Diagnostic Value of Ankle-Brachial Index in Peripheral Arterial Disease: A Meta-analysis

Background

In a previous review, we reported that ankle brachial index (ABI) ≤ 0.90 could reliably identify patients with peripheral artery disease (PAD). Since then, more studies have been published which may extend the power of a meta-analysis of studies of diagnostic accuracy of the ABI. MEDLINE and several other databases were searched for studies on sensitivity and specificity of using ABI ≤ 0.90 for PAD diagnosis compared with angiography.

Methods

Quality of each study was assessed by standards for reporting diagnostic accuracy initiative and quality assessment for studies of diagnostic accuracy tool. Heterogeneity was assessed using the Cochran Q statistic, χ², and inconsistency index. The area under the curve and Q* were estimated using summary receiver operator curve. The pooled diagnostic odds ratio (DOR), sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of ABI ≤ 0.90 to diagnose PAD were estimated using Meta-DiSc software (Meta-DiSc, Madrid, Spain).

Results

Four studies comprising 569 patients (922 limbs) met inclusion criteria. Significant heterogeneity among these studies was not detected in DOR but was evident in pooled sensitivity, specificity, PLR, and NLR. The area under the curve under the summary receiver operator curve is 0.87 (standard error = 0.02) and diagnostic accuracy (Q*) is 0.80 (standard error = 0.02). Additionally, DOR was 15.33 with corresponding 95% confidence intervals of 9.39-25.02. The pooled sensitivity and specificity of ABI ≤ 0.90 for PAD diagnosis were 75% and 86% and the pooled PLR and NLR were 4.18 and 0.29, respectively.

Conclusions

We conclude that test of ABI ≤ 0.90 can be a useful tool to identify PAD with serious stenosis in clinical practice.     

Diagnostic utility of the two methods of ankle brachial index in the detection of peripheral arterial disease of lower extremities.

BACKGROUND: Peripheral arterial disease (PAD) is a common disease that is diagnosed with a screening test called the Ankle Brachial Index (ABI). Different methods of ABI have been described in the literature. We wanted to estimate and compare the sensitivity and specificity of an alternative method of calculating the ABI (LAP ABI, low ankle pressure ABI) with the current method (named high ankle pressure (HAP)), using digital subtraction angiography (DSA) as the gold standard. METHODS: We reviewed the records of all patients who had undergone DSA at a major academic center between August 2003 and October 2005.The study includes 107 patients/208 limbs. Inclusion criteria included patients with an ABI performed within 30 days prior to the DSA. Patients with non-compressible vessels and ABI >1.40 were excluded. Abnormal ABI was defined as < or = 0.9 for both methods. Disease on angiogram was defined as the presence of 50% or more stenosis of any lower extremity artery from the aorto-iliac bifurcation to the ankle arteries. RESULTS: The sensitivity of the HAP and LAP ABI for the diagnosis of PAD was 69 and 84%, respectively (P < 0.001). The specificity of the HAP and the LAP method was 83 and 64% respectively (P < 0.01). The overall accuracy of LAP ABI and HAP ABI was 80 and 72%, respectively. CONCLUSIONS: The LAP ABI has better sensitivity and overall accuracy in comparison to the HAP ABI to diagnose PAD.     

Sensitivity and specificity of ankle-brachial index for detecting angiographic stenosis of peripheral arteries.

