of asymptomatic organ damage in the management of hypertension includes low (<0.9) ankle brachial index (ABI) values. No recommendations are given for patients with high ABI (≥1.3), despite evidence of an association with increased risk. We aimed to study the association of high ABI with all-cause mortality and cardiovascular outcomes in a hypertensive population.

METHODS

In anonymized clinical records from the Catalan Primary Care (SIDIAP) database, we designed a large cohort of hypertensive patients aged 35-85 years at the start date. Participants were excluded if they had previous heart failure, coronary heart disease, stroke, diabetes mellitus, or chronic kidney disease. The study population was categorized according to ABI values. Cox proportional hazards models were used to assess all-cause mortality, heart failure, acute myocardial infarction, and stroke.

RESULTS

From 2006 through 2015, SIDIAP records included 44 657 hypertensive patients with an ABI measurement 9126 of whom met inclusion criteria. The median follow-up (first to third quartiles) was 6.0 years (4.7-7.6). High ABI (≥ 1.3) was associated with an increase in mortality risk, hazard ratio, and 95% confidence interval: 1.44 (1.10-1.88), similar to the group with ABI at least 0.9 and less than 1.1, hazard ratio 1.36 (1.12-1.65), and lower than all groups with ABI less than 0.9. High ABI values tended to associate with heart failure, hazard ratio 1.34 (0.95-1.91), but the relation of high ABI with acute myocardial infarction and stroke was nonsignificant, hazard ratios 1.30 (0.72-2.35) and 0.97 (0.65-1.42), respectively.

CONCLUSION

Patients with high ABI values and hypertension presented an increased all-cause mortality risk that could be considered when advising such patients.

Association of 4-limb systolic blood pressure heterogeneity with peripheral artery disease and left ventricular mass index

A large interarm and interleg systolic blood pressure (SBP) difference and ankle-brachial index (ABI) <0.9 were associated with peripheral artery disease and left ventricular hypertrophy. These 3 parameters were derived from 4-limb SBP data. However, there is no study to assess clinical significance of SBP heterogeneity in 4 limbs. The aim of this study was to evaluate the association of 4-limb SBP standard deviation (SD) with peripheral vascular parameters and echocardiographic data in patients with or without clinical findings of peripheral artery disease.A total of 1240 patients were included, of whom 1020 had no clinical evidence of overt peripheral artery disease. The 4-limb blood pressures, brachial-ankle pulse wave velocity, and ABI were measured simultaneously by an ABI-form device.In the multivariable linear regression analysis, increased left ventricular mass index (LVMI), ABI < 0.9, interarm SBP difference >10 mm Hg, and interleg SBP difference >15 mm Hg (P ≤ .030) were associated with increased 4-limb SBP SD. Additionally, a subgroup multivariable linear regression analysis in 1020 patients without ABI < 0.9, interarm SBP difference >10 mm Hg, and interleg SBP difference >15 mm Hg found 4-limb SBP SD still had a positive correlation with LVMI (P < .001).In addition to significant association with ABI < 0.9, interarm SBP difference >10 mm Hg, and interleg SBP difference >15 mm Hg, 4-limb SBP SD was positively correlated with LVMI in the multivariable linear regression analysis in all study patients. Furthermore, in the subgroup of patients without clinical evidence of peripheral artery disease, 4-limb SBP SD still had a positive correlation with LVMI. Hence, assessment of 4-limb SBP heterogeneity is useful in identification of high-risk group of peripheral artery disease and/or increased LVMI, irrespective of the presence of overt peripheral artery disease.

Significance of the combination of inter-limb blood pressure differences in the elderly: The Northern Shanghai Study

Whether the combination of inter-arm and inter-leg systolic blood pressure differences (BPDs) and ankle-brachial index is of clinical significance remains unclear. In this study, we aimed to investigate the association of the combination of inter-limb systolic BPDs with cardiovascular risk factors and hypertension-mediated organ damage (HMOD). A total of 2621 elderly subjects from the Northern Shanghai Study were divided into Group A, B, and C consisting of participants with 0, 1, and ≥2 abnormal inter-limb systolic BPDs, respectively. Comparisons of cardiovascular risk factors and parameters of cardiac, vascular, and renal damage between groups and logistic regression models were conducted. The proportions of subjects presenting 0, 1, and ≥2 abnormal inter-limb systolic BPDs were 60.9%, 25.1%, and 14.0%, respectively. Upward trends, from Group A, through Group B, to Group C, were observed for the level or prevalence of nearly all cardiovascular risk factors and HMOD (P for trend ≤0.007 for all). In multiple logistic regression, Group C showed significantly higher odds for carotid plaque (vs Group A: Odds ratio [OR] = 1.88, 95% confidence interval [CI] = 1.43-2.48; vs Group B: OR = 1.46, 95% CI = 1.08-1.97), arterial stiffness (vs Group A: OR = 1.26, 95% CI = 0.96-1.65; vs Group B: OR = 1.36, 95% CI = 1.01-1.83), and left ventricular hypertrophy (vs Group A: OR = 1.35, 95% CI = 1.04-1.76; vs Group B: OR = 1.25, 95% CI = 0.93-1.67), when compared with Group A and B. In conclusion, the combination of abnormal inter-limb systolic BPDs significantly associates with greater burden of cardiovascular risk factors and higher likelihood for HMOD, especially carotid plaque, arterial stiffness, and left ventricular hypertrophy.

Validity and reliability of lower-limb pulse-wave velocity assessments using an oscillometric technique

NEW FINDINGS

What is the central question of this study? There is growing interest in the effects of sedentarism on central and peripheral cardiovascular health. To permit further investigation, including larger epidemiological studies, there is a need to identify arterial health assessment tools that are valid (accurate) and reliable (precise), yet practical. What is the main finding and its importance? Lower-limb vascular health (femoral-ankle pulse-wave velocity) can be determined in a supine position with accuracy and precision using an oscillometrically based device. This technology might help to improve our understanding of the pathological mechanisms linking cardiovascular disease to sedentarism, including the interaction between peripheral and central vasculature.

ABSTRACT

There is a growing interest in the deleterious effects of sedentary behaviour on lower-limb arterial health. To permit further investigation, including larger epidemiological studies, there is a need to identify lower-limb arterial health assessment tools that are valid and reliable, yet simple to administer. In this study, we sought to determine the validity and between-day reliability of femoral-ankle pulse-wave velocity (faPWV) measures obtained using an oscillometrically based device (SphygmocCor XCEL) in supine and seated positions. Doppler ultrasound was used as the criterion. A total of 47 healthy adults were recruited for validity (n = 32) and reliability (n = 15) analyses. Validity was determined by measuring faPWV in seated and supine positions using the XCEL and Doppler ultrasound devices, in a randomized order. Between-day reliability was determined by measuring seated and supine faPWV using the XCEL on three different mornings, separated by a maximum of 7 days. The validity criterion [absolute standard error of estimate (aSEE) < 1.0 m s^-1 ] was met in the supine [aSEE = 0.8 m s^-1 , 95% confidence interval (CI) 0.4-1.0], but not in the seated (aSEE = 1.2 m s^-1 , 95% CI 1.1-1.2) position. Intraclass correlation coefficient (ICC) estimates revealed that the XCEL demonstrated good reliability in the supine position (ICC = 0.83, 95% CI 0.65-0.93), but poor reliability in the seated position (ICC = 0.29, 95% CI 0.23-0.63). The oscillometric XCEL device can be used to determine lower-limb pulse-wave velocity with acceptable validity and reliability in the conventionally recommended supine position, but not in the seated position.

