Ankle brachial index for the diagnosis of lower limb peripheral arterial disease

Background Peripheral arterial disease (PAD) of the lower limb is common, with prevalence of both symptomatic and asymptomatic disease estimated at 13% in the over 50 age group. Symptomatic PAD affects about 5% of individuals in Western populations between the ages of 55 and 74 years. The most common initial symptom of PAD is muscle pain on exercise that is relieved by rest and is attributed to reduced lower limb blood flow due to atherosclerotic disease (intermittent claudication). The ankle brachial index (ABI) is widely used by a variety of healthcare professionals, including specialist nurses, physicians, surgeons and podiatrists working in primary and secondary care settings, to assess signs and symptoms of PAD. As the ABI test is non‐invasive and inexpensive and is in widespread clinical use, a systematic review of its diagnostic accuracy in people presenting with leg pain suggestive of PAD is highly relevant to routine clinical practice. Objectives To estimate the diagnostic accuracy of the ankle brachial index (ABI) ‐ also known as the ankle brachial pressure index (ABPI) ‐ for the diagnosis of peripheral arterial disease in people who experience leg pain on walking that is alleviated by rest. Search methods We carried out searches of the following databases in August 2013: MEDLINE (Ovid SP),Embase (Ovid SP), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO), Latin American and Caribbean Health Sciences (LILACS) (Bireme), Database of Abstracts of Reviews of Effects and the Health Technology Assessment Database in The Cochrane Library, the Institute for Scientific Information (ISI) Conference Proceedings Citation Index ‐ Science, the British Library Zetoc Conference search and Medion. Selection criteria We included cross‐sectional studies of ABI in which duplex ultrasonography or angiography was used as the reference standard. We also included cross‐sectional or diagnostic test accuracy (DTA) cohort studies consisting of both prospective and retrospective studies.Participants were adults presenting with leg pain on walking that was relieved by rest, who were tested in primary care settings or secondary care settings (hospital outpatients only) and who did not have signs or symptoms of critical limb ischaemia (rest pain, ischaemic ulcers or gangrene).The index test was ABI, also called the ankle brachial pressure index (ABPI) or the Ankle Arm Index (AAI), which was performed with a hand‐held doppler or oscillometry device to detect ankle vessels. We included data collected via sphygmomanometers (both manual and aneroid) and digital equipment. Data collection and analysis Two review authors independently replicated data extraction by using a standard form, which included an assessment of study quality, and resolved disagreements by discussion. Two review authors extracted participant‐level data when available to populate 2×2 contingency tables (true positives, true negatives, false positives and false negatives).After a pilot phase involving two review authors working independently, we used the methodological quality assessment tool the Quality Assessment of Diagnostic Accuracy Studies‐2 (QUADAS‐2), which incorporated our review question ‐ along with a flow diagram to aid reviewers' understanding of the conduct of the study when necessary and an assessment of risk of bias and applicability judgements. Main results We screened 17,055 records identified through searches of databases. We obtained 746 full‐text articles and assessed them for relevance. We scrutinised 49 studies to establish their eligibility for inclusion in the review and excluded 48, primarily because participants were not patients presenting solely with exertional leg pain, investigators used no reference standard or investigators used neither angiography nor duplex ultrasonography as the reference standard. We excluded most studies for more than one reason.Only one study met the eligibility criteria and provided limb‐level accuracy data from just 85 participants (158 legs). This prospective study compared the manual doppler method of obtaining an ABI (performed by untrained personnel) with the automated oscillometric method. Limb‐level data, as reported by the study, indicated that the accuracy of the ABI in detecting significant arterial disease on angiography is superior when stenosis is present in the femoropopliteal vessels, with sensitivity of 97% (95% confidence interval (CI) 93% to 99%) and specificity of 89% (95% CI 67% to 95%) for oscillometric ABI, and sensitivity of 95% (95% CI 89% to 97%) and specificity of 56% (95% CI 33% to 70%) for doppler ABI. The ABI threshold was not reported. Investigators attributed the lower specificity for doppler to the fact that a tibial or dorsalis pedis pulse could not be detected by doppler in 12 of 27 legs with normal vessels or non‐significant lesions. The superiority of the oscillometric (automated) method for obtaining an ABI reading over the manual method with a doppler probe used by inexperienced operators may be a clinically important finding. Authors' conclusions Evidence about the accuracy of the ankle brachial index for the diagnosis of PAD in people with leg pain on exercise that is alleviated by rest is sparse. The single study included in our review provided only limb‐level data from a few participants. Well‐designed cross‐sectional studies are required to evaluate the accuracy of ABI in patients presenting with early symptoms of peripheral arterial disease in all healthcare settings. Another systematic review of existing studies assessing the use of ABI in alternative patient groups, including asymptomatic, high‐risk patients, is required.Publisher PDFPeer reviewe

