Brachial Blood Pressure Measurements Research Articles

Actigraphy-Based Sleep and Muscle Sympathetic Nerve Activity in Humans.

Short and insufficient sleep are prevalent and associated with cardiovascular disease, with the sympathetic nervous system as a suspected mediator. The purpose of the present study was to investigate the association between objective, actigraphy-based total sleep time (TST), sleep efficiency (SE) and cardiovascular and sympathetic regulation in healthy adults. We hypothesized that short TST and low SE would be associated with elevated resting blood pressure, heart rate (HR), and muscle sympathetic nerve activity (MSNA). Participants included 94 individuals (46 males, 48 females, age: 30±15 years, body mass index (BMI): 26±4 kg/m2). All participants underwent at least 7 days of at-home, wristwatch actigraphy monitoring (avg: 10 ± 3 days). Seated blood pressures were assessed using brachial blood pressure measurements, followed by a 10-minute supine autonomic testing session consisting of continuous HR (electrocardiogram), beat-by-beat blood pressure (finger plethysmograph), and MSNA (microneurography) monitoring. Partial correlations were used to determine the relationship between sleep and cardiovascular parameters while accounting for the influence of age, sex, and BMI. TST was not associated with MAP (R=-0.105, p=0.321), HR (R=0.093, p=0.383), or MSNA burst frequency (BF; R=-0.168, p=0.112) and incidence (BI; R=-0.162, p=0.124). Similarly, SE was not associated with MAP (R=-0.088, p=0.408), HR (R=-0.118, p=0.263), MSNA BF (R=0.038, p=0.723), or MSNA BI (R=0.079, p=0.459). In contrast to recent preliminary findings, our results do not support a significant association between actigraphy-based sleep duration or efficiency and measures of resting blood pressure, heart rate, and MSNA.

COMPARISON OF CALIBRATION METHODS IN THE PRECISION OF A RING-TYPE CUFFLESS BLOOD PRESSURE MEASUREMENT DEVICE

Objective: This study aimed to compare the efficacy of two calibration methods for a ring-type cuffless blood pressure (BP) measurement device, CART-I Plus, to assess if regular calibration with a traditional brachial arm cuff device enhances its precision. Design and method: The study involved 40 patients, with 28 completing the study. Participants underwent calibration in three different positions (sitting, standing, supine). Prior to the initial calibration, they were seated quietly for 3–5 minutes. Calibration was executed using a conventional brachial arm cuff device on the same arm. In each position, calibration was performed twice, separated by a minimum interval of one minute. A rest period exceeding two minutes was allowed between position changes for stabilization. BP estimates from the CART-I Plus, derived from photoplethysmography signals, were then compared with corresponding conventional 24-hour ambulatory BP monitoring (ABPM) measurements. Results: The mean differences between the CART-I Plus and ABPM, when calibrated using the sitting position alone (twice), were -2.12±8.53/2.36±7.82 mmHg (awake/sleep SBP) and -4.11±7.73/0.27±7.99 mmHg (awake/sleep DBP), respectively. When calibration included all three positions (six total calibrations), the mean differences remained similar; -2.14±8.95/2.17±8.53 mmHg (awake/sleep SBP) and -4.10±7.91/0.25±7.73 mmHg (awake/sleep DBP) (p > 0.5). Neither the standing nor the supine position, nor a combination of sitting and supine positions, significantly improved precision. In both standing and supine positions, the devices demonstrated a strong correlation for systolic blood pressure (SBP) (r=0.86 and r=0.90, respectively) and diastolic blood pressure (DBP) (r=0.90 for both), with all correlations being statistically significant (p < 0.001). Conclusions: Provided that patient stabilization is adequately ensured, and precise brachial BP measurements are taken by medical personnel, a single sitting position calibration appears to be sufficient. The addition of dynamic three-point calibration involving standing and supine positions did not significantly enhance precision.

Sex Differences in Central Hemodynamics of Patients with Untreated Obstructive Sleep Apnea

