Non-invasive Pulse Wave Research Articles

Objective functional improvement and vital prognosis after TAVR in patients with low-gradient aortic stenosis. Development of a predictive score

Abstract Introduction Patients with low-gradient aortic stenosis (mean gradient < 40 mmHg) (LGAS) supose a clinical challenge because in these patients the degree of functional recovery after TAVR could be lower and their prognostic evolution more adverse. This is relevant for the optimal indication of TAVR, especially with the growing number of patients with a borderline indication due to comorbidities or advanced age with certain degree of frailty. Purpose To develop a clinical model to predict the response to TAVR in LGAS patients based in non invasive physiological parameters at baseline. Methods In a cohort of patients undergoing TAVR a prospective evaluation of multiple pathophysiological parameters was performed derived from pre- and post-TAVR assessment with echocardiography, computed tomography, and non-invasive arterial pulse wave analysis with the Sphygmocor XCEL system. Objective functional improvement 6 months after TAVR was assessed by the 6-minute walk test and NT-proBNP levels. Clinical follow-up was performed at 1 year. Results Of the 450 patients included, 310 showed high aortic gradient and 140 (31%) low gradient, with an objective functional improvement in 90% and 64% (p<0.001) respectively, and with 1-year mortality of 4% and 12% (p=0.001). In the LGAS group, 1-year mortality was 20% in the subgroup without functional improvement and 8% (p=0.001) in the subgroup showing functional improvement. In the LGAS group, the pathophysiological parameters predictive of functional improvement were the augmentation index75 ≥ 45% (OR 4, CI 95% 1.9–11.3; p=0.006), posterior wall thickness ≤ 12 mm (OR 3.2, CI 95% 1.4–8; p=0.01) and absence of atrial fibrillation (OR 2.7, CI 95% 1.5–8.4; p=0.01). To generate a simple integer-based point score for each predictive variable, each beta coefficient was divided by the absolute value of the smallest coefficient, multiplied by 5, and rounded to the nearest integer. The values were 7, 6 and 5 respectively. Among the low-gradient population, in 55 patients with 0-6 score points the functional improvement was only 29%, while in the remaining 85 patients with 7-18 score points the functional improvement was 86% (p<0.001). Conclusions LGAS patients account for a relatively high proportion of patients undergoing TAVR. They show less objective functional recovery, which is associated with a significantly higher mortality at follow-up. We have developed a score based on 3 variables (augmentation index75, posterior wall thickness and atrial fibrillation) that can help predict the functional and prognostic response to TAVR in these patients.

Flexible Sphere Elastomer Structural Pressure Sensor for Non-invasive Pulse Wave Monitoring

Flexible Sphere Elastomer Structural Pressure Sensor for Non-invasive Pulse Wave Monitoring

#2539 Effects of relative blood volume and ultrafiltration volume on pulse wave characteristics during hemodialysis