Little Association between Intracranial Arterial Stenosis and Lacunar Stroke

Atheromatous middle cerebral artery (MCA) stenosis could cause lacunar stroke by occluding lenticulostriate artery origins, but atheroma is common, and previous studies lacked suitable controls. We aimed to determine if intracranial atheroma was more common in lacunar than in cortical ischaemic stroke. We recruited patients with lacunar stroke and controls with mild cortical stroke, confirmed the stroke subtype with magnetic resonance imaging and used transcranial Doppler ultrasound imaging to record flow velocity and focal stenoses in the basal intracranial arteries 1 month after stroke. We compared ipsi- and contralateral MCA mean flow velocities between stroke subtypes and tested for associations using linear mixed models. Amongst 67 lacunar and 67 mild cortical strokes, mean age 64 and 67 years, respectively, we found no difference in MCA mean flow velocity between cortical and lacunar patients. Increasing age and white matter lesion scores were independently associated with lower MCA flow velocities (0.2 cms−1 fall in velocity per year increase in age, p = 0.045; 3.75 cms−1 fall in flow velocity per point increase in white matter lesion score, p = 0.004). We found no intracranial arterial stenoses. MCA atheromatous stenosis is unlikely to be a common cause of lacunar stroke in white populations. Falling velocities with increasing white matter lesion scores may reflect progressive brain tissue loss leaving less tissue to supply

Neuropsychiatric symptoms as a sign of small vessel disease progression in cognitive impairment

BACKGROUND: Neuropsychiatric symptoms associate cross-sectionally with cerebral small vessel disease but it is not clear whether these symptoms could act as early clinical markers of small vessel disease progression. We investigated whether longitudinal change in Neuropsychiatric Inventory (NPI) scores associated with white matter hyperintensity (WMH) progression in a memory clinic population. MATERIAL AND METHODS: We included participants from the prospective Sunnybrook Dementia Study with Alzheimer's disease and vascular subtypes of mild cognitive impairment and dementia with two MRI and ≥ 1 NPI. We conducted linear mixed-effects analyses, adjusting for age, atrophy, vascular risk factors, cognition, function, and interscan interval. RESULTS: At baseline (n=124), greater atrophy, age, vascular risk factors and total NPI score were associated with higher baseline WMH volume, while longitudinally, all but vascular risk factors were associated. Change in total NPI score was associated with change in WMH volume, χ2 = 7.18, p = 0.007, whereby a one-point change in NPI score from baseline to follow-up was associated with a 0.0017 change in normalized WMH volume [expressed as cube root of (WMH volume cm³ as % intracranial volume)], after adjusting for age, atrophy, vascular risk factors and interscan interval. CONCLUSIONS: In memory clinic patients, WMH progression over 1–2 years associated with worsening neuropsychiatric symptoms, while WMH volume remained unchanged in those with stable NPI scores in this population with low background WMH burden

Reliability of an automatic classifier for brain enlarged perivascular spaces burden and comparison with human performance