BACKGROUND: The aim of the present study was to prospectively evaluate the sensitivity, specificity, positive and negative likelihood ratios (LR+, LR-) of the ankle - brachial index (ABI), using conventional digital subtraction angiography (DSA) as the reference standard, in the assessment of lower extremity arteries, and to research the threshold value of the ABI in diagnosing periphery arterial disease (PAD), as well as the relationship between the ABI value and stenosis in the artery of the lower extremity in Chinese high-risk cardiovascular patients. METHODS AND RESULTS: A total of 298 consecutive patients (199 men, 99 women, 64.9+/-11.3 years old) underwent conventional DSA and ABI measurement. Receiver operator characteristics (ROC) analysis was performed to assess possible threshold values that predict PAD in these patients. The greater the stenosis in the artery of the lower extremity, the lower the measured ABI value. DSA was used as the gold standard in defining lesions >or=30%, >or=50%, and >or=70% and the respective areas under the ROC curve were 0.786 (95% confidence interval (CI) 0.712, 0.860), 0.927 (95% CI 0.869, 0.984), and 0.963 (95% CI 0.927, 0.999). Conventional DSA was the gold standard in defining >or=50% luminal stenosis for the diagnosis of lower extremity PAD. The 0.95 is the overall cutoff of the ABI that was associated with 91% sensitivity, 86% specificity, 6.5 LR+ and 0.1 LR- for detection of hemodynamically significant stenosis (lesions >or=50%) in all 298 subjects (p<0.001). CONCLUSION: The ABI value shows a decreasing tendency with increasing severity of stenosis in patients with PAD. ABI measurement is an accurate and reliable noninvasive alternative to conventional DSA in the assessment of lower extremity arteries and the cut-off of 0.95 is the threshold ABI value for detecting PAD in Chinese patients.     

The accuracy of the physical examination for the detection of lower extremity peripheral arterial disease

BACKGROUND:

Peripheral arterial disease (PAD) is a major risk factor for adverse cardiovascular events. There has been a definite push for wider use of the ankle-brachial index (ABI) as a simple screening tool for PAD. Perhaps this has occurred to the detriment of a thorough physical examination.

OBJECTIVE:

To assess the accuracy of the physical examination to detect clinically significant PAD compared with the ABI.

METHODS:

PADfile, the PAD module of CARDIOfile (the Kingston Heart Clinic’s cardiology database [Kingston, Ontario]), was searched for all patients who underwent peripheral arterial testing. Of 1619 patients, 1236 had all of the necessary data entered. Patients’ lower limbs were divided into two groups: those with a normal ABI between 0.91 and 1.30, and those with an abnormal ABI of 0.90 or lower. Peripheral pulses were graded as either absent or present. Absent was graded as 0/3, present but reduced (1/3), normal (2/3) or bounding (3/3). Femoral bruits were graded as either present (1) or absent (0). Using the ABI as the gold standard, the sensitivity, specificity, negative predictive value (NPV), positive predictive value and overall accuracy were calculated for the dorsalis pedis pulse, the posterior tibial pulse, both pedal pulses, the presence or absence of a femoral bruit and, finally, for a combination of both pedal pulses and the presence or absence of a femoral bruit.

RESULTS:

In 1236 patients who underwent PAD testing and who underwent a complete peripheral vascular physical examination (all dorsalis pedis and posterior tibial pulses palpated and auscultation for a femoral bruit), the sensitivity, specificity, NPV, positive predictive value and accuracy for PAD were 58.2%, 98.3%, 94.9%, 81.1% and 93.8%, respectively.

CONCLUSIONS:

The clinical examination of the peripheral arterial foot pulses and the auscultation for a femoral bruit had a high degree of accuracy (93.8%) for the detection or exclusion of PAD compared with the ABI using the cut-off of 0.90 or lower. If both peripheral foot pulses are present in both lower limbs and there are no femoral bruits, the specificity and NPV of 98.3% and 94.9%, respectively, make the measurement of the ABI seem redundant. The emphasis in PAD detection should be redirected toward encouraging a thorough physical examination.     

Limitation of the resting ankle-brachial index in symptomatic patients with peripheral arterial disease

