High Ankle-brachial Pressure Index Research Articles

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

BackgroundOnly 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). MethodsWe 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. ResultsWe 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. ConclusionsA 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.

High ankle brachial index predicts high risk of cardiovascular events amongst people with peripheral artery disease.

Ankle-brachial pressure index (ABPI) is commonly measured in people referred to vascular specialists. This study aimed to assess the association of high ABPI (≥ 1.4) with cardiovascular events in people with peripheral artery disease (PAD). 1533 participants with PAD diagnosed by a vascular specialist were prospectively recruited from four out-patient clinics in Australia. ABPI was measured at recruitment and the occurrence of myocardial infarction (MI), stroke or cardiovascular death (major cardiovascular events; MACE) and any amputation were recorded over a median (inter-quartile range) follow-up of 3.3 (1.0–7.1) years. The association of high, compared to normal, low (0.5–0.9) or very low (<0.5), ABPI with clinical events was estimated using Cox proportional hazard analyses, adjusting for traditional risk factors and reported as hazard ratio with 95% confidence intervals. 596 (38.9%), 676 (44.1%), 157 (10.2%) and 104 (6.8%) participants had normal, low, very low and high ABPI, respectively. Participants with high ABPI had increased risk of MACE, MI and death by comparison to those with either normal ABPI [1.69 (1.07, 2.65), 1.93 (1.07, 3.46) and 1.67 (1.09, 2.56)] or either low or very low ABPI [1.51 (1.02, 2.23), 1.92 (1.16, 3.19) and 1.47 (1.02, 2.14)] after adjusting for other risk factors. Findings were similar in a sensitivity analysis excluding people with ABPI only measured in one leg (n = 120). Participants with high ABPI also had an increased risk of MACE and MI compared to those with very low ABPI alone. High ABPI is a strong indicator of excess risk of cardiovascular events amongst people with PAD.

Oxidative stress and inflammation associated with decreased fibrinolysis as an early marker for peripheral vascular disease stratification: A clinical study

Abstract Background Peripheral vascular disease may manifest as either arterial stenosis or calcification of the arterial wall. Arterial stenosis is characterized by a lowered ankle-brachial-pressure index (ABPI), whereas calcified arteries lead to an increased ABPI. The current study investigates whether inflammatory and oxidative stress markers differ in low versus high ABPI groups suggesting different biochemical processes. Methods Eighty-seven patients attending the diabetes complications clinic agreed to the study. Participants were divided into a low ( 1.23) ABPI tertile groups and compared for traditional and emerging biomarker differences. A clinical history and demographic data were obtained. Emerging biomarkers included C-reactive protein, interleukin-6, 8-hydroxy deoxy-guanosine, D-dimer, reduced glutathione and malondialdehyde. Data was analyzed using a Student T-test with significance set at 0.05. A multivariate normal linear regression model was applied to determine the contributions of traditional and emerging biomarkers to the classification of low and high ABPI. Results No differences were observed between the two groups for the traditional biomarkers but D-dimer (p Discussion A decreased inflammatory component with increased oxidative stress is more likely to lead to calcification of the arteries and a higher ABPI, despite normal BGL, HbA1c and cholesterol profile. Our study shows that emerging biomarkers provide a sound basis for differentiating pathophysiological processes associated with low and high ABPI. Traditional biomarkers showed a high accuracy for identification of low ABPI in our model but failed to do better than chance for identification of high ABPI, suggesting different pathophysiological pathways that include oxidative stress and inflammatory components. Clinically, validation of novel and more comprehensive risk factors for PVD sheds light on the etiology of the disease and mechanics of progression toward better preventative care, early detection and targeted drug delivery.

Complex nonlinear autonomic nervous system modulation link cardiac autonomic neuropathy and peripheral vascular disease.

