Comparison of accuracy of two different methods to determine ankle-brachial index to predict peripheral arterial disease severity confirmed by angiography

Effectiveness of bedside investigations to diagnose peripheral artery disease among people with diabetes mellitus: A systematic review

As a progressive disease process, early diagnosis and ongoing monitoring and treatment of lower limb peripheral artery disease (PAD) is critical to reduce the risk of diabetes-related foot ulcer (DFU) development, non-healing of wounds, infection and amputation, in addition to cardiovascular complications. There are a variety of non-invasive tests available to diagnose PAD at the bedside, but there is no consensus as to the most diagnostically accurate of these bedside investigations or their reliability for use as a method of ongoing monitoring. Therefore, the aim of this systematic review was to first determine the diagnostic accuracy of non-invasive bedside tests for identifying PAD compared to an imaging reference test and second to determine the intra- and inter-rater reliability of non-invasive bedside tests in adults with diabetes. A database search of Medline and Embase was conducted from 1980 to 30 November 2022. Prospective and retrospective investigations of the diagnostic accuracy of bedside testing in people with diabetes using an imaging reference standard and reliability studies of bedside testing techniques conducted in people with diabetes were eligible. Included studies of diagnostic accuracy were required to report adequate data to calculate the positive likelihood ratio (PLR) and negative likelihood ratio (NLR) which were the primary endpoints. The quality appraisal was conducted using the Quality Assessment of Diagnostic Accuracy Studies and Quality Appraisal of Reliability quality appraisal tools. From a total of 8517 abstracts retrieved, 40 studies met the inclusion criteria for the diagnostic accuracy component of the review and seven studies met the inclusion criteria for the reliability component of the review. Most studies investigated the diagnostic accuracy of ankle -brachial index (ABI) (N = 38). In people with and without DFU, PLRs ranged from 1.69 to 19.9 and NLRs from 0.29 to 0.84 indicating an ABI <0.9 increases the likelihood of disease (but the extent of the increase ranges from a small to large amount) and an ABI within the normal range (≥0.90 and <1.3) does not exclude PAD. For toe-brachial index (TBI), a threshold of <0.70 has a moderate ability to rule PAD in and out; however, this is based on limited evidence. Similarly, a small number of studies indicate that one or more monophasic Doppler waveforms in the pedal arteries is associated with the presence of PAD, whereas tri- or biphasic waveform suggests that PAD is less likely. Several forms of bedside testing may also be useful as adjunct tests and 7 studies were identified that investigated the reliability of bedside tests including ABI, toe pressure, TBI, transcutaneous oxygen pressure (TcPO2 ) and pulse palpation. Inter-rater reliability was poor for pulse palpation and moderate for TcPO2. The ABI, toe pressure and TBI may have good inter- and intra-rater reliability, but margins of error are wide, requiring a large change in the measurement for it to be considered a true change rather than error. There is currently no single bedside test or a combination of bedside tests that has been shown to have superior diagnostic accuracy for PAD in people with diabetes with or without DFU. However, an ABI <0.9 or >1.3, TBI of <0.70, and absent or monophasic pedal Doppler waveforms are useful to identify the presence of disease. The ability of the tests to exclude disease is variable and although reliability may be acceptable, evidence of error in the measurements means test results that are within normal limits should be considered with caution and in the context of other vascular assessment findings (e.g., pedal pulse palpation and clinical signs) and progress of DFU healing.

Traditional and non-traditional risk factors for peripheral artery disease development/progression in patients with type 2 diabetes: the Rio de Janeiro type 2 diabetes cohort study

BACKGROUND

The prognostic importance of non-traditional risk factors for peripheral artery disease (PAD) development/progression is scarcely studied in diabetes. We investigated if carotid intima-media thickness (CIMT) and carotid-femoral pulse wave velocity (cf-PWV) added prognostic information beyond traditional cardiovascular risk markers for PAD outcomes.

METHODS

Ankle-brachial index (ABI) was measured at baseline and after a median of 91 months of follow-up in 681 individuals with type 2 diabetes. Multivariate Cox regressions examined the associations between the candidate variables and the outcome. PAD development/progression was defined by a reduction in ABI ≥ 0.15 (to a level < 0.9) or limb revascularization procedures, lower-extremity amputations or death due to PAD. The improvement in risk discrimination was assessed by increases in C-statistics of the models.