Peripheral arterial disease (PAD) has been demonstrated to be prevalent in the primary care setting. However, it has also been shown to be unrecognized and under-treated. Owing to the association with cardiovascular disease it has been recommended to screen high-risk patients for PAD in the primary care setting using the ankle-brachial index (ABI). ABI has been demonstrated to be highly sensitive and specific in diagnosing PAD in patients with significant stenosis. However, the utility in patients with less severe stenosis and calcified vessels is in question. The aims of this study were to determine the diagnostic utility of measuring the ABI at rest in patients referred to the vascular laboratory for evaluation of suspected PAD, and to assess the added value of pulse volume recordings and post-exercise studies in patients with a normal ABI. A computerized vascular diagnostic laboratory database was queried for symptomatic outpatients referred for measurement of segmental blood pressure, the ABI or pulse volume recordings by physicians not specialized in the evaluation and management of patients with peripheral vascular disease. Of 707 patients undergoing outpatient physiologic arterial evaluations between February 1, 2003 and July 31, 2004, 396 met these inclusion criteria. Data recorded included resting ABI, ABI following treadmill exercise test and the presence of abnormal pulse volume recordings. The study population (n = 396) consisted of equal numbers of men and women (mean age 69 years, range 19-100 years). Among 396 studies, resting ABI values were normal in 183 (46.2%) and abnormal in 159 (40.2%). Of the 138 patients who underwent exercise testing, 84 had normal ABI readings at rest. In the 84 patients who had a normal ABI at rest and underwent exercise testing, the ABI fell below 0.9 after exercise in 26 (31%). Arterial non-compressibility was detected in 54 (13.6%) patients, whose average age was 67 years. Thirteen (24%) of those with non-compressible vessels had abnormal pulse volume recording (PVR) results, compared to five with normal resting ABI who had abnormal PVR findings (2.7%). In conclusion, this study demonstrated that nearly half of patients referred to the outpatient vascular laboratory because of suspected arterial disease had a normal resting ABI. While it is recommended that the ABI be measured at rest in patients at risk of PAD in primary care practice, these findings suggest that patients with symptoms of PAD should be more completely evaluated in a vascular laboratory. Furthermore, when the ABI is normal at rest in patients with symptoms of intermittent claudication, exercise testing is recommended to enhance the sensitivity for detection of PAD.     

Classic intermittent claudication is an uncommon manifestation of lower extremity peripheral arterial disease in hospitalized patients with coronary artery disease

Synchronous peripheral arterial disease (PAD) and coronary artery disease (CAD) is common. Standardized questionnaires such as the Rose/WHO questionnaire and later the Edinburgh modification of this questionnaire were developed to screen for PAD. Little data are available on the sensitivity of these questionnaires in hospitalized patients with CAD. The aim of this study was to determine the accuracy of these questionnaires and the prevalence of classic intermittent claudication in hospitalized patients with CAD. Medically stable patients with CAD were invited to participate before hospital discharge. The patients answered both the Rose/WHO and Edinburgh modification claudication questionnaires and had an ankle-brachial index (ABI) measured. An ABI less than or equal to 0.9 was considered to be indicative of significant PAD. Patients who had undergone previous lower extremity revascularization for PAD and had a corrected ABI greater than 0.9 were excluded. Ninety-five patients (66 men) were recruited. By measuring the ABI, 35 patients (25 men) were found to have significant PAD. An additional 3 patients who had an ABI corrected by lower extremity revascularization were excluded from the analysis. The Rose/WHO questionnaire had a sensitivity, specificity, and overall accuracy (95% CI) of 14.3% (2.7-25.9%), 96.7% (92.1-100%), and 66.3% (56.8-75.8%), respectively. The Edinburgh modification of the Rose/WHO questionnaire had a sensitivity, specificity, and overall accuracy (95% CI) of 28.6% (13.6-43.5%), 90.0% (82.4-97.6%), 67.4% (57.9-76.8%), respectively. Despite the high incidence of synchronous PAD in hospitalized patients with CAD, traditional claudication questionnaires are insensitive to PAD detection. Classic claudication is an uncommon manifestation of PAD in hospitalized patients with CAD.     

Frailty across the spectrum of ankle-brachial index

We investigated the burden of frailty across the spectrum of ankle-brachial index (ABI < 0.9, 0.9 ≤ ABI < 1.1, 1.1 ≤ ABI < 1.4 and ≥1.4) using data from the National Health and Nutritional Examination Survey (NHANES) in respondents aged >50 years. Criteria used to identify frailty status included weight loss, slow walking speed, weakness, exhaustion, and low physical activity. Participants meeting 1 to 2 criteria were classified as prefrail, and those meeting ≥3 criteria were classified as frail. Prevalence of frailty in respondents with ABI < 0.9 (17.5%) and 0.9 ≤ ABI < 1.1 (6.7%) was higher than in participants with normal ABI-1.1 ≤ ABI < 1.4 (4.7%). In multivariable multinomial logistic regression models, ABI < 0.9 predicted frailty (odds ratio [OR] = 2.31, 95% confidence interval [CI] = 1.08-4.94) and prefrailty (OR = 1.36, 95% CI = 0.90-2.07). Higher prevalence of frailty was seen in participants with ABI ≥ 1.4 (7.3%), P = .39. Frailty predicted general and cardiovascular mortality in participants with ABI < 0.9. Frailty mediates increased morbidity and mortality seen in peripheral arterial disease (PAD).     

