Central Blood Pressure Measurements Research Articles

VALIDATION OF A BRACHIAL OSCILLOMETRY AND MODEL-BASED ESTIMATE OF STROKE VOLUME AGAINST MAGNETIC RESONANCE IMAGING

Objective: Technological progress recently facilitated 24 hour measurement of central blood pressure and pulsatile hemodynamics, using brachial blood pressure cuffs and dedicated software. A complementary estimate of cardiac function is desirable. Design and method: Our proposed method mathematically describes left ventricular outflow during systole according to a given pressure wave. The model combines a modified 3-element like Windkessel system and transmission line theory, and provides an estimate of stroke volume (SV). For this study, pulse waves, recorded with a brachial cuff at the level of diastolic blood pressure, are utilized. In 97 patients with reperfused acute myocardial infarction and in 2 healthy controls, cardiac magnetic resonance imaging (CMRI; 1.5 Tesla Magnetom, Siemens, Germany) was performed, and SV was measured with standard protocols from short axis cine images (11 slices). Images were acquired using breath hold, retrospective ECG triggered TrueFISP bright blood sequences, and evaluated with standard software (ARGUS, Siemens, Erlangen, Germany). SV from both methods were compared with Pearson[Combining Acute Accent]s correlation coefficients and Bland Altman Plots. Results: Mean age of participants was 56.8 years, 21 were women, 56 smokers, mean nt-proBNP was 1350 pg/ml, mean EF 54% (range 28–76). MRI-derived SV was 76 ml (range 28.5–122), oscillometric device-derived SV was 67 ml (range 35–113). Both SVs was moderately correlated (r = 0.54 (CI 0.39–0.67), p < 0.001). Using the method of Bland-Altman, mean difference between both methods was 8.7 ml (1.96 limits of agreement were 36.7 and −19.3 ml), with no systematic bias - Figure. Both MRI-based and oscillometric method-based SV were inversely related to nt-proBNP levels (r = −0.31, p = 0.002 and r = −0.25, p = 0.01, respectively). Conclusions: Brachial oscillometry and mathematical modeling provide a reasonable estimate of stroke volume, which may be a useful addition to 24 hour measurements of blood pressure and pulsatile hemodynamics.

Isolated systolic hypertension of the young and its association with central blood pressure in a large multi-ethnic population. The HELIUS study.

BackgroundIsolated systolic hypertension (ISH) of the young has been associated with both normal and increased cardiovascular risk, which has been attributed to differences in central systolic blood pressure and arterial stiffness.MethodsWe assessed the prevalence of ISH of the young and compared differences in central systolic blood pressure and arterial stiffness between ISH and other hypertensive phenotypes in a multi-ethnic population of 3744 subjects (44% men), aged <40 years, participating in the HELIUS study.ResultsThe overall prevalence of ISH was 2.7% (5.2% in men and 1.0% in women) with the highest prevalence in individuals of African descent. Subjects with ISH had lower central systolic blood pressure and pulse wave velocity compared with those with isolated diastolic or systolic-diastolic hypertension, resembling central systolic blood pressure and pulse wave velocity values observed in subjects with high-normal blood pressure. In addition, they had a lower augmentation index and larger stroke volume compared with all other hypertensive phenotypes. In subjects with ISH, increased systolic blood pressure amplification was associated with male gender, Dutch origin, lower age, taller stature, lower augmentation index and larger stroke volume.ConclusionISH of the young is a heterogeneous condition with average central systolic blood pressure values comparable to individuals with high-normal blood pressure. On an individual level ISH was associated with both normal and raised central systolic blood pressure. In subjects with ISH of the young, measurement of central systolic blood pressure may aid in discriminating high from low cardiovascular risk.

A Comparison and Calibration of a Wrist-Worn Blood Pressure Monitor for Patient Management: Assessing the Reliability of Innovative Blood Pressure Devices.