RESULTS

Seventy-seven patients developed/progressed PAD: 50 reduced ABI to < 0.9, seven had lower-limb revascularizations, and 20 had amputations or death. Age, male sex, diabetes duration, presence of microvascular complications (peripheral neuropathy and diabetic kidney disease), baseline HbA_1c, 24-h systolic BP (SBP) and mean cumulative office SBP and LDL-cholesterol were associated with PAD development/progression in several models. CIMT and cf-PWV were additionally associated with PAD outcomes, and their inclusion further improved risk discrimination (with C-statistic increases between 0.025 and 0.030). The inclusion of ambulatory 24-h SBP, instead of office SBP, also improved PAD risk discrimination.

CONCLUSIONS

Increased CIMT and aortic stiffness are associated with greater risks of developing/progressing PAD, beyond traditional risk factors, in type 2 diabetes.

Estimating the diagnostic accuracy of the ankle-brachial pressure index for detecting peripheral arterial disease in people with diabetes: A systematic review and meta-analysis

AIM

To systematically evaluate research investigating the accuracy of the ankle-brachial index (ABI) for diagnosing peripheral artery disease (PAD) in people with diabetes, as the accuracy is thought to be reduced in this cohort.

METHODS

A database search of EBSCO Megafile Premier, Embase and The Cochrane Library was conducted to 28 February 2019. Prospective and retrospective investigations of the diagnostic accuracy of the ABI for PAD in people with diabetes using an imaging reference standard were eligible. Sensitivity and specify of the ABI and bivariate meta-analysis against reference tests, or a standard summary receiver operating curve analysis (SROC) was performed.

RESULTS

Thirty-three studies met the inclusion criteria. ABI was compared with angiography in 12 studies and with colour duplex ultrasound (CDUS) in 21 studies. A SROC analysis of studies using angiography as the reference standard found a diagnostic odds ratio (DOR) of 9.06 [95% confidence interval (CI) 3.61 to 22.69], and area under the curve (AUC) of 0.76 (95% CI 0.66 to 0.86). Bivariate analysis of studies using CDUS demonstrated mean sensitivity of 0.60 (95% CI 0.48 to 0.71; P = 0.097) and mean specificity of 0.87 (95% CI 0.78 to 0.92; P < 0.001) with a DOR of 9.76 (95% CI 5.24 to 18.20; P < 0.0001) and AUC 0.72.

CONCLUSIONS

These results suggest the ABI has a high specificity but lower sensitivity in detecting imaging diagnosed PAD in people with diabetes. The low probability of the testing being able to rule diagnosis in or out suggest that the ABI has limited effectiveness for early detection of PAD in this cohort.

Could the arm blood pressure measured with simultaneous bilateral arm method be used for hypertension diagnosis?

OBJECTIVE

Simultaneous bilateral arm blood pressure (BP) measurement (bilateral arm method) is suggested for the first BP measurement in clinical practice, but whether the arm BP measured with bilateral arm method (RA-2) is similar to that with unilateral arm method (RA-1) is unclear.

DESIGN

Quantitative research, paired sample T-test, Bland-Altman and multivariate linear regression analyses were used.

SETTING

This study included 295 subjects (18-90 years, 60.0±14.6 years old, 126 males) in the clinic of cardiovascular medicine of the Second Affiliated Hospital of Nanchang University. They were randomly instructed to one of two BP measurement proposals: (1) right-arm-bilateral arm-right-arm-bilateral arm, or (2) bilateral arm-right-arm-bilateral arm-right-arm to attenuate bias induced by BP measurement order.

PARTICIPANTS

From June to October of 2019, 295 outpatients (18-90 years, 60.0±14.6 years old, 126 males and 169 females) with sinus rhythm (SR) were enrolled. The exclusion criteria were acute myocardial infarction, congenital heart disease, acute heart failure, syncope, hemiplegia, arrhythmia and pulseless (by palpation).

OUTCOME MEASURES

We compared the BP differences between bilateral arm method and unilateral arm method. The difference between RA-2 and RA-1 was calculated as Dif-RA. Data are expressed as means±SD for continuous variables. The percentage increase (PI) was calculated on the formula: (RA-2-RA-1)/RA-1.