Abstract Background and Aims Measures of non-invasive pulse wave (PW) analysis can help to assess the status of the central cardiovascular system and to predict clinical outcomes, including morbidity and mortality. During hemodialysis (HD), fluid is extracted from blood. The resulting reduction in relative blood volume (RBV) and collected ultrafiltration volume (UFV) were hypothesized to substantially influence PW characteristics during HD. Volume overload (VO) is common in HD patients and may affect the chance of improving the cardiovascular status of patients during HD. The present study aimed to explore associations between RBV, UFV, VO and a wide range of PW parameters. Method In a single center in Vienna, Austria, 24 patients on maintenance HD underwent four HD sessions each, with whole-body bioimpedance spectroscopy (BIS) before, and automated, cuff-based PW measurements every 15 minutes, RBV- and UFV-monitoring throughout each session. Associations between RBV or UFV as independent variable and 26 different PW characteristics as dependent variables (52 separate models) were tested using confounder-adjusted generalized estimating equations with sandwich estimator and multilevel nested working covariance structure, reporting standardized effect estimates and drop-in-R² to assess variable importance. Sensitivity models including both RBV and UFV as predictors (26 models) were used to assess effects adjusted for confounding and mediation, respectively. The intra-patient correlation between BIS-derived VO and PW parameters at the start of sessions and PW parameter change by end of sessions was assessed using repeated measures correlation analysis. Results Data from 990 PW measurements were available for analysis from an 88% male cohort with median age of 66 years. In half of the PW parameters analyzed, each percent RBV was significantly associated with in summary about 4.3 to 5.7% (95% confidence intervals [CI] 0.9 to 10.46) of the PW parameter's respective standard deviation (SD), negatively so only in heart rate and R-Peak. UFV was negatively associated with a third of PW parameters (effects ranging from −2.5 to −5.47% SD [95% CIs −0.9 to −10.0]), mostly in classical peripheral and central pressures and peripheral resistance. In models including both predictors, RBV overall exhibited greater effect size and variance capture than UFV, except for peripheral resistance. On within-patient level, VO was positively correlated with initial medians of pressure excess (r=0.34, p=0.034), augmentation-index (0.34, p=0.031) and augmentation-pressure (0.32, p=0.042), increase in heart rate (0.32, p=0.04) and decreases in peripheral resistance (0.31, p=0.05), peripheral (systolic: 0.34, p=0.032; diastolic: 0.45, p=0.004; mean: 0.41, p=0.008) and central (diastolic: 0.46, p=0.003) blood pressures during HD. Conclusion The observed PW characteristics were associated with RBV and UFV during HD and may represent modifiable targets for intervention studies. Pressure excess, S-Peak, R-Peak, cardiac and preload parameters were more closely associated with RBV, while classic (especially diastolic) blood pressure parameters, ejection duration and S/D-Ratio were more associated with UFV, in models using both predictors. On average, blood pressure and peripheral resistance tended to decrease less when a patient began HD in a volume-expanded state, which may affect day-to-day feasibility of more classical pressure targets, but perhaps not of other PW parameters. Multiple PW characteristics have previously been shown to be associated with mortality and morbidity and are potential target parameters for future intervention trials. Utilizing RBV modification as an intervention may offer superior precision compared to UFV goals, requiring further studies. PW technology could also be adopted by HD-machine manufacturers at low cost, enabling more precise and individualized treatment options.

Effect of systemic vascular resistance on the agreement between stroke volume by non-invasive pulse wave analysis and Doppler ultrasound in healthy volunteers.

Stroke volume can be estimated beat-to-beat and non-invasively by pulse wave analysis (PWA). However, its reliability has been questioned during marked alterations in systemic vascular resistance (SVR). We studied the effect of SVR on the agreement between stroke volume by PWA and Doppler ultrasound during reductions in stroke volume in healthy volunteers. In a previous study we simultaneously measured stroke volume by PWA (SVPWA) and suprasternal Doppler ultrasound (SVUS). We exposed 16 healthy volunteers to lower body negative pressure (LBNP) to reduce stroke volume in combination with isometric hand grip to elevate SVR. LBNP was increased by 20 mmHg every 6 minutes from 0 to 80 mmHg, or until hemodynamic decompensation. The agreement between SVPWA and SVUS was examined using Bland-Altman analysis with mixed regression. Within-subject limits of agreement (LOA) was calculated from the residual standard deviation. SVRUS was calculated from SVUS. We allowed for a sloped bias line by introducing the mean of the methods and SVRUS as explanatory variables to examine whether the agreement was dependent on the magnitude of stroke volume and SVRUS. Bias ± limits of agreement (LOA) was 27.0 ± 30.1 mL. The within-subject LOA was ±11.1 mL. The within-subject percentage error was 14.6%. The difference between methods decreased with higher means of the methods (-0.15 mL/mL, confidence interval (CI): -0.19 to -0.11, P<0.001). The difference between methods increased with higher SVRUS (0.60 mL/mmHg × min × L-1, 95% CI: 0.48 to 0.72, P<0.001). PWA overestimated stroke volume compared to Doppler ultrasound during reductions in stroke volume and elevated SVR in healthy volunteers. The agreement between SVPWA and SVUS decreased during increases in SVR. This is relevant in settings where a high level of reliability is required.