BackgroundClinical guidelines recommend monitoring of blood pressure at home using an automatic blood pressure device for the management of hypertension. Devices are not often calibrated against direct blood pressure measures, leaving health care providers and patients with less reliable information than is possible with current technology. Rigorous assessments of medical devices are necessary for establishing clinical utility.ObjectiveThe purpose of our study was 2-fold: (1) to assess the validity and perform iterative calibration of indirect blood pressure measurements by a noninvasive wrist cuff blood pressure device in direct comparison with simultaneously recorded peripheral and central intra-arterial blood pressure measurements and (2) to assess the validity of the measurements thereafter of the noninvasive wrist cuff blood pressure device in comparison with measurements by a noninvasive upper arm blood pressure device to the Canadian hypertension guidelines.MethodsThe cloud-based blood pressure algorithms for an oscillometric wrist cuff device were iteratively calibrated to direct pressure measures in 20 consented patient participants. We then assessed measurement validity of the device, using Bland-Altman analysis during routine cardiovascular catheterization.ResultsThe precalibrated absolute mean difference between direct intra-arterial to wrist cuff pressure measurements were 10.8 (SD 9.7) for systolic and 16.1 (SD 6.3) for diastolic. The postcalibrated absolute mean difference was 7.2 (SD 5.1) for systolic and 4.3 (SD 3.3) for diastolic pressures. This is an improvement in accuracy of 33% systolic and 73% diastolic with a 48% reduction in the variability for both measures. Furthermore, the wrist cuff device demonstrated similar sensitivity in measuring high blood pressure compared with the direct intra-arterial method. The device, when calibrated to direct aortic pressures, demonstrated the potential to reduce a treatment gap in high blood pressure measurements.ConclusionsThe systolic pressure measurements of the wrist cuff have been iteratively calibrated using gold standard central (ascending aortic) pressure. This improves the accuracy of the indirect measures and potentially reduces the treatment gap. Devices that undergo auscultatory (indirect) calibration for licensing can be greatly improved by additional iterative calibration via intra-arterial (direct) measures of blood pressure. Further clinical trials with repeated use of the device over time are needed to assess the reliability of the device in accordance with current and evolving guidelines for informed decision making in the management of hypertension.Trial RegistrationClinicalTrials.gov NCT03015363; https://clinicaltrials.gov/ct2/show/NCT03015363 (Archived by WebCite at http://www.webcitation.org/6xPZgseYS)

Abstract P243: Endothelial Function, Arterial Stiffness and Central Blood Pressure are Not Affected by a Single Dose of Dietary Nitrate in Healthy Normotensive Females

Intro: Hypertension is a prominent risk factor for cardiovascular disease and arterial stiffness is a related predictor of both mortality and longitudinal onset of hypertension in normotensive individuals. Both vascular compliance and blood pressure have been shown to improve following dietary nitrate supplementation in some healthy and diseased individuals. Dietary nitrate supplementation increases plasma nitrite and may, therefore, enhance bioavailability of endothelium derived nitric oxide. Chronic increased flow mediated dilation (FMD) and reduction of pulse wave velocity (PWV) reduce a person’s long-term risk for developing endothelial dysfunction, atherosclerosis and hypertension. Hypothesis: We hypothesized that an acute dose of dietary nitrate would improve FMD, decrease PWV and reduce central blood pressure (cBP) in healthy, young females. Methods: Seven healthy, young (21 ± 2 years) females participated in a randomized, double blind, placebo controlled, crossover protocol. Participants had endothelial function measured via FMD, arterial stiffness via PWV and applanation tonometry, and cBP was determined non-invasively using pulse wave analysis following a 12-hour fasting period and 48-hour NIH approved low nitrate diet. Baseline values were measured the day before each treatment visit (placebo or nitrate-rich, separated by a 1-week washout period). Participants consumed either a placebo or nitrate-rich supplement (negligible and 6.2 mmol nitrate, respectively) 2 hours prior to their laboratory visit. Upon arrival, blood was drawn and participants assumed a supine position for 15 minutes. Then brachial artery FMD was assessed via high definition ultrasound imaging following 5 minutes of proximal forearm occlusion, followed by PWV and central blood pressure measurements. Results: Plasma nitrite was elevated following consumption of the nitrate rich supplement compared to placebo (26.33 ± 15.76 and 1.18 ± 0.96 arbitrary units, respectively; p&lt;0.05). However, there was no difference between nitrate rich and placebo treatments for endothelial function as measured by FMD (10.33 ± 1.82 and 9.11 ± 5.43%, respectively; p=0.70). No difference was present between nitrate and placebo groups for PWV (5.99 ± 0.85 and 6.16 ± 0.80 m/s, respectively; p=0.90), systolic cBP (101.57 ± 9.29 and 96.90 ± 20.95 mmHg, respectively; p=0.40) and diastolic cBP (72.57 ± 7.67 and 73.20 ± 5.01 mmHg, respectively; p=0.97). Conclusion: While a single dose of dietary nitrate does increase plasma nitrite, supplementation has minimal effects on FMD, PWV and cBP in young healthy females. Future research should examine longer duration supplementation protocols as well as the changes in vascular health of patients with known disease such as hypertension or peripheral artery disease.

