Ankle-arm blood pressure index as a marker for atherosclerotic vascular diseases in hemodialysis patients

A high triglyceride-glucose index is associated with left ventricular dysfunction and atherosclerosis

Background: The triglyceride-glucose (TyG) index has been reported to be a simple and reliable surrogate marker of insulin resistance. The aim of this study was to investigate associations between the TyG index and echocardiographic parameters including left ventricular mass (LVM), left atrial diameter (LAD) and left ventricular ejection fraction (LVEF), and markers of peripheral artery disease, ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV). Methods: A total of 823 (483 males and 340 females) patients were enrolled from 2007 to 2011 at a regional hospital in southern Taiwan. Multivariable stepwise linear regression analysis was performed to identify the factors related to echocardiographic parameters and peripheral artery disease. Results: The patients were stratified into four groups according to TyG index quartile. Multivariable stepwise linear regression analysis showed that a higher TyG index was associated with elevated observed/predicted LVM (p = 0.081), increased LAD (p = 0.004), decreased LVEF (p = 0.003) and lower ABI (p = 0.030), but not observed/predicted LVM and baPWV. Conclusions: A high TyG index was significantly associated with high LAD, low LVEF and low ABI. However, the TyG index was not significantly associated with inappropriate LVM or baPWV. The results suggest that the TyG index, as a simple indicator of insulin resistance, may reflect cardiac remodeling and dysfunction and atherosclerosis.

Investigation of Acoustic Cardiographic Parameters before and after Hemodialysis

Patients with end-stage renal disease are at an increased risk of cardiovascular diseases and associated mortality. Acoustic cardiography is a technique in which cardiac acoustic data is synchronized with electric information to detect and characterize heart sounds and detect heart failure early. The aim of this study was to investigate acoustic cardiographic parameters before and after hemodialysis (HD) and their correlations with ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and ratio of brachial preejection period to ejection time (bPEP/bET) obtained from an ABI-form device in HD patients. This study enrolled 162 HD patients between October 2016 and April 2018. Demographic, medical, and laboratory data were collected. Acoustic cardiography was performed before and after HD to assess parameters including third heart sound (S3), fourth heart sound (S4), systolic dysfunction index (SDI), electromechanical activation time (EMAT), and left ventricular systolic time (LVST). The mean age of the enrolled patients was 60.4 ± 10.9 years, and 86 (53.1%) patients were male. S4 (p < 0.001) and LVST (p < 0.001) significantly decreased after HD, but EMAT (p < 0.001) increased. Multivariate forward linear regression analysis showed that EMAT/LVST before HD was negatively associated with albumin (unstandardized coefficient β = ‐0.076; p = 0.004) and ABI (unstandardized coefficient β = ‐0.115; p = 0.011) and positively associated with bPEP/bET (unstandardized coefficient β = 0.278; p = 0.003). Screening HD patients with acoustic cardiography may help to identify patients at a high risk of malnutrition, peripheral artery disease, and left ventricular systolic dysfunction.

A Low Ankle-Brachial Index and High Brachial-Ankle Pulse Wave Velocity Are Associated with Poor Cognitive Function in Patients Undergoing Hemodialysis

Patients with end-stage renal disease (ESRD) have an increased risk of both impaired cognitive function and peripheral artery disease (PAD) than the general population. The association between PAD and dementia is recognized, but there are limited studies in patients with ESRD. The aim of this study was to evaluate the relationship between ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) and cognitive impairment in patients receiving hemodialysis (HD). We enrolled 136 prevalent HD patients (mean age 59.3 ± 10.5 years, 55.9% male). Cognitive performance was measured using the Montreal Cognitive Assessment (MoCA) and Cognitive Abilities Screening Instrument (CASI) by trained psychiatrists. Associations between the cognitive function and ABI and baPWV were assessed using multiple linear regression analysis. Compared with HD patients with ABI ≥ 0.9, patients with ABI < 0.9 had lower MoCA score (p = 0.027) and lower CASI score but did not achieve significant level (p = 0.056). In the multivariate stepwise linear regression analysis, ABI (per 0.1) was independently positively associated with the MoCA score (β coefficient = 0.62, p = 0.011) and the CASI score (β coefficient = 1.43, p = 0.026). There is a negative association between baPWV (per 100 cm/s) and CASI (β coefficient = −0.70, p = 0.009). In conclusion, a low ABI or high baPWV was associated with a lower cognitive function in HD patients.

Association between albumin and C-reactive protein and ankle-brachial index in haemodialysis

AIM

Peripheral artery occlusive disease (PAOD) is associated with increased rates of cardiovascular mortality, morbidity and hospitalization in patients undergoing dialysis. An ankle-brachial index (ABI) less than 0.9 has been used to diagnose PAOD. The aim of this study was to evaluate associations among inflammation, malnutrition and their interactions on the risk of PAOD.

METHODS

Two hundred and twenty-two haemodialysis patients (mean age 61.0 ± 11.7 years, 56.8% men) were enrolled and stratified into four groups according to median values of albumin (3.87 g/dL) and logarithm of C-reactive protein (CRP) (0.48 mg/L). Associations between the study groups and an ABI less than 0.9 were assessed using multiple logistic regression analysis. Receiver operating characteristic curves were constructed to predict an ABI less than 0.9.