G-PROTEIN-COUPLED RECEPTORS ANTIBODIES HAVE SUBSTANTIAL VASOREGULATIVE IMPLICATIONS IN LONG-COVID

Objective: The Long-COVID syndrome is associated with the generation of autoantibodies to vasoregulative G-protein coupled receptors (GPCR), playing a potential key role in this disease. How far GPCR are related to vascular dysfunction in this context remains elusive. Design and method: We performed a cross-sectional study, enrolling 80 patients with Long-COVID. GPCR antibodies encompassed autoantibodies against Angiotensin-II-Receptor-1 (AGTR2), Beta-1 Adrenergic Receptor (ADRB1), Beta-2 Adrenergic Receptor (ADRB2), Endothelin Receptor (EDNRA), Muscarinergic Choline Receptor 3 (CHRM3), and Muscarinergic Choline Receptor 4 (CHRM4), all measured by ELISA. Vascular endothelial function was assessed by flow mediated dilation (FMD). We checked for vascular and systemic inflammation by measuring lipoprotein-associated phospholipase A2 (Lp-PLA2) and high-sensitive C-reactive protein (hsCRP). We performed a non-invasive pulse wave analysis to investigate central aortic blood pressure as well as nailfold capillaroscopy. Results: 52 (65%) patients had positive antibody findings above previously established cut-off values. The median concentrations for AGTR2, ADRB1, ADRB2, EDNRA, CHRM3 and CHRM4 were 13.21 (interquartile range [IQR] 11.57-18.51) U/ml, 19.12 (IQR 16.03-27.54) U/ml, 14.18 (IQR 10.83-31.26) U/ml, 14.07 (IQR 11.30-25.19) U/ml, 13.73 (IQR 12.04-25.30) U/ml and 9.27 (IQR 7.15-13.02) U/ml, respectively. Correlation analysis showed strong and significant negative correlation of several GPCR antibodies with aortic systolic blood pressure (AGTR2 p=0.026, ADRB1 p=0.001, ADRB2 p=0.012) and aortic diastolic blood pressure (ADRB1 p=0.005, CHRM4 p=0.046). High EDNRA antibodies titers were associated with increasing FMD (p=0.038). ATGR2, ADRB2 and EDNRA had substantial negative correlation with inflammation as seen by lower hsCRP concentrations (p=0.025, p=0.001, p=0.017, respectively). None of the above mentioned antibodies were associated with Lp-PLA2 (p&gt;0.05 each). None of the investigated subentities of nailfold capillaroscopy were significant for GPCR-antibodies. Conclusions: GPCR antibodies are present in Long-COVID and show various vascular implications in terms of vasorelaxation as seen in lower aortic systolic and diastolic blood pressure as well as in an amelioration of FMD. If this is the result of anti-inflammatory properties remains elusive.

Noninvasive hemodynamic indices of vascular aging: an in silico assessment.

Vascular aging (VA) involves structural and functional changes in blood vessels that contribute to cardiovascular disease. Several noninvasive pulse wave (PW) indices have been proposed to assess the arterial stiffness component of VA in the clinic and daily life. This study investigated 19 of these indices, identified in recent review articles on VA, by using a database comprising 3,837 virtual healthy subjects aged 25-75 yr, each with unique PW signals simulated under various levels of artificial noise to mimic real measurement errors. For each subject, VA indices were calculated from filtered PW signals and compared with the precise theoretical value of aortic Young's modulus (EAo). In silico PW indices showed age-related changes that align with in vivo population studies. The cardio-ankle vascular index (CAVI) and all pulse wave velocity (PWV) indices showed strong linear correlations with EAo (Pearson's rp > 0.95). Carotid distensibility showed a strong negative nonlinear correlation (Spearman's rs < -0.99). CAVI and distensibility exhibited greater resilience to noise compared with PWV indices. Blood pressure-related indices and photoplethysmography (PPG)-based indices showed weaker correlations with EAo (rp and rs < 0.89, |rp| and |rs| < 0.84, respectively). Overall, blood pressure-related indices were confounded by more cardiovascular properties (heart rate, stroke volume, duration of systole, large artery diameter, and/or peripheral vascular resistance) compared with other studied indices, and PPG-based indices were most affected by noise. In conclusion, carotid-femoral PWV, CAVI and carotid distensibility emerged as the superior clinical VA indicators, with a strong EAo correlation and noise resilience. PPG-based indices showed potential for daily VA monitoring under minimized noise disturbances.NEW & NOTEWORTHY For the first time, 19 noninvasive pulse wave indices for assessing vascular aging were examined together in a single database of nearly 4,000 subjects aged 25-75 yr. The dataset contained precise values of the aortic Young's modulus and other hemodynamic measures for each subject, which enabled us to test each index's ability to measure changes in aortic stiffness while accounting for confounding factors and measurement errors. The study provides freely available tools for analyzing these and additional indices.

