Abstract Background Antares is an algorithm for oscillometric blood pressure (BP) monitors to determine aortic pulse wave velocity (PWV) solely using oscillometric pulse waves without dependence of any other input. The aim of this study is to test Antares PWV for feasibility and whether the known age and blood pressure dependence of PWV can be shown with Antares PWV. Methods In total, 259 patients were investigated for PWV as sub-study of the invasive validation of Antares algorithm, of which 219 entered analyses. Non-invasive PWV determination by Antares algorithm, integrated into an oscillometric BP monitor (custo screen 400) was compared to five different ePWV equations based on age, BP, or both. Additionally, in a subset of 27 patients, comparison of ARCSolver PWV algorithm (Mobil-O-Graph) with Antares PWV and ePWV was conducted. Results Mean differences ± SD between Antares PWV and (A) ePWV (based on age and systolic BP) was − 0.05 ± 1.06 m/s (Spearman’s rank correlation coefficient, r S = 0.805); (B) ePWV (based on age) was − 1.75 ± 1.17 m/s ( r S = 0.829); (C) ePWV (based on mean BP) was − 1.35 ± 1.24 m/s ( r S = 0.763), and (D) ePWV (based on age and mean BP) was − 1.64 ± 1.22 m/s ( r S = 0.810) and − 1.69 ± 1.18 m/s ( r S = 0.802). Comparison of Antares PWV with ARCSolver PWV revealed a mean difference of − 0.65 ± 1.31 m/s ( r S = 0.854). Conclusion The Antares algorithm confirmed its feasibility to use an oscillometric BP monitor as a single-point measurement device to calculate aortic PWV with acceptable comparability and high correlation to both estimated PWV and ARCSolver PWV. Antares achieves these results solely based on analysis of waveform features without requiring any secondary input, like BP or age.
In the European Society of Cardiology–European Society of Hypertension guidelines of the year 2007, the consequences of arterial stiffness and wave reflection on cardiovascular mortality have a major role. But the investigators claimed the poor availability of devices/methods providing easy and widely suitable measuring of arterial wall stiffness or their surrogates like augmentation index (AIx) or aortic systolic blood pressure (aSBP). The aim of this study was the validation of a novel method determining AIx and aSBP based on an oscillometric method using a common cuff (ARCSolver) against a validated tonometric system (SphygmoCor). aSBP and AIx measured with the SphygmoCor and ARCSolver method were compared for 302 subjects. The mean age was 56 years with an s.d. of 20 years. At least two iterations were performed in each session. This resulted in 749 measurements. For aSBP the mean difference was −0.1 mm Hg with an s.d. of 3.1 mm Hg. The mean difference for AIx was 1.2% with an s.d. of 7.9%. There was no significant difference in reproducibility of AIx for both methods. The variation estimate of inter- and intraobserver measurements was 6.3% for ARCSolver and 7.5% for SphygmoCor. The ARCSolver method is a novel method determining AIx and aSBP based on an oscillometric system with a cuff. The results agree with common accepted tonometric measurements. Its application is easy and for widespread use.
Background: We investigated, whether AT2 receptor (AT2R) stimulation by compound 21 alone or combined with AT1 receptor (AT1R) blockade prevented aortic stiffening in L-NAME-induced hypertension. Design and methods: Male adult Wistar rats (n = 65) were randomized into 6 groups: control, L-NAME and L-NAME + either compound 21, olmesartan or compound 21 + olmesartan. Blood pressure (BP) was measured each week. After 6-week treatment, aortic hydroxyproline content, PWV, wall thickness (WT) and inner diameter were determined and aortic stiffness (elasticity modulus) was estimated. Results: L-NAME led to increased BP, PWV, WT, aortic stiffness and hydroxyproline concentration. Olmesartan completely prevented BP, PWV, WT and stiffness increase and partly prevented hydroxyproline accumulation. Compound 21 partly prevented all these alterations, yet without concomitant prevention of BP rise. Although the combination therapy with olmesartan and compound 21 led to BP levels, PWV and WT comparable to olmesartan-alone-treated rats, only in the combination group complete prevention of increased hydroxyproline deposition was achieved, resulting in even more pronounced stiffness reduction. Conclusions: In rats with inhibited NO-synthase, the BP-independent effect on aortic stiffening and collagen accumulation by AT2R stimulation was additive to AT1R blockade.