The effects of metformin on maternal haemodynamics in gestational diabetes mellitus: A pilot study

BackgroundGestational diabetes mellitus (GDM) is a major clinical challenge and is likely to remain so as the incidence of GDM continues to increase. AimTo assess longitudinal changes in maternal haemodynamics amongst women diagnosed with GDM requiring either metformin or dietary intervention in comparison to low-risk healthy controls. MethodologyFifty-six pregnant women attending their first appointment at the GDM clinic and 60 low-risk healthy pregnant controls attending their routine antenatal clinics were recruited and assigned to three groups: GDM Metformin (GDM-M), GDM Diet (GDM-D) and Control. Non-invasive assessment of maternal haemodynamics, using recognised measures of arterial stiffness and central blood pressure (Arteriograph®), were undertaken under controlled conditions within four gestational windows: antenatal; AN1 (26–28 weeks), AN2 (32–34 weeks) and AN3 (37–40 weeks), and postnatal (PN) (6–8 weeks after delivery). Data were analysed using a linear mixed model incorporating gestational age and other relevant predictors, including age, blood pressure (BP), baseline bodyweight and pulse as fixed effects, and patient as a random effect. ResultsFitted linear mixed models showed evidence of a two-way interaction effect between groups (GDM-D, GDM-M and Control) and stages of gestation (AN1, AN2, AN3 and PN) for maternal haemodynamic parameters: brachial artery augmentation index (AIx) (p = 0.004), aortic AIx (p = 0.008), and central systolic BP (p = 0.001). However, differences in respect of aortic pulse wave velocity (p = 0.001) and heart rate (p < 0.001) were only significant for gestational stage. At AN2, we did not observe any evidence that the mean brachial Aix in the GDM-M was different from the control group (p = 0.158). ConclusionAIx and central systolic BP measures of arterial stiffness are adversely affected by GDM in comparison to controls during pregnancy. The possible beneficial effects of metformin therapy seen at 32 to 34 weeks of gestation require further exploration.

Correlation among lipid parameters, pulse wave velocity and central blood pressure in young Korean population

ABSTRACTBackground: Central blood pressure is closely related to the important cardiovascular intermediate end points, such as vascular hypertrophy and extent of carotid atherosclerosis. Therefore it is prudent to study correlation among central aortic blood pressure, body composition, lipid profiles, and pulse wave velocity in population-based study. Consequently, we investigate the correlation between central aortic blood pressure and other risk parameters of hypertension such as body composition and lipid profile. Methods: We recruited 20 young participants diagnosed with hypertension as well as 30 without hypertension. The study used an X-SCAN PLUS 950 machine for measurement of overall body composition. Measurements of central blood pressure and carotid–femoral pulse wave velocity were carried out using SphygmoCor XCEL. Results: The hypertensive participants had significantly higher total weight without fat, body moisture mass, muscle mass, body mass index, basal metabolic rate, intracellular and extracellular water contents, protein and mineral contents along with brachial and central aortic blood pressures. In both hypertensive and non-hypertensive participants, central aortic diastolic blood pressure were significantly related to the lipid parameters. Conclusion: Overall, the correlations between central blood pressure, pulse wave velocity, and lipid profile in hypertensive and non-hypertensive participants were substantial.

Comparison of laboratory and ambulatory measures of central blood pressure and pulse wave reflection: hitting the target or missing the mark?