RESULTS

The RA-2 on systolic blood pressure (SBP)/diastolic blood pressure (DBP) was slightly, but statistically higher by 1.2/0.4 mm Hg against the RA-1. Multivariate regression analyses showed that hypertension therapy type was positive impact factor, but RA-1 was negative factor for PI of Dif-RA on SBP, DBP and pulse pressure.

CONCLUSION

The SBP and DBP of right arm measured with bilateral arm method are slightly, but statistically higher (1.2 and 0.4 mm Hg) than those with the unilateral arm BP method.

Vascular Assessment of the Lower Extremity with a Chronic Wound

Peripheral arterial disease (PAD) affects many individuals worldwide and is associated with increased morbidity and mortality. Controversy exists on whether or not to screen asymptomatic patients. Further complicating this is that many patients with a chronic lower extremity wound are often asymptomatic. PAD and traditional noninvasive vascular studies may be inaccurate in providing a correct diagnosis. A review of current and novel vascular assessment modalities along with their benefits and limitations are presented here. A combination of these vascular assessments may help improve accuracy in diagnosis, providing timely care to those patients in need.

Is the blood pressure of right arm measured with synchronous four-limb method is equal to that with single arm method?

OBJECTIVE

Synchronous four-limb blood pressure (BP) measurement (four-limb method) is widely used for diagnosing peripheral artery diseases in clinical practise, but it is unclear whether the BP of right arm measured with this method is similar to that measured with single arm method.

METHODS

This study included 198 in-patients (aged 18-89, mean age 60.1± 13.9 years old, 109 males). They were divided into four groups on the therapy as renin-angiotensin system inhibitor (46 patients), calcium channel blocker (43 patients), beta receptor blocker (27 patients), and combination (Com, 82 patients) groups. The patients were randomly instructed to follow one of two BP measurement proposals designed to avoid the bias induced by BP measurement order. The result with single arm method was recorded as RA-1 and that with four-limb method as RA-4. The difference between RA-4 and RA-1 was calculated as Dif-RA. The percentage increase (PI) was also calculated on the formula: (RA-4 - RA-1)/RA-1.

RESULTS

The mean Dif-RA on SBP and DBP were 1.9/1.5 mmHg. Although the levels of SBP, DBP and pulse pressure of RA-1 were different, the PI of these parameters were comparable among four treatment groups. Multivariate regression analyses showed that age and SBP of RA-1 were positive independent factors for Dif-RA on SBP.

CONCLUSION

The SBP and DBP of right arm measured with synchronous four-limb method are 1.9/1.5 mmHg higher against the single arm method in treated hypertensives, and the increase extent of BP is not associated with the used drugs.

Relationship between lower limb vascular characteristics, peripheral arterial disease and gait in rheumatoid arthritis

OBJECTIVES

Rheumatoid arthritis (RA) is associated with higher risk of atherosclerotic vascular disease, including peripheral arterial disease (PAD). The aim of this study was to measure lower limb vascular characteristics (indicative of PAD), using non-invasive chairside testing methods, in people with RA compared to matched controls, and to determine the association between vascular characteristics and gait velocity as a measure of functional capacity in people with RA.

METHODS

This was a cross-sectional pilot study which measured lower limb vascular characteristics (bilateral continuous wave Doppler, toe brachial index [TBI] and ankle brachial index [ABI]) and gait velocity (6-m walk test) in people with RA and controls. Differences in vascular characteristics between groups were determined using linear regression models, and associations between vascular characteristics and gait were determined using logistic regression models.

RESULTS

Seventy-two participants were included: 34 participants with RA mean disease duration 26.2 (SD 12.1) and 38 age- and sex-matched controls. The control group contained 30 females (79%), and the RA group had 28 females (82%). There were no significant differences between the RA and control groups for lower limb vascular characteristics. People with RA walked significantly slower compared to controls (1.10 m/s vs 0.91 m/s, P < .001). People with RA who had abnormal TBI, or abnormal qualitative Doppler walked significantly slower compared to those with normal TBI (0.86 m/s vs 0.95 m/s, P = .043 and 0.81 m/s, vs 0.93 m/s, P = .028). There was no significant association between ABI and gait velocity.