RESULTS

A lower level of albumin and higher level of CRP were significantly associated with an ABI less than 0.9 in multivariate analysis (odds ratio, 5.688; 95% confidence interval, 1.369-23.626; P = 0.017) after adjusting for demographic, clinical, biochemical and medication data. The interaction between albumin and CRP in relation to an ABI less than 0.9 was significant in multivariate analysis (odds ratio, 1.797; 95% confidence interval, 1.258-2.568; P = 0.001). The areas under the curve for albumin, CRP and albumin + CRP for the prediction of ABI less than 0.9 were 0.311, 0.654 and 0.733, respectively.

CONCLUSION

Patients undergoing haemodialysis with a lower albumin level and higher CRP level have an increased risk of PAOD. A combination of malnutrition and inflammation may be associated with PAOD in haemodialysis patients.

Ankle-Brachial Index as a Predictor of Mortality in Hemodialysis: A 5-Year Cohort Study

Background

Abnormal ankle-brachial index (ABI) has been found to be a strong predictor of mortality in some hemodialysis populations in studies with relatively short periods of follow-up, lower than 2 years.

Objective

This study aimed to assess the predictive value of abnormal ABI as a risk factor for death among patients on maintenance hemodialysis after a 5-year follow-up.

Methods

A total of 478 patients on hemodialysis for at least 12 months were included in the study. ABI measurement was performed using a mercury column sphygmomanometer and portable Doppler. Patients were divided into 3 groups according to ABI (low: <0.9; normal: 0.9 to 1.3; and high: >1.3) and followed for a 60-month period.

Results

The prevalence rates of low, normal and high ABI were 26.8%, 64.6% and 8.6%, respectively. The 5-year survival rate was lower in the groups with low ABI (44.1%, P<0.0001) and high ABI (60.8%, P= 0.025) than in the group with normal ABI (71.7%). Cox regression was used to evaluate the association between ABI and mortality, adjusting for potential confounders. Using normal ABI as reference, a low, but not a high ABI was found to be an independent risk factor for all-cause mortality (HR2.57; 95% CI, 1.84-3.57 and HR 1.62; 95% CI, 0.93-2.83, respectively).

Conclusions

long-term survival rates of patients with either low or high ABI were lower than the one from those with normal ABI. However, after adjustment for potential confounders, only low ABI persisted as an independent risk factor for all-cause mortality among hemodialysis patients.

Close correlation between the ankle-brachial index and symptoms of depression in hemodialysis patients

BACKGROUND

As both of peripheral arterial disease (PAD) and depression carried a poor prognosis in patients on maintenance hemodialysis (MHD), we investigated the correlation between the ankle-brachial index (ABI), an indicator of subclinical PAD, and symptoms of depression in patients on MHD.

METHODS

One hundred and twenty-nine patients on MHD (75 males and 54 females, mean age 64.8 ± 12 years) were enrolled in this cross-sectional study, which aimed at evaluating the relationship between symptoms of depression and ABI. Demographic as well as clinical and laboratory variables including status of diabetes, chronic hepatitis C infection, dialysis duration, Charlson comorbidity index (CCI), plasma levels of albumin, C-peptide, insulin, high-sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), adiponectin, and lipid profile were obtained. The self-administered beck depression inventory (BDI) was used to determine the presence or absence of symptoms of depression, and depression was defined as a BDI score ≧14. Multivariable-adjusted linear regression models were constructed to confirm the independent association of biologic parameters of symptoms of depression. Significance was defined as P < 0.05. Statistical analyses were performed using SPSS/Windows software (SPSS Science, v. 15.0, Chicago, IL).

RESULTS

The mode of multivariate analysis showed that diabetes (β = 3.594; P = 0.040), hepatitis C infection (β = 4.057; P = 0.008), levels of serum albumin (β = -5.656; P = 0.024), C-peptide (β = -0.292; P = 0.002), ABI (β = -9.041; P = 0.031), and Ln-transformed hsCRP were significantly associated with BDI.

CONCLUSIONS

Hepatitis C infection, serum levels of albumin, C-peptide, and ABI levels were found to be correlated with BDI (P < 0.05).

Interankle systolic blood pressure difference and renal outcomes in patients with chronic kidney disease

AIM

Interankle blood pressure (BP) difference has been associated with peripheral artery disease and adverse cardiovascular outcomes. However, the relationship between interankle BP difference and renal outcomes in chronic kidney disease (CKD) has never been evaluated. The purpose of this study was to determine whether interankle BP difference is associated with the rate of renal function decline and progression to renal end points in patients with stage 3-5 CKD.

METHODS

We enrolled 144 patients with CKD from one regional hospital. The BP in four limbs was simultaneously measured using an ABI-form device. The decline in renal function was evaluated using an estimated glomerular filtration rate (eGFR) slope. Rapid renal progression was defined as an eGFR slope < -3 mL/min per 1.73 m(2) per year. The renal end points were defined as ≥ 25% decline in eGFR or commencement of dialysis during the follow-up period.