Low-intensity pulsed ultrasound in obstetrics and gynecology: advances in clinical application and research progress.

In the past decade, research on ultrasound therapy in obstetrics and gynecology has rapidly developed. Currently, high-intensity ultrasound has been widely used in clinical practice, while low-intensity ultrasound has gradually emerged as a new trend of transitioning from pre-clinical research to clinical applications. Low-intensity pulsed ultrasound (LIPUS), characterized by a non-invasive low-intensity pulse wave stimulation method, employs its non-thermal effects to achieve safe, economical, and convenient therapeutic outcomes. LIPUS converts into biochemical signals within cells through pathways such as cavitation, acoustic flow, and mechanical stimulation, regulating molecular biological mechanisms and exerting various biological effects. The molecular biology mechanisms underlying the application of LIPUS in obstetrics and gynecology mainly include signaling pathways, key gene expression, angiogenesis, inflammation inhibition, and stem cell differentiation. LIPUS plays a positive role in promoting soft tissue regeneration, bone regeneration, nerve regulation, and changes in cell membrane permeability. LIPUS can improve the treatment benefit of premature ovarian failure, pelvic floor dysfunction, nerve damage caused by intrauterine growth restriction, ovariectomized osteoporosis, and incomplete uterine involution through the above biological effects, and it also has application value in the adjuvant treatment of malignant tumors such as ovarian cancer and cervical cancer. This study outlines the biological mechanisms and applications of LIPUS in treating various obstetric and gynecologic diseases, aiming to promote its precise application and provide a theoretical basis for its use in the field.

In silico assessment of non-invasive pulse wave indices of vascular ageing

In silico assessment of non-invasive pulse wave indices of vascular ageing

In silico assessment of non-invasive pulse wave indices of vascular ageing

In silico assessment of non-invasive pulse wave indices of vascular ageing

RISK FACTORS FOR ARTERIAL STIFFNESS IN ADOLESCENCE

Objective: To investigate the arterial stiffness and risk factors in adolescence. Arterial stiffness often (AS) results from the degenerative process of the media layer of elastic arteries causing rigidity of the arteries. Arterial stiffness increases with age and it is associated with several risk factors as a disease predictor. But, arterial stiffness can be also increased in a healthy arteries as well. The increased sympathetic activity promotes vasoconstriction of resistant blood vessels i.e. arteries and arterioles that result in peripheral vasoconstriction. Adolescence age is the most important period of life for promoting future health. The certain dynamic risk factors in adolescence like, emotional dysregulation, psychological family stress, education pressure, lack of sleep, gambling, substance abuse, smartphone overuse and obesity can cause arterial stiffness. Design and method: The prospective open randomized study was designed. Adolescence age between 10 and 19 years have been investigated for increased arterial stiffness and risk factors. The inclusion criteria was healthy adolescence, while exclusion criteria was any disorder present. Arterial stiffness, non-invasive blood pressure and pulse wave datas have been measured using Agedio device. The risk factors were evaluated in every subject. The vascular age have been outlined as the final measure. Results: The preliminary results indicate the increase of Augmentation Index and Coefficient of Reflection. The average percentage of Augmentation Index was 40% and Coefficient of Reflection 65% (normal value 28% and 60% respectively). The main risk factors were educational pressure, lack of sleep and smartphone influence. The vascular age was on average, 3 years higher than biological age. Conclusions: Arterial stiffness in adolescence is increased mainly by peripheral vasoconstriction, manifested with Augmentation index and Coefficient of wave Reflection.

High Fidelity Pressure Wires Provide Accurate Validation of Non-Invasive Central Blood Pressure and Pulse Wave Velocity Measurements.