Comparison of ankle-brachial index and upstroke time in association with target organ damage: the Northern Shanghai Study

A recent study indicated that upstroke time per cardiac cycle (UTCC) in lower extremities is equivalent to ankle-brachial index (ABI) in diagnosing peripheral arterial disease and in predicting cardiovascular mortality. In this study, we aimed to compare ABI and UTCC in relation to target organ damage. A cohort of 1841 elderly participants from the Northern Shanghai Study was studied. ABI and UTCC were measured using VP-1000 device. Target organ damage including left ventricular hypertrophy and diastolic dysfunction, carotid intima-media thickness and plaque, carotid-femoral pulse wave velocity (CF-PWV), and renal damage, were evaluated by standardized methods. In correlation analysis, ABI and UTCC both significantly correlated with CF-PWV, carotid plaque, and estimated glomerular filtration rate, but not with cardiac damage. Compared with ABI, UTCC showed stronger correlation with CF-PWV. When ABI and UTCC separately put into fully adjusted multivariate logistic regression models, both ABI (OR: 2.27; 95% CI: 1.63-3.17) and UTCC (OR: 1.63; 95% CI: 1.18-2.24) significantly associated with carotid plaque, but only UTCC significantly associated with increased CF-PWV (OR: 1.66; 95% CI: 1.15-2.42) and renal damage (OR: 1.63; 95% CI: 1.07-2.47). When ABI and UTCC both put into multivariate stepwise logistic regression models together with covariates, consistent results were observed. In ROC curve analysis, after adjusted for cofounding factors, UTCC showed slightly greater area under curve than ABI in detecting increased CF-PWV (area under curve: 0.79 vs. 0.78; P = .008); however, no difference was observed between UTCC and ABI in discriminating renal damage and carotid plaque. In conclusion, compared with ABI, UTCC showed significantly stronger association with vascular and renal damage in this elderly Chinese cohort.

Cardiovascular magnetic resonance in an adult human population: serial observations from the multi-ethnic study of atherosclerosis

The Multi-Ethnic Study of Atherosclerosis (MESA) is the first large-scale multi-ethnic population study in the U.S. to use advanced cardiovascular magnetic resonance (CMR) imaging. MESA participants were free of cardiovascular disease at baseline between 2000 and 2002, and were followed up between 2009 and 2011 with repeated CMR examinations as part of MESA. CMR allows the clinician to visualize and accurately quantify volume and dimensions of all four cardiac chambers; measure systolic and diastolic ventricular function; assess myocardial fibrosis; assess vessel lumen size, vessel wall morphology, and vessel stiffness. CMR has a number of advantages over other imaging modalities such as echocardiography, computed tomography, and invasive angiography, and has been proposed as a diagnostic strategy for high-risk populations. MESA has been extensively evaluating CMR imaging biomarkers, as markers of subclinical disease, in the last 15 years for low-risk populations. On a more practical level, some of the imaging biomarkers developed and studied are translatable to at-risk populations. In this review, we discuss the progression of subclinical cardiovascular disease and the mechanisms responsible for the transition to symptomatic clinical outcomes based on our findings from MESA.

Ankle-brachial index and physical function in older individuals: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

Most prior studies investigating the association of lower extremity peripheral artery disease (PAD) with physical function were small or analyzed selected populations (e.g., patients at vascular clinics or persons with reduced function), leaving particular uncertainty regarding the association in the general community.

METHODS

Among 5262 ARIC participants (age 71-90 years during 2011-2013), we assessed the cross-sectional association of ankle-brachial index (ABI) with the Short Physical Performance Battery (SPPB) score (0-12), its individual components (chair stands, standing balance, and gait speed) (0-4 points each), and grip strength after accounting for potential confounders, including a history of coronary disease, stroke, or heart failure.

RESULTS

There were 411 participants (7.8%) with low ABI ≤0.90 and 469 (8.9%) participants with borderline low ABI 0.91-1.00. Both ABI ≤0.90 and 0.91-1.00 were independently associated with poor physical function (SPPB score ≤6) compared to ABI 1.11-1.20 (adjusted odds ratio 2.10 [95% CI 1.55-2.84] and 1.86 [1.38-2.51], respectively). The patterns were largely consistent across subgroups by clinical conditions (e.g., leg pain or other cardiovascular diseases), in every SPPB component, and for grip strength. ABI >1.3 (472 participants [9.0%]), indicative of non-compressible pedal arteries, was related to lower physical function as well but did not necessarily reach significance.

CONCLUSIONS

In community-dwelling older adults, low and borderline low ABI suggestive of PAD were independently associated with poorer systemic physical function compared to those with normal ABI. Clinical attention to PAD as a potential contributor to poor physical function is warranted in community-dwelling older adults.

Lower Extremity Peripheral Artery Disease and Quality of Life Among Older Individuals in the Community

Background

Evidence regarding the association of lower extremity peripheral arterial disease with quality of life (QOL) is mainly from selected clinical populations or relatively small clinical cohorts. Thus, we investigated this association in community‐derived populations.

Methods and Results

Using data of 5115 participants aged 66 to 90 years from visit 5 (2011‐2013) of the Atherosclerosis Risk in Communities Study, we quantified the associations of ankle‐brachial index (ABI) with several QOL parameters, including 12‐item Short‐Form Health Survey (SF‐12), after accounting for potential confounders using linear and logistic regression models. Peripheral arterial disease defined by an ABI <0.90 (n=402), was independently associated with a low SF‐12 Physical Component Summary score (−3.26 [95% CI −5.60 to −0.92]), compared to the ABI reference 1.10 to 1.19 (n=1900) but not with the Mental Component Summary score (−0.07 [−2.21 to 2.06]). A low ABI was significantly associated with poorer status of all SF‐12 physical domains (physical functioning, role‐physical, bodily pain, and general health) but only vitality out of 4 mental domains. Similarly, low ABI values were more consistently associated with other physically related QOL parameters (leisure‐time exercise/activity/walking) than mentally related parameters (significant depressive symptoms and hopeless feeling). Lower physical QOL was observed even in individuals with borderline low ABI (0.90 to 0.99; n=426).

Conclusions

Low ABI (even borderline) was independently associated with poor QOL, especially for physical components, in community‐dwelling older adults. QOL is a critical element for older adults, and thus, further studies are warranted to assess whether peripheral arterial disease‐specific management can improve QOL in older populations.

Early Detection System of Vascular Disease and Its Application Prospect

Markers of imaging, structure, and function reflecting vascular damage, integrating a long time accumulation effect of traditional and unrecognized cardiovascular risk factors, can be regarded as surrogate endpoints of target organ damage before the occurrence of clinical events. Prevention of cardiovascular disease requires risk stratification and treatment of traditional risk factors, such as smoking, hypertension, hyperlipidemia, and diabetes. However, traditional risk stratification is not sufficient to provide accurate assessment of future cardiovascular events. Therefore, vascular injury related parameters obtained by ultrasound or other noninvasive devices, as a surrogate parameter of subclinical cardiovascular disease, can improve cardiovascular risk assessment and optimize the preventive treatment strategy. Thus, we will summarize the research progress and clinical application of early assessment technology of vascular diseases in the present review.

Subclinical myocyte injury, fibrosis and strain in relationship to coronary plaque in asymptomatic HIV-infected individuals

BACKGROUND

Cardiovascular disease (CVD) rates are increased in HIV. The degree to which myocyte injury, strain, and fibrosis occur prior to clinical disease and relate to coronary plaque in HIV is unknown.

OBJECTIVE

To investigate newer cardiac biomarkers of subclinical myocyte injury [high-sensitivity troponin T (hs-cTnT)], strain (amino terminal proB-type natriutretic peptide), fibrosis (soluble ST2, Galectin-3), and vascular inflammation (oxidized LDL, lipoprotein-associated phospholipase A2) in HIV-infected individuals and non-HIV controls and relate these to coronary plaque by cardiac computed tomography angiography.