Diagnostic accuracy of adenosine deaminase in tuberculous pleurisy: a meta-analysis

BACKGROUND: Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of adenosine deaminase (ADA) in pleural fluid for the early diagnosis of tuberculous pleurisy. We conducted a meta-analysis to determine the accuracy of ADA measurements in the diagnosis of tuberculous pleurisy. METHODS: After a systematic review of English language studies, sensitivity, specificity, and other measures of accuracy of ADA concentration in the diagnosis of pleural effusion were pooled using random effects models. Summary receiver operating characteristic curves were used to summarize overall test performance. RESULTS: Sixty-three studies met our inclusion criteria. The summary estimates for ADA in the diagnosis of tuberculous pleurisy in the studies included were sensitivity 0.92 (95% confidence interval 0.90-0.93), specificity 0.90 (95% confidence interval 0.89-0.91), positive likelihood ratio 9.03 (95% confidence interval 7.19-11.35), negative likelihood ratio 0.10 (95% confidence interval 0.07-0.14), and diagnostic odds ratio 110.08 (95% confidence interval 69.96-173.20). CONCLUSIONS: ADA determination is a relative sensitive and specific test for the diagnosis of tuberculous pleurisy. Measurement of ADA in pleural effusion is thus likely to be a useful diagnostic tool for tuberculous pleurisy. The results of ADA assays should be interpreted in parallel with clinical findings and the results of conventional tests.     

Performance of systolic pressure index for lower limb peripheral arterial disease in a group of elderly in sub-Saharan Africa

BackgroundThe automatic measurement of the ankle-brachial index (ABI) constitutes a reliable, simple, safe, rapid, and inexpensive alternative diagnostic screening test compared with the Doppler method for peripheral arterial disease (PAD). We aimed to compare the diagnostic performance of automatic ABI measurement tests to Doppler ultrasound for PAD in a group of patients aged 65 years and above, in Sub-Saharan Africa.MethodsThis was an experimental comparative study of the performance of Doppler ultrasound to the automated ABI test in the diagnosis of PAD in patients aged ≥ 65 years followed-up at the Yaoundé Central Hospital, Cameroon between January to June 2018. An ABI threshold < 0.90 is defined as a PAD. We compare the sensitivity, and specificity of the high ankle-brachial index (ABI-HIGH), low ankle-brachial index (ABI-LOW), and the mean ankle-brachial index (ABI-MEAN) for both tests.ResultsWe included 137 subjects with an average age of 71.7 ± 6.8 years. In the ABI-HIGH mode, the automatic device had a sensitivity of 55% and a specificity of 98.35% with a difference between the two techniques of d = 0.024 (p = 0.016). In the ABI-MEAN mode, it had a sensitivity of 40.63% and a specificity of 99.15%; d = 0.071 (p < 0.0001). In the ABI-LOW mode, it had a sensitivity of 30.95% and a specificity of 99.11%; d = 0.119 (p < 0.0001).ConclusionThe Automatic measurement of systolic pressure index has a better diagnostic performance in the detection of Peripheral Arterial Disease compared to the reference method by continuous Doppler in sub-Saharan African subjects aged ≥ 65 years.     

Thigh and buttock exertional pain for the diagnosis of peripheral arterial disease