Central blood pressure (cBP) is known to be a better predictor of the damage caused by hypertension in comparison with peripheral blood pressure. During cardiac catheterization, we measured cBP in the ascending aorta with a fluid-filled guiding catheter (FF) in 75 patients and with a high-fidelity micromanometer tipped wire (FFR) in 20 patients. The wire was withdrawn into the brachial artery and aorto-brachial pulse wave velocity (abPWV) was calculated from the length of the pullback and the time delay between the ascending aorta and the brachial artery pulse waves by gating to the R-wave of the ECG for both measurements. In 23 patients, a cuff was inflated around the calf and an aorta-tibial pulse wave velocity (atPWV) was calculated from the distance between the cuff around the leg and the axillary notch and the time delay between the ascending aorta and the tibial pulse waves. Brachial BP was measured non-invasively and cBP was estimated using a new suprasystolic oscillometric technology. The mean differences between invasively measured cBP by FFR and non-invasive estimation were -0.4 ± 5.7 mmHg and by FF 5.4 ± 9.4 mmHg in 52 patients. Diastolic and mean cBP were both overestimated by oscillometry, with mean differences of -8.9 ± 5.5 mmHg and -6.4 ± 5.1 mmHg compared with the FFR and -10.6 ± 6.3 mmHg and -5.9 ± 6.2 mmHg with the FF. Non-invasive systolic cBP compared accurately with the high-fidelity FFR measurements, demonstrating a low bias (≤5 mmHg) and high precision (SD ≤ 8 mmHg). These criteria were not met when using the FF measurements. Invasively derived average Ao-brachial abPWV was 7.0 ± 1.4 m/s and that of Ao-tibial atPWV was 9.1 ± 1.8 m/s. Non-invasively estimated PWV based on the reflected wave transit time did not correlate with abPWV or with atPWV. In conclusion, we demonstrate the advantages of a novel method of validation for non-invasive cBP monitoring devices using acknowledged gold standard FFR wire transducers and the possibility to easily measure PWV during coronary angiography with the impact of cardiovascular risk factors.

A learning-based image processing approach for pulse wave velocity estimation using spectrogram from peripheral pulse wave signals: An in silico study.

Carotid-to-femoral pulse wave velocity (cf-PWV) is considered a critical index to evaluate arterial stiffness. For this reason, estimating Carotid-to-femoral pulse wave velocity (cf-PWV) is essential for diagnosing and analyzing different cardiovascular diseases. Despite its broader adoption in the clinical routine, the measurement process of carotid-to-femoral pulse wave velocity is considered a demanding task for clinicians and patients making it prone to inaccuracies and errors in the estimation. A smart non-invasive, and peripheral measurement of carotid-to-femoral pulse wave velocity could overcome the challenges of the classical assessment process and improve the quality of patient care. This paper proposes a novel methodology for the carotid-to-femoral pulse wave velocity estimation based on the use of the spectrogram representation from single non-invasive peripheral pulse wave signals [photoplethysmography (PPG) or blood pressure (BP)]. This methodology was tested using three feature extraction methods based on the semi-classical signal analysis (SCSA) method, the Law's mask for texture energy extraction, and the central statistical moments. Finally, each feature method was fed into different machine learning models for the carotid-to-femoral pulse wave velocity estimation. The proposed methodology obtained an $R2\geq0.90$ for all the peripheral signals for the noise-free case using the MLP model, and for the different noise levels added to the original signal, the SCSA-based features with the MLP model presented an $R2\geq0.91$ for all the peripheral signals at the level of noise. These results provide evidence of the capacity of spectrogram representation for efficiently assessing the carotid-to-femoral pulse wave velocity estimation using different feature methods. Future work will be done toward testing the proposed methodology for in-vivo signals.

Pulse Wave Analysis Predicts Invasive Hemodynamics in Pre-Capillary Pulmonary Hypertension.

We tested the hypothesis that non-invasive pulse wave analysis (PWA)-derived systemic circulation variables can predict invasive hemodynamics of pulmonary circulation and the indicator of right heart function, N-terminal pro-brain natriuretic peptide (NT-proBNP), in patients with precapillary pulmonary hypertension (PH). This prospective study enrolled patients with group 1 and 4 PH who had complete PWA, NT-proBNP, and hemodynamics data. Risk assessment-based "hemodynamic score (HS)" and principal component analysis-based PWA variable grouping were determined/performed. Models of hierarchical multiple linear regression (HMLR) and receiver operating characteristic (ROC) curves were used to determine the relationships of PWA variables with HS and NT-proBNP and to predict the latter parameters. Fifty-three PWAs were included. PWA variables were classified into 4 eigenvalue principal components (representing 90% configuration). Univariate analysis showed that left ventricular ejection time (LVET) was significantly negatively associated with HS and NT-proBNP levels. HMLR analysis showed that LVET was still significantly, negatively, and independently associated with HS (B = -0.006 [-0.010~-0.001]) and NT-proBNP (B = -13.47 [-21.20~-5.73]). ROC curve analysis showed that LVET > 306.9 msec and > 313.2 msec predicted the low-risk group of HS (AUC: 0.802; p = 0.001; sensitivity: 100%; and specificity: 59%) and low-to-intermediate risk levels of NT-proBNP (AUC: 0.831; p < 0.001; sensitivity: 100%; and specificity: 59%). The non-invasive PWA parameter, LVET, is an independent predictor of invasive right heart HS and NT-proBNP levels; it may serve as a novel biomarker of right ventricular function in patients with pre-capillary PH.