Patients with obstructive sleep apnea (OSA) have increased risk for cardiovascular diseases. Data from the Atherosclerosis Risk in the Communities and Sleep Heart Health Study suggest that OSA is more deleterious to females versus males, although mechanistic data are lacking. Estimates of central (aortic) blood pressure (BP) are superior in predicting future cardiovascular events than traditional brachial BP measurements. While patients with OSA have altered central hemodynamics (e.g., higher aortic pulse wave velocity; PWV), potential sex differences are unexplored. We tested the hypothesis that females with OSA (n=7, 50±3yrs, 35.1±1.9kg/m2, 22.2±7.6 events/hr) have worse central hemodynamics than males with OSA (n=9, 47±3yrs, 35.0±1.4kg/m2, 31.7±6.2 events/hr). Data collection consisted of an overnight sleep study (polysomnography) to identify the presence, and characterize the severity, of OSA via the apnea-hypopnea index (AHI). Then, duplicate measures of central (aortic) and peripheral (brachial) BP, as well as central artery stiffness (PWV) and wave reflection (AIx), were made in the morning after ≥15min of quiet, supine rest. Additional hemodynamic measurements were made if data differed by ≥2% (AIx) or ≥0.5m/s (PWV). Data that met these criteria were averaged and used for analysis. Comparisons were made using two-tailed, independent samples t-tests or nonparametric Mann-Whitney Rank Sum tests, as indicated. No differences were observed in age (p=0.44), body mass index (p=0.96), nor AHI (p=1.00) between sexes. Similarly, no sex differences were observed in brachial systolic (female vs. male: 129±7 vs. 134±8mmHg, p=0.83), diastolic (77±5 vs. 85±4mmHg, p=0.26), or mean BP (96±6 vs. 101±5mmHg, p=0.45). Similarly, central systolic (122±6 vs. 125±7mmHg, p=0.96), diastolic (78±5 vs. 86±4mmHg, p=0.25), and augmentation (21±2 vs. 15±2mmHg, p=0.07) BP did not differ between sexes. Resting heart rate was also comparable between groups (67±3 vs. 65±2bpm, p=0.64). However, AIx (AIx; 42±3 vs. 35±4%) and AIx normalized to a heart rate of 75bpm (42±3 vs. 30±3%) were higher in females with OSA relative to males with OSA (p<0.05 for both). Interestingly, the forward (30±3 vs. 28±2mmHg, p=0.63) and reflected (20±2 vs. 18±2mmHg, p=0.44) pulse heights, as well as PWV (7.3±0.6 vs. 7.4±0.6m/s, p=0.85), were similar between groups. Our data indicate that despite a trend towards higher BP in males with OSA (~5mmHg) that may be clinically, though not statistically different, females with OSA have a higher AIx. As AIx is positively associated with left ventricular hypertrophy, these data also suggest that altered central (aortic) hemodynamics may contribute to the sex differences in cardiovascular risk with OSA. This work was supported by the National Institutes of Health T32-HL007111 and U54AG044170 (JMB), HL065176 (PS and VKS), and HL134885 (VKS). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Hypertension Severity and Declines in Left Ventricular Ejection Fraction Among Women Receiving Adjuvant Chemotherapy for Breast Cancer (WF-97415 UPBEAT).

Hypertension is a risk factor for experiencing left ventricular ejection fraction (LVEF) declines during receipt of potentially cardiotoxic breast cancer (BC) treatment. We sought to determine whether the hypertension stage is associated with LVEF decline during BC treatment. Across 24 centers, cardiac magnetic resonance measures of LVEF and brachial arterial blood pressure (BP) measurements were performed in women with stages I to III BC before and 3 months after initiating potentially cardiotoxic chemotherapy. Using multivariable analysis, we assessed in a blinded fashion the association between 3-month ΔLVEF and precancer treatment American Heart Association/American College of Cardiology stages of hypertension. Among 204 women, age averaged 56±1 years with 75% being White and 20% of Black race. Participants received anthracycline (45.6%), trastuzumab (22.5%), cyclophosphamide (52.9%), or paclitaxel (50%). After accounting for pretreatment LVEF, diabetes status, tobacco use, age, the number of antihypertensive medications, and body mass index, those with stage II hypertension experienced an LVEF decline of -2.89% ([95% CI, -0.69% to -5.19%]; P=0.01) relative to individuals with normal BP. Other stages saw nonsignificant declines relative to normal BP to elevated BP (-1.63% [95% CI, -0.62% to 3.88%]; P=0.16) and stage I hypertension (-0.94% [95% CI, -0.90% to 2.78%]; P=0.32). Compared with women receiving treatment for BC with normal BP, there is a stronger association of decline in LVEF in women with stage II hypertension relative to women with other hypertension stages. This raises the possibility that stage along with hypertension presence may be associated with an increased risk for the LVEF decline among women receiving potentially cardiotoxic chemotherapy for BC. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02791581 and NCT01719562.

Differences between brachial and aortic blood pressure in adolescence and their implications for diagnosis of hypertension.

Blood pressure (BP) is the leading global cause of mortality, and its prevalence is increasing in children and adolescents. Aortic BP is lower than brachial BP in adults. We aimed to assess the extent of this difference and its impact on the diagnosis of hypertension among adolescents. We used data from 3850 participants from a UK cohort of births in the early 1990s in the Southwest of England, who attended their ∼17-year follow-up and had valid measures of brachial and aortic BP at that clinic [mean (SD) age 17.8 (0.4) years, 66% female individuals]. Data are presented as mean differences [95% prediction intervals] for both sexes. Aortic systolic BP (SBP) was lower than brachial SBP [male, -22.3 (-31.2, -13.3) mmHg; female, -17.8 (-25.5, -10.0) mmHg]. Differences between aortic and brachial diastolic BP (DBP) were minimal. Based on brachial BP measurements, 101 male individuals (6%) and 22 female individuals (1%) were classified as hypertensive. In contrast, only nine male individuals (<1%) and 14 female individuals (<1%) met the criteria for hypertension based on aortic BP, and the predictive value of brachial BP for aortic hypertension was poor (positive-predictive value = 13.8%). Participants with aortic hypertension had a higher left ventricular mass index than those with brachial hypertension. Brachial BP substantially overestimates aortic BP in adolescents because of marked aortic-to-brachial pulse pressure amplification. The use of brachial BP measurement may result in an overdiagnosis of hypertension during screening in adolescence.