ObjectivesTo evaluate the prevalence of both non-calf intermittent claudication (IC) and classic IC in patients with no known atherosclerotic disease, and their accuracy to detect peripheral arterial disease (PAD).DesignCross sectional, observational study conducted at 96 internal medicine services.Materials and methods1487 outpatients with no known atherosclerotic disease, and either diabetes or a SCORE risk estimation of at least 3% were enrolled. IC was assessed using the Edinburgh Claudication Questionnaire and PAD was confirmed by an ankle-brachial index (ABI) < 0.9.ResultsOverall, 7.2% met criteria of classic and 5.8% of non-calf IC. PAD was diagnosed in 393 cases (26.4%). In these PAD patients, 17.8% exhibited classic and 13.2% non-calf IC. Both calf and non-calf IC had similar overall accuracy for detecting PAD. Considering both categories as a whole, the sensitivity of IC to predict a low ABI was 31% and the specificity 93%.ConclusionsNon-calf IC is comparable to classic IC for the diagnosis of PAD in patients with no known arterial disease. The systematic implementation of Edinburgh Claudication Questionnaire could be a valuable call-to-action to improve clinical evaluation of PAD, bearing in mind that PAD detected by either non-calf or classic IC must be confirmed by ABI testing.     

Validation of a new method of detecting peripheral artery disease by determination of ankle-brachial index using an automatic blood pressure device

Peripheral artery disease (PAD) is a predictor of total and cardiovascular mortality; its most valuable simple index is the ankle-brachial index (ABI). The present study was designed to assess whether a commercially available automatic device could be used to determine ABI in comparison with the classical Doppler method. The ABI was defined as the ratio of systolic blood pressure at each ankle to the maximal brachial systolic pressure, a pathological index being defined for a ratio <0.90. The ABI were calculated in 219 consecutive patients (aged 55 +/-19 years) with systolic blood pressure measured either by using a mercury sphygmo-manometer and a continuous-wave Doppler probe or an automatic manometer Omron M4. This device has been validated for measurements in upper limbs, and so the authors undertook validation in the lower limbs versus intraarterial measurements. There was an excellent correlation between intraarterial measurements and automatic readings in the range of 70-220 mm Hg, r=0.99, p<0.001. The systolic pressures measured in upper limbs correlated well in the right (r=0.87, p<0.001) and the left (r=0.89, p<0.001) upper limbs; and in the left (r=0.72, p<0.001) and the right (r=0.68, p<0.001) lower limbs. Correlations between ABI in both methods were good in the left (r=0.66, p<0.001) and the right (r=0.61, p<0.001) lower limbs. The sensitivity (76%), specificity (95%), positive predictive value (86%), negative predictive value (90%), and global accuracy (89%) of a pathological automatic index to predict an abnormal Doppler index were good. The use of a simple, automatic blood pressure device to determine ABI appears feasible, easy, and precise. It would provide a practical tool for physicians not trained in Doppler to detect PAD.     

踝臂指数与老老年患者冠状动脉狭窄程度的相关性研究

目的探讨老老年冠心病患者踝臂指数(ABI)与冠状动脉狭窄严重程度的相关性,评价ABI对冠状动脉狭窄严重程度的预测价值。方法连续入选78例冠状动脉造影的老老年患者(年龄≥80岁)进行研究,根据冠状动脉造影结果分为无病变者(8例)、单支病变患者(10例)、2支病变患者(14例)、3支或左主干病变患者(46例)。对所有患者进行ABI测量、病史采集及血液生化检测。结果 ABI与Gensini评分呈负相关;冠状动脉3支或左主干病变患者ABI显著降低,差异有统计学意义(P0.001),而无病变、单支病变、2支病变患者ABI差异无统计学意义;ABI对3支或左主干病变预测价值的ROC曲线下面积为(0.79±0.04,95% CI:0.69～0.85,P0.001);ABI≤0.9作为截断值预测3支或左主干病变具有较高的特异性(89.5%)和敏感性(53.6%)。结论老老年冠心病患者ABI与冠状动脉狭窄严重程度呈负相关,ARI≤0.9对预测冠状动脉3支和左主干病变具有较高的特异性和敏感性。     