Prior studies demonstrating clinical significance of noninvasive estimates of central blood pressure (BP) and pulse wave reflection have relied primarily on discrete resting measures. The aim of this study was to compare central BP and pulse wave reflection measures sampled during a single resting laboratory visit against those obtained under ambulatory conditions. The secondary aim was to investigate the reproducibility of ambulatory central BP and pulse wave reflection measurements. Forty healthy participants (21 males; 24 ± 3 years) completed three measurements of brachial artery pulse wave analysis (Oscar 2 with SphygmoCor Inside) in the laboratory followed by 24 hours of ambulatory monitoring. Seventeen participants repeated the 24-hour ambulatory monitoring visit after at least 1 week. Ambulatory measures were divided into daytime (9 AM–9 PM), nighttime (1 AM–6 AM), and 24-hour periods. Compared with laboratory measurements, central systolic BP, augmentation pressure, and augmentation index (with and without heart rate normalization) were higher (all P < .01) during daytime and 24-hour periods but lower during the nighttime period (all P < .001). The drop in nighttime brachial systolic BP was larger than central systolic pressure (Δ −20 ± 6 vs. −15 ± 6 mm Hg; P < .0001). Repeat ambulatory measurements of central BP and pulse wave reflection displayed good-to-excellent intraclass correlation coefficients (r = 0.58–0.86; all P < .01), although measures of pulse wave reflection had higher coefficients of variation (14%–41%). The results highlight absolute differences in central BP and pulse wave reflection between discrete laboratory and ambulatory conditions. The use of ambulatory measures of central BP and pulse wave reflection warrant further investigation for clinical prognostic value.

Validation of a new piezoelectric device for noninvasive measurement of central aortic systolic blood pressure

The objective of this study was to compare the aortic piezoelectric device for noninvasive measurement of central aortic systolic blood pressure (cSBP) with the SphygmoCor. A total of 85 participants from both sexes, aged 18-80 years, were stratified into three age groups (<30, 30-60, >60 years), with an equal number of healthy volunteers and hypertensive patients. We performed three cSBP measurements with each device, in an alternate manner, using the Bland-Altman method to determine the level of agreement. The standard of the Association for the Advancement of Medical Instrumentation for brachial blood pressure evaluation was used for the comparison. The mean cSBPs were 109.3±12.05 and 109.0±12.2 mmHg with the SphygmoCor and the Aortic device, respectively, showing a strong correlation (r=0.98, P<0.001). A mean difference of 0.35±2.43 mmHg (95% confidence interval: 0.17-0.87, P=NS) was obtained with the Bland-Altman method. The 95% limits of agreement was -4.4 to +5.1 mmHg. Complying with the Association for the Advancement of Medical Instrumentation criteria, cSBP measurements obtained with the Aortic and the SphygmoCor devices are equivalent.

Association between ambulatory blood pressure values and central aortic pressure in a large population of normotensive and hypertensive patients.

Our aim was to examine the association of ambulatory blood pressure monitoring (ABPM) and central blood pressure (CBP) data in a large set of normotensive and hypertensive patients and its relation with pulse wave velocity (PWV). This cross-sectional study was carried out in a single centre and included 2864 individuals who carried out an ABPM, measurement of CBP from the aortic waveform (SphygmoCor) and carotid-femoral PWV (Complior). In our study, 26.6% of the normotensive individuals and 32.5% of controlled hypertensive patients had abnormal values of at least one or of both ABPM and CBP values, compared with 96.6% of uncontrolled hypertensive patients. In the overall population, normal ABPM and CBP occurred in 25.3% (group 1), abnormal ABPM and CBP occurred in 44.4% (group 4), abnormal ABPM and normal CBP occurred in 10.5% (group 3) and normal ABPM and abnormal CBP occurred in 19.8% (group 2). PWV was significantly superior in group 4 versus group 3; group 4 versus group 1 and group 3 versus group 2 and group 2 versus group 1 (Mann-Whitney U-test; P<0.001). At least 26-32% of patients classified as normotensive or controlled hypertensive patients have abnormal ABPM or CBP associated with target organ damages. When abnormal values of ABPM and CBP coexist, target organ damage (aortic stiffness) is greater than that occurring when only one abnormal ABPM or CBP is present in the absence of the other. Isolated central hypertension entails greater organ damage than both normal ABPM and CBP. These patients may be at higher risk of further target organ damage because of unawareness of their central hypertension.