Physiological interactions are abundant within, and between, body systems. These interactions may evolve into discrete states during pathophysiological processes resulting from common mechanisms. An association between arterial stenosis, identified by low ankle-brachial pressure index (ABPI) and cardiovascular disease (CVD) as been reported. Whether an association between vascular calcification-characterized by high ABPI and a different pathophysiology-is similarly associated with CVD, has not been established. The current study aims to investigate the association between ABPI, and cardiac rhythm, as an indicator of cardiovascular health and functionality, utilizing heart rate variability (HRV). Two hundred and thirty six patients underwent ABPI assessment. Standard time and frequency domain, and non-linear HRV measures were determined from 5-min electrocardiogram. ABPI data were divided into normal (n = 101), low (n = 67) and high (n = 66) and compared to HRV measures.(DFAα1 and SampEn were significantly different between the low ABPI, high ABPI and control groups (p < 0.05). A possible coupling between arterial stenosis and vascular calcification with decreased and increased HRV respectively was observed. Our results suggest a model for interpreting the relationship between vascular pathophysiology and cardiac rhythm. The cardiovascular system may be viewed as a complex system comprising a number of interacting subsystems. These cardiac and vascular subsystems/networks may be coupled and undergo transitions in response to internal or external perturbations. From a clinical perspective, the significantly increased sample entropy compared to the normal ABPI group and the decreased and increased complex correlation properties measured by DFA for the low and high ABPI groups respectively, may be useful indicators that a more holistic treatment approach in line with this more complex clinical picture is required.

Beyond the Ankle-Brachial Pressure Index for the Diagnosis of Peripheral Arterial Disease—Time for A New Look at Photoplethysmography

Peripheral arterial disease (PAD) is common, affecting about 20% of people over 60 years. The PAD confers a high cardiovascular risk and there is a need for an easy test to confirm its presence in the primary care so that appropriate specialist referral can be made. For many years, the ankle-brachial pressure index (ABPI) has been available as a first-line quantitative assessment of PAD. However, it has been unpopular due to concerns about its repeatability in a nonspecialist setting. In this issue, Ro et al describe a comparison continuous wave (CW) Doppler ultrasound with ABPI and photoplethysmography (PPG) in the detection of stenotic peripheral disease. They show that the sensitivity of ABPI is poor particularly in diagnosing the disease in the tibial segment and that an improvement in sensitivity is gained by performing CW Doppler together with ABPI and PPG. The ABPI has previously been shown to have good sensitivity and specificity compared to angiographic imaging. It is also readily available in the community in primary care with lowcost equipment. However, 2 important factors affect the quality of ABPI results. The first is the presence of calcified vessels seen in patients with diabetes, renal disease, and some elderly patients. This leads to underestimation of arterial disease through falsely high readings, as the calcified vessels are relatively incompressible. This can usually be recognized by a high ABPI score of >1.3. The second factor is the need to perform the test to a high standard using a clear protocol. Often, the failure to get reliable results has been due to poor training and performance of the test by relatively inexperienced health care professionals in primary care. The PPG is a low-cost, quick, and simple to do optical technique, but it is however seldom used in routine clinical assessments, largely because of a lack of normal reference ranges, uncertainties due to beat-to-beat variability in pulse characteristics and poorly applied quantitative analysis leading to subjective waveform interpretation. Allen and coworkers have employed systematic pulse wave analysis techniques to show that PPG at the great toe site has good sensitivity and specificity for PAD when compared to the ABPI reference. They provided evidence that normalized pulse shape and its deformity with disease ranks high as an accurate marker for the disease, followed closely second by exploiting bilateral timing differences between the toes. To achieve such confidence in the diagnostic performance of PPG for PAD detection, it has been established that beat-to-beat averaging of the pulse features was essential. Before other techniques for quantifying PAD are introduced there needs to be consideration of the sensitivity and specificity of the technique, ease of use, and the cost and training required to achieve reliable results. The question of training community carers is particularly pertinent, where the technique relies on interpreting waveform shapes rather than performing a protocol that gives a set of numbers that can be recorded. This would be the case with Doppler waveform and PPG techniques as described by Ro et al. Unless there is a very clear-cut distinction between significant and nonsignificant disease, the reliability and reproducibility are likely to be poor. In the case of Doppler waveform analysis, the cost, portability of equipment, and time taken to perform the measurements probably make this modality more suited to a referral center where a full duplex ultrasound can be performed giving both anatomical and hemodynamic information. The key factor in any screening technique is that all disease that warrants further assessment is picked up while recognizing those who clearly do not have significant disease, to avoid unnecessary referral. This implies a test with reasonable sensitivity and high specificity, so that those who definitely do not have disease are not referred unnecessarily. When performed outside a specialist center, it also implies a test that can be reliably performed by a range