DESIGN

Observational.

METHODS

Markers were investigated in 155 HIV-infected and 70 non-HIV-infected participants without known CVD and with low traditional CVD risk and related to cardiac computed tomography angiography data.

RESULTS

Age, sex, and race did not differ between the groups. Hs-cTnT [3.1 (3.0, 6.4) vs. 3.0 (3.0, 4.0) ng/l, P = 0.03], Galectin-3 [13.5 (10.6, 18.1) vs. 11.6 (9.9, 14.5) ng/ml, P = 0.002], and soluble ST2 [31.5 (24.5, 41.5) vs. 28.3 (20.2, 33.5) ng/ml, P = 0.01] were significantly higher in HIV-infected participants vs.

CONTROLS

Detectable hs-cTnT (seen in 50% of HIV participants) related to the overall presence of plaque [odds ratio (OR) 2.3, P = 0.01] and particularly to coronary calcium (OR for Agatston calcium score > 0, 3.3, P = 0.0008 and OR for calcified plaque 7.4, P = 0.01) in HIV, but not in non-HIV.

CONCLUSION

Subclinical myocyte injury is observed among young, asymptomatic HIV-infected individuals with low traditional cardiac risk factors. In the setting of HIV infection, the presence of detectable cardiac troponin is strongly associated with coronary plaque, particularly calcified plaque among an asymptomatic group. Future studies are needed to assess if early subclinical injury marked by hs-cTnT predicts plaque progression and cardiac events in HIV.

Peripheral Artery Disease and Aortic Disease

We reviewed published MESA (Multi-Ethnic Study of Atherosclerosis) study articles concerning peripheral arterial disease, subclavian stenosis (SS), abdominal aortic calcium (AAC), and thoracic artery calcium (TAC). Important findings include, compared to non-Hispanic whites, lower ankle-brachial index (ABI) and more SS in African Americans, and higher ABI and less SS in Hispanic and Chinese Americans. Abnormal ABI and brachial pressure differences were associated with other subclinical cardiovascular disease (CVD) measures. Both very high and low ABI independently predicted increased CVD events. Looking at aortic measures, TAC and AAC were significantly associated with other subclinical CVD measures. Comparisons of AAC with coronary artery calcium (CAC) showed that both were less common in ethnic minority groups. However, although CAC was much more common in men than in women in multivariable analysis, this was not true of AAC. Also, when AAC and CAC were adjusted for each other in multivariable analysis, there was a stronger association for AAC than for CAC with CVD and total mortality.

Pulsatile Load Components, Resistive Load and Incident Heart Failure: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Left ventricular (LV) afterload is composed of systemic vascular resistance (SVR) and components of pulsatile load, including total arterial compliance (TAC), and reflection magnitude (RM). RM, which affects the LV systolic loading sequence, has been shown to strongly predict HF. Effective arterial elastance (E_a) is a commonly used parameter initially proposed to be a lumped index of resistive and pulsatile afterload. We sought to assess how various LV afterload parameters predict heart failure (HF) risk and whether RM predicts HF independently from subclinical atherosclerosis.

METHODS

We studied 4345 MESA participants who underwent radial arterial tonometry and cardiac output (CO) measurements with the use of cardiac MRI. RM was computed as the ratio of the backward (P_b) to forward (P_f) waves. TAC was approximated as the ratio of stroke volume (SV) to central pulse pressure. SVR was computed as mean pressure/CO. E_a was computed as central end-systolic pressure/SV.

RESULTS

During 10.3 years of follow-up, 91 definite HF events occurred. SVR (P = .74), TAC (P = .81), and E_a (P = .81) were not predictive of HF risk. RM was associated with increased HF risk, even after adjustment for other parameters of arterial load, various confounders, and markers of subclinical atherosclerosis (standardized hazard ratio [HR] 1.49, 95% confidence interval [CI] 1.18-1.88; P = .001). P_b was also associated with an increased risk of HF after adjustment for P_f (standardized HR 1.43, 95% CI 1.17-1.75; P = .001).

CONCLUSIONS

RM is an important independent predictor of HF risk, whereas TAC, SVR, and E_a are not. Our findings support the importance of the systolic LV loading sequence on HF risk, independently from subclinical atherosclerosis.

Association of High Ankle Brachial Index With Incident Cardiovascular Disease and Mortality in a High-Risk Population

OBJECTIVE

The objective of this present study is to determine whether high ankle brachial index (ABI) as compared with ABIs within reference limits is associated with an increased incidence of cardiovascular disease (CVD) events and all-cause mortality in a high-risk population and whether this association is the same for patients with and without diabetes mellitus or prevalent CVD.

APPROACH AND RESULTS

Seven thousand five hundred and thirty-eight patients with ABI>0.9 and either prevalent CVD or a high risk for CVD were selected from the Second Manifestations of Arterial Disease (SMART) study. Three hundred and thirty-six participants (4.5%) had high ABI (≥1.4 or incompressible). Higher age, male sex, higher body mass index, and diabetes mellitus were associated with higher prevalences of high ABI; smoking and higher non-high-density lipoprotein levels were associated with lower prevalences of high ABI. Cox proportional hazards models were fitted assessing the association of high ABI (as compared with ABI 0.9-1.4) with the risk of myocardial infarction, stroke, cardiovascular death, the combined outcome of these 3, and total mortality (median follow-up 6.9 years). After multivariable adjustment, high ABI was associated with an increased risk of myocardial infarction (hazard ratio 1.83 [95% confidence interval 1.22-2.76]), but not with stroke (hazard ratio 0.86 [95% confidence interval 0.44-1.69]), cardiovascular (hazard ratio 1.14 [95% confidence interval 0.70-1.84]), or all-cause mortality (hazard ratio 0.95 [95% confidence interval 0.67-1.34]). Associations of high ABI with CVD outcomes tended to be stronger in patients with diabetes mellitus but without statistically significant interactions.

CONCLUSIONS

In a high-risk population, the presence of an ABI≥1.4 was associated with an increased risk for myocardial infarction, but not with stroke, all-cause, or vascular mortality.

Reflection magnitude as a predictor of mortality: the Multi-Ethnic Study of Atherosclerosis

Arterial wave reflections have been associated with mortality in an ethnically homogenous Asian population. It is unknown whether this association is present in a multiethnic population or whether it is independent of subclinical atherosclerosis. We hypothesized that reflection magnitude (defined as the ratio of the amplitude of the backward wave [Pb] to that of the forward wave [Pf]) is associated with all-cause mortality in a large multiethnic adult community-based sample. We studied 5984 participants enrolled in the Multi-Ethnic Study of Atherosclerosis who had analyzable arterial tonometry waveforms. During 9.8±1.7 years of follow-up, 617 deaths occurred, of which 134 (22%) were adjudicated cardiovascular deaths. In Cox proportional hazards models, each 10% increase in reflection magnitude was associated with a 31% increased risk for all-cause mortality (hazard ratio [HR]=1.31; 95% confidence interval [CI]=1.11-1.55; P=0.001). This relationship persisted after adjustment for various confounders and for markers of subclinical atherosclerosis (HR=1.23; 95% CI=1.01-1.51; P=0.04), including the coronary calcium score, ankle-brachial index, common carotid intima-media thickness, and ascending thoracic aortic Agatston score. Pb was independently associated with all-cause mortality in a similarly adjusted model (HR per 10 mm Hg increase in P(b)=2.18; 95% CI=1.21-3.92; P=0.009). Reflection magnitude (HR=1.71; 95% CI=1.06-2.77; P=0.03) and P(b) (HR=5.02; 95% CI=1.29-19.42; P=0.02) were mainly associated with cardiovascular mortality. In conclusion, reflection magnitude is independently associated with all-cause mortality in a multiethnic population initially free of clinically evident cardiovascular disease. This relationship persists after adjustment for a comprehensive set of markers of subclinical atherosclerosis.