pp. 1465-1481En el cerebro, los espacios perivasculares agrandados (PVS) se relacionan con la enfermedad de los vasos pequeños (SVD), mala cognición, inflamación e hipertensión. Proponemos un esquema totalmente automático que utiliza una máquina de vectores de soporte (SVM) para clasificar la carga de PVS en los ganglios basales (BG) como baja o alta. Evaluamos el rendimiento de tres tipos diferentes de descriptores extraídos de la región BG en imágenes de RMN ponderadas en T2: (I) estadísticas obtenidas de los coeficientes de la transformada de Wavelet, (II) patrones binarios locales y (III) bolsa de palabras visuales (BoW), descriptores basados en la caracterización de claves locales obtenidas de una rejilla densa con las características de transformación de la función de escala-invariante (SIFT). Cuando se utilizaron estos últimos, el SVM clasificador alcanzó la mejor precisión (81,16%). Lo obtenido del clasificador utilizando los descriptores del BoW se comparó con las calificaciones visuales realizadas por un neurorradiólogo experimentado (observador 1) y por un analista de imágenes entrenado (observador 2). El acuerdo y la correlación cruzada entre el clasificador y el observador 2 (κ = 0,67 (0,58 – 0,76)) fueron ligeramente más altos que entre el clasificador y el observador 1 (κ = 0,62 (0,53 – 0,72)) y entre ambos observadores (κ = 0,68 (0,61 – 0,75)). Por último, se construyeron tres modelos de regresión logística que utilizan variables clínicas como variable independiente y cada una de las clasificaciones de PVS como variable dependiente, para evaluar clínicamente lo significativas que resultan las predicciones del clasificador. El ajuste del modelo para el clasificador era bueno (área bajo la curva (AUC) valores: 0,93 (modelo 1), 0,90 (modelo 2) y 0,92 (modelo 3)) y un poco mejor (es decir, valores de AUC: 0,02 unidades superiores) que las del modelo para el observador 2. Estos resultados sugieren que, aunque se puede mejorar, un clasificador automático para evaluar la carga de PVS de la resonancia magnética del cerebro puede proporcionar resultados clínicamente significativos cercanos a los de un observador entrenado.S

Longitudinal changes of white matter hyperintensities in sporadic small vessel disease: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES: White matter hyperintensities (WMHs) are frequent imaging features of small vessel disease (SVD) and related to poor clinical outcomes. WMH progression over time is well described, but regression was also noted recently, although the frequency and associated factors are unknown. This systematic review and meta-analysis aims to assess longitudinal intraindividual WMH volume changes in sporadic SVD. METHODS: We searched EMBASE and MEDLINE for articles up to 28 January 2022 on WMH volume changes using MRI on ≥2 time points in adults with sporadic SVD. We classified populations (healthy/community-dwelling, stroke, cognitive, other vascular risk factors, and depression) based on study characteristics. We performed random-effects meta-analyses with Knapp-Hartung adjustment to determine mean WMH volume change (change in milliliters, percentage of intracranial volume [%ICV], or milliliters per year), 95% CI, and prediction intervals (PIs, limits of increase and decrease) using unadjusted data. Risk of bias assessment tool for nonrandomized studies was used to assess risk of bias. We followed Preferred Reporting in Systematic Review and Meta-Analysis guidelines. RESULTS: Forty-one articles, 12,284 participants, met the inclusion criteria. Thirteen articles had low risk of bias across all domains. Mean WMH volume increased over time by 1.74 mL (95% CI 1.23–2.26; PI −1.24 to 4.73 mL; 27 articles, N = 7,411, mean time interval 2.7 years, SD = 1.65); 0.25 %ICV (95% CI 0.14–0.36; PI −0.06 to 0.56; 6 articles, N = 1,071, mean time interval 3.5 years, SD = 1.54); or 0.58 mL/y (95% CI 0.35–0.81; PI −0.26 to 1.41; 8 articles, N = 3,802). In addition, 13 articles specifically mentioned and/or provided data on WMH regression, which occurred in asymptomatic, stroke, and cognitive disorders related to SVD. DISCUSSION: Net mean WMH volume increases over time mask wide-ranging change (e.g., mean increase of 1.75 mL ranging from 1.25 mL decrease to 4.75 mL increase), with regression documented explicitly in up to one-third of participants. More knowledge on underlying mechanisms, associated factors, and clinical correlates is needed, as WMH regression could be an important intervention target

Resonancia magnética versus tomografía computada para la detección de lesiones vasculares agudas en pacientes que consultan por síntomas de accidente cerebrovascular