Comparison of the Assessment of Orthostatic Hypotension Using Peripheral and Central Blood Pressure Measurements.

BackgroundOrthostatic hypotension (OH) is associated with falls and cardiovascular events. There is growing evidence that central blood pressure (CBP) is better than peripheral blood pressure (PBP) in predicting adverse outcomes. The objectives of this study were to assess 1) the prevalence of OH identified using PBP and CBP and the levels of agreement, 2) the respective associations between OH and falls and cardiovascular comorbidities, by PBP and CBP, and 3) the association of OH with arterial wall stiffness markers (augmentation pressure (AP) and augmentation index (AI)).MethodsAn observational case-control study of subjects aged 50 years and above was conducted at the University of Alberta Hospital inpatient wards and outpatient clinics. This study used a non-invasive technology called SphygmoCor to assess changes in CBP between lying, 1, 3 and 6 min of standing. AP and AI, which are markers of arterial wall stiffness, were also measured in this study. Dementia, significant psychological problems, and isolation precautions were exclusion criteria. Both PBP and CBP were measured with arm cuffs in lying and standing positions. OH was diagnosed using consensus criteria.ResultsOf the 71 participants recruited, mean age was 72.3 ±10.3 years, 52% were males, 32% had a history of falls and 72% had hypertension. OH occurred within 1, 3 or 6 min of standing (transient OH) in 31% by PBP and 27% by CBP (kappa = 0.56). OH persisted for all 6 min (persistent OH) in 16% by both PBP and CBP (kappa = 0.68). A significant relationship was observed between transient OH by CBP and baseline hypertension (P = 0.05) and dyslipidemia (P = 0.02). There was a significant difference in the mean AP between subjects with and without central persistent OH (P = 0.02), but not between subjects with and without peripheral persistent OH. The mean AI was not significantly different between subjects with or without central or peripheral persistent OH and between subjects with and without peripheral or central transient OH.ConclusionPrevalence of OH was similar between PBP and CBP. However, there was only moderate agreement with OH identified by PBP and CBP indicating some inconsistencies across the sample in identifying OH.

Different Relevance of Peripheral, Central or Nighttime Blood Pressure Measurements in the Prediction of Chronic Kidney Disease Progression in Patients with Mild or No-Proteinuria

Background/Aims: Arterial hypertension is one of the leading factors aggravating the course of chronic kidney disease (CKD). It seems that the novel parameters used in the assessment of the blood pressure (BP) load (i.e. central blood pressure, nighttime blood pressure) may be more precise in predicting the cardiovascular risk and the progression of CKD in comparison with the traditional peripheral blood pressure measurements in the office conditions. The aim of the study was to assess the impact of the central, or nighttime blood pressure on the progression of CKD in patients with mild or no-proteinuria (autosomal, dominant polycystic kidney disease or IgA nephropathy). Methods: In each of the enrolled 46 patients with CKD stage 3 or 4, serum creatinine concentration was assessed, eGFR (MDRD) was calculated, also central blood pressure and pulse wave velocity (PWV) was assessed and the 24-hour ambulatory blood pressure monitoring (ABPM) was conducted at the beginning of the study and then repeated after one-year observation period. Results: During the observation period mean eGFR decreased from 44.1 (33.2-50.6) mL/min to 36.7 (29.7-46.3) mL/min. No significant differences were observed in the peripheral blood pressure or central blood pressure parameters. After one-year observation period the values of diastolic blood pressure dipping during the night significantly decreased from 16 (13-19) mmHg to 12 (10-15) mmHg; p< 0.05. The values of systolic dipping during the night or the mean BP values recorded in ABPM did not change significantly. Additionally, no significant differences in the PWV values were found. In the multivariate regression model the change of serum creatinine concentration was explained by the initial diastolic dipping values. Conclusion: 1. In patients with CKD stages 3 or 4 and mild or no- proteinuria, peripheral and central blood pressure did not change significantly during a one-year observation period despite the significant decline of eGFR and seems not to participate in the CKD progression. 2. Reduced magnitude of the diastolic dipping, which reflects the increase of diastolic blood pressure load during the nighttime, may play an important role in the pathogenesis of deterioration of kidney function in these patients.