RESULTS

During a mean follow-up period of 3.1 years, 90 patients (62.5%) reached renal end points. Multivariate analysis showed that an increased interankle systolic BP difference (per 5 mmHg) was associated with a worse eGFR slope (regression β, -0.292; 95% confidence interval [CI], -0.482 to -0.102; P = 0.003), rapid renal progression (odds ratio, 1.189; 95% CI, 1.015-1.394; P = 0.032), and an increased risk of progression to renal end points (hazard ratio, 1.126; 95% CI, 1.052-1.204, P = 0.001).

CONCLUSION

Interankle systolic BP difference was associated with rapid renal progression and progression to renal end points in patients with stage 3-5 CKD in our study.

Abnormally Low or High Ankle-Brachial Index Is Associated with Proliferative Diabetic Retinopathy in Type 2 Diabetic Mellitus Patients

Although some studies have reported that low ankle-brachial index (ABI) is associated with diabetic retinopathy (DR) in diabetic patients, it remains controversial as to which stage of DR. The aim of this study is to assess whether peripheral artery disease (PAD), indicated by abnormally low or high ABI, is associated with different stages of DR in patients with type 2 diabetes mellitus (DM), and further evaluate the risk factors. A total of 2001 (858 men and 1143 women) patients with type 2 DM who underwent ABI measurement in an outpatient clinic were enrolled. PAD was defined as ABI < 0.9 or ≧ 1.3 in either leg. DR was classified as non-DR, nonproliferative DR and proliferative DR stages. The clinical data were analyzed and the risk factors for abnormal ABI were determined by multivariate logistic regression analysis. The prevalence of ABI < 0.9 or ≧ 1.3 was 3.0%. Multivariate forward logistic regression analysis identified proliferative DR (vs. non-DR) was associated with abnormal ABI (odds ratio, 1.718; 95% confidence interval, 1.152 to 2.562; p = 0.008), but nonproliferative DR was not. Furthermore, the presence of coronary artery disease, cerebrovascular disease, declining renal function and patients without diuretics use were associated with abnormal ABI in patients with proliferative DR. Our study in patients of type 2 DM demonstrated that PAD was associated with proliferative DR. We emphasize the recommendation of performing the ABI test in this population at risk.

Sites of peripheral artery occlusive disease as a predictor for all-cause and cardiovascular mortality in chronic hemodialysis

Background

The ankle—brachial blood pressure (BP) index (ABI) not only indicates the presence of peripheral artery occlusive disease (PAOD) but predicts mortality in patients undergoing hemodialysis (HD). However, whether the site of PAOD can provide additional contribution to predicting mortality have not been investigated yet. Our primary objective was to determine the associations between the site of PAOD and all-cause and cardiovascular mortality in chronic HD (CHD) patients.

Methods

A retrospective cohort study was conducted to evaluate 444 Taiwanese CHD patients between December 2006 and June 2013. The site of PAOD together with other explanatory variables such as demographic data, body mass index, a history of cardiovascular diseases, HD vintage, biochemical data, and cardiothoracic ratio (CTR) were assessed by the Cox proportional hazards regression model.

Results

The frequency of PAOD was 14.6% in both legs, 4.9% in the right side only, and 5.1% in the left side only. During the study period, 127 all-cause and 93 cardiovascular deaths occurred. PAOD site was found to have significant predictive power for all-cause mortality with the order of 3.04 (95% CI: 1.56–5.90) hazard ratio on the right side, 2.48 (95% CI: 1.27–4.82) on the left side, and 4.11 (95% CI: 2.76–6.13) on both sides. The corresponding figures for cardiovascular mortality were 3.81 (95% CI: 1.87–7.76) on the right side, 2.76 (95% CI: 1.30–5.82) on the left side, and 3.95 (95% CI: 2.45–6.36) on both sides. After adjustment for other explanatory variables, only right-sided PAOD still remained to have significant predictive power for all-cause and cardiovascular mortality and bilateral PAOD kept the significant association with all-cause mortality.

Conclusions

The site of PAOD revealed various predictive powers for all-cause and cardiovascular mortality in CHD patients and only right-sided PAOD remained an independent predictor for both types of mortality making allowance for relevant confounding factors.

Association of interleg difference of ankle brachial index with overall and cardiovascular mortality in chronic hemodialysis patients

BACKGROUND

The ankle-brachial index (ABI) is associated with peripheral vascular atherosclerosis, adverse cardiovascular outcomes, and all-cause mortality. However, there were limited data available on studying the effect of interleg ABI difference.

METHODS

We investigated the association of the interleg ABI difference with overall and cardiovascular mortality in chronic hemodialysis in a retrospective observational cohort of 369 Taiwanese patients undergoing chronic hemodialysis.