Combination of high ankle-brachial index and hard coronary heart disease Framingham Risk Score in predicting the risk of ischemic stroke in general population

Our previous study showed that the patients with more metabolic risk factors had higher risk of high ankle–brachial index (ABI), but the relationship between high ABI and the risk of severe cardiovascular and cerebrovascular diseases is still under debate. This study aims to evaluate this association in the general population. 1486 subjects of South China were recruited in the study. 61 subjects were defined as high ABI group (ABI≥1.3) and 65 subjects were randomly selected as normal ABI group (0.9<ABI<1.3). Biochemical parameters, clinical characteristics and 10-year hard coronary heart disease (HCHD) Framingham Risk Score (FRS) were compared between two groups. The results showed that the 10-year HCHD FRS of high ABI group was significantly higher than normal ABI group (7.87±6.11 vs. 3.98±2.90%, P<0.001). There was a positive correlation between ABI value and HCHD FRS in overweight participants (R = 0.576, P<0.01). The prevalence of ischemic stroke was higher in high ABI group than normal ABI group (21.3% vs. 6.2%, P<0.05), and it was higher in participants with HCHD FRS≥6% than those with HCHD FRS<6% (19.1% vs. 6.9%, P<0.05). Moreover, the prevalence of ischemic stroke was higher in participants with high ABI and HCHD FRS≥6% than those with normal ABI and HCHD FRS<6% (26.7% vs. 4.1%, P<0.05). BMI, hypertension, hsCRP and smoking were proved to be the independent factors and effective predictors for high ABI (P<0.05). In conclusion, high ABI combined with high HCHD FRS should be a potential predictor of ischemic stroke in the general population of South China.

Association of brachial-ankle pulse wave velocity, ankle-brachial index and ratio of brachial pre-ejection period to ejection time with left ventricular hypertrophy

BACKGROUND

Arterial stiffness, peripheral artery disease and left ventricular systolic dysfunction contributed to left ventricular hypertrophy (LVH). Using an ABI-form device, we can obtain brachial-ankle pulse wave velocity (baPWV), ankle-brachial index (ABI) and the ratio of brachial pre-ejection period to ejection time (bPEP/bET), which are markers for arterial stiffness, peripheral artery disease and left ventricular systolic function, respectively. The aim of this study was to assess whether "BAP score" calculated from the 3 measures of baPWV, ABI and bPEP/bET is associated with LVH.

METHODS

A total of 1,146 patients were included in the study. BAP score was calculated based on a point system in which 1 point was assigned for baPWV above the median value of 1670 cm/s, ABI < 0.9 or ≥ 1.3 in either leg and bPEP/bET > 0.38.

RESULTS

There was a significant trend for a stepwise increase in the left atrial diameter, left ventricular mass index (LVMI) and the prevalence of LVH and a stepwise decrease in the left ventricular ejection fraction corresponding to advancement in BAP score from 0 to 3. In addition, increased BAP score is significantly associated with increased LVMI and LVH.

CONCLUSIONS

Our results demonstrated increased BAP score was related to increased LVMI and LVH independent of traditional risk factors such as old age, diabetes, hypertension, obesity, anemia, hyperlipidemia and chronic kidney disease. Therefore, the BAP score obtained from the same examination might be useful and convenient in identifying patients with increased LVMI and LVH.

Left ventricular mass progression despite stable blood pressure and kidney function in stage 3 chronic kidney disease

BACKGROUND/AIMS

Progressive chronic kidney disease (CKD) is associated with worsening cardiovascular (CV) risk not explained by traditional risk factors. Left ventricular (LV) hypertrophy (LVH) is an important CV risk factor, but its progression has not been documented in early CKD. We explored whether progression of LVH in early CKD would occur despite stable kidney function.

METHODS

We conducted a post hoc analysis of a 12-month study of lanthanum carbonate in stage 3 CKD, which included longitudinal assessments of CV biomarkers. Primary outcome for the analysis was the change in LV mass (LVM) indexed to height in meters(2.7) (LVM/Ht(2.7)). Secondary outcomes were changes in blood pressure (BP), pulse-wave velocity, LV systolic/diastolic function, fibroblast growth factor 23 (FGF23), klotho, and estimated glomerular filtration rate (eGFR).

RESULTS

Thirty-one of 38 original subjects had sufficient data for analysis. LVM/Ht(2.7) increased (47 ± 13 vs. 53 ± 13 g/m(2.7), p = 0.006) over 12 months despite stable BP, stable eGFR and normal LV systolic function. Vascular stiffness and LV diastolic dysfunction persisted throughout the study. Klotho levels decreased (748 ± 289 to 536 ± 410 pg/ml, p = 0.03) but were unrelated to changes in LVM/Ht(2.7). The change in FGF23/klotho ratio was strongly correlated with changes in LVM/Ht(2.7) (r2 = 0.582, p = 0.03).

CONCLUSION

Subjects with stage 3 CKD exhibited increasing LVM, persistent LV diastolic dysfunction and vascular stiffness despite stable kidney function, BP and LV systolic function. Abnormal FGF23 signaling due to reduced klotho expression may be associated with increasing LVM.

Association of fibroblast growth factor-23 with arterial stiffness in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Serum fibroblast growth factor-23 (FGF-23) is associated with cardiovascular disease (CVD), yet the mechanisms remain uncertain. Our objective was to determine whether higher FGF-23 concentrations are associated with arterial stiffness.

METHODS

In this cross-sectional study, serum FGF-23 concentrations were measured in 5977 participants without known CVD in the Multi-Ethnic Study of Atherosclerosis. The primary outcomes of interest were large (LAE) and small artery elasticity (SAE), pulse pressure and ankle-brachial index (ABI) > 1.30. LAE and SAE were measured by pulse contour analysis of the radial artery. Pulse pressure was measured with an automated sphygmomanometer using the average of two resting blood pressure measurements. ABI was calculated as the ratio of the ankle and brachial systolic blood pressures.

RESULTS

Serum FGF-23 concentrations were not significantly associated with LAE [relative difference (RD) per doubling: 0%; 95% confidence interval (CI): -2-1%], SAE (RD per doubling: 0%; 95% CI: -3-2%), pulse pressure (β per doubling: 0.44; 95% CI: -0.31-1.19), or a high ABI (odds ratio per doubling: 1.14; 95% CI: 0.84-1.55). Findings were similar irrespective of chronic kidney disease status.

CONCLUSIONS

Higher serum FGF-23 concentrations are not associated with arterial stiffness, as measured by pulse pressure, LAE, SAE or high ABI, in a community-based population without CVD.

High-density lipoproteins and cerebrovascular integrity in Alzheimer's disease

Cerebrovascular dysfunction significantly contributes to the clinical presentation and pathoetiology of Alzheimer's disease (AD). Deposition and aggregation of β-amyloid (Aβ) within vascular smooth muscle cells leads to inflammation, oxidative stress, impaired vasorelaxation, and disruption of blood-brain barrier integrity. Midlife vascular risk factors, such as hypertension, cardiovascular disease, diabetes, and dyslipidemia, increase the relative risk for AD. These comorbidities are all characterized by low and/or dysfunctional high-density lipoproteins (HDL), which itself is a risk factor for AD. HDL performs a wide variety of critical functions in the periphery and CNS. In addition to lipid transport, HDL regulates vascular health via mediating vasorelaxation, inflammation, and oxidative stress and promotes endothelial cell survival and integrity. Here, we summarize clinical and preclinical data examining the involvement of HDL, originating from the circulation and from within the CNS, on AD and hypothesize potential synergistic actions between the two lipoprotein pools.

