Monitorización ambulatoria de la presión arterial en adultos y población pediátrica. Una revisión narrativa / Ambulatory blood pressure monitoring, adult and pediatric population. A narrative review

La hipertensión arterial (HTA) se ha convertido en un factor de riesgo central para el desarrollo de enfermedades cardiovasculares (CV), lo que subraya la importancia de su diagnóstico preciso. Numerosos estudios han establecido una estrecha relación entre los valores elevados de la presión arterial sistólica (PAS) y diastólica (PAD) y un incremento en el riesgo de padecer algún evento cardiovascular (ECV). Tradicionalmente, las mediciones de la presión arterial (PA) realizadas en entornos clínicos han sido el principal método para diagnosticar y evaluar la HTA. No obstante, en los últimos años, se ha reconocido que las mediciones de la PA obtenidas fuera del ambiente clínico, mediante la automedida de la presión arterial (AMPA) y la monitorización ambulatoria de la presión arterial (MAPA), ofrecen una perspectiva más realista de la vida cotidiana de los pacientes y, por lo tanto, brindan resultados más fiables. Dada la evolución de los dispositivos médicos, los criterios diagnósticos y la creciente relevancia de componentes de la MAPA en la predicción de ECV, se requiere una actualización integral que sea práctica para la clínica. Esta revisión tiene como objetivo proporcionar una actualización de la MAPA, enfocándose en su importancia en la evaluación de la HTA. Además, se analizarán los umbrales diagnósticos, los distintos fenotipos según el ciclo circadiano y las recomendaciones en diferentes poblaciones, asimismo, se ofrecerán sugerencias concretas para la implementación efectiva de la MAPA en la práctica clínica, lo que permitirá a los profesionales de la salud tomar decisiones fundamentadas y mejorar la atención de sus pacientes.(AU)

Hypertension has become a central risk factor for the development of cardiovascular disease, underscoring the importance of its accurate diagnosis. Numerous studies have established a close relationship between elevated systolic (SBP) and diastolic (DBP) blood pressure and an increased risk of cardiovascular event (CVE). Traditionally, blood pressure (BP) measurements performed in clinical settings have been the main method for diagnosing and assessing hypertension. However, in recent years, it has been recognized that BP measurements obtained outside the clinical setting, using self-monitoring blood pressure (SMBP) and ambulatory blood pressure monitoring (ABPM), offer a more realistic perspective of patients’ daily lives and therefore provide more reliable results. Given the evolution of medical devices, diagnostic criteria, and the increasing relevance of certain components of ABPM in the prediction of adverse cardiovascular outcomes, a comprehensive update that is practical for daily clinical practice is required. The main objective of this article is to provide an updated review of ABPM, focusing on its importance in the evaluation of hypertension and its impact on public health in Colombia. In addition, it will discuss the implications of changes in diagnostic thresholds and provide concrete recommendations for the effective implementation of ABPM in clinical practice, allowing health professionals to make informed decisions and improve the care of their patients.(AU)

Hypertensive states of pregnancyEstados hipertensivos del embarazo / Estados hipertensivos del embarazo

Hypertensive disorders in pregnancy (HDP) remain a leading cause of pregnancy-related maternal and foetal morbidity and mortality worldwide, including chronic hypertension, gestational hypertension, and pre-eclampsia. Affected women and newborns also have an increased risk of cardiovascular disease later in life, independent of traditional cardiovascular disease risks. Despite these risks, recommendations for optimal diagnosis and treatment have changed little in recent decades, probably due to fear of the foetal repercussions of decreased blood pressure and possible drug toxicity. In this document we review the diagnostic criteria and classification of (HDP), as well as important aspects regarding pathophysiology and early detection that allows early identification of women at risk, with the aim of preventing both immediate and long-term consequences. Prophylactic treatment with aspirin is also reviewed early and a therapeutic approach is carried out that involves close maternal and foetal monitoring, and if necessary, the use of safe drugs in each situation. This review aims to provide an updated vision for the prevention, diagnosis, and treatment of HDP that is useful in our usual clinical practice.(AU)

Los estados hipertensivos del embarazo (EHE) siguen siendo una de las principales causas de morbilidad y mortalidad materna y fetal relacionada con el embarazo en todo el mundo, incluyen la hipertensión crónica, la hipertensión gestacional y la preeclampsia. Las mujeres afectadas y los recién nacidos también tienen un mayor riesgo de sufrir enfermedades cardiovasculares en el futuro, independientemente de los riesgos tradicionales de la enfermedad cardiovascular. A pesar de estos riesgos, las recomendaciones para un diagnóstico y un tratamiento óptimo han cambiado poco en las últimas décadas, probablemente por el miedo a las repercusiones fetales de la disminución de la presión arterial y la posible toxicidad farmacológica. En ese documento revisamos los criterios diagnósticos y la clasificación de los EHE, así como aspectos importantes en cuanto a fisiopatología y la detección temprana que permita la identificación precoz de las mujeres en riesgo, con el objetivo de prevenir tanto las secuelas inmediatas como a largo plazo. También se revisa el tratamiento profiláctico con aspirina de forma precoz y se realiza una aproximación terapéutica que implica una estrecha vigilancia materna y fetal, y si es necesario, el uso de fármacos seguros en cada situación. Esta revisión pretende dar una visión actualizada para la prevención, diagnóstico y tratamiento de los EHE que sea de utilidad en nuestra práctica clínica habitual.(AU)

Validation of a Suprasystolic Cuff System for Static and Dynamic Representation of the Central Pressure Waveform.

BACKGROUND: Noninvasive pulse waveform analysis is valuable for central cardiovascular assessment, yet controversies persist over its validity in peripheral measurements. Our objective was to compare waveform features from a cuff system with suprasystolic blood pressure hold with an invasive aortic measurement. METHODS AND RESULTS: This study analyzed data from 88 subjects undergoing concurrent aortic catheterization and brachial pulse waveform acquisition using a suprasystolic blood pressure cuff system. Oscillometric blood pressure (BP) was compared with invasive aortic systolic BP and diastolic BP. Association between cuff and catheter waveform features was performed on a set of 15 parameters inclusive of magnitudes, time intervals, pressure-time integrals, and slopes of the pulsations. The evaluation covered both static (subject-averaged values) and dynamic (breathing-induced fluctuations) behaviors. Peripheral BP values from the cuff device were higher than catheter values (systolic BP-residual, 6.5 mm Hg; diastolic BP-residual, 12.4 mm Hg). Physiological correction