RESULTS

An interleg ABI difference of ≥0.15 in hemodialysis patients had significant predictive power for all-cause and cardiovascular mortality in crude analysis. The hazard ratio (HR) for all-cause mortality was 3.00 [95% confidence interval (CI), 1.91-4.71]; the HR for cardiovascular mortality was 3.13 (95% CI, 1.82-5.38). After adjustment for confounding variables, this difference continued to have significant predictive power for all-cause mortality but lost its predictive power for fatal cardiac outcome. ABI <0.9 and high brachial-ankle pulse wave velocity were independently associated with an interleg ABI difference of ≥0.15 in hemodialysis patients. Moreover, in the subgroup analysis, we found that this difference was an independent factor for overall and cardiovascular mortality, particularly in elder patients, female patients, or those with ABI <0.9.

CONCLUSION

Detection of an interleg ABI difference of ≥0.15 was an independent risk factor for overall mortality in hemodialysis patients but it may affect cardiovascular mortality through the effect of peripheral vascular disease.

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.

Association of bilateral brachial-ankle pulse wave velocity difference with peripheral vascular disease and left ventricular mass index

Unequal arterial stiffness had been associated with cardiovascular risks. We investigated whether an association existed between unequal arterial stiffness indicated by bilateral brachial-ankle pulse wave velocity (baPWV) difference and ankle-brachial index (ABI), baPWV, echocardiographic parameters and interarm and interankle systolic blood pressure (BP) differences. A total of 1111 patients referred for echocardiographic examination were included in this study. The BPs, ABI and baPWV were measured simultaneously by an ABI-form device. The ΔbaPWV was defined as absolute value of difference between bilateral baPWV. We performed three multivariate analyses for determining the factors associated with a ΔbaPWV ≧ 185 cm/s (90 percentile of ΔbaPWV) (model 1: significant variables in univariate analysis and ABI <0.9 and baPWV; model 2: significant variables in univariate analysis and left ventricular mass index [LVMI]; model 3: significant variables in univariate analysis and interankle systolic BP difference ≧ 15 mmHg). The ABI <0.9 and high baPWV (both P<0.001) in model 1, high LVMI (P = 0.021) in model 2 and an interankle systolic BP difference ≧ 15 mmHg (P = 0.026) in model 3 were associated with a ΔbaPWV ≧ 185 cm/s, but the interarm systolic BP difference ≧ 10 mmHg was not (P = NS). Our study demonstrated ABI <0.9, high baPWV, high LVMI and an interankle systolic BP difference ≧ 15 mmHg were associated with unequal arterial stiffness.

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.

Peripheral arterial disease in the Middle East: Underestimated predictor of worse outcome

Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis and is associated with significant morbidity and mortality. The prevalence of PAD in the developed world is approximately 12% among adult population, which is age-dependent and with men being affected slightly more than women. Despite the strikingly high prevalence of PAD, the disease is underdiagnosed. Surprisingly, more than 70% of primary health care providers in the US were unaware of the presence of PAD in their patients. The clinical presentation of PAD may vary from asymptomatic to intermittent claudication, atypical leg pain, rest pain, ischemic ulcers, or gangrene. Claudication is the typical symptomatic expression of PAD. However, the disease may remains asymptomatic in up to 50% of all PAD patients. PAD has also been reported as a marker of poor outcome among patients with coronary artery disease. Despite the fact that the prevalence of atherosclerotic disease is increasing in the Middle East with increasing cardiovascular risk factors (tobacco use, diabetes mellitus and the metabolic syndrome), data regarding PAD incidence in the Middle East are scarce.

Decrease in ankle-brachial index over time and cardiovascular outcomes in patients with hemodialysis

INTRODUCTION

Abnormal ankle-brachial index (ABI) is associated with increased morbidity and mortality in hemodialysis patients. However, whether the decrease in ABI over time carries the prognostic value is unknown. The aim of this study was to assess whether the decrease in ABI over time was a good predictor of poor cardiovascular (CV) prognosis in hemodialysis patients.

METHODS

This study enrolled 234 routine hemodialysis patients and 173 patients completed the follow-up. The ABI was measured by an ABI-form device at baseline and at the first year follow-up. The ΔABI was defined as ABI measured at the first year follow-up minus ABI measured at baseline. Progressors of ABI were defined as patients with ΔABI < -0.3. CV events were defined as CV death, hospitalization for unstable angina, nonfatal myocardial infarction, hospitalization for arrhythmia, hospitalization for congestive heart failure and stroke.

RESULTS

The follow-up period was 37.8 ± 11.1 months. In the multivariate analysis, progressors of ABI (hazard ratio, 2.71; 95% confidence interval, 1.10-6.68, P = 0.03), decreased albumin and increased high-sensitivity C-reactive protein were associated with increased CV events.

CONCLUSIONS

This longitudinal study showed ΔABI < -0.3 was independently associated with an increase in CV events. Hence, a great decrease in ABI over time might be a useful indicator of poor CV prognosis in hemodialysis patients.