Abstract TP99: Non-invasive Aortic Pulse Wave Velocity Is Related To Gold Standard Carotid-femoral Pulse Wave Velocity: Implications For Monitoring Large Artery Stiffness In The Clinic

Introduction: Aortic stiffness is an independent predictor of fatal stroke in both hypertensive populations and healthy subjects, but traditional monitoring methods have had difficulty being incorporated into routine practice. The gold standard, carotid-femoral pulse wave velocity (cfPWV), poses methodological challenges as this method bypasses the most distensible vessel, the proximal aorta. We propose a new method, aortic arch pulse wave velocity (aaPWV) assessed via ultrasound, which encompasses the proximal aorta and can be performed during standard cardiac echocardiography. We sought to determine if the two methods were related. Methods: We recruited 44 healthy volunteers (38.1y [SEM: 2.39], range 20-62y, 80% female) for this study. Both aaPWV and cfPWV were measured by the wave-foot method using a commercial Logic S8 Ultrasound system (GE Healthcare) with synchronous electrocardiogram. cfPWV was calculated by determining the time delay between the two vessels and dividing by the measured distance between the two sites. aaPWV was calculated by determining the time delay between onset of aortic ejection from the apical 5-chamber view and the arrival of the pulse wave at the start of descending aorta in the suprasternal view. Distance for aaPWV was estimated using regression equation from the literature. Results: Paired t-tests revealed cfPWV was significantly greater than aaPWV (5.98 ± 0.17m/s vs. 4.7 ± 0.29m/s; P&lt;0.001). Pearson correlation revealed the two methods were related (r=0.35, P=0.01) and intraclass correlation coefficient revealed good agreement within and between raters (0.75, 0.85 respectively; 0.75-0.9 indicate good agreement). Conclusion: We report that while aaPWV and cfPWV are correlated, significant differences exist, which was expected given the proximal segment is the most elastic portion of the aorta. The findings from this study suggest aaPWV could be a more feasible method to measure large artery stiffness in routinely in the clinic, but future studies are needed to determine if aaPWV is similarly predictive of adverse cardiovascular outcomes.

783 RELATIONSHIP BETWEEN PULSE WAVE VELOCITY AND MYOCARDIAL WORK IN UNTREATED HYPERTENSIVE PATIENTS WITH PRESERVED LVEF

Abstract Introduction Hemodynamic interaction between left ventricular (LV) and arterial system is a key determinant of cardiovascular performance. The non-invasive carotid-femoral Pulse Wave Velocity (PWV), obtained with applanation tonometry, is considered the most precise way of estimating arterial stiffness. The LV myocardial work (MW), based on non-invasive LV pressure-strain loop (PSL), is a new promising tool to assess LV function. Aims The aim of the study was to evaluate the correlation between PWV and MW parameters in a population of non-hypertensive and newly diagnosed untreated hypertensive people. Materials and methods 80 people (M=48), divided in hypertensive (group 1 n=40, 45±10 years) and non-hypertensive (group 2 n=40, 40±12 years), were prospectively enrolled. All underwent conventional transthoracic echocardiogram and at the same day carotid femoral PWV was calculated with applanation tonometry (SphygmoCor® XCEL). MW parameters were obtained using 2D Speckle-tracking technique. Results Comparing the two groups, PWV and Global Work Wasted (GWW) were significantly higher in the hypertensives group (9,73±2,4 vs 7,79±1,1; p=0,001 and 146±50 vs 85±27, p=0,001), as shown in Figure 1, whereas Global Work Efficiency (GWE) and Global Work Constructive (GWC) were significantly lower (93,6±2,5 vs 95,6±1,2, p=0,001 and 2410±122 vs 2167±65, p=0,002). We found a linear and positive correlation of PWV with GWW (r=0,271, p=0,016), as seen in Figure 2, and a linear and negative correlation of PWV with GWE (r=-0,282, p=0,012). Conclusion This study highlights the role of PWV and MW evaluation in hypertensives. Higher PWV and GWW could be considered as red flags of myocardial damage suggesting the need of an early appropriate antihypertensive therapy.