Vascular Health of Females with History of Assisted Reproductive Technology.

The use of assisted reproductive technologies (ART) for the treatment of infertility is gaining popularity. Limited data on the overall vascular health of females with history of ART are available. This pilot study aimed to investigate the overall vascular health of females with history of ART compared to individuals who conceived spontaneously. The assessment of overall vascular health included the measurement of brachial blood pressure, central blood pressure, and pulse wave velocity, as well as the evaluation of the arterial stiffness and carotid intima-media thickness (cIMT) of the common carotid arteries. Conventional blood lipids including lipoprotein a (Lp(a)) were also determined. In total, 45 females with history of ART and 52 females who conceived spontaneously were included (mean age: 47.72 ± 5.96 years vs. 46.84 ± 7.43 years, p = 0.525). An initial comparison revealed a significantly higher prevalence of elevated Lp(a) in ART females (p = 0.011). However, after multiple comparison correction, the significant result disappeared (p = 0.132). Within the cohort of ART females, no significantly higher cardiovascular risk was detected regarding vascular function. The potentially higher prevalence of elevated Lp(a) in ART females must be further investigated in future studies, as it might contribute to the impaired reproductive process in this cohort.

Synchronous Bilateral Brachial Blood Pressure Measurements Increased Orthostatic Hypotension Detection in the Elderly.

Orthostatic hypotension (OH) is a common clinical sign, but its detection rate is low, and it is difficult to repeat because there is no standardized screening method available. This study aimed to establish a method for detecting blood pressure and assess whether it could increase the OH detection rate in the elderly. From May to October, 2022, 178 patients with symptomatic OH and 286 subjects with asymptomatic OH were selected. BP from the bilateral brachial artery was measured using two electronic sphygmomanometers on both arms at the same time, in the order of supine, sitting, and standing at 0-3 min. OH should meet 20/10 mmHg, standing BP minus sitting BP. The OH detection rates were calculated and compared. The symptomatic OH group was more often older, slimmer, had lower ADL scores, and contained fewer smokers (all P< 0.05). The detection rate of the symptomatic OH group using the modified method was 59.55%, which was higher than that of the routine method (34.83% vs. 59.55%, P<0.05). The detection rate using the modified method in the OH group with asymptomatic OH was 20.63%, which was higher than that of the routine method (20.63% vs. 5.59%, P< 0.01). Synchronous measurement of bilateral brachial artery BP in supine, sitting, and standing positions increased the detection rate of OH in the elderly.

Contractility, ventriculoarterial coupling, and stroke work after acute myocardial infarction using CMR-derived pressure-volume loop data.

Noninvasive left ventricular (LV) pressure-volume (PV) loops derived by cardiac magnetic resonance (CMR) have recently been shown to enable characterization of cardiac hemodynamics. Thus, such PV loops could potentially provide additional diagnostic information such as contractility, arterial elastance (Ea ) and stroke work (SW) currently not available in clinical routine. This study sought to investigate to what extent PV-loop variables derived with a novel noninvasive method can provide incremental physiological information over cardiac dimensions and blood pressure in patients with acute myocardial infarction (MI). A total of 100 patients with acute MI and 75 controls were included in the study. All patients underwent CMR 2-6 days after MI including assessment of myocardium at risk (MaR) and infarct size (IS). Noninvasive PV loops were generated from CMR derived LV volumes and brachial blood pressure measurements. The following variables were quantified: Maximal elastance (Emax ) reflecting contractility, Ea , ventriculoarterial coupling (Ea /Emax ), SW, potential energy, external power, energy per ejected volume, and efficiency. All PV-loop variables were significantly different in MI patients compared to healthy volunteers, including contractility (Emax : 1.34 ± 0.48 versus 1.50 ± 0.41 mmHg/mL, p = .024), ventriculoarterial coupling (Ea /Emax : 1.27 ± 0.61 versus 0.73 ± 0.17, p < .001) and SW (0.96 ± 0.32 versus 1.38 ± 0.32 J, p < .001). These variables correlated to both MaR and IS (Emax : r2 = 0.25 and r2 = 0.29; Ea /Emax : r2 = 0.36 and r2 = 0.41; SW: r2 = 0.21 and r2 = 0.25). Noninvasive PV-loops provide physiological information beyond conventional diagnostic variables, such as ejection fraction, early after MI, including measures of contractility, ventriculoarterial coupling, and SW.

Smartphone-Based versus Non-Invasive Automatic Oscillometric Brachial Cuff Blood Pressure Measurements: A Prospective Method Comparison Volunteer Study.