Association of interarm systolic blood pressure difference with atherosclerosis and left ventricular hypertrophy

An interarm systolic blood pressure (SBP) difference of 10 mmHg or more have been associated with peripheral artery disease and adverse cardiovascular outcomes. We investigated whether an association exists between this difference and ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and echocardiographic parameters. A total of 1120 patients were included in the study. The bilateral arm blood pressures were measured simultaneously by an ABI-form device. The values of ABI and baPWV were also obtained from the same device. Clinical data, ABI<0.9, baPWV, echocariographic parameters, and an interarm SBP difference ≥10 mmHg were compared and analyzed. We performed two multivariate forward analyses for determining the factors associated with an interarm SBP difference ≥10 mmHg [model 1: significant variables in univariate analysis except left ventricular mass index (LVMI); model 2: significant variables in univariate analysis except ABI<0.9 and baPWV]. The ABI<0.9 and high baPWV in model 1 and high LVMI in model 2 were independently associated with an interarm SBP difference ≥10 mmHg. Female, hypertension, and high body mass index were also associated with an interarm SBP difference ≥10 mmHg. Our study demonstrated that ABI<0.9, high baPWV, and high LVMI were independently associated with an interarm SBP difference of 10 mmHg or more. Detection of an interarm SBP difference may provide a simple method of detecting patients at increased risk of atherosclerosis and left ventricular hypertrophy.

Increasing prevalence of peripheral artery occlusive disease in hemodialysis patients: a 2-year follow-up

INTRODUCTION

Peripheral artery occlusive disease (PAOD) has been reported to be prevalent in hemodialysis patients and influence their mortality. Ankle-brachial index (ABI) <0.9 is a reliable marker for PAOD. The aims of the 2-year longitudinal study were to assess whether there was a progression in PAOD and to find out the determinants of ABI progression in hemodialysis patients.

METHODS

This study enrolled 237 routine hemodialysis patients and 154 patients completed the 2-year follow-up. The ABI was measured by an ABI-form device at baseline and at the first and second year follow-up. The change in ABI (ΔABI) was defined as ABI measured at the second year follow-up minus ABI measured at baseline.

RESULTS

The prevalence of ABI <0.9 increased yearly (10.4%, 22.7% and 27.9%, respectively; P < 0.001) and the values of ABI decreased yearly (1.11 ± 0.16, 0.97 ± 0.17 and 0.96 ± 0.19, respectively; P < 0.001) in the 154 follow-up patients. Multiple stepwise analysis identified fasting glucose level, calcium-phosphorous product, high-sensitivity C-reactive protein and homocysteine level as independent determinants of ΔABI.

CONCLUSIONS

Our results demonstrated the prevalence of PAOD increased and the values of ABI decreased yearly in hemodialysis patients. The ABI progression was associated with high fasting glucose level, high calcium-phosphorous product, high-sensitivity C-reactive protein and low homocysteine levels.

Association of interleg BP difference with overall and cardiovascular mortality in hemodialysis

BACKGROUND AND OBJECTIVES

An interarm BP difference has been associated with atherosclerosis and adverse cardiovascular outcomes. This study investigated whether an interleg BP difference was associated with peripheral vascular disease and overall and cardiovascular mortality in hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study enrolled 210 hemodialysis patients from December 2006 to January 2007. Bilateral leg BPs were measured simultaneously by an ankle-brachial index (ABI)-form device before hemodialysis.

RESULTS

The mean follow-up period was 4.4±1.5 years. ABI <0.9 and high brachial-ankle pulse wave velocity were independently associated with an interleg difference in systolic BP of ≥15 mmHg or diastolic BP of ≥10 mmHg. Furthermore, this difference was an independent predictor for overall mortality (hazard ratio [HR], 3.36; 95% confidence interval [CI], 1.68-6.72; P<0.01) and cardiovascular mortality (HR, 4.84; 95% CI, 1.84-12.71; P<0.01) after adjustment for demographic, clinical, and biochemical parameters. After further adjustment for ABI <0.9 and brachial-ankle pulse wave velocity, the relation remained significant to overall mortality (HR, 2.91; 95% CI, 1.28-6.64; P=0.01) and cardiovascular mortality (HR, 3.15; 95% CI, 1.05-9.44; P=0.04).

CONCLUSIONS

A difference in systolic BP of ≥15 mmHg or diastolic BP of ≥10 mmHg between legs was associated with peripheral vascular disease and increased risk for overall and cardiovascular mortality in hemodialysis patients. Detection of an interleg BP difference may identify hemodialysis patients at increased risk of peripheral vascular disease and overall and cardiovascular mortality.

Arterial stiffness in female patients with fibromyalgia and its relationship to chronic emotional and physical stress

BACKGROUND AND OBJECTIVES

In patients with fibromyalgia (FM) syndrome, stress and pain may chronically enhance sympathetic activity, altering cardiovascular responses and inducing the arterial wall-stiffening process. We investigated arterial stiffness in FM patients using pulse wave velocity (PWV) and analyzed whether arterial stiffness was affected by the clinical parameters of FM.