Association of EZSCAN values with arterial stiffness in individuals without diabetes or cardiovascular disease

Background

The EZSCAN test was recently developed to screen for early dysglycemia through an assessment of sudomotor function. Given the associations of dysglycemia and autonomic dysfunction with the development of arterial stiffness, EZSCAN may also detect early arterial stiffness. The aim of this study was to investigate the association of EZSCAN with arterial stiffness across blood glucose levels.

Methodology and Principal Findings

A total of 5532 participants without diabetes or established cardiovascular disease were evaluated with EZSCAN. Their central systolic blood pressure (cSBP), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) were also measured. Multivariate linear regression analyses were used to assess the association between the EZSCAN value and the cSBP, baPWV, and ABI measurements in all of the participants, with additional subgroup analysis that separated participants into a normal glucose tolerance (NGT) group and an impaired glucose regulation (IGR) group. The frequency of the IGRs increased with quartiles of the EZSCAN value (P for trend <0.0001). The levels of cSBP and baPWV increased while the levels of ABI decreased across quartiles of EZSCAN value in both NGT and IGR individuals (P for trend <0.0001 for all). In multivariable analyses, the EZSCAN value was positively associated with cSBP (log-transformed beta = 8.20, P<0.0001) and baPWV (log-transformed beta = 1.82, P<0.0001) but inversely associated with ABI (log-transformed beta = −0.043, P<0.0001) and was independent of conventional factors. Further adjustment for fasting and postprandial glucoses did not attenuate the associations. The results were also unchanged when stratified by IGR.

Conclusions and Significance

The EZSCAN results were associated with arterial stiffness independent of conventional factors, blood glucose levels, and glucose tolerance status, suggesting a probable link between the EZSCAN value and arterial stiffness through autonomic dysfunction. The EZSCAN test may help us detect the development of arterial stiffness in high risk individuals to prevent unfavorable cardiovascular events.

Photoplethysmography: a simplified method for the office measurement of ankle brachial index in individuals with diabetes

OBJECTIVE

To compare the use of photoplethysmography (PPG) and Doppler techniques to measure the ankle brachial index (ABI) for the evaluation of peripheral arterial disease (PAD) in individuals with diabetes.

METHODS

Consecutive patients with diabetes (n = 103) referred for PAD evaluation had ABI measured by PPG and Doppler techniques in our diabetes center. Medical records were reviewed, and the results of the Doppler and PPG testing were compared.

RESULTS

Mean age was 60 years, 57% were female, and 79% had type 2 diabetes with an average duration of 17 years. PPG readings could not be obtained in 3 individuals. Of 200 limbs evaluated, 17 (8.5%) had noncompressible (NC) vessels by both techniques. In the remaining 183 limbs, the correlation coefficient comparing the two methods was 0.864. Mean ABI values were 1.11 ± 0.14 for Doppler and 1.12 ± 0.14 for PPG. The sensitivity of PPG compared to the Doppler technique for detection of an abnormal result was 88.2%, and the specificity was 99.4%. ABI results were classified as discordant if Doppler and PPG varied by more than 0.15, placing them in different diagnostic categories (abnormal low [≤0.9], borderline [0.91-0.99], normal [1.0-1.4], or abnormal high [>1.4 or NC vessels]). There were only 4 (2%) discordant results.

CONCLUSIONS

We found excellent concordance between PPG and the gold standard Doppler technique for ABI measurement in individuals with diabetes. PPG requires less training and takes less time to perform, making it highly suitable for use in an office setting.

Arterial compliance across the spectrum of ankle-brachial index: the Multiethnic Study of Atherosclerosis

OBJECTIVE

A low ankle-brachial index is associated with cardiovascular disease and reduced arterial compliance. A high ankle-brachial index is also associated with an increased risk of cardiovascular events. We tested the hypothesis that subjects with a high ankle-brachial index demonstrate a lower arterial compliance. In addition, we assessed whether pulse pressure amplification is increased among subjects with a high ankle-brachial index.

METHODS

We studied 6814 adults enrolled in the Multiethnic Study of Atherosclerosis who were, by definition, free of clinical cardiovascular disease at baseline. Differences in total arterial compliance (ratio of stroke volume to pulse pressure), aortic and carotid distensibility (measured with magnetic resonance imaging and duplex ultrasound, respectively) were compared across ankle-brachial index subclasses (≤0.90, 0.91-1.29; ≥1.30) with analyses adjusted for cardiovascular risk factors and subclinical atherosclerosis.

RESULTS

Peripheral arterial disease was detected in 230 (3.4%) and high ABI in 648 (9.6%) of subjects. Those with high ankle-brachial index demonstrated greater aortic/radial pulse pressure amplification than those with a normal ankle-brachial index. In adjusted models aortic and carotid distensibility as well as total arterial compliance, were lowest among those with ankle-brachial index≤0.9 (p<0.01 vs. all), but were not reduced in subjects with an ankle-brachial index≥1.3.

CONCLUSION

Lower aortic, carotid and total arterial compliance is not present in subjects free of overt cardiovascular disease and with a high ankle-brachial index. However, increased pulse pressure amplification contributes to a greater ankle-brachial index in the general population and may allow better characterization of individuals with this phenotype.

Association of interankle systolic blood pressure difference with peripheral vascular disease and left ventricular mass index

BACKGROUND

An interankle systolic blood pressure (SBP) difference has been associated with overall and cardiovascular mortality. We investigated whether an association existed between this difference and ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and echocardiographic parameters.

METHODS

A total of 1,059 patients referred for echocardiographic examination were included in the study. The 4 limb blood pressures were measured simultaneously using an ABI-form device.

RESULTS

We performed multivariate forward analysis to determine the factors associated with an interankle SBP difference ≥ 15mm Hg. An ABI < 0.9 (P < 0.001), high baPWV (P < 0.001), and increased left ventricular mass index (LVMI; P = 0.004) were associated with an interankle SBP difference ≥ 15mm Hg. Also, the addition of an interankle SBP difference ≥ 15mm Hg to a model of clinical features could significantly improve the value in predicting ABI < 0.9 (P < 0.001) and increased LVMI (P = 0.036).

CONCLUSIONS

Our study demonstrated that ABI < 0.9, high baPWV, and increased LVMI were independently associated with an interankle SBP difference ≥ 15mm Hg. Also, an interankle SBP difference ≥ 15mm Hg could offer an extra benefit in identifying patients with ABI < 0.9 and increased LVMI beyond conventional clinical features. Hence, calculation of interankle SBP difference may provide additional information for identifying patients with peripheral vascular disease and increased LVMI.

Non-compressible arterial disease and the risk of coronary calcification in type-2 diabetes

OBJECTIVE

Ankle-brachial index (ABI) screening is recommended for the detection of asymptomatic peripheral arterial disease (PAD) in at-risk populations, including diabetics. A low ABI identifies obstructive lower extremity vascular disease and predicts CVD events and increased mortality. A high ABI represents non-compressible arterial disease (NCAD), and is also associated with increased mortality and vascular events. Our objective is to investigate whether low and high ABI have distinct patterns of association with cardiovascular disease (CVD) risk factors and subclinical atherosclerosis in individuals with type-II diabetes mellitus.

METHODS

The Penn Diabetes Heart Study (PDHS) is a prospective observational cohort of diabetic individuals without clinically evident CVD. Multivariate logistic and Tobit linear regression were used to compare CVD risk factors and coronary artery (CAC) among 1863 subjects with PAD (ABI ≤ 0.9), NCAD (ABI ≥ 1.4 or non-compressible) or normal ABI (0.91-1.39).

