Redefining the cerebral autoregulatory range of blood pressures: Not as wide as previously reported.

This editorial summarizes the manuscript by Brassard and colleagues entitled, "Losing the dogmatic view of cerebral autoregulation". The main take-home message is that the cerebral autoregulatory plateau is much smaller than previously accepted and needs to be re-introduced as such.

Blood Pressure Pattern and Target Organ Damage in Patients With Chronic Kidney Disease.

In patients with chronic kidney disease, data on blood pressure (BP) pattern and its association with target organ damage, which indicates elevated cardiovascular risk, are sparse. In 305 treated hypertensive chronic kidney disease patients, we assessed BP pattern, left ventricular mass (magnetic resonance imaging), intima-media thickness (ultrasound), 24-hour-pulse wave velocity and 24-hour-central augmentation index (Mobil-O-Graph). Controlled hypertension (normal office and ambulatory BP) was found in 41% and sustained uncontrolled hypertension (elevated office and ambulatory BP) in 30% of patients. Misclassification of BP status occurred in 29%: white coat uncontrolled hypertension (elevated office but normal ambulatory BP) was detected in 11% and masked uncontrolled hypertension (normal office but elevated ambulatory BP) in 18% of patients. Left ventricular mass was increased in white coat uncontrolled hypertension (+11.2 g), masked uncontrolled hypertension (+9.4 g), and sustained uncontrolled hypertension (+16.6 g) compared with controlled hypertension. Intima-media thickness was similar across all 4 BP groups. Twenty-four hour-pulse wave velocity and 24-hour-central augmentation index were increased in masked uncontrolled hypertension (+0.5 m/sec and +2.5%) and sustained uncontrolled hypertension (+0.5 m/sec and +2.9%) compared with controlled hypertension. In conclusion, based on office BP measurements, misclassification of true BP status occurred in almost one-third of chronic kidney disease patients. Both types of misclassification (white coat uncontrolled hypertension and masked uncontrolled hypertension) were associated with parameters of target organ damage. Ambulatory BP monitoring should be used routinely to identify chronic kidney disease patients at high cardiovascular risk.

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.

Validation of the RisingSun RS-651 Blood Pressure Monitor Based on Auscultation in Adults According to the ANSI/AAMI/ISO 81060-2:2013 Standard.

This study validated the RisingSun RS-651 blood pressure (BP) monitor based on auscultation in adults according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 standard. The RS-651 device was evaluated in a study of 97 participants. The same arm simultaneous method, as defined in the ANSI/AAMI/ISO standard, was used. The mean differences±standard deviation for criterion 1 were 0.8±2.3 mm Hg for systolic BP (SBP) and -0.1±2.9 mm Hg for diastolic BP (DBP). Analysis for criterion 2 resulted in values of 0.8±1.5 mm Hg for SBP and -0.1±2.1 mm Hg for DBP. All of the data fulfilled the ANSI/AAMI/ISO 81060-2:2013 standard requirements to pass the validation. The RisingSun RS-651 device can be recommended for both clinical and self/home use in adults according to the ANSI/AAMI/ISO 81060-2:2013 standard.

Misclassification and discordance of measured blood pressure from patient's true blood pressure in current clinical practice: a clinical trial simulation case study.

Treatment decisions for hypertension using sphygmomanometer based measurements and the current clinical practice paradigm do not account for the timing of blood pressure (BP) measurement. This study aimed to evaluate the clinical implications of discordance between measured and true BP, to quantify BP misclassification rate at a typical clinical visit in current clinical practice, and to propose a BP calibration system to decrease the impact of timing of BP measurement. A clinical trial simulation case study was performed using an in silico Monte Carlo Simulation approach. The time-courses of BPs with and without an antihypertensive treatment effect were simulated from a baseline BP model combined with an antihypertensive PK/PD model. Virtual subject characteristics were sampled from the FDA internal database. The baseline BP model was qualified using observed 24 h ambulatory BP monitoring (ABPM) data from 225 subjects by a visual predictive check as well as a global sensitivity analysis. First of all, our results showed that the measured cuff BP in current typical clinical practice deviated from the true values. (1) Cuff BP deviated from the true values by more than 5 mmHg in 57 % (95 % CI: 54-61 %) of patients and more than 10 mmHg in 26 % (95 % CI: 22-32 %) of patients respectively. (2) These discordances were reduced to 28 % (deviation ≥ 5 mmHg, 95 % CI: 18-40 %) and 9 % (deviation ≥ 10 mmHg, 95 % CI: 4-18%) of patients assuming perfect sphygmomanometer measurement and thus represent the contribution of ignoring the daily circadian rhythm of BP. Secondly, our results showed 23-32 % of patients were misclassified to an incorrect BP category for a casual clinical visit based on JNC 7 guideline. In addition, the accuracy of the measured cuff BP varied by time of clinic visit. Specifically, 11:00 AM to 3:00 PM was identified to be the better time frame, while times before 9:00 AM were the worst time frame. Therefore, clinic visit time may need to be adjusted accordingly. Finally, we proposed an easy BP calibration method for clinic use to adjust for time of day differences due to circadian variability in case that the desirable clinic visit time cannot be tailored for practical reasons.