SUBJECTS AND METHODS

This study included 108 female FM patients (51.5±8.9 years) without any known cardiovascular diseases and 76 healthy female controls (50.1±8.9 years). FM patients underwent a manual tender point survey for tender point counts, and completed the visual analogue scale (VAS) of pain and fibromyalgia impact questionnaire (FIQ), which were composed of a physical and feel score. Brachial-ankle pulse-wave velocity (baPWV) was measured with an automated device. The study participants were subdivided into 2 groups based on the sum of the FIQ score (group A: FIQ ≥50, group B: <50).

RESULTS

Patients with FM had significantly higher baPWV than the controls, and significant increase were noted in baPWV values of group A compared with those of group B. BaPWV showed a significant positive correlation (correlation coefficient=6.83, p=0.022) with severity of disease assessed by FIQ.

CONCLUSION

The patients with FM showed significantly increased arterial stiffness, suggesting a pathophysiologic link between FM and endothelial dysfunction. This study provides a basis for clarifying the mechanism by which chronic pain syndrome is associated with an increased risk of vascular stiffness.

Leveraging informatics for genetic studies: use of the electronic medical record to enable a genome-wide association study of peripheral arterial disease

BACKGROUND

There is significant interest in leveraging the electronic medical record (EMR) to conduct genome-wide association studies (GWAS).

METHODS

A biorepository of DNA and plasma was created by recruiting patients referred for non-invasive lower extremity arterial evaluation or stress ECG. Peripheral arterial disease (PAD) was defined as a resting/post-exercise ankle-brachial index (ABI) less than or equal to 0.9, a history of lower extremity revascularization, or having poorly compressible leg arteries. Controls were patients without evidence of PAD. Demographic data and laboratory values were extracted from the EMR. Medication use and smoking status were established by natural language processing of clinical notes. Other risk factors and comorbidities were ascertained based on ICD-9-CM codes, medication use and laboratory data.

RESULTS

Of 1802 patients with an abnormal ABI, 115 had non-atherosclerotic vascular disease such as vasculitis, Buerger's disease, trauma and embolism (phenocopies) based on ICD-9-CM diagnosis codes and were excluded. The PAD cases (66+/-11 years, 64% men) were older than controls (61+/-8 years, 60% men) but had similar geographical distribution and ethnic composition. Among PAD cases, 1444 (85.6%) had an abnormal ABI, 233 (13.8%) had poorly compressible arteries and 10 (0.6%) had a history of lower extremity revascularization. In a random sample of 95 cases and 100 controls, risk factors and comorbidities ascertained from EMR-based algorithms had good concordance compared with manual record review; the precision ranged from 67% to 100% and recall from 84% to 100%.

CONCLUSION

This study demonstrates use of the EMR to ascertain phenocopies, phenotype heterogeneity and relevant covariates to enable a GWAS of PAD. Biorepositories linked to EMR may provide a relatively efficient means of conducting GWAS.

Determinants of peripheral arterial stiffness in patients with chronic kidney disease in southern Taiwan

High prevalences of peripheral artery occlusive disease (PAOD) and increased arterial stiffness have been reported in patients with chronic kidney disease (CKD). However, these have not been assessed in Taiwan where the prevalence of CKD is high. The aim of this study was to investigate the determinants of PAOD and arterial stiffness in patients with CKD in southern Taiwan. We enrolled 169 patients with stage 3-5 CKD in one regional hospital. Ankle-brachial index (ABI) and brachial-ankle pulse wave velocity were measured using an ABI-form device (Colin VP1000). In multivariate analysis, ABI<0.9 was positively correlated with the presence of diabetes mellitus (p=0.014) and negatively correlated with the estimated glomerular filtration rate (eGFR) (p=0.049), and increased brachial-ankle pulse wave velocity was correlated with increased age, diabetes mellitus, increased systolic blood pressure, decreased pulse pressure and decreased eGFR. This study identified determinants of PAOD and arterial stiffness in patients with CKD in one hospital in southern Taiwan. In addition to the traditional atherosclerotic risk factors, decreased eGFR was also correlated with PAOD and increased arterial stiffness in these patients.

Significant correlation between ankle-brachial index and vascular access failure in hemodialysis patients

BACKGROUND AND OBJECTIVES

Vascular access failure (VAF) is associated with increased morbidity and mortality in hemodialysis patients. The most common cause of VAF is stenosis at the arteriovenous anastomosis because of abnormal neointimal proliferation and extracellular matrix deposition. These two changes are also observed in the classic atheroma, which means atherosclerotic lesions and venous stenosis in VAF may share some similar pathogenic mechanisms. The ankle-brachial index (ABI) is a reliable marker for atherosclerosis. The aim of this study was to evaluate the relationship between ABI <0.9 and VAF.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All routine hemodialysis patients in one regional hospital were included except for six patients refusing ABI examinations and four patients with atrial fibrillation. Finally, 225 patients formed our study group. The study subjects were observed from arteriovenous access creation until the first episode of VAF. The mean observation period was 42.2 +/- 42.8 mo. The relative VAF risk was analyzed by Cox-regression methods with adjustments for demographic and comorbid conditions.

RESULTS

VAF episodes were recorded in 111 patients. In multivariate analysis, ABI <0.9 (hazard ratio, 1.893; P = 0.039), vascular access type of arteriovenous graft (P = 0.004), and serum triglyceride level (P = 0.043) were positively associated with VAF, and serum parathyroid hormone level (P = 0.043) was negatively associated with VAF.