Introduction: Mobile health diagnostics have demonstrated effectiveness in detecting and managing chronic diseases. This method comparison study aims to assess the accuracy and precision of the previously evaluated OptiBP™ technology over a four-week study period. This device uses optical signals recorded by placing a patient's fingertip on a smartphone's camera to estimate blood pressure (BP). Methods: In adult participants without cardiac arrhythmias and minimal interarm blood pressure difference (systolic arterial pressure (SAP) < 15 mmHg or diastolic arterial pressure (DAP) < 10 mmHg), three pairs of 30 s BP measurements with the OptiBP™ (test method) were simultaneously compared using three pairs of measurements with the non-invasive oscillometric brachial cuff (reference method) on the opposite arm over a period of four consecutive weeks at a rate of two measurements per week (one in the morning and one in the afternoon). The agreement of BP values between the two technologies was analyzed using Bland-Altman and error grid analyses. The performance of the smartphone application was investigated using the International Organization for Standardization (ISO) definitions, which require the bias ± standard deviation (SD) between two technologies to be lower than 5 ± 8 mmHg. Results: Among the 65 eligible volunteers, 53 participants had adequate OptiBP™ BP values. In 12 patients, no OptiBP™ BP could be measured due to inadequate signals. Only nine participants had known chronic arterial hypertension and 76% of those patients were treated. The mean bias ± SD between both technologies was -1.4 mmHg ± 10.1 mmHg for systolic arterial pressure (SAP), 0.2 mmHg ± 6.5 mmHg for diastolic arterial pressure (DAP) and -0.5 mmHg ± 6.9 mmHg for mean arterial pressure (MAP). Error grid analyses indicated that 100% of the pairs of BP measurements were located in zones A (no risk) and B (low risk). Conclusions: In a cohort of volunteers, we observed an acceptable agreement between BP values obtained with the OptiBPTM and those obtained with the reference method over a four-week period. The OptiBPTM fulfills the ISO standards for MAP and DAP (but not SAP). The error grid analyses showed that 100% measurements were located in risk zones A and B. Despite the need for some technological improvements, this application may become an important tool to measure BP in the future.

Association of Central Blood Pressure and Carotid Intima Media Thickness with New-Onset Hypertension in People with High Normal Blood Pressure.

People with high normal blood pressure (BP) have a higher risk of cardiovascular events than those with normal BP; therefore, progression to hypertension (HT) should be prevented. We aimed to assess the HT risk using central BP and carotid intima media thickness (CIMT) in people with high normal BP. This prospective cohort study used the Tohoku Medical Megabank Community-Based Project Cohort Study (conducted from 2013 in Miyagi Prefecture in Japan). The participants had a high normal BP, defined as a systolic BP of 120-139 mmHg and diastolic BP ＜90 mmHg using brachial BP measurement during the baseline survey. The outcome was new-onset HT during the secondary survey, conducted four years after the baseline survey. Overall, 4,021 participants with high normal BP during the baseline survey, with an average age of 58.7 years, were included; 1,030 (26%) were diagnosed with new-onset HT during the secondary survey, 3.5±0.7 years after the baseline survey. The multivariable odds ratio (95% confidence interval) for HT in the highest versus lowest quartile of central BP was 1.7 (1.2-2.4, p=0.0030), and that of CIMT was 1.8 (1.4-2.4, p＜0.001). Subgroup analysis according to age (＜60 and ≥ 60 years) and sex revealed that the central BP was influential in groups with younger age and female individuals; CIMT was influential in all groups. Higher central BP and thicker CIMT at the baseline were correlated with new-onset HT in individuals with high normal BP, independent of brachial systolic BP and other cardiovascular risk factors.

Non-invasive estimation of left ventricular systolic peak-pressure: a prerequisite to calculate of myocardial work in hypertrophic obstructive cardiomyopathy