Exploring the Utility of Pulse Wave Analysis in Patients with Uncontrolled Brachial Blood Pressures in the Routine Outpatient Setting

Background: Hypertension if left untreated can lead to arteriosclerosis, heart attacks, strokes and kidney disease. Studies suggest that central pressure may be more strongly related to future cardiovascular events than brachial pressure. Proportion of patients not at goal blood pressure is astounding. The aim of this study was to identify patients with hypertension not achieving goal brachial blood pressure and to investigate the co-relation between brachial blood pressure and central systolic blood pressure by using Pulse Wave Analysis (PWA). Methods: We conducted a single center, prospective, cohort study at the Outpatient Nephrology clinic operated by West Virginia University Hospitals between January 2017 and February 2018. Results: 22 patients met the inclusion criteria for the study, however only 14 (63.6%) followed through with getting at least one follow up PWA testing. 7/14 (50%) were males. 12/14 (85.7%) were older than 60 yrs. 10/14 (71.4%) had elevated central systolic pressures and pulse pressures at the initial visit and 2/14 (14.3%) an elevated augmented index. At the end of the study 9/14 (64.2%) were at goal central systolic blood pressure, 6/14 (42.9%) at goal Pulse pressure, with 8/14 (57.1%) at goal augmented index. At study end there was on average a 8.2mm Hg decrease in the central systolic pressure and 9.8mm Hg reduction in the pulse pressure after the lifestyle and anti-hypertensive regimen modification. Conclusion: Our results showed a predominantly elderly and obese population. Discrepancies between brachial and central systolic blood pressure may exist. Patients may benefit from the management of their blood pressure with the use of central blood pressure, pulse pressure and augmented index measurements as obtained by the Atcor Medical XCEL Pulse wave analysis machine. Further studies are needed to reinforce the importance of the utility of Pulse wave analysis and central blood pressure monitoring in the treatment of hypertension.

Cross-sectional variations of white and grey matter in older hypertensive patients with subjective memory complaints.

Mild cognitive impairment and Alzheimer's dementia involve a grey matter disease, quantifiable by 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET), but also white matter damage, evidenced by diffusion tensor magnetic resonance imaging (DTI), which may play an additional pathogenic role. This study aimed to determine whether such DTI and PET variations are also interrelated in a high-risk population of older hypertensive patients with only subjective memory complaints (SMC).Sixty older hypertensive patients (75 ± 5 years) with SMC were referred to DTI and FDG-PET brain imaging, executive and memory tests, as well as peripheral and central blood pressure (BP) measurements. Mean apparent diffusion coefficient (ADCmean) was determined in overall white matter and correlated with the grey matter distribution of the metabolic rate of glucose (CMRGlc) using whole-brain voxel-based analyses of FDG-PET images.ADCmean was variable between individuals, ranging from 0.82 to 1.01.10− 3 mm2 sec− 1, and mainly in relation with CMRGlc of areas involved in Alzheimer's disease such as internal temporal areas, posterior associative junctions, posterior cingulum but also insulo-opercular areas (global correlation coefficient: − 0.577, p < 0.001). Both the ADCmean and CMRGlc of the interrelated grey matter areas were additionally and concordantly linked to the results of executive and memory tests and to systolic central BP (all p < 0.05).Altogether, our findings show that cross-sectional variations in overall white brain matter are linked to the metabolism of Alzheimer-like cortical areas and to cognitive performance in older hypertensive patients with only subjective memory complaints. Additional relationships with central BP strengthen the hypothesis of a contributing pathogenic role of hypertension.

The effect of intermittent fasting on blood pressure variability in patients with newly diagnosed hypertension or prehypertension

Intermittent fasting is a phenomenon which can be observed in most humans. The effect of intermittent fasting on blood pressure variability (BPV) has not previously been investigated. The purpose of this study was to assess the effect of fasting on blood pressure (BP) (with office, home, central, and ambulatory blood pressure monitoring [ABPM]) and on BPV. Sixty individuals were included in the study. Office, home, ABPM, and central BP measurements were performed before and during intermittent fasting. Standard deviation and coefficient variation were used for office and home BPV measurement, while the smoothness index was used to calculate ABPM variability. Patients’ BP and BPV values before and during intermittent fasting were then compared. Intermittent fasting resulted in a significant decrease in office BP values and ABPM measurements but caused no significant change in home and central BP measurements. Twenty-four hour urinary sodium excretion decreased. Smoothness values obtained from ABPM measurements were low; in other words, BPV was greater. BPV was higher in patients who woke up to eat before sunrise, but BPV was low in patients with high body mass index. Intermittent fasting produced a significant decrease in BP values in terms of office and ABPM measurements in this study but caused no significant change in central BP and home measurements. We also identified an increase in BPV during intermittent fasting, particularly in patients who rose before sunrise.