Arterial stiffness, as measured by arterial pulse wave velocity (PWV), is an established biomarker for cardiovascular risk and target-organ damage in individuals with hypertension. With the emergence of new devices for assessing PWV, it has become evident that some of these devices yield results that display significant discrepancies compared with previous devices. This discrepancy underscores the importance of comprehensive validation procedures and the need for international recommendations.
Antares is a pulse wave analysis (PWA) algorithm designed to allow a non-invasive estimation of central (aortic) blood pressure (cBP) using automated oscillometric blood pressure (BP) devices. Diabetes may affect elastic and muscular arteries differently, resulting in disparate pulse wave characteristics in central and peripheral arteries, which may limit the accuracy of PWA devices. The aim of our study was to evaluate the accuracy of Antares for estimating cBP as compared with invasively measured cBP in patients with type 2 diabetes.In this study, consecutive patients undergoing elective coronary angiography were recruited between November 2017 and September 2020. In 119 patients with type 2 diabetes, cBP was measured invasively and simultaneously determined non-invasively using the custo screen 400 device with the integrated Antares algorithm.The mean difference between the estimated and invasively measured cBP was 1.2±6.3 mmHg for central systolic BP (cSBP), 1.0±4.3 mmHg for central mean arterial pressure (cMAP) and 3.6±5.7 mmHg for central diastolic BP (cDBP). High correlations were found between estimated cBP and invasively measured cBP (cSBP: r=0.916; cMAP: r=0.882; cDBP: r=0.791; all p<0.001).The present study suggests that the Antares algorithm incorporated into the custo screen 400 device can estimate cBP with high accuracy turning a conventional oscillometric BP device into a type II device for the non-invasive estimation of cBP, which is applicable in patients with type 2 diabetes. Integration of Antares into commercially available BP devices could facilitate the introduction of cBP into routine clinical practice as a part of disease and risk management.
Objective: Evaluation of cardiac output (CO) is crucial for understanding cardiac function and diagnosis of heart failure. While invasive thermodilution procedures serve as the gold standard for CO assessment, routine clinical practice has widely adopted transthoracic Doppler echocardiography (TTE) as the established non-invasive method. Nevertheless, there is a persistent demand for alternative non-invasive approaches, aiming to improve the efficiency of CO estimation, mitigate complications associated with invasive methods, and extend its application to non-intensive care settings, all of which potentially can be offered by oscillometric pulse wave analysis (PWA). This study aims to compare the non-invasive estimation of CO using TTE and the oscillometric PWA algorithm Antares. Design and method: We compared non-invasive cardiac output data obtained through two-dimensional transthoracic echocardiography with data obtained from an oscillometric blood pressure device (custo med GmbH, Ottobrunn, Germany) utilizing the integrated Antares algorithm (Redwave Medical GmbH, Jena, Germany). A total of 59 patients, undergoing elective cardiac catheterization for clinical reasons, were included in the study (mean age 71±10 years, 24% females), but only echocardiography-data with CO were used for analysis. Agreement between the two CO measurement methods (TTE versus Antares) was evaluated through Bland-Altman analysis, Student's t-test, and Pearson correlations. Results: The mean difference in CO was 0.04 ± 1.03 l/min. No statistically significant difference in means was observed between the two CO measurement methods. Significant correlations between transthoracic echocardiography (TTE) and Antares CO were evident in the overall population (r=0.71), as well as in both, female (r=0.80) and male patients (r=0.67; all p<0.001). Conclusions: The oscillometric PWA algorithm Antares and the established TTE exhibit strong correlations for non-invasive CO estimation in both male and female patients, with no statistically significant differences between the two approaches. This study opens the door to a valid and simple detection of heart failure that is seamlessly integrated into a quick and easy-to-perform upper arm blood pressure measurement.