Abstract Introduction Myocardial work (MW) is an echocardiographic parameter to estimate global and regional myocardial performance. This method utilizes pressure strain loops derived from global longitudinal strain (GLS) and left ventricular systolic pressure (LVSP) estimated by brachial blood pressure (BP). Purpose Since LVSP cannot be equated with BP in pts with HOCM, we investigated whether the LVSP can be calculated non-invasively by combining Doppler echo parameters and the BP. This estimation is mandatory to make MW applicable for HOCM-pts. Methods We studied 20 consecutive pts (8 women, 12 men; mean age 57.0±13.9 years; NYHA class 2.1±0.8) with indication for first alcohol septal ablation. 6 pts had hypertension and 2 pts unexplained syncope. 18 (90%) pts were in sinus rhythm. NTproBNP was 1431 pg/ml (1912 IQR). Echo baseline measurements showed subaortic septal (IVS) thickness of 21.0±5.0 mm and maximal IVS thickness of 24.7±6.3 mm. Pts showed high-normal left ventricular ejection fraction (70.4±10.1%). Left atrial (LA) volume was 101.2±26 ml. All measurements of pressures and gradients were performed in the catheterization laboratory after placement of a 5F Judkins JR4 in the ascending aorta and a 5.2F special pigtail catheter in the apex of LV beyond the obstruction. Simultaneous measurements of BP at left upper arm, echo intraventricular gradients (instantaneous and mean) with CW Doppler (GE Vivid E70), and invasive pressures and gradients (peak-to-peak and mean) of the LV and ascending aorta were performed. Echo and invasive gradients were averaged over 3 cardiac cycles. Finally, we tried to identify an estimation of invasively measured LV systolic pressure by combining systolic BP and echo measured gradients. Results Systolic BP was 143±21 mmHg. Max. CW Doppler gradient was 65±29 mmHg and mean gradient was 31±14 mmHg. Invasive simultaneous measurements at rest showed peak-to-peak gradient of 55±24 mmHg and mean gradient of 34±13 mmHg between apical LV and ascending aorta. Mean LVSP was 190±40 mmHg. Systolic pressure of the ascending aorta was 134±28 mmHg. Adding systolic peripheral BP and maximal echo-gradient mean value was 208±38 mmHg. Adding systolic peripheral BP and echo-mean gradient mean value was 174±26 mmHg. Correlating these values with the invasively measured systolic LV pressure we found a slightly higher correlation of the sum of systolic BP and mean-echo gradient (Pearson correlation coefficient: 0.867 p&amp;lt;0.001) compared with the sum of systolic BP and maximal echo-gradient (Pearson correlation coefficient: 0.851; p&amp;lt;0.001). Bland–Altman plots demonstrated good levels of agreements between invasively measured LVSP and both non-invasively estimated LVSP. Conclusions Non-invasive estimation of LVSP is feasible by combining conventional BP and CW Doppler measured mean LV outflow tract gradient in HOCM. Hereby estimation of MW in pts with HOCM is applicable.

Invasively Measured Aortic Systolic Blood Pressure and Office Systolic Blood Pressure in Cardiovascular Risk Assessment in CKD

IntroductionCentral aortic blood pressure (BP) could be a better risk predictor than brachial BP. This study examined whether invasively measured aortic systolic BP improved outcome prediction beyond risk prediction by conventional cuff-based office systolic BP in patients with and without chronic kidney disease (CKD). MethodsIn a prospective, longitudinal cohort study aortic and office systolic BPs were registered in patients undergoing elective coronary angiography. CKD was defined as estimated glomerular filtration rate <60 ml/min/1.73 m2. Multivariable Cox models were used for the association with incident myocardial infarction (MI), stroke, and death. ResultsAortic and office systolic BPs were available in 39,866 patients (mean age: 64 years; 58% males; 64% with hypertension) out of which 6,605 (17%) had CKD. During a median follow-up of 7.2 years (interquartile range: 4.6-10.1 years), 1,367 strokes (CKD: 353), 1,858 MIs (CKD: 446) and 7,551 deaths (CKD: 2,515) occurred. CKD increased the risk of stroke, MI and death significantly. Office and aortic systolic BP were both associated with stroke in non-CKD patients (adjusted hazard ratios with 95% confidence interval per 10 mmHg: 1.08 (1.05–1.12) and 1.06 (1.03–1.09), respectively) and with MI in CKD patients (adjusted hazard ratios: 1.08 (1.03–1.13) and 1.08 (1.04–1.12), respectively). There was no significant difference between prediction of outcome with office or aortic systolic BP when adjusted models were compared with C-statistics. ConclusionRegardless of CKD status, invasively measured central aortic systolic BP does not improve the ability to predict outcome compared with brachial office BP measurement.

Association of subendocardial viability ratio and mortality in the elderly population: results from the CARdiovascular disease, Living and Ageing in Halle study.

The subendocardial viability ratio (SEVR) reflects the balance of myocardial oxygen supply and demand. Low SEVR indicates a reduced subendocardial perfusion and has been shown to predict mortality in patients with kidney disease and diabetes. The aim of this study is to investigate the association of SEVR and mortality in the elderly population. We analysed data from the CARdiovascular disease, Living and Ageing in Halle (CARLA) study. SEVR was estimated noninvasively by radial artery tonometry and brachial blood pressure measurement. The study population was divided into a low (SEVR ≤130%) and normal (SEVR >130%) SEVR group. Cox-regression was used for survival analysis. In total, 1414 participants (635 women, 779 men) aged from 50 to 87 years (mean age 67.3 years) were included in the analysis. The all-cause mortality was 22.7% during a median follow-up of 10.5 years. The unadjusted association of SEVR with all-cause mortality decreased from 3.52 (1.31-9.46) [hazard ratio (95% confidence interval) for low SEVR ≤ 130% versus normal SEVR > 130%] among those younger than 60 years to 0.86 (0.50-1.48) among those older than 80 years and from 1.81 (0.22-14.70) to 0.75 (0.30-1.91) for cardiovascular mortality. Sex-specific unadjusted analyses demonstrated an association of SEVR with all-cause and cardiovascular mortality in men [2.32 (1.61-3.34) and 2.24 (1.18-4.24)], but not in women [1.53 (0.87-2.72) and 1.14 (0.34-3.82)]. Our data suggests that SEVR is an age dependent predictor for all-cause mortality, predominantly in men younger than 60 years.