踝臂指数评价缺血性脑卒中患者脑动脉狭窄程度的临床研究

目的评价踝臂指数(ABI)对脑动脉狭窄程度的预测价值,探讨ABI与缺血性脑卒中的关系。方法选择缺血性脑卒中患者200例,采用多普勒超声检测仪对每例患者行ABI测量,同时进行脑血管造影检查。根据北美症状性颈动脉内膜切除试验NASCET分级法将患者分为正常组(40例)、轻度狭窄组(51例)、中度狭窄组(44例)和重度狭窄组(65例),比较每组ABI值,并分析脑动脉狭窄程度与ABI的相关性,计算不同的ABI截断值对缺血性脑卒中患者发生重度脑动脉狭窄的预测作用。结果 200例缺血性脑卒中患者ABI异常率34.5%。与重度狭窄组比较,正常组、轻度狭窄组、中度狭窄组ABI明显升高(P<0.05)。ABI异常是重度颅内动脉狭窄的独立预测因素;ABI≤0.9作为截断值预测缺血性脑卒中脑动脉重度狭窄具有较好的敏感性(83.6%)和特异性(71.5%);颈内动脉、大脑中动脉狭窄程度与ABI呈负相关。结论 ABI≤0.9对脑动脉重度狭窄有较好的预测作用。ABI技术可定量地反映脑动脉粥样硬化程度,有助于临床评价和诊断早期脑动脉粥样硬化性疾病。     

踝臂指数与缺血性脑卒中患者颅内动脉狭窄的相关性

目的 探讨缺血性脑卒中患者踝臂指数（ABI）与颅内动脉狭窄程度、数量、部位以及不同类型缺血性脑卒中的关系.方法 选择82例行全脑血管造影（DSA）的缺血性脑卒中患者,所有患者在造影前均进行ABI测量和常规生化检查.按血管狭窄程度及病变血管数量对患者进行分组,并进行中国缺血性脑卒中亚型（CISS）分型,比较颅内动脉狭窄程度、病变数量、部位以及不同类型脑卒中与ABI的关系.运用SPSS 13.5统计学软件进行统计学分析.结果 （1）颅内动脉狭窄组的ABI值（1.00±0.23）较无狭窄组（1.07±0.33）显著降低（t=1.990,P〈0.05）.3支及以1：病变组与无狭窄组、1支病变组和2支病变组ABI值有显著差异（t=1.684,t=2.441,P〈0.05）,但无狭窄组（ABI为1.07±0.33）、1支病变组（ABI为1.04±0.11）、2支病变组（ABI为1.02±0.35）之间比较没有显著性差异（t=1.684,t=1.688,t=1.711,P〉0.05）.（2）前后循环均狭窄组（0.89±0.08）的患者与无狭窄组（1.07±0.33）、颈内动脉狭窄组（1.02±0.17）、椎基底动脉狭窄组（1.04±0.15）比较ABI水平有显著性降低（t=1.725,t=2.0,t=2.12,P〈0.05）.（3）AB1≤0.9时预测重度颅内动脉狭窄的敏感度、特异度、准确度分别为85.4%、92.5%和69.7%.（4）大动脉粥样硬化（LAA）组ABI异常率显著高于穿支动脉疾病（PAD）组（P〈0.01）,LAA组ABI值（0.89±0.17）显著降低（t=2.639,P〈0.01）.结论 缺血性脑卒中患者ABI与颅内动脉狭窄严重程度、病变支数、病变部位相关,重度颅内动脉狭窄、3支以上病变以及前后循环系统均狭窄的缺血性脑卒中患者ABI值明显降低.ABI对重度颅内动脉狭窄有较高的预测价值.ABI与LAA有关,与PAD无关.     

冠心病合并代谢综合征患者踝臂指数与冠脉病变程度的关系

目的：研究合并代谢综合征（MS）冠心病患者MS与踝臂指数和冠脉病变的严重程度的关系。方法：连续人选经冠状动脉造影明确诊断为冠心病的老年患者．评估冠脉病变情况，测定其踝臂指数（ABI），根据是否存在MS及ABI正常与否进行分组。分析单独及联合MS、ABI≤0．90预测冠心病冠脉病变程度的状况。结果：共人选151例冠心病患者，其中合并MS者64例，无MS者87例。相对于无MS组，MS组的低ABI（≤0．9）比例明显增高（43．8％：27．6％．P=0．039）；ABI值更低（0．91±0．31）：（1．02±0．25），P=0．016；低ABI者三支病变显著增多（60．9％：32．2％．P=0．000）．而单支病变明显较少（18．8％：42．5%，P=0．002）。结论：冠心病患者如合并代谢综合征．则ABI值更低．冠状动脉病变更加严重，应进行强化治疗。     

Ankle-brachial index and coronary artery lesion complexity in patients with acute coronary syndromes