Relationship between Pulse Wave Velocity and Myocardial Work in untreated hypertensive patients with preserved LVEF

Abstract Introduction Hemodynamic interaction between left ventricular (LV) and arterial system is a key determinant of cardiovascular performance. The non-invasive carotid-femoral Pulse Wave Velocity (PWV), obtained with applanation tonometry, is considered the most precise way of estimating arterial stiffness. The LV myocardial work (MW), based on non-invasive LV pressure-strain loop (PSL), is a new promising tool to assess LV function. Purpose The aim of the study was to evaluate the correlation between PWV and MW parameters in a population of non-hypertensive and newly diagnosed untreated hypertensive people. Material and methods 50 people (M=30), divided in hypertensive (group 1: n=25, 40±8 years) and non-hypertensive (group 2: n=25, 38±9 years), were prospectively enrolled. All underwent conventional transthoracic echocardiography and at the same day carotid femoral PWV was calculated with applanation tonometry (SphygmoCor® XCEL). MW parameters were obtained using 2D Speckle-tracking technique. Results Comparing the two groups, PWV and Global Work Wasted (GWW) were significantly higher in the hypertensives group (9.44±2.4 vs 7.56±1.1; p=0.001 and 130±2.5 vs 80.60±1.5, p=0.002), as shown in Figure 1, whereas Global Work Efficiency (GWE) and Global Work Constructive (GWC) were significantly lower (94±2.5 vs 95.8±1.2, p=0.003 and 2393±20 vs 2166±18, p=0.02). We found a linear and positive correlation of PWV with GWW (r=0.315, p=0.026), as seen in Figure 2, and a linear and negative correlation of PWV with GWE (r=−0.315, p=0.026). Conclusion This study highlights the role of PWV and MW evaluation in hypertensives. Higher PWV and GWW could be considered as red flags of myocardial damage suggesting the need of an early appropriate antihypertensive therapy. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): University Ospital G. Martino - Messina

A Multiple Linear Regression Model for Carotid-to-Femoral Pulse Wave Velocity Estimation Based on Schrodinger Spectrum Characterization.

In this paper, a multiple linear regression model for estimating the Carotid-to-femoral pulse wave velocity (cf-PWV) from a single non-invasive peripheral pulse wave, namely blood pressure or photoplethysmography, is proposed. The training and testing datasets were extracted from in-silico, publicly available, pulse waves and hemodynamics data. The proposed model relies on a preprocessing and features extraction steps, which are performed using a semi-classical signal analysis (SCSA) method. The obtained results provide more evidence for the feasibility of machine learning and the SCSA method as a smart tool for the efficient assessment of the cf-PWV.

Multiple non-invasive peripheral vascular function parameters with obesity and cardiometabolic risk indicators in school-aged children

BackgroundThe Peripheral Arterial Tonometry (PAT) technique measured by Endo-PAT™, is recently introduced for peripheral vascular assessment in youth, primarily benefits from its easy and non-invasive operation. However, the value of Endo-PAT as early indicator of obesity-related cardiometabolic risk factors remains unclear, with few studies focusing solely on Reactive Hyperemia Index (RHI). A wider coverage of Endo-PAT algorithms is recommended to be applied simultaneously in youth. We evaluated the value of multiple Endo-PAT parameters on obesity and cardiometabolic risk indication in school-aged children, in comparison with another non-invasive Brachial-ankle Pulse Wave Velocity (BaPWV) method.MethodsThis cross-sectional sample included 545 youth (80 with overweight and 73 with obesity) aged 7–17 years. RHI, Framingham-Reactive Hyperemia Index (F-RHI), peak response and Augmentation Index normalized to Heart Rate 75 bpm (AIx75) were measured by Endo-PAT™ 2000 device. Spearman correlations of abovementioned Endo-PAT parameters and BaPWV, with adiposity (weight, waist circumference, BMI, body fat mass) and cardiometabolic indicators (glycemic response, blood pressure, lipid profiles) were calculated with non-linear adjustment on age, height, gender and baseline pulse-wave amplitude (PWA) using fractional polynomials. Analysis was repeated in students with obesity only [median BMI z score: 3.0 (2.5,3.5)] for sensitivity analysis.ResultsThe correlations of Endo-PAT parameters with adiposity measures and cardiometabolic indicators were overall mixed and weak (DBP: r ranged from − 0.20 to − 0.13, others: |r| < 0.1) after adjustment. Except that body fat mass (AIx75: r = 0.52 p < 0.01) and triglyceride level (RHI: r = − 0.32 p < 0.01, F-RHI: r = − 0.21 p > 0.05) was moderately reversed in students with obesity. In contrast, BaPWV showed consistently moderate correlations (|r| ranged from 0.123 to 0.322, p < 0.05) with almost all adiposity measures and cardiometabolic indicators regardless of obesity status.ConclusionContrary to previous suggestion, various Endo-PAT parameters performed similarly weak for early cardiometabolic risk indication in school-aged children, and less preferable than that by another non-invasive BaPWV method. Despite further investigation is needed to improve certainty of relevant research evidence, innovative technology and algorithms taking into account specifics of young population are worthy of consideration.