CONCLUSIONS

Our findings show that ABI <0.9 is significantly correlated with increased VAF. Screening hemodialysis patients by means of ABI may help to identify a high-risk group for VAF.

Associated risk factors for abnormal ankle-brachial index in hemodialysis patients in a hospital

Ankle-brachial index (ABI) is a marker for peripheral artery disease and can predict mortality in hemodialysis patients. However, it is seldom studied in southern Taiwan, an area with high prevalence of end-stage renal disease (ESRD). The aim of this study was to investigate the prevalence and associated risk factors for peripheral artery disease in the ESRD population in a hospital. All routine hemodialysis patients in one regional hospital were included except for six patients who refused ABI examinations and four patients with atrial fibrillation. Finally, 225 patients formed our study group. ABI was measured using an ABI-form device (Colin VP1000). The prevalence of ABI < 0.9 and > or = 1.3 was 15.6% and 5.8%, respectively. ABI < 0.9 was independently associated with advanced age (p = 0.027), increased pulse pressure (p = 0.005), increased hematocrit (p = 0.008) and decreased serum albumin level (p = 0.009). In addition, ABI > or = 1.3 was significantly associated with diabetes mellitus (p = 0.019). This study demonstrated the associated risk factors of peripheral artery disease in patients with hemodialysis in a hospital. ESRD patients of advanced age and with increased pulse pressure, increased hematocrit and decreased serum albumin level had a relatively high risk for ABI < 0.9 and patients with diabetes had a relatively high risk for ABI > or = 1.3.

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.

Subclinical Peripheral Arterial Disease and Incompressible Ankle Arteries Are Both Long-Term Prognostic Factors in Patients Undergoing Coronary Artery Bypass Grafting

OBJECTIVES

This study was designed to determine the prevalence of peripheral arterial disease (PAD) in candidates for coronary artery bypass grafting (CABG) and to assess the predictive value of different types of subclinical PAD (peripheral occlusive disease and medial arterial calcification [incompressible ankle arteries]).

BACKGROUND

Observational studies report poor prognosis after CABG in the presence of clinical PAD, but data on subclinical PAD are scarce.

METHODS

We prospectively enrolled CABG candidates and measured ankle-brachial index (ABI) preoperatively. Patients were divided into four groups: clinical PAD, subclinical PAD (ABI <0.85), incompressible arteries (ABI >1.5), and no PAD. The primary end point was a composite combining death, acute coronary syndrome, stroke or transient ischemic attack (TIA), and coronary or peripheral revascularization. Secondary end points were overall and cardiovascular death, acute coronary syndrome, and stroke or TIA. Statistical analyses were performed using the Cox regression model.

RESULTS

We consecutively enrolled 1,022 patients (mean age 66.9 +/- 9.2 years). In addition to the 14% with clinical PAD, we detected subclinical PAD in 13% and medial artery calcification in 12%. During an actuarial follow-up of 4.4 years, 81.2% of patients remained event-free. Adverse factors were (p < 0.05) supraventricular arrhythmia (odds ratio [OR] 2.5), ejection fraction <0.40 (OR 2.3), combined valvular surgery (OR 2.5), clinical PAD (OR 3.6), subclinical PAD (OR 3.3), and medial artery calcification (OR 1.9). The latter three factors were also independently predictive for overall and cardiovascular death.

CONCLUSIONS

Beyond clinical PAD, the measurement of ABI before coronary surgery provides substantial information on long-term postoperative prognosis. To our knowledge, this is the first study highlighting the prognostic role of incompressible ankle arteries in secondary prevention.

L’index de pression systolique, un puissant marqueur de risque d’AOMI

A MARKER OF PERIPHERAL ARTERIAL DISEASE: The measurement of the ankle/arm index (AAI) is a simple, rapid and inexpensive means for the assessment of distal lower limb perfusion. Its decrease reveals an alteration in the patient's arterial status. Consecutively, AAI is an excellent marker of peripheral arterial disease, well before the onset of functional consequences. A TRIPLE MARKER: Beyond the diagnosis of peripheral arterial disease, AAI provides other interests: it is not only a tool for the functional assessment of lower limb perfusion, but also a marker of local and general atherosclerosis, as well as cardiovascular events.

Peripheral vascular occlusive disease in renal transplant recipients: risk factors and impact on kidney allograft survival

BACKGROUND

This study evaluated the relationship between renal transplantation and the evolution of lower extremity peripheral vascular occlusive disease (PVOD).

METHODS

A total of 664 adult renal allograft recipients from 1985-1995 were retrospectively reviewed for atherosclerotic risk factors and peripheral vascular occlusive disease (PVOD). PVOD events were defined as bypass, major amputation, claudication, or percutaneous angioplasty. Follow-up ranged from 2-12 years.