We investigated the relationship between peripheral artery disease (PAD) and coronary artery disease (CAD) complexity in patients with acute coronary syndromes (ACS). Consecutive patients with first time diagnosis of ACS (n = 150) were enrolled. SYNTAX score (SS), a marker of CAD complexity, was assessed by dedicated computer software and diagnosis of PAD was established by ankle-brachial index (ABI) value. SYNTAX score was higher in patients with overt and borderline PAD (ABI ≤ 0.99) than normal participants (ABI 1-1.29; 16.7 ± 8.2 vs 10.1 ± 5.5; P < .001). In addition, there was a strong negative correlation between ABI and SS (r = -.46; P < .001).We have demonstrated increased CAD complexity in patients with ACS and PAD and strong correlation between degree of PAD and coronary lesion complexity.     

运动平板试验对下肢动脉粥样硬化早期病变的诊断价值

目的 评估运动平板试验(Bruce方案)对下肢动脉粥样硬化早期病变的临床诊断价值.方法 2008年3～9月解放军总医院心血管内科门诊患者,随机选取173例周围动脉疾病高危患者,采取运动平板试验结合踝臂指数(ABI)检测,并于同1周内完成下肢动脉超声检查,以下肢动脉超声结果为诊断标准,分析运动平板试验诊断下肢动脉粥样硬化早期病变的敏感性、特异性、阳性似然比及阴性似然比,并采用ROC曲线评价其临床诊断价值.结果 随着下肢动脉粥样硬化病变程度的加重,运动后ABI下降幅度(R值)逐渐增大;分别以下肢动脉存在动脉粥样硬化Ⅳ级(斑块病变面积>20 mm2)、Ⅲ级(存在动脉粥样硬化斑块)及Ⅱ级(存在动脉粥样硬化病变)为阳性诊断标准,R值的ROC曲线下面积分别为0.80(95% CI:0.72～0.88)、0.78(95% CI:0.71～0.85)及0.60(95% CI:0.44～0.76).以下肢动脉粥样硬化大斑块病变为阳性诊断,R值为0.80时,其敏感性54.0%,特异性96.7%,阳性似然比为16.4,阴性似然比为0.58;R值为0.85时,其敏感性70.0%,特异性91.9%,阳性似然比为8.64,阴性似然比为0.33.结论 运动平板试验结合ABI检查是检测下肢动脉粥样硬化早期病变较为准确的客观工具.R值为0.85作为运动平板诊断下肢动脉粥样硬化大斑块病变(面积>20 mm2)的阈值为宜.     

Diagnostic value of anti-cyclic citrullinated peptide antibody for rheumatoid arthritis in a Chinese population: a meta-analysis

To use meta-analysis to determine the accuracy of anti-cyclic citrullinated peptide (CCP) antibody in diagnosis of patients with rheumatoid arthritis (RA) in a Chinese population, we searched MEDLINE and CNKI databases for studies published in English or Chinese between January 2000 and June 2010. Two investigators independently evaluated studies for inclusion, data extraction, and quality assessment. We used a random-effects model to combine estimates of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). One hundred and eighteen studies met our inclusion criteria. All studies were of high quality. The summary estimates for anti-CCP antibody in the diagnosis of RA in a Chinese population were as follows: sensitivity 0.65 (95% confidence interval (CI) 0.65-0.66), specificity 0.95 (95% CI 0.95-0.96), positive likelihood ratio (LR+) 15.84 (95% CI 13.55-18.54), negative likelihood ratio (LR-) 0.33 (95% CI 0.31-0.35), and diagnostic odds ratio (DOR) 51.60 (95% CI 43.64-61.01). With high specificity and moderate sensitivity, anti-CCP antibody tests play an important role in conforming the diagnosis of RA in a Chinese population.     