Central blood pressure measurement and validation: What is still needed?

Accurate measurement of blood pressure (BP) is a critical goal for appropriate diagnosis and management of high BP. The measurement reference standard is brachial cuff BP, but recent large-scale meta-analyses show major deficiencies in the accuracy of this method. Indeed, irrespective of cuff technique (e.g. mercury auscultation or oscillometry) brachial cuff BP measures lack precision for representing the BP within both the brachial artery and the central aorta. These data clearly indicate the need to refine and improve methods to measure BP accurately, whether at the brachial or central aortic level, with preference towards the latter as the best representation of pressure loading experienced by the organs at risk from hypertension. The current focus to improve measurement of central aortic BP is on better calibration methods, with mean arterial pressure (MAP) and diastolic BP (DBP) proposed as the best solution. However, the ability to accurately estimate central aortic BP using this calibration method appears to be device-specific and related to the capacity of different devices to accurately measure MAP/DBP using conventional cuff BP. Beyond this, even if we can accurately measure MAP/DBP using non-invasive cuff methods, this does not necessarily provide a final solution because characteristic waveform features and the level of systolic BP amplification still influence accuracy. Thus, altogether, manufacturers of devices purporting to measure central aortic BP need to provide robust evidence about accuracy performance; preferably according to ARTERY Society recommendations.

Primary Aldosteronism With Type 2 Diabetes Mellitus Requires More Antihypertensive Drugs for Blood Pressure Control: A Retrospective Observational Study

BackgroundDiabetes mellitus (DM) and primary aldosteronism (PA) have been reported to induce drug-resistant hypertension and atherosclerosis. It is likely that blood pressure (BP) control becomes far more difficult in PA patients with DM. However, precise clinical characteristics of PA with type 2 DM especially in the aspect of BP control are not clear.MethodsThe study included 18 patients who were diagnosed as PA with DM and 52 PA patients without DM who matched age and sex and chosen as a control group. We have compared differences in BP control, use of antihypertensive agents and clinical characteristics between PA patients with and without DM.ResultsThere was no difference with regard to the duration of hypertension and BP control between either group. Interestingly, the PA with DM group was found to require more antihypertensive agents than the PA without DM group (number of antihypertensive agents used, 2.0 ± 1.5 vs. 1.3 ± 1.1; P < 0.05, respectively). In the 28 patients who underwent measurement of central BP (CBP) values, plasma aldosterone concentration (PAC) was high in the PA with DM group. Furthermore, a positive correlation was shown between PAC and CBP (r = 0.58; P < 0.01); the higher the PAC, the higher the CBP of patient.ConclusionsThese results might suggest that hypertension becomes more difficult to control in PA patients with DM in the future.

Central Blood Pressure Monitoring via a Standard Automatic Arm Cuff

Current oscillometric devices for monitoring central blood pressure (BP) maintain the cuff pressure at a constant level to acquire a pulse volume plethysmography (PVP) waveform and calibrate it to brachial BP levels estimated with population average methods. A physiologic method was developed to further advance central BP measurement. A patient-specific method was applied to estimate brachial BP levels from a cuff pressure waveform obtained during conventional deflation via a nonlinear arterial compliance model. A physiologically-inspired method was then employed to extract the PVP waveform from the same waveform via ensemble averaging and calibrate it to the brachial BP levels. A method based on a wave reflection model was thereafter employed to define a variable transfer function, which was applied to the calibrated waveform to derive central BP. This method was evaluated against invasive central BP measurements from patients. The method yielded central systolic, diastolic, and pulse pressure bias and precision errors of −0.6 to 2.6 and 6.8 to 9.0 mmHg. The conventional oscillometric method produced similar bias errors but precision errors of 8.2 to 12.5 mmHg (p ≤ 0.01). The new method can derive central BP more reliably than some current non-invasive devices and in the same way as traditional cuff BP.