RESULTS

Compared to those with normal ABI, PAD was associated with smoking, obesity, and lower HDL-c; while diabetes duration and reduced renal function were associated with NCAD. Both PAD and NCAD were independently associated with increased CAC compared to those with normal ABI, and these relationships were not attenuated in multiply adjusted models.

CONCLUSION

NCAD bears a distinct relationship to traditional CVD risk factors among diabetics, though like PAD is independently associated with increased CAC. These findings support the recognition of NCAD as a high-risk phenotype and provide additional relevance to ABI screening in diabetics.

Clinical detection, risk factors, and cardiovascular consequences of medial arterial calcification: a pattern of vascular injury associated with aberrant mineral metabolism

Patients with end-stage renal disease are characterized by extensive vascular calcification and high cardiovascular disease (CVD) risk. Calcification in end-stage renal disease patients represents at least two distinct pathologic processes. Calcification within the tunica intima frequently is associated with lipid-laden, flow-limiting atherosclerotic plaques. These appear as spotty areas of calcification interspersed with noncalcified arterial segments on plain radiography and generally are found near arterial branch points in medium-sized conduit arteries. In contrast, medial arterial calcification (MAC) involves deeper layers of the arterial wall; tends to affect the artery diffusely, appearing as a linear contiguous tram-track pattern of calcification on plain radiography; and often involves smaller muscular arteries such as the radial artery, intermammary arteries, and arteries in the ankle and foot. Both are related to CVD events, but potentially through different mechanisms. Atherosclerotic calcification may be marking the total burden of atherosclerosis, whereas MAC may lead to arterial stiffness and left ventricular hypertrophy. Existing data suggest that altered mineral metabolism may promote MAC, whereas heightened inflammation and oxidative stress contribute to atherosclerosis. Dysregulation of normal anticalcification factors and elastin degradation are common to both processes. Risk of vascular calcification also may be increased by the use of certain medications in the setting of chronic kidney disease. This review compares and contrasts known risk factors for MAC and atherosclerosis, describes existing and emerging technologies to distinguish between them, and reviews the existing literature linking each with CVD events in dialysis patients and in other settings.

The value of Doppler waveform analysis in predicting major lower extremity amputation among dialysis patients treated for diabetic foot ulcers

AIMS

This study examined the predictors for lower extremity amputation (LEA) in patients with diabetic foot ulcers according to kidney function and, in the case of dialysis patients, specifically evaluated the vasculature with the ankle-brachial index (ABI) and Doppler waveforms.

METHODS

Among 658 diabetic patients admitted to the Diabetic Foot Care Center, 286 had an estimated glomerular filtration rate (eGFR)≥ 60 ml/min per 1.73 m(2), 275 had an eGFR<60, and 97 patients were under maintenance dialysis. All clinical variables were analyzed. A specialist retrospectively reviewed Doppler images of 78 of the patients in dialysis to evaluate peripheral arterial disease.

RESULTS

Forty-two percent of patients with eGFR<60 presented with ABI≤0.90. For ABI values>1.40, the proportion of dialysis patients (31.3%) was greater than the proportion of patients with eGFR<60 (5.3%). Wagner wound classifications, reduced serum albumin levels, and low ABI values were the predictors for major LEA among patients in the non-dialysis groups. Nevertheless, these indicators were not predictive of the risk of amputation in diabetic patients on dialysis. The presence of poor monophasic waveforms in the dorsalis pedis artery or posterior tibial artery served as an independent predictor (odds ratio: 7.61; P=0.008) for major LEA among dialysis patients. The sensitivity and specificity were 88.0% and 59.6%, respectively.

CONCLUSIONS

Poor monophasic Doppler waveforms of below-the-knee arteries, commonly found among dialysis patients in treatment for diabetic foot ulcers, can serve as an independent predictor for major LEA.

Lower-extremity arterial stiffness vs. aortic stiffness in the general population

While determinants of aortic pulse wave velocity (aPWV) are well known, much less is known about factors affecting lower-extremity pulse wave velocity (lePWV). Unlike aPWV, increased lePWV does not predict cardiovascular risk, but limits lower-extremity blood flow and is associated with increased left ventricular mass. The aim of this study was to compare the effect of cardiovascular risk factors on aPWV and lePWV. A total of 911 individuals from the Czech post-MONICA study (a randomly selected 1% representative population sample, mean age 54±13.5 years, 47% men) were examined. Pulse wave velocity was measured using the SphygmoCor device. Aging had a large effect on aPWV, but only a small effect on lePWV. After adjustment for covariates, we observed that hypertension, diabetes, chronic kidney disease and dyslipidemia were positively and significantly associated with aPWV. However, only hypertension had a significant effect on lePWV. Increased ankle systolic blood pressure was associated with increased aPWV independently of brachial blood pressure. Ankle systolic blood pressure was more closely related to aPWV than lePWV. Subjects with an ankle-brachial index <1.0 had higher aPWV and lower lePWV compared with individuals with a normal ankle-brachial index. Lower-extremity arterial stiffness is affected by age and cardiovascular risk factors to a lesser extent than aortic stiffness. Increased ankle systolic blood pressure is linked not only to increased lower-extremity arterial stiffness, but also increased aortic stiffness. In subjects with a low ankle-brachial index, lower-extremity arterial stiffness is spuriously decreased.

Inflammation and oxidative stress are associated with the prevalence of high aankle-brachial index in metabolic syndrome patients without chronic renal failure

AIMS

High ankle-brachial index (ABI) is marker of increased cardiovascular morbidity and mortality, while the relationship and mechanism between high ABI and metabolic syndrome (MetS) are unclear. The objectives of this study were to determine the relationship and possible mechanism of MetS with high ABI.

METHODS

341 participants without CRF were recruited. Among these participants, 58 participants (ABI ≥ 1.3) were include in high ABI group and the other 283 participants (0.9 < ABI < 1.3) were include in normal ABI group. Furthermore, these 341 participants were also divided into MetS group (n = 54) and non-MetS group (n = 287). All participants received examinations including body mass index (BMI), ABI and related biochemical parameters.

RESULTS

Compared with non-MetS group, the prevalence of high ABI was higher in MetS group (27.8% vs. 15%, p < 0.05). Participants with 3-4 metabolic risk factors had higher prevalence of high ABI than those with 0-1 metabolic risk factors (27.8% vs. 12.7%, p < 0.05). The prevalence of high ABI in overweight participants was higher than those with normal body weight. And the participants with hypertension also had higher prevalence of high ABI than normotensive participants. BMI, high-sensitivity C-reactive protein (hsCRP) and superoxide dismutase (SOD) were all higher in high ABI group than normal ABI group (p < 0.05).

CONCLUSIONS

More metabolic risk factors have increased the risk of high ABI. Inflammation and oxidative stress are associated with prevalence of high ABI in metabolic syndrome patients without chronic renal failure.