RESULTS

The cumulative 5- and 10-year incidences of lower extremity PVOD after renal transplantation were 4.2 and 5.9%. Eight of 14 patients (57%) with pretransplant PVOD had additional PVOD events versus de novo appearance of PVOD in 21/650 patients (3.2%; P<0.0001). In a proportional hazards model, age, preoperative PVOD, diabetes, and postoperative smoking were independent risk factors for the development of PVOD after transplantation. Recipients with lower extremity PVOD had significantly lower 10-year patient and graft survival. Increased graft failure was due to an excess of deaths with a functioning graft. A total of 34 major interventions were performed. One- and two-year limb salvage rates were 64.2 and 53.8%.

CONCLUSIONS

Lower extremity PVOD after renal transplantation is associated with diminished patient survival, and affects kidney graft survival via disproportionate patient attrition. Age, preoperative PVOD, diabetes, and postoperative smoking are important risk factors. Transplantation does not appear to either accelerate or retard the progression of disease. An aggressive approach towards limb salvage in properly selected patients is justifiable.

The significance of serum homocysteine levels in diabetic patients on haemodialysis

BACKGROUND

Atherosclerotic diseases are the major cause of mortality and morbidity in patients on haemodialysis (HD). Furthermore, the prognosis of diabetic patients on HD is especially poor due to atherosclerotic complications. Because homocysteine (Hcy), a sulfur-containing amino acid, is emerging as an important risk factor for atherosclerosis in patients with end-stage renal disease, we examined the significance of serum Hcy levels in diabetic patients on HD.

METHODS

We measured total serum Hcy levels (tHcy) in 31 patients with diabetes mellitus on HD (DM group) and 37 non-diabetic patients on HD (N group), adjusting for age and HD duration. Linear regression analysis was used to assess the correlation of multiple variables to tHcy.

RESULTS

The proportion of atherosclerotic disease in the DM group was significantly higher than in the N group. However, serum tHcy, serum creatinine and per cent creatinine generation rate in the DM group were significantly lower than in the N group. In the DM group, serum tHcy was positively correlated with creatinine, albumin and per cent creatinine generation rate, respectively. This was not the case in the N group.

CONCLUSIONS

The demethylation pathway in methionine metabolism in the liver, which is linked directly to the creatinine generation system, may be disturbed in diabetic patients on HD. This may be the reason why serum tHcy and creatinine in diabetic patients on HD are lower than in non-diabetic patients on HD. Therefore, it is necessary to consider the possibility of an altered relation between serum tHcy and vessel disease when evaluating the atherogenic risk in diabetic patients on HD.

Biologic markers as predictors of cardiovascular disease

Epidemiologic data obtained over the past 30 years suggest that a number of new biologic markers are associated with increased risk for cardiovascular disease. These include indices related to (1) altered glucose metabolism, particularly insulin resistance; (2) hyperlipidemia; (3) elevated levels of lipoprotein(a) and homocysteine; (4) increased levels of molecules reflecting decreased fibrinolysis and increased activation of the coagulation cascade; (5) elevations in cell adhesion molecules and other markers of endothelial function; and (6) elevations in molecules associated with infection, inflammation, and vascular remodeling. Changes in molecules associated with increased risk usually occur in clusters. This clustering suggests that effective treatment of one marker may have positive effects on multiple markers. Indeed, several studies have demonstrated that therapies designed to reduce hyperlipidemia may also lower the plasma levels of factors associated with increased coagulation and reduced fibrinolysis. Thus, careful assessment of patient risk factors, and the development of therapies directed toward chains of markers associated with increased risk, may significantly alter the course of cardiovascular disease.

Ankle-arm blood pressure index as a predictor of mortality in hemodialysis patients

The ankle-arm blood pressure index (AAI, ratio of ankle to arm systolic blood pressure), a simple, noninvasive, and inexpensive screening test, has recently been found to be highly predictive of subsequent mortality in several populations. The purpose of this study was to evaluate the relationship of the AAI to cardiovascular and all-cause mortality in hemodialysis patients. A cohort of 132 patients was followed for 1 year. The primary outcome measures were cardiovascular and all-cause mortality. An AAI of <0.9 was associated with a relative risk (RR) of cardiovascular mortality of 7.5, (95% CI, 2.3 to 24.8). Other predictive variables included diabetes mellitus RR 3.0, (95% CI, 1.2 to 7.3), and a history of any vascular disease RR 2.6 (95% CI, 1.0 to 7.0). An AAI of <0.9 was also predictive of all-cause mortality, RR 2.4 (95% CI, 1.2 to 4.7). Other predictive variables for all-cause mortality included older age, RR 1.4 per 10 years (95% CI, 1.0 to 2.1), decreased serum albumin RR 0.9 per 0.1 mg/dL (95% CI, 0.8 to 1.0), and diabetes mellitus RR 2.0 (95% CI, 1.0 to 3.7). Multivariate analysis showed an AAI of <0.9 and diabetes mellitus to be the only independent predictors of cardiovascular mortality, and an AAI of <0.9, older age, and a decreased serum albumin were independent predictors of all-cause mortality. In conclusion, we have found an AAI of <0.9 to be a powerful, independent predictor of mortality in hemodialysis patients.