The central arterial stiffness parameters in decompensated versus compensated states of heart failure: a paired comparative cohort study

BackgroundArterial stiffness is strongly linked to the pathogenesis of heart failure and the development of acute decompensation in patients with stable chronic heart failure. This study aimed to compare arterial stiffness indices in patients with heart failure with reduced ejection fraction (HFrEF) during the acute decompensated state, and three months later after hospital discharge during the compensated state.ResultsOne hundred patients with acute decompensated HFrEF (NYHA class III and IV) and left ventricular ejection fraction ≤ 35% were included in the study. During the initial and follow-up visits, all patients underwent full medical history taking, clinical examination, transthoracic echocardiography, and non-invasive pulse wave analysis by the Mobil-O-Graph 24-h device for measurement of arterial stiffness. The mean age was 51.6 ± 6.1 years and 80% of the participants were males. There was a significant reduction of the central arterial stiffness indices in patients with HFrEF during the compensated state compared to the decompensated state. During the decompensated state, patients presented with NYHA FC IV (n = 64) showed higher AI (24.5 ± 10.0 vs. 16.8 ± 8.6, p < 0.001) and pulse wave velocity (9.2 ± 1.3 vs. 8.5 ± 1.2, p = 0.021) than patients with NYHA FC III, and despite the relatively smaller number of females, they showed higher stiffness indices than males.ConclusionsCentral arterial stiffness indices in patients with HFrEF were significantly lower in the compensated state than in the decompensated state. Patients with NYHA FC IV and female patients showed higher stiffness indices in their decompensated state of heart failure.

Vascular hemodynamics and blood pressure differences between young and older women

BackgroundCardiovascular disease is one of the main causes of death in the United States, and hypertension is a primary risk factor. Therefore, the primary causes of hypertension need to be identified so they may be addressed for treatment. The purpose of this study was to compare blood pressure with hemodynamic values and identify factors that may explain blood pressure differences between a cohort of healthy normotensive younger and older women.MethodsParticipants were 49 young (age: 33.8 ± 5.9) and 103 old (age: 65.8 ± 4) who were non-hypertensive, had no previous history of heart disease or type 2 diabetes, body mass index less than 30 kg/m2, normal electrocardiography response at rest and during exercise, nonsmokers, and no use of medications known to affect cardiovascular or metabolic function. Body composition measured by dual-energy X-ray absorptiometry. Hemodynamic values measured by non-invasive pulse wave velocity through radial artery tonometry. Markers of inflammation measured through blood sample analysis.ResultsSignificant differences exist between young and old groups in %fat (P < 0.001), systolic blood pressure (SBP) (P = 0.001), large artery elasticity (P = 0.005), small artery elasticity (P < 0.001), systemic vascular resistance (P = 0.004), total vascular impedance (P < 0.001), estimated cardiac output (P < 0.001), and tumor necrosis factor-⍺ (TNF-⍺) (P < 0.001). Using ANCOVA the difference in SBP between age groups was no longer significant after adjusting for small artery elasticity (P < 0.001) and TNF-⍺ (P = 0.041).ConclusionsThese data demonstrate that blood pressure and vascular hemodynamic measures differ significantly between young and old women independent of body composition. Furthermore, these differences may be explained by the inflammation marker TNF-⍺ and/or small artery elasticity.