Association of chronic kidney disease and peripheral artery disease with inappropriate left ventricular mass

Inappropriate left ventricular mass index (LVM) may develop as a response to particular hemodynamic and metabolic alterations. Inappropriate LVM and peripheral artery disease (PAD) characterized by abnormally low or high ankle-brachial index (ABI) are common in chronic kidney disease (CKD) patients, in whom there may be a close and cause-effect relationship. The aim of this study is to assess whether CKD and abnormal ABI has an independent and additive association with inappropriate LVM. A total of 1110 patients were included in the study. Inappropriate LVM was defined as observed LVM more than 28% of the predicted value. The ABI was measured using an ABI-form device. PAD was defined as ABI <0.9 or >1.3 in either leg. Multivariate analysis showed that patients with estimated glomerular filtration rate (eGFR) <45 ml/min/1.73 m² (odds ratio [OR], 1.644; P = 0.011) and PAD (OR, 2.082; P = 0.002) were independently associated with inappropriate LVM. The interaction between eGFR <45 ml/min/1.73 m² and PAD on inappropriate LVM was statistically significant (P = 0.044). Besides, eGFR<45 ml/min/1.73 m² (change in observed/predicted LVM, 19.949; P<0.001) and PAD (change in observed/predicted LVM, 11.818; P = 0.003) were also significantly associated with observed/predicted LVM. Our findings show that eGFR <45 ml/min/1.73 m² and PAD are independently and additively associated with inappropriate LVM and observed/predicted LVM. Assessments of eGFR and ABI may be useful in identifying patients with inappropriate LVM.

Association of diabetes and hemodialysis with ankle pressure and ankle-brachial index in Japanese patients with critical limb ischemia

OBJECTIVE

To investigate whether diabetes and regular hemodialysis are associated with false elevation of ankle systolic blood pressure and ankle-brachial systolic pressure index (ABI) because of their arterial calcification in patients with critical limb ischemia (CLI).

RESEARCH DESIGN AND METHODS

We recruited 269 Japanese patients who underwent endovascular therapy for CLI. Ankle systolic blood pressure and ABI were assessed before endovascular therapy. Arterial stenosis and calcification were evaluated angiographically. We investigated the associations among clinical comorbidities, arterial calcification, and measurements of ankle systolic blood pressure and ABI.

RESULTS

Ankle systolic blood pressure was 85 ± 56 mmHg, and ABI was 0.59 ± 0.37. Arterial calcification was observed in 69% of the patients. The prevalence of diabetes and regular hemodialysis was 71 and 47%. Diabetes and regular hemodialysis were both significantly associated with the presence of arterial calcification; their adjusted odds ratios were 2.33 (P = 0.01) and 7.40 (P < 0.01), respectively. However, there was no significant difference in ankle systolic blood pressure or ABI level between those with and without these comorbidities. Furthermore, the presence of arterial calcification was not associated with ankle systolic blood pressure or ABI level, whereas arterial stenoses of all segments in the lower body had independent associations with reduced ankle systolic blood pressure and ABI level.

CONCLUSIONS

Diabetes and regular hemodialysis were significantly associated with arterial calcification, but not with elevated measurements of ankle systolic blood pressure or ABI, in CLI patients.

Abnormally low and high ankle-brachial indices are independently associated with increased left ventricular mass index in chronic kidney disease

Abnormally low and high ankle-brachial indices (ABIs) are associated with high cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD), but the mechanisms responsible for the association are not fully known. This study is designed to assess whether there is a significant correlation between abnormal ABI and echocariographic parameters in patients with CKD stages 3-5. A total of 684 pre-dialysis CKD patients were included in the study. The ABI was measured using an ABI-form device. Patients were classified into ABI <0.9, ≥ 0.9 to <1.3, and ≥ 1.3. Clinical and echocariographic parameters were compared and analyzed. Compared with patients with ABI of ≥ 0.9 to <1.3, the values of left ventricular mass index (LVMI) were higher in patients with ABI <0.9 and ABI ≥ 1.3 (P ≤ 0.004). After the multivariate analysis, patients with ABI <0.9 (β = 0.099, P = 0.004) and ABI ≥ 1.3 (β = 0.143, P<0.001) were independently associated with increased LVMI. Besides, increased LVMI (odds ratio, 1.017; 95% confidence interval, 1.002 to 1.033; P = 0.031) was also significantly associated with ABI <0.9 or ABI ≥1.3. Our study in patients of CKD stages 3-5 demonstrated abnormally low and high ABIs were positively associated with LVMI. Future studies are required to determine whether increased LVMI is a causal intermediary between abnormal ABI and adverse cardiovascular outcomes in CKD.

Test characteristics of the ankle-brachial index and ankle-brachial difference for medial arterial calcification on X-ray in type 1 diabetes

OBJECTIVE

Medial arterial calcification (MAC) is common in diabetes, has a characteristic appearance on X-ray imaging, and has been linked with peripheral arterial stiffness and cardiovascular disease. However, few studies have measured X-ray MAC. It has been suggested that an ankle-brachial index (ABI) >1.30 or an ankle-brachial difference (ABD) >75 mm Hg may identify X-ray MAC, but test characteristics are unknown. We hypothesized that an ABI >1.30 and ABD >75 mm Hg would have high specificity but low sensitivity for MAC on X-ray imaging.

METHODS

This was a cross-sectional study of 185 community-living individuals with type 1 diabetes. The ABI and the ABD were assessed. The outcome was linear "tram-track" calcifications in the lower limbs characteristic of MAC.

RESULTS

Mean age was 32 ± 6 years, and mean diabetes duration was 23 ± 7 years. X-ray MAC was noted in 97 individuals (57%), 15 (8%) had ABI >1.30, and 14 (8%) had ABD >75 mm Hg. As assessed by the ABI, the area under the receiver operating characteristic curve for MAC was modest (0.65) and was slightly higher for the ABD (0.75). An ABI >1.30 had high specificity (99%) and positive predictive value (93%) but poor sensitivity (14%) and an overall accuracy of 55% for MAC. An ABD >50 mm Hg remained highly specific (98%) but had higher sensitivity (30%) and overall accuracy (62%).

CONCLUSIONS

Individuals with type 1 diabetes and an ABI >1.30 or ABD >50 mm Hg are very likely to have MAC on X-ray imaging, yet many with MAC will not have an ABI or ABD above these thresholds. Given the high specificity, evaluating high ABI or ABD may be useful to understand correlates of MAC but may underestimate MAC prevalence.

Survival in patients with poorly compressible leg arteries

OBJECTIVES

This study sought to compare survival of patients with poorly compressible arteries (PCA) to those with a normal ankle-brachial index (ABI) and those with peripheral arterial disease (PAD).

BACKGROUND

Limited data are available regarding survival in patients with PCA identified in the clinical setting by noninvasive lower extremity arterial evaluation.

METHODS

We conducted a historical cohort study of consecutive patients who underwent outpatient, noninvasive lower extremity arterial evaluation at the Mayo Clinic, Rochester, Minnesota, from January 1998 through December 2007, and who were followed for a mean duration of 5.8 ± 3.1 years. An ABI 1.00 to 1.30 was considered normal, PAD was defined as a resting or post-exercise ABI ≤0.90, and PCA defined as an ABI ≥1.4 and/or an ankle systolic blood pressure >255 mm Hg. Patients were followed for all-cause mortality through September 30, 2009.

RESULTS

Of 16,493 individuals (mean age 67.8 ± 13.0 years, 59% male); 29% had normal ABI, 54% had PAD, and 17% had PCA. During follow-up (mean duration 5.8 ± 3.1 years), 4,365 patients (26%) died. The percent alive at the end of the study period was 88%, 70%, and 60% for normal ABI, PAD, and PCA, respectively. After adjustment for age, sex, cardiovascular risk factors, comorbid conditions, and medication use, the hazard ratios (95% confidence intervals) of death associated with PCA were 2.0 (1.8 to 2.2) and 1.3 (1.2 to 1.4) compared with the normal ABI and PAD groups, respectively.

CONCLUSIONS

Patients identified by noninvasive vascular testing to have poorly compressible leg arteries have poor survival, worse than those with a normal ABI or those with PAD.

[Prevalence of arterial calcification and related risk factors. The multicenter population-based ARTPER study]

OBJECTIVE

To determine the prevalence of arterial calcification (ankle-brachial index ≥1.4) and its related factors among the general population aged >49 years.