ResumenAntecedentesLa resonancia magnética (RM) se utiliza cada vez con mayor frecuencia para el diagnóstico del accidente cerebrovascular isquémico agudo aunque ha sido debatida su sensibilidad para la detección precoz de la hemorragia intracerebral. La tomografía computada (TC) se usa ampliamente en el tratamiento clínico del accidente cerebrovascular agudo, especialmente para la exclusión rápida de la hemorragia intracerebral.ObjetivosComparar la precisión diagnóstica de la RM de difusión (RMD) y la CT para el accidente cerebrovascular isquémico agudo, y estimar la precisión diagnóstica de la RMD para el accidente cerebrovascular hemorrágico agudo.Estrategia de búsquedaSe efectuaron búsquedas en MEDLINE y EMBASE (enero de 1995 hasta marzo de 2009) y se examinó la bibliografía de los estudios pertinentes en busca de otras referencias.Criterios de selecciónSe seleccionaron los estudios que compararon RMD y TC en los mismos pacientes para la detección del accidente cerebrovascular isquémico o examinaron la utilidad de la RM para la detección del accidente cerebrovascular hemorrágico, que realizaron la imaginología dentro de las 12 horas de la aparición de los síntomas de accidente cerebrovascular y presentaron datos suficientes como para construir tablas de contingencia.Obtención y análisis de los datosTres autores de forma independiente extrajeron los datos de las características del estudio y las medidas de precisión. Los datos sobre el accidente cerebrovascular isquémico se evaluaron mediante metanálisis de efectos aleatorios y de efectos fijos.Resultados principalesOcho estudios, con un total de 308 participantes, cumplieron los criterios de inclusión. Siete estudios contribuyeron a la evaluación del accidente cerebrovascular isquémico y dos estudios a la evaluación del accidente cerebrovascular hemorrágico. El espectro de pacientes fue relativamente limitado en todos los estudios, los tamaños de las muestras fueron pequeños, hubo un significativo sesgo de incorporación y los procedimientos de cegamiento fueron a menudo incompletos. Entre los pacientes en quienes posteriormente se confirmó el diagnóstico de accidente cerebrovascular isquémico agudo (161/226), las estimaciones de resumen para la RMD fueron: sensibilidad 0,99 (IC del 95%: 0,23 a 1,00), especificidad 0,92 (IC del 95%: 0,83 a 0,97). Las estimaciones de resumen para la TC fueron: sensibilidad 0,39 (IC del 95%: 0,16 a 0,69), especificidad 1,00 (IC del 95%: 0,94 a 1,00).Los dos estudios sobre accidente cerebrovascular hemorrágico informaron estimaciones altas para las secuencias de difusión y ecogradiente pero tenían estándares de referencia inconsistentes. No se calcularon las estimaciones generales para estos dos estudios. No fue posible evaluar la practicidad o los temas relativos a la relación entre costo y efectividad.Conclusiones de los autoresLa RMD parece ser más sensible que la TC para la detección precoz del accidente cerebrovascular isquémico en pacientes sumamente seleccionados. Sin embargo, la variabilidad en la calidad de los estudios incluidos y la presencia de los sesgos de espectro e incorporación tornan dudosa la confiabilidad y la posibilidad de generalizar los resultados observados. Se requieren estudios adicionales bien diseñados, sin sesgos metodológicos, con muestras de pacientes más representativas y estimaciones de la practicidad y los costos, a fin de determinar qué pacientes deben ser sometidos a RM y qué pacientes a TC en el caso de presunto accidente cerebrovascular agudo

Impact of Small Vessel Disease Progression on Long-term Cognitive and Functional Changes after Stroke

Funding Information: This study was supported in part by the Wellcome Trust (WT088134/Z/09/A; funded most of the data collection and S.D.J.M). For the purpose of open access, the author has applied a CC-BY public copyright license to any Author Accepted Manuscript version arising from this submission. The 3-year follow-up was also funded by Chest, Heart Stroke Scotland:Res14/A157 (C.A.M.); support for the research was also received from NHS Research Scotland (V.C., F.D.); Row Fogo Charitable Trust Centre for Research Into Aging and the Brain (BROD.FID3668413; M.d.C.V.H., E.S.); the European Union Horizon 2020 project 666,881, SVDs@Target (F.M.C); Scottish Funding Council, Scottish Imaging Network, A Platform for Scientific Excellence Initiative; Chief Scientist Office Scotland (U.C.; CAF/18/08); Stroke Association Princess Margaret Research Development Fellowship (U.C.); and Stroke Association–Garfield Weston Foundation Senior Clinical Lectureship (FND;TSALECT 2015/04). Funding provided by the Fondation Leducq (16-CVD-05) and UK Dementia Research Institute (J.M.W.), funded by the UK Medical Research Council, Alzheimer's Society, and Alzheimer's Research UK, is gratefully acknowledged.Peer reviewedPublisher PD