CONCLUSION

This study did not identify different lower limb vascular characteristics in people with RA compared to matched controls. However, in people with RA, abnormal Doppler and TBI results are associated with slower walking velocity.

Perfusion Assessment in Critical Limb Ischemia: Principles for Understanding and the Development of Evidence and Evaluation of Devices: A Scientific Statement From the American Heart Association

There are >12 million patients with peripheral artery disease in the United States. The most severe form of peripheral artery disease is critical limb ischemia (CLI). The diagnosis and management of CLI is often challenging. Ethnic differences in comorbidities and presentation of CLI exist. Compared with white patients, black and Hispanic patients have higher prevalence rates of diabetes mellitus and chronic renal disease and are more likely to present with gangrene, whereas white patients are more likely to present with ulcers and rest pain. A thorough evaluation of limb perfusion is important in the diagnosis of CLI because it can not only enable timely diagnosis but also reduce unnecessary invasive procedures in patients with adequate blood flow or among those with other causes for ulcers, including venous, neuropathic, or pressure changes. This scientific statement discusses the current tests and technologies for noninvasive assessment of limb perfusion, including the ankle-brachial index, toe-brachial index, and other perfusion technologies. In addition, limitations of the current technologies along with opportunities for improvement, research, and reducing disparities in health care for patients with CLI are discussed.

Four-Limb Blood Pressure Measurement with an Oscillometric Device: a Tool for Diagnosing Peripheral Vascular Disease

PURPOSE OF REVIEW

Traditionally, the term peripheral vascular disease (PAD) is restricted to the occlusive arterial disease in the leg, but now, the connotation of PAD is more widespread as it encompasses all extracoronary and extracerebral vascular disease. The incidence of PAD is increasing worldwide; therefore, it is necessary to diagnose PAD at an early stage.

RECENT FINDINGS

Oscillometric BP device is widely used for four-limb measurement in clinical practice and provides several parameters for evaluating inter-limb BP difference, such as ankle-brachial index (OS-ABI), inter-arm BP differences (IAD), and inter-ankle BP difference (IAND). Using angiographic results as reference, the ABI, IAD, and IAND from an oscillometric BP device have been demonstrated having high accuracy for diagnosis of PAD. Meanwhile, combination of these parameters could further improve the accuracy of PAD, including the occlusive artery disease in the arm, leg, and aorta. For example, some patients with severe PAD in the leg have normal ABI; in this situation, an increased sIAND could confirm the diagnosis of PAD in the leg. Because ABI, IAD, and IAND from inter-limb oscillometric BP measurement can also predict adverse prognosis, we encourage the use of an oscillometric device to measure four-limb BP and to evaluate the inter-limb BP difference.

A novel computer-aided diagnostic approach for detecting peripheral arterial disease in patients with diabetes

Peripheral arterial disease (PAD) is an important manifestation of systemic atherosclerosis, with diabetes being one of its most significant risk factors. Owing to medial arterial calcification (MAC), the ankle–brachial index (ABI) is not always a reliable tool for detecting PAD. Arterial Doppler flow parameters, such as systolic maximal acceleration (ACCmax) and relative pulse slope index (RPSI), may serve as effective surrogates to detect stenosis-induced flow alteration. In the present study, ACCmax and RPSI were prospectively evaluated in 166 patients (304 arteries) with clinical suspicion of PAD, including 76 patients with and 90 patients without diabetes. In the overall sample, the sensitivity of ACCmax (69%) was superior to that of ABI (58%) and RPSI (56%). In patients with diabetes, the sensitivity of ACCmax (57%), ABI (56%) and RPSI (57%) were similar, though a parallel test taking both ACCmax and RPSI into account further increased sensitivity to 68%. The specificity (98%) and accuracy (78%) of ACCmax were superior to those of ABI (83% and 70%, respectively), as were the specificity (95%) and accuracy (77%) of RPSI in patients with diabetes. The diagnostic properties of ACCmax and RPSI were superior to those of ABI for detecting PAD in patients with diabetes. Our acceleration algorithm (Gefäßtachometer^®) provides a rapid, safe, noninvasive tool for identifying PAD in patients with diabetes.