Hypertension in Coarctation of the Aorta: Challenges in Diagnosis in Children.

Evidence indicates that patients with coarctation of the aorta (COA) suffer from increased cardiovascular morbidity and mortality in later life despite successful repair of COA in childhood. Systolic arterial hypertension is common, presenting in up to one-third of patients, and is regarded as the main driver of premature cardiovascular events in this group of patients. In this review, we discuss the prevalence and pathophysiology of hypertension in children following successful COA repair with no residual arch obstruction. The challenges in accurate blood pressure assessment at this early phase are considered and non-invasive measures of central blood pressure are discussed. Although the pathways for investigations in adults are well defined, we highlight the need to address the issues of cardiovascular surveillance in children and describe techniques which can provide complementary information for cardiovascular assessment in this group of patients such that timely treatment can occur.

Twenty-four-hour central blood pressure is not better associated with hypertensive target organ damage than 24-h peripheral blood pressure.

Central blood pressure (BP) is increasingly considered as a better estimator of hypertension associated risks. We aimed to evaluate the association of 24-h central BP, in comparison with 24-h peripheral BP, with the presence of target organ damage (TOD). Cross-sectional study of 208 hypertensive patients, aged 57 ± 12 years, 34% women. Office (mean of 4 measurements) and 24-h central and peripheral BP were measured by the oscillometric Mobil-O-Graph device. TOD was assessed at cardiac (left ventricular hypertrophy by echocardiography), renal (reduction of glomerular filtration rate and/or microalbuminuria), and arterial (increased aortic pulse wave velocity) levels. A total of 107 patients (51.4%) had TOD (77, 35% patients left ventricular hypertrophy; 54, 25.9% renal abnormalities; and 40, 19.2% arterial stiffness). All SBP and pulse BP estimates (office, 24-h, daytime, and night-time) were associated with the presence of TOD, after adjustment for age, sex, and antihypertensive treatment, with higher odds ratios for ambulatory-derived values. Odds ratios for central and peripheral BP were similar for all office, 24-h, daytime, and night-time BP. After simultaneous adjustment, peripheral, but not central, 24-h and night-time SBP and pulse pressures were associated with the presence of TOD. TOD in hypertension is associated with BP elevation, independently of the type of measurement (office or ambulatory, central or peripheral). Central BP, even monitored during 24 h, is not better associated with TOD than peripheral BP. These results do not support a routine measurement of 24-h central BP.

Isolated systolic hypertension — evaluation of the scale of the problem among medical students — pilot study

Introduction. Interest in isolated systolic hypertension (ISH) in young people has increased in recent years. The applanation tonometry technique provides new diagnostic opportunities in this group of patients. The aim of the study was to evaluate the incidence of ISH among young adults and factors contributing to its occurrence. Material and methods. One hundred and two medical students aged 21 to 26 years were examined. The study was based on three peripheral blood pressure measurements and central blood pressure measurement. Information on health status and physical activity was collected using the author-developed questionnaire. Results. Based on the mean of peripheral blood pressure measurements, hypertension (HT) was detected in 23 students (22.55%): 18 had ISH, 4 — combined systolic/diastolic HT and 1 — isolated diastolic HT. Pulse wave analysis showed that all individuals with ISH had central blood pressure within the normal range — higher than those without HT, but lower than in the combined systolic/diastolic HT group (p < 0.001). Subjects with ISH were characterized by higher pulse pressure amplitude and lower augmentation index (AIx) compared to those with normal blood pressure. Subjects with ISH were taller, had a higher body mass index (BMI) and were more likely to have a positive family history of HT compared to normotensives. They also reported more frequent coffee consumption; and 22% of them used creatine supplements (vs. 0% in non-HT group). Conclusions. Measurement of central arterial blood pressure by applanation tonometry should be an integral part of the assessment of young patients with ISH. The study confirmed that ISH patients are characterized by higher growth, weight and physical activity. Further studies are needed to assess the clinical significance of ISH.