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Arterial Biomarkers
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
The ABI is calculated as the ratio of the ankle to brachial systolic BP and is a simple, noninvasive and inexpensive test. Systolic BP in the lower limbs is normally higher than that in the upper limbs, and normal ABI values range from 1.1 to 1.3 (Aboyans et al., 2012). Values <0.9 indicate with high specificity and positive predictive value the presence of flow-limiting arterial stenoses along the course of the arterial lower body beds investigated. A supranormal ABI (i.e. >1.4) may be found in patients with generalized stiffening of blood vessels and advanced medial calcification most commonly seen in diabetic patients and patients with chronic kidney disease. There is a U-shaped association between ABI and CV events with a significantly increased risk in both low (<0.9) and high (>1.4) ABI groups (Ankle Brachial Index Collaboration, 2008). A clinically useful interpretation of ABI can be made only in accordance with the fact that this index becomes abnormal in already progressed atherosclerotic disease. In this sense, it can be applied in the diagnosis of peripheral arterial disease in symptomatic patients and in the assessment of vascular risk in asymptomatic patients with CV risk factors (Williams et al., 2018a), but it is not advocated by current American guidelines for use in asymptomatic patients (Curry et al., 2018). Nevertheless, it remains the first screening test for peripheral arterial disease but, of course, after clinical evaluation of arterial pulses by the physician (Aboyans et al., 2018).
Current imaging strategies in cardio-oncology
Published in Susan F. Dent, Practical Cardio-Oncology, 2019
Mirela Tuzovic, Melkon Hacobian, Eric H. Yang
Ankle-brachial index (ABI) is a simple test, which provides an accurate and rapid way for detecting the presence and severity of lower extremity arterial disease. The ABI is defined as the ratio of the systolic blood pressure in the upper arm compared to the ankle. Brachial and dorsalis pedis arterial systolic pressures are measured by applying an appropriately sized blood pressure cuff and using a continuous wave Doppler probe to record the arterial signal. Values below 0.9 are indicative of peripheral arterial disease (30). ABI can be performed at baseline and annually in asymptomatic patients at risk for peripheral artery disease such as patients receiving abdominal and/or pelvic radiation. In symptomatic patients, especially treated with high-risk agents such as nilotinib or ponatinib, direct visualization with arterial ultrasonography or CT/MR angiography may be indicated (2).
2018 ESC/ESH Guidelines for the Management of Arterial Hypertension
Published in Giuseppe Mancia, Guido Grassi, Konstantinos P. Tsioufis, Anna F. Dominiczak, Enrico Agabiti Rosei, Manual of Hypertension of the European Society of Hypertension, 2019
Bryan Williams, Giuseppe Mancia, Wilko Spiering, Enrico Agabiti Rosei, Michel Azizi, Michel Burnier, Denis L. Clement, Antonio Coca, Giovanni de Simone, Anna F. Dominiczak, Thomas Kahan, Felix Mahfoud, Josep Redon, Luis M. Ruilope, Alberto Zanchetti, Mary Kerins, Sverre E. Kjeldsen, Reinhold Kreutz, Stéphane Laurent, Gregory Y.H. Lip, Richard McManus, Krzysztof Narkiewicz, Frank Ruschitzka, Roland E. Schmieder, Evgeny Shlyakhto, Konstantinos P. Tsioufis, Victor Aboyans, Ileana Desormais
Ankle-brachial index (ABI) may be measured either with automated devices, or with a continuous wave Doppler unit and a BP sphygmomanometer. A low ABI (i.e. >0.9) indicates lower extremity artery disease (LEAD), is usually indicative of advanced atherosclerosis [152], and has predictive value for cardiovascular events [153], being associated with an almost two-fold greater 10-year cardiovascular mortality and major coronary event rate, compared with the overall rate in each Framingham category [153]. Even asymptomatic LEAD, detected by a low ABI, is associated in men with a high incidence of cardiovascular morbid and fatal events, approaching 20% in 10 years [153,154]. Routine use of ABI is not recommended in hypertensive patients, but should be considered in patients with symptoms or signs of LEAD, or in moderate-risk patients in whom a positive test would reclassify the patient as high-risk.