METHODS

We performed a cross-sectional study of 3,786 people randomly selected from 28 centers. To assess the factors associated with arterial calcification using a multivariate logistic model, the whole sample was used to compute prevalence, excluding persons with peripheral arterial disease (ankle-brachial index <0.9).

RESULTS

Arterial calcification was found in 235 persons (prevalence: 6.2%; 95% CI: 5.6-7.0), and was twice as frequent in men as in women. Patients with arterial calcification were older, had more previous cardiovascular events, diabetes and obesity, and were less able to perform physical activity than persons with a healthy ankle-brachial index.

CONCLUSIONS

We recommend measurement of the ankle-brachial index in primary care centers to detect arterial calcification among men, persons with diabetes, overweight, obesity or difficulty in performing physical activity, and in those with left ventricular hypertrophy.

Ankle--brachial index, vascular calcifications and mortality in dialysis patients

BACKGROUND

The ankle-brachial index (ABI) is a noninvasive method to evaluate peripheral artery disease (PAD). ABI <0.9 diagnoses PAD; ABI >1.3 is a false negative caused by noncompressible arteries. The aim of this study is to evaluate the association between ABI with vascular calcifications (VC) and with mortality, in haemodialysis (HD) patients.

METHODS

We studied 219 HD patients (60% male; 20% diabetic). At baseline, ABI was evaluated by a Doppler device. VCs were evaluated by two methods: the abdominal aorta calcification score (AACS) in a lateral plain X-ray of the abdominal aorta and the simple vascular calcification score (SVCS) in plain X-rays of the pelvis and hands. VC were also classified by their anatomical localization in main vessels (aorta and iliac-femoral axis) and in peripheral or distal vessels (pelvic, radial or digital). The cutoff values for the different VC scores in relation with ABI were determined by receiver operating characteristic curve analysis. Biochemical parameters were time averaged for the 6 months preceding ABI evaluation.

RESULTS

An ABI <0.9, an ABI >1.3 or a normal ABI were found, respectively, in 90 (41%), in 42 (19%) and in 87 (40%) patients. AACS ≥6 and SVCS >3 were found, respectively, in 98 (45%) and 95 (43%) patients. The adjusted odds ratio (OR) for having an ABI <0.9 was 2.5 (P = 0.007) for AACS ≥6 and 4.5 (P < 0.001) for iliac-femoral calcification score (CS) ≥2. The adjusted OR for having an ABI >1.3 was 4.2 (P = 0.003) for pelvic CS and 3.7 (P = 0.006) for hand CS ≥2. During an observational period of 28.9 months, all-cause and cardiovascular mortality occurred, respectively, in 50 (23%) and in 29 (13%) patients. Adjusting for age, diabetes, P levels, HD duration and cardiovascular disease at baseline, an ABI <0.9 [hazard ratio (HR) = 3.9, P < 0.001] and an ABI >1.3 (HR = 2.7, P = 0.038) were associated with all-cause mortality; an ABI <0.9 (HR = 7.2, P = 0.002) and an ABI >1.3 (HR = 5.1, P = 0.028) were associated with cardiovascular mortality.

CONCLUSIONS

Both low and high ABI were independent predictors of all-cause and cardiovascular mortality. VC in main arteries were associated with an ABI <0.9. VC in peripheral and distal arteries were associated with an ABI >1.3. ABI is a simple and noninvasive method that allows the identification of high cardiovascular risk patients.

A high ankle-brachial index is associated with increased aortic pulse wave velocity: the Czech post-MONICA study

Background: Ankle brachial index (ABI) has been increasingly used in general practice to identify individuals with low ABI at high cardiovascular risk. However, there has been no consensus on the clinical significance of high ABI. The aim of our study was to compare aortic stiffness as a marker of cardiovascular risk in individuals with low (<1.0), normal (1.0–1.4), and high ABI (>1.4).

Methods: A total of 911 individuals from the Czech post-MONICA study (a randomly selected 1% representative population sample, aged 54 ± 13.5 years, 47% of men) were examined. ABI was measured using a handheld Doppler and aortic pulse wave velocity (aPWV) using the Sphygmocor device.

Results: Of the 911 individuals, 28 (3.1%) had low ABI and 23 (2.5%) high ABI. There was a U-shaped association between aPWV and ABI. aPWV was significantly higher in individuals with low and high ABI compared with the normal ABI group (11.1 ± 2.8, 8.3 ± 2.3, p < 0.001; 10.8 ± 2.5, 8.3 ± 2.3 m/s, p < 0.001, respectively). In a model adjusted for age, sex, systolic, diastolic, mean blood pressure and examiner, aPWV remained increased in both extreme ABI groups compared with the normal ABI group. In logistic regression analysis, aPWV together with glucose level, male sex, and a history of deep venous thrombosis were independent predictors of high ABI, while cholesterol was not.

Conclusion: This is the first study showing increased aortic stiffness in individuals with high ABI, presumably responsible for increased left ventricular mass described previously in this group. These findings suggest increased cardiovascular risk of high ABI individuals.

Association between ankle blood pressure and central arterial wave reflection

There is an increasing recognition that central aortic pressure is more relevant than brachial measure for the prediction and pathophysiology of cardiovascular disease. Central pressure is influenced by the phenomenon of arterial wave reflections returning from the peripheral vasculature, which can be quantified by augmentation index. Accordingly, the primary aim of this study was to determine the association between central augmentation index and arterial blood pressures (BPs), recorded in both the upper and lower limbs. A total of 833 apparently healthy adults of varying ages were studied. All of the BP (brachial and ankle, systolic, mean, diastolic and pulse) measurements were significantly associated with carotid augmentation index. Among them, ankle mean arterial pressure was the strongest correlate of carotid augmentation index (r=0.51, P<0.0001). This relation remained highly significant even after the influence of potential confounders was accounted for by the partial correlation analyses. Stepwise regression analyses revealed that ankle mean arterial pressure was the strongest independent predictor of carotid augmentation index. Ankle BP is strongly associated with the augmentation of central BP, and this relation is independent of other BP measures (brachial BP).

Increased serum N-terminal pro-B-type natriuretic peptide levels in patients with medial arterial calcification and poorly compressible leg arteries

OBJECTIVE

To determine whether serum levels of N-terminal (NT) pro-B-type natriuretic peptide (pro-BNP) are higher in patients with poorly compressible arteries (PCA) than in patients with peripheral artery disease (PAD) and control subjects without PCA or PAD.

METHODS AND RESULTS

Medial arterial calcification in the lower extremities results in PCA and may be associated with increased arterial stiffness and hemodynamic/myocardial stress. PCA was defined as having an ankle-brachial index >1.4 or an ankle blood pressure >255 mm Hg, whereas PAD was defined as having an ankle-brachial index ≤0.9. Study participants with PCA (n=100; aged 71±10 years; 70% men) and age- and sex-matched patients with PAD (n=300) were recruited from the noninvasive vascular laboratory. Age- and sex-matched controls (n=300) were identified from a community-based cohort and had no history of PAD. NT pro-BNP levels were approximately 2.5-fold higher in patients with PCA than in patients with PAD and approximately 4-fold higher than in age- and sex-matched controls. In multivariable regression analyses that adjusted for age, sex, smoking, hypertension, history of coronary heart disease/stroke, systolic blood pressure, and serum creatinine, NT pro-BNP levels remained significantly higher in patients with PCA than in patients with PAD and controls (P<0.001).

CONCLUSIONS

Patients with medial arterial calcification and PCA have higher serum levels of NT pro-BNP than patients with PAD and controls, which is suggestive of an adverse hemodynamic milieu and increased risk for adverse cardiovascular outcomes.