Blood Pressure Measurement Based on the Camera and Inertial Measurement Unit of a Smartphone: Instrument Validation Study.

Even though several mobile apps that can measure blood pressure have been developed, the data about the accuracy of these apps are limited. We assessed the accuracy of AlwaysBP (test) in blood pressure measurement compared with the standard, cuff-based, manual method of brachial blood pressure measurement (reference). AlwaysBP is a smartphone software that estimates systolic blood pressure (SBP) and diastolic blood pressure (DBP) based on pulse transit time (PTT). PTT was calculated with a finger photoplethysmogram and seismocardiogram using, respectively, the camera and inertial measurement unit sensor of a commercially available smartphone. After calculating PTT, SBP and DBP were estimated via the Bramwell-Hill and Moens-Korteweg equations. A calibration process was carried out 3 times for each participant to determine the input parameters of the equations. This study was conducted from March to August 2021 at Chungnam National University Sejong Hospital with 87 participants aged between 19 and 70 years who met specific conditions. The primary analysis aimed to evaluate the accuracy of the test method compared with the reference method for the entire study population. The secondary analysis was performed to confirm the stability of the test method for up to 4 weeks in 15 participants. At enrollment, gender, arm circumference, and blood pressure distribution were considered according to current guidelines. Among the 87 study participants, 45 (52%) individuals were male, and the average age was 35.6 (SD 10.4) years. Hypertension was diagnosed in 14 (16%) participants before this study. The mean test and reference SBPs were 120.0 (SD 18.8) and 118.7 (SD 20.2) mm Hg, respectively (difference: mean 1.2, SD 7.1 mm Hg). The absolute differences between the test and reference SBPs were <5, <10, and <15 mm Hg in 57.5% (150/261), 84.3% (220/261 ), and 94.6% (247/261) of measurements. The mean test and reference DBPs were 80.1 (SD 12.6) and 81.1 (SD 14.4) mm Hg, respectively (difference: mean -1.0, SD 6.0 mm Hg). The absolute differences between the test and reference DBPs were <5, <10, and <15 mm Hg in 75.5% (197/261), 93.9% (245/261), and 97.3% (254/261) of measurements, respectively. The secondary analysis showed that after 4 weeks, the differences between SBP and DBP were 0.1 (SD 8.8) and -2.4 (SD 7.6) mm Hg, respectively. AlwaysBP exhibited acceptable accuracy in SBP and DBP measurement compared with the standard measurement method, according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization protocol criteria. However, further validation studies with a specific validation protocol designed for cuffless blood pressure measuring devices are required to assess clinical accuracy. This technology can be easily applied in everyday life and may improve the general population's awareness of hypertension, thus helping to control it.

Central blood pressure obtained by cuff-based oscillometry as a determinant of left ventricular hypertrophy in hypertensive patients.

Limited and conflicting data have been reported on the prognostic relevance of central blood pressure (CBP) compared with brachial blood pressure (BP) in the anticipation of hypertension-mediated organ damage and the majority of data derived using applanation tonometry with its known complexities. The objective of the present study was to investigate the diagnostic factors of left ventricular hypertrophy (LVH) with a special highlight on the utility of non-invasive oscillometric CBP measurement and derived hemodynamic indices compared to brachial BP as indicators of LVH. This cross-sectional study included 300 hypertensive patients (mean age 55.3 years, 61.3% female, 51.7% obese) with a mean duration of hypertension was 5.8 years. They underwent measurement of brachial BP, using a mercury sphygmomanometer, and CBP, using a Mobil-O-Graph, alongside the determination of left ventricular (LV) mass by two-dimensional transthoracic echocardiography. LVH and LV geometric patterns were defined by LV mass index/height 2.7 and relative wall thickness. Bivariate then multivariate analysis showed that age, BMI, central systolic BP (SBP), and pulse wave velocity (PWV) were significant determinants of LVH and optimally controlled brachial BP was a significant negative determinant for LVH. Central SBP had an acceptable diagnostic performance to determine LVH in patients with hypertension (AUC = 0.722, 95% confidence interval: 0.618-0.824, SE = 0.21, P -value <0.001). Using one-way ANOVA, a comparison of means among age groups showed that the steady increase in central SBP and PWV with aging was greater among LVH patients than non-LVH patients. Estimated central SBP using Mobil-O-Graph showed a significantly higher correlation to LVH than brachial SBP values. The consistent increase in central SBP and PWV with aging was greater among LVH patients than non-LVH patients.