Subclinical atherosclerosis in the carotid artery: can the ankle-brachial index predict it in type 2 diabetes patients?
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2021
The ankle-brachial index (ABI) is a non-invasive, easy-to-perform, inexpensive test to detect occlusive vascular disease. It is the ratio between highest blood pressure posterior tibial artery or dorsalis pedis artery and brachial artery. There is general agreement that ABI <0.9 describes patients with ≥50% stenosis in the peripheral distal artery and has 75% sensitivity and 86% specificity to diagnose PAD [17]. A clear and strong association between low ABI (<0.9) as a marker of systemic atherosclerosis and cardiovascular events has been demonstrated in several studies [18–20]. Although ABI 1.1–1.3 is considered normal, there is plenty of grey area between the values 0.9 and 1.1. ABI <1.0 is assumed to be indicative of an increased probability of atherosclerosis, primarily because some critical risk factors may affect the value of ABI [18,21,22]. Foot ulcers, neuropathy, and arterial calcification may lead to wrong ABI values in diabetic patients. It may be falsely considered normal and therefore dismiss atherosclerotic disease. The ROC curve analysis showed that a cut-off set at 1.0–1.1 could identify >80% of the patients with PAD regardless of presence or absence of DM [21]. A study on Japanese patients with T2DM recommended using an ABI level of 0.9–1.0 as a potential marker of systemic atherosclerosis in asymptomatic patients in clinical practice [22]. In light of the above, there is no specific ABI value for early atherosclerosis.
Accuracy and repeatability of the Dopplex Ability
Published in Expert Review of Medical Devices, 2018
Rebecca N. Millen, Kate N. Thomas, Arunesh Majumder, Brigid G. Hill, Andre M. Van Rij, Jo Krysa
Peripheral arterial disease (PAD) is a common circulatory disease involving atherosclerosis of the lower limb arteries. There is little epidemiological data on the prevalence of PAD in New Zealand; however, literature of developed countries estimates a prevalence of around 10% in those aged over 65 years, and the prevalence is significantly increasing over time [1]. The consequences of late-stage PAD include arterial ulcers and lower limb ischemia. Ulcer care has been estimated at approximately $1000 USD/month, and revascularization and amputations have been estimated at a cost of approximately $35,000 USD each, with ongoing assisted living costs also significant [2]. Therefore, efficient ways of early diagnosis of PAD would be beneficial in the community clinical setting, to reduce the late-stage complications of the disease. The ankle-brachial index (ABI) is one of the most common tests used to identify PAD, which measures the ratio of the systolic ankle to brachial pressure. It is low cost, non-invasive, and reliable and has a high sensitivity and specificity [2]. Pulse volume recording (PVR) is another useful non-invasive arterial test, based on the volume changes with each pulse in the lower limb using air plethysmography technology [3]. PVR are especially beneficial for assessing lower limb perfusion in patients with non-compressible vessels in whom the ABI cannot be relied upon due to spuriously high values. Despite these advantages, both the ABI and PVR can be time consuming in the primary care setting, and also require specialized equipment and training.
When are the cardiovascular and stroke risks too high? Pharmacotherapy for stroke prophylaxis
Published in Expert Opinion on Pharmacotherapy, 2018
Antonio Gómez-Outes, Mª Luisa Suárez-Gea, Jose Manuel García-Pinilla
Inappropriate extrapolation to populations that are different may lead to an underestimation or overestimation of risk, and a decrease or increase in the target population for medical intervention, as repeatedly published in the literature. In addition, there may be individuals in whom the risk could be underestimated due to the presence of concomitant risk factors not included in many of the scores as qualifying risk factors, such as sedentary habits, obesity (particularly central obesity), strong family history of premature CVD, socially disadvantaged subjects, renal impairment, low HDL-C or high triglycerides, and pre-clinical (asymptomatic) atherosclerosis (e.g. reduced ankle-brachial index or presence of carotid stenosis in imaging tests).