CONTRIBUTION OF TRANSCUTANEOUS OXYMETRY IN DIABETIC FOOT SYNDROME

Four major complications are participating in tissue damage in diabetic foot syndrome – diabetic angiopathy, neuropathy, osteoarthropathy and inflammation. Low ankle-brachial pressure index (ABI) is a well-known indicator for ischemia of lower limbs, but in patients with diabetes mellitus is common also a high ABI (over 1.3) as reliable predictor of the presence of arterial calcification – medial calcinosis. Aim of the study is to determine the degree of ischemia using transcutaneous oximetry in patients with diabetic foot syndrome - with clinical manifestations of peripheral arterial occlusive disease (PAOD) and medial calcinosis. We investigated three groups: first consisted of 46 members in IInd stage of PAOD according to Fontaine classification, in second group were 30 members in IIIrd stage of PAOD and third had 29 members in IVth stage of PAOD. The ABI was determined with Doppler ultrasound examination. Transcutaneous oxygen tension (TcPO2) was measured with Oxykapnomonitor Hellige SMK Germany equipment with sensing probe – transoxode. Resting values of TcPO2 were obtained in lying patient on the foot in first metatarsal space. Subsequently leg was passively elevated into 30 degree angle for 3 minutes and then reimposed into primary position. One minute exercise – plantar and dorsal feet flexion was performed and after the TcPO2 values stabilization the patient hung his shin from the edge of the bed touching the floor. TcPO2 values were continuously recorded by analog waveform. In more severe stages of PAOD according to Fontaine stage III and IV we detected lower levels of TcPO2 under basal resting conditions: 20 respectively 5 mmHg. Patients with IInd stage of PAOD had basal TcPO2 values of 40 mmHg. Conclusions of the study are: TcPO2 values are not affected by the presence of medial calcinosis and sothis method is particularly beneficial in patients where Doppler ultrasound examination shows artificial high pressure values on lower limbs. In the third and fourth stage of PAOD passive leg elevation is as effective in determination of ischemia as working test.

Abstract 271: Lack Of Prognostic Value Of High Ankle Brachial Pressure Index (ABI) In Patients With Advanced Heart Failure

Introduction: Ankle brachial pressure index (ABI) is a noninvasive test to diagnose peripheral arterial disease (PAD). Abnormally high ABI has been associated with increased LV mass and mortality in patients free of cardiovascular disease, while low ABI is often indicative of PAD that portends poor prognosis. But the prognostic significance of high ABI in advanced heart failure patients has not been studied. Methods: We reviewed 342 consecutive patients with advanced heart failure who underwent transplant evaluation between 2007 and 2011. Patients with history of PAD or ABI &lt; 0.9 on either side were excluded. ABI values on both sides were added to create total ABI. Based on this total ABI, patients were divided into tertiles. Survival (death or heart transplant) analysis was assessed by Kaplan-Meier curves in different tertiles. Results: Mean total ABI was 2.29 ± 0.39. Mortality/transplant rates were 52.4%, 43.2% and 50.4% in increasing ABI tertiles. Kaplan-Meier survival analysis did not show any statistically significant prognostic importance (log rank, p = 0.39, Figure.1). Similar results were obtained when patients with ischemic (p = 0.094) and non-ischemic cardiomyopathy (p =0.899) were analyzed separately. ABI was not an independent predictor of mortality in Cox regression analysis (HR 0.95, 95% CI 0.66, 1.36). Conclusion: Higher tertiles of ABI were not associated with poor prognosis in patients with stage D heart failure. This remained true for both ischemic and non-ischemic cardiomyopathy.

Non-linear association between ankle-brachial pressure index and prevalence of silent cerebral infarction in Japanese patients with type 2 diabetes

ObjectivePatients with peripheral artery disease (PAD), defined as having low ankle-brachial pressure index (ABI), have increased risk for incident stroke compared with those without PAD. We aimed to reveal whether ABI abnormality, especially high ABI is associated with prevalent silent cerebral infarction (SCI) in type 2 diabetic patients. MethodsWe studied 538 Japanese type 2 diabetic patients, 227 women and 311 men, with a mean [±SD] age of 64±11 years. All patients underwent cranial magnetic resonance imaging (MRI). Values of ABI were classified as low (<0.9), normal (0.9≤ and <1.3), and high (1.3≤). Logistic regression model was used to calculate odds ratio and 95% confidence interval (95% CI) for prevalent SCI. ResultsThe mean ABI among the overall 538 patients was 1.09±0.16. Low and high ABI values were found in 52 (9.7%) and 33 (6.1%) patients, respectively. SCI was detected in 297 (55.2%) patients. The prevalence in patients with low, normal, and high ABI values were 88.5%, 49.7%, and 78.8 (p<0.001), respectively. In the multivariate logistic regression analysis, both patients with high and low ABI were significantly increased risk of prevalent SCI (odds ratio 4.53, 95% CI 1.67–12.34, p=0.003 and odds ratio 3.50, 95% CI 1.50–10.29, p=0.005), independently of other traditional cardiovascular risk factors, than those with normal ABI. ConclusionsBoth high and low ABI may be strongly associated with prevalent SCI in Japanese patients with type 2 diabetes.