Vascular determinants of hippocampal viscoelastic properties in healthy adults across the lifespan

Arterial stiffness and cerebrovascular pulsatility are non-traditional risk factors of Alzheimer’s disease. However, there is a gap in understanding the earliest mechanisms that link these vascular determinants to brain aging. Changes to mechanical tissue properties of the hippocampus (HC), a brain structure essential for memory encoding, may reflect the impact of vascular dysfunction on brain aging. We tested the hypothesis that arterial stiffness and cerebrovascular pulsatility are related to HC tissue properties in healthy adults across the lifespan. Twenty-five adults underwent measurements of brachial blood pressure (BP), large elastic artery stiffness, middle cerebral artery pulsatility index (MCAv PI), and magnetic resonance elastography (MRE), a sensitive measure of HC viscoelasticity. Individuals with higher carotid pulse pressure (PP) exhibited lower HC stiffness (β = −0.39, r = −0.41, p = 0.05), independent of age and sex. Collectively, carotid PP and MCAv PI significantly explained a large portion of the total variance in HC stiffness (adjusted R2 = 0.41, p = 0.005) in the absence of associations with HC volumes. These cross-sectional findings suggest that the earliest reductions in HC tissue properties are associated with alterations in vascular function.

Aortic-brachial stiffness mismatch as potential marker of subclinical arterial damage in patients with rheumatoid arthritis

Aortic-brachial stiffness mismatch is a potential new marker of a subclinical vascular damage that has never been studied in patients with rheumatic diseases. The aim of the study was to assess the frequency of arterial stiffness mismatch in rheumatoid arthritis (RA) and to evaluate its clinical associations. Materials and Methods. The study group included 85 patients with RA (males 22.4 %, aged 59.7 ± 14.3 years, hypertension in 65 %, mean disease activity score (DAS-28 (C-reactive protein) 3.7 ± 1.1), and the control group included 40 subjects matched by gender, age and risk factors. The study methods included measurements of clinical and ambulatory brachial and aortic blood pressure (BP) (BPLab-Vasotens), arterial stiffness parameters parameters (applanation tonometry, SphygmoCorAtCor), cardio-ankle vascular index (VaSera) and cardio-vascular risk assessments using the SCORE, American College of Cardiology/American Heart Association (ACC/AHA) 2013 pooled cohort equations and QRisk2 scoring systems. The arterial stiffness gradient was calculated as a ratio between carotid-femoral (cf) and carotid-radial (cr) pulse wave velocity, and its elevation of ≥ 1 was considered as arterial stiffness mismatch. A p-value of 0.05 was considered significant. Results and Discussion. The mean stiffness gradient in RA patients without and with hypertension was 1.1 ± 0.1 and 1.4 ± 0.4, respectively (р 0.001); in controls, 0.99 ± 0.2 and 1.3 ± 0.3, respectively (р 0.001). The frequency of stiffness mismatch in the RA group was significantly higher compared to the controls in the whole study population (88.2 % vs 65 % (р = 0.002)) and in both normotensive and hypertensive subgroups (76.7 % vs 43.8 % (p = 0.03), and 94.5 % vs 79.2 % (p = 0.04), respectively). The same trend was observed in the subgroups with normal carotid-femoral pulse wave velocity: arterial stiffness mismatch was present in 82.1 % of RA patients vs. 51.9 % control subjects (p = 0.004). The stiffness gradient was associated with age (r = 0.63), hypertension duration (r = 0.56), cardio-vascular risk by the ACC/AHA 2013 (r = 0.69) and Qrisk2 (r = 0.7) scoring systems, nocturnal aortic systolic BP (r = 0.53), cardio-ankle vascular index (r = 0.60) and diurnal index of brachial systolic BP (r = -0.4). Significant differences in stiffness gradient values were observed in the subgroups based on elevation of aortic systolic BP and pulse wave velocity above individual reference values, aortic pulse pressure 50 mmHg, cardio-ankle vascular index 9, presence of high cardio-vascular risk, masked and nocturnal hypertension, and non-dipping. Conclusion. Patients with RA are characterized by higher frequency of arterial stiffness mismatch compared to controls, irrespective of the history of hypertension or the values of carotid-femoral pulse wave velocity. Arterial stiffness mismatch is associated with unfavorable 24-h BP profile, higher frequency of nocturnal hypertension and cardio-vascular risk.