Detection of Peripheral Artery Disease by Duplex Ultrasonography among Hemodialysis Patients

Background and objectives: Peripheral arterial disease (PAD) is a known predictor of cardiovascular morbidity and mortality among hemodialysis patients. Although ankle-brachial BP index (ABI) is a simple and reliable test for PAD screening, its sensitivity has been suggested to decrease among dialysis patients.Design, setting, participants, & measurements: We performed a cross-sectional outpatient cohort study to examine prevalence of PAD among hemodialysis patients using duplex ultrasonography of the lower extremity artery. We also evaluate the influence of increased arterial stiffness on impaired accuracy of ABI for PAD screening.Results: Of 315 total patients, 23.8% had PAD. PAD was associated with younger age, diabetes, current smoking, atherosclerotic comorbidities, increased total cholesterol levels, increased triglyceride levels, and lower Kt/V. The receiver operating characteristic analysis (area under the receiver operating characteristic curve = 0.846) showed that sensitivity and specificity of ABI values for PAD were 49.0 and 94.8%, respectively. An ABI cut-off value of 1.05 resulted in the best sensitivity (74.5%) and specificity (84.4%). There was a significant difference in sensitivity of ABI levels <0.9 for detecting PAD among patients in different brachial-ankle pulse wave velocity quartiles. In patients with the highest brachial-ankle pulse wave velocity quartile, PAD was most prevalent (46.5%), and ABI had the highest accuracy in detecting PAD (area under the curve, 0.933).Conclusions: These results suggest that duplex ultrasonography was a useful tool for screening asymptomatic PAD among hemodialysis patients and that the diagnostic value of ABI for PAD was affected by various factors.Long-term hemodialysis patients are at an increased risk for atherosclerotic disorders, including coronary artery disease (CAD), stroke, and peripheral arterial disease (PAD) (1). PAD, which is strongly associated with CAD and stroke, is a strong predictor for subsequent all-cause and cardiovascular mortality in hemodialysis patients, as well as the general population (2,3).Ankle-brachial BP index (ABI) is a simple, noninvasive, and reliable test for PAD screening; the cut-off point for detecting PAD at rest is <0.9 (4,5). Clinical guidelines for PAD recommend ABI as a screening test for asymptomatic PAD of the lower extremities (5–7). ABI has also been reported to correlate well with PAD severity and angiographic findings (8). In addition to its diagnostic value for PAD, an abnormal ABI value is a significant predictor of all-cause and cardiovascular mortality among hemodialysis patients (9). However, ABI has been suggested to be unsuitable for assessing PAD in patients with diabetes, older age, history of intervention for PAD, or advanced chronic kidney disease (CKD) (10–12). In particular, increased arterial stiffness might interfere with ABI measurements and affect the sensitivity of ABI for detecting PAD among dialysis patients. It is important to establish a screening test for PAD that has sufficient diagnostic value and is safe and inexpensive.In this study, we examined the prevalence of asymptomatic PAD among long-term hemodialysis patients, using a noninvasive imaging test, duplex ultrasonography (US), as the reference. We also evaluated the influence of arterial stiffness on impaired accuracy of ABI for PAD screening.     

Hypertension in type 2 diabetes mellitus: effect of the disease and treatment on development of peripheral artery disease

Coexistence of diabetes and hypertension is well known so as their role as a risk factor for vasculopathy of lower limbs. Ankle brachial index (ABI) offers a simple, fairly reliable mean to quantify this problem. Very few studies in India have assessed the role of angiotensin-converting enzyme inhibitors (ACEI) in preventing vasculopathy in type 2 diabetics. A heterogeneous representative sample of 149 type 2 diabetics (103 ACEI user and 46 non-ACEI user) taking regular pharmacotherapy was tested by ABI using vascular Doppler to assess peripheral artery disease (PAD) following standard protocol. Distribution of risk factors for PAD and ABI values were compared between ACEI user and non-ACEI user diabetics. ABI ≤0.9 was defined as PAD and P value <0.05 considered as statistical significance. ACEI user and non-ACEI user group showed slight difference in prevalence of risk factors for PAD. ACEI user diabetics taking ACEI showed better ABI profile (ABI >0.9) than non-ACEI user diabetics. The non-ACEI user diabetics did not show statistically significant lower ABI difference. But by defining ABI ≤0.9 as PAD, type 2 diabetics not using ACEI proved to be at 2.12 times risk (OR to develop PAD) than those receiving it. Type 2 diabetic hypertensives taking ACEI with strict blood pressure control have an added benefit against PAD along with other established benefits, and the same pharmacotherapy may be used in non-ACEI user diabetics to turn secondary prevention into primary one.