Blood pressure variability and classification of prehypertension and hypertension in adolescence.

OBJECTIVE: There is little information in pediatrics on the persistence of the prehypertension and hypertension classifications or on the progression of prehypertension to hypertension. This study aimed to examine those issues. METHODS: An analysis of data from the National Childhood Blood Pressure database was conducted to examine the longitudinal blood pressure outcomes for adolescents classified after a single measurement of blood pressure. Adolescent subjects (N = 8535) for whom serial single blood pressure measurements were obtained at intervals of 2 years were identified. Subjects were stratified according to blood pressure status at the initial measurement, as having normotension, prehypertension, or hypertension. RESULTS: Among subjects designated as having prehypertension (n = 1470), 14% of boys and 12% of girls had hypertension 2 years later. Among subjects designated as having hypertension, 31% of boys and 26% of girls continued to exhibit hypertension, and 47% of boys and 26% of girls had blood pressure values in the prehypertensive range. Regression models showed no significant effect of race on blood pressure changes but significant effects of initial BMI and changes in BMI. CONCLUSIONS: These data indicated that the rate of progression of prehypertension to hypertension was approximately 7% per year. Prehypertension can be predictive of future hypertension and may benefit from preventive interventions, especially lifestyle changes.

Fiabilidad de un aparato de medición automática de presión arterial en un servicio de Medicina Interna: Accutorr Plus PNI / Reliability of blood pressure automatic measuring device in an Internal Medicine service: the Accutorr Plus PNI

Fundamento. En nuestro servicio utilizábamos dos aparatos para medir la presión arterial, uno automático y un esfigmomanómetro de mercurio. Nuestro objetivo es estimar las diferencias entre ambas mediciones y determinar su significación clínica. Método. Se recogieron 68 mediciones de presión arterial. El grado de acuerdo entre ambos métodos se valoró mediante el coeficiente de correlación intraclase y el método de la media de las diferencias. Resultados. Se encontraron diferencias que afectaron básicamente a la presión diastólica. Estas diferencias estaban comprendidas entre (+20, -20 mmHg) con un coeficiente de correlación de 0,64 (0,74; 0,51) para las dos determinaciones automáticas. Cuando se compararon las mediciones con el esfigmomanómetro y la media de las dos determinaciones automáticas, las diferencias estaban comprendidas entre (+16, -20 mmHg) con un coeficiente de correlación de 0,68 (0,77; 0,56). Conclusiones. Consideramos que las diferencias halladas no tienen consecuencias para la toma de decisiones clínicas. (AU)

[The measurement of arterial pressure and the diagnosis of hypertension]. / Mesure de la pression artérielle et diagnostic de l'hypertension.

Blood pressure measurement remains the determining factor in defining hypertension. In daily practice, measurement in the practitioner's office is the reference used for diagnosis and follow-up. According to the classification established in the VIth Report of the NIH Joint National Committee in 1997, the upper normal value is below 139 mmHg for systolic and 89 mmHg for diastolic pressure. Hypertension cannot be confirmed by a single high measurement or at a single consultation. In addition, it should be remembered that: self-measurement should remain under medical control; its upper normal values (135/85) have the advantage of being obtained outside the medical setting; exercise tolerance tests, often using an ergometric bicycle, demonstrate the possibility of cardiovascular adaptation to physical exercise; ambulatory blood pressure measurement affords repeated measurements over 24 h, also with lower reference values (135/85 mmHg), and detects "white coat" hypertension and anomalies of the nycthemeral cycle.

Inaccuracy of the Hawksley random zero sphygmomanometer.

To examine the accuracy of the Hawksley random zero sphygmomanometer two studies were done with subjects with a wide range of blood pressure. When readings made by one observer on the UK model of the Hawksley sphygmomanometer were compared with readings by two independent observers on separate mercury sphygmomanometers, the Hawksley device underestimated systolic readings by a mean (SD) of 2.0 (2.4) and 0.5 (3.6) mm Hg and diastolic readings by a mean of 3.7 (2.7) and 2.8 (2.9) mm Hg. When readings made on the UK and US models of the Hawksley sphygmomanometer were compared with those made on mercury sphygmomanometers, with observers exchanging devices half way during the experiment, the UK Hawksley device underestimated systolic pressure by a mean of 3.8 (SD 3.5) mm Hg and diastolic blood pressure by 7.5 (3.8) mm Hg; and the US model by 2.6 (3.4) mm Hg for systolic pressure and 6.2 (3.7) mm Hg for diastolic pressure. There was better agreement between two observers using standard sphygmomanometers than between an observer using the Hawksley random zero sphygmomanometer and an observer using a standard sphygmomanometer. Thus, the quantitative aspects of blood pressure in epidemiological and intervention studies in which the Hawksley random zero sphygmomanometer was used need re-evaluation. Moreover, the Hawksley random zero sphygmomanometer, in its present design, should not be used in hypertension research.