Incremental value of continuous non-invasive blood pressure control to assess hypotension during atrial fibrillation ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atrial Fibrillation (AF) ablation is associated with continuous blood pressure (BP) variations related to anesthesiological regimen and energy delivery. Conventional BP monitoring with non-invasive periodic brachial BP controls can miss potential hypotensive events. Continuous non-invasive blood pressure (CNBP) measurement using the volume-clamp method (Clearsight) was demonstrated to be a reliable and effective tool for the assessment of BP during AF ablation. Purpose Aim of the study was to investigate the incidence of hypotensive events during AF ablation. Methods We included consecutive patients scheduled for AF ablation and monitored in parallel with a periodic (10 minutes) brachial BP cuff and in continuous with the CNBP System (Clearsight). All CNBP data were analyzed with the Acumen Analytics software for hypotension evaluation. According to the anesthesiological regimen, patients were divided in 2 Groups, the General Anesthesia (GA) and the Deep Sedation (DS) group. Area under the threshold (AUT, mmHg x min) of 65 mmHg and Time Weighted Average (TWA, mmHg, i.e., the AUT divided by the total duration of procedure in minutes) of area under threshold (MAP &amp;lt;65 mmHg) were compared between the two groups. Results Forty-eight patients were included, 10 (21%) in the General Anesthesia Group and 38 (79%) in the Sedation Group. Hypotension was detected in 18 patients, 9/10 (90%) were recorded in the GA group and 9/38 (23.7%) in the DS one. A total of 85 hypotensive events were recorded, 68 (80%) in the GA and 17 (20%) in the DS Group. In the overall population, mean duration of hypotensive events was 4.87 minutes (range 0 – 14.73 minutes), mean MAP &amp;lt; 65 mmHg was 54.25 ± 7.2 mmHg, mean AUT (MAP &amp;lt;65 mmHg) was 79.4 mmHg x min (range 0 – 1237.7) and mean TWA was 0.41 mmHg (range 0 – 6.9). Hypotensions were more often documented in GA than in DS patients (mean difference 6.35 events/procedure, C.I. 2.66 – 10.10, p&amp;lt;0.05) so as AUTs (mean difference 319.90 mmHg x min, C.I. 30.00 – 609.80, p=0.034) and TWAs (mean difference 1.64 mmHg, C.I. 0.18 – 3.09, p=0.032) which were significantly higher in the GA group. Brachial periodic BP measurement every 10 minutes missed the majority (n=52, 61.2%) of hypotensive events. Conclusions CNBP demonstrated a high incidence of hypotension during AF ablation, specially under GA, which are usually missed by the standard intermittent brachial non-invasive BP monitoring. Real time hypotension predictive CNBP indexes could be valuable in this setting.

Are portable ankle brachial pressure index measurement devices suitable for hypertension screening?

In a large-scale population cardiovascular screening programme, peripheral artery disease (PAD) and hypertension would ideally be rapidly assessed using a single device. The ankle-brachial pressure index (ABPI) is calculated by comparing the ankle and brachial blood pressure (BP). However, it is currently unclear whether brachial BP measurements provided by automated PAD screening systems are sufficiently accurate for simultaneous hypertension screening. Two portable PAD screening devices, the MESI ABPI MD and Huntleigh's Dopplex ABIlity, were evaluated following the European Society of Hypertension International Protocol (ESH-IP) Revision 2010 using a mercury-free sphygmomanometer as a reference device. On average, the MESI slightly underestimated brachial systolic blood pressure (BP) with a bias and standard deviation (SD) of -3.5 (SD: 3.3) mmHg and diastolic BP with a bias of -1.5 (SD: 2.3) mmHg. For systolic BP estimates, the Dopplex was more accurate than the MESI with a lower bias of -0.5 (SD: 4.2) mmHg but less precise. The MESI successfully fulfilled all the requirements of the ESH-IP for hypertension screening. The Dopplex device failed the ESH-IP due to the absence of DBP measurements. The MESI device appears to be suitable for simultaneous PAD and hypertension screening as part of a preventative care programme. Huntleigh's Dopplex ABIlity failed to pass the ESH-IP validation test. Further clinical trials are underway to assess the use of the MESI for simultaneous screening for hypertension and PAD in a population screening setting.

PS-C08-5: VALIDATE-CKD - PRELIMINARY FINDINGS ON CENTRAL BLOOD PRESSURE DEVICES ACCURACY IN PATIENTS WITH STAGES G4-G5 CHRONIC KIDNEY DISEASE

Objective: Measurement of brachial cuff blood pressure (BP) was designed as a convenient surrogate to the aortic BP, which is the BP that dictates perfusion to target organs. In the general population, brachial cuff systolic BP (SBP) has a somewhat acceptable accuracy towards aortic BP but less is know in populations with marked high arterial stiffness, such as in G4-G5 CKD. Central BP devices were designed to directly estimate the aortic BP through pulse wave analysis to a greater accuracy than brachial cuff BP. The aim of the ongoing VALIDATE-CKD study is to compare the accuracy of brachial and central BP readings towards the intraarterial aortic SBP, in patients with and without Stage G4-G5 CKD. Design and method: In patients with and without Stage G4-G5 CKD (eGFR &lt; 30 ml/min/1.73m2) undergoing non-urgent coronary angiograms, invasive aortic and non-invasive (WatchBP and Mobil-o-graph devices) BPs were measured simultaneously following the ARTERY Society protocol. Accuracy was defined by the mean difference (± SD) between the aortic SBP and the corresponding non-invasive SBP. Results: To date, 8 individuals with Stage G4-G5 CKD and 26 control subjects are enrolled. The following table presents clinical characteristics and non-invasive BPs accuracies in patients with and without Stage G4-G5 CKD. Conclusion: These preliminary results indicate that brachial SBP significantly underestimates aortic SBP in patients with Stage G4-5 CKD as compared to control subject. Furthermore, central BP devices provide a highly accurate estimation of aortic SBP in this population. The ongoing VALIDATE-CKD study may support that the use of central BP devices could be beneficial for the management of patients with advanced CKD.