Prognostic value of low and high ankle-brachial index in hospitalized medical patients

BackgroundPeripheral arterial disease (PAD) is frequently underdiagnosed in the clinical practice, leading to a lack of opportunity to detect subjects at a high risk for cardiovascular (CV) death. The ankle-brachial pressure index (ABI) represents a noninvasive, objective tool to diagnose PAD and to predict adverse outcome. MethodsABI was determined by means of Doppler velocimetry, in 707 patients, aged 50years or older, consecutively hospitalized in an internal medicine ward, who were followed-up for at least 12months in order to assess all-cause and CV mortality. ResultsSymptomatic PAD affected 8% of the population while the prevalence of PAD, defined as ABI <0.90, was 29%; high ABI (>1.40) was found in 8% of the patients. After a mean follow-up period of 1.6years, both low and high ABI were independently associated with CV mortality with a hazard ratio of 1.99 (p=0.016) for low and 2.13 (p=0.04) for high ABI, compared with normal ABI (0.90–1.40). High ABI also independently predicted all-cause mortality with a hazard ratio of 1.77 (p=0.04). DiscussionABI measurement reveals a large number of individuals with asymptomatic PAD among those hospitalized in an internal medicine department. An increased mortality was observed in patients with both low and high ABI. Hospital admission for any reason may serve as an opportunity to detect PAD and start appropriate preventive actions.

Relation of Serum Phosphorus Levels to Ankle Brachial Pressure Index (from the Third National Health and Nutrition Examination Survey)

Higher levels of serum phosphorus that remain within the reference range are associated with increased risk of cardiovascular disease (CVD). However, the mechanisms by which higher serum phosphorus concentrations may contribute to the development of CVD remain unclear. Cross-sectional association between serum phosphorus levels and arterial stiffness as estimated by an ankle brachial pressure index (ABPI) >1.3 was examined in 581 participants in the Third National Health and Nutrition Examination Survey. Logistic regression analysis was performed to evaluate whether higher serum phosphorus levels were associated with high ABPI, independently of several potential confounders. Of 581 participants, 38% and 10% had a serum phosphorus levels >3.5 and >4.0 mg/dl, respectively. An ABPI >1.3 was present in 7.3% of participants. Higher quartiles of serum phosphorus levels were associated with a greater prevalence of high ABPI: 5.4%, 3.7%, 7.8%, and 12.9% for quartiles 1 (<3.1 mg/dl), 2 (3.1 to 3.4 mg/dl), 3 (3.4 to 3.7 mg/dl), and 4 (3.7 to 5.0 mg/dl), respectively. There was a strong, positive association between the highest quartile of serum phosphorus (3.7 to 5.0 mg/dl) and high ABPI compared to the reference group (3.1 to 3.4 mg/dl) after adjustment for demographics, traditional CVD risk factors, kidney function, C-reactive protein, serum calcium, and 25-hydroxyvitamin D levels (adjusted odds ratio 4.78, 95% confidence interval 1.73 to 13.2, p = 0.003). In conclusion, serum phosphorus levels, even within the reference range, are independently associated with high ABPI, a marker of arterial stiffness, in the US adult population.

Distribution of the Ankle-Brachial Index and Associated Cardiovascular Risk Factors in a Population of Middle-Aged and Elderly Koreans

The Doppler ankle-brachial pressure index (ABI) is an objective and efficient tool that can be used to determine the presence and severity of peripheral arterial disease in the lower extremities. The ABI value is inversely associated with other cardiovascular risk factors. To date, there have been no studies of the distribution of ABI in Korea. We performed a cross-sectional study of 1,943 subjects (681 men and 1,262 women; 45-74 yr old) in Namwon, Korea. The prevalence of a low ABI (<0.90) was 2.2% in men and 1.8% in women, and a high ABI (≥1.30) was prevalent in 3.1% of men and 0.8% of women. Age, smoking habits, waist circumference, hypertension, and blood pressure were associated with ABI values in both sexes. The presence of carotid plaques was associated with ABI values only in men, whereas pulse pressure was associated with ABI values only in women (p<0.05). Although the prevalence of a low ABI in the present study was lower than those reported previously for Western populations and Japanese men, our results suggest that the ABI might be used as an indicator of cardiovascular risk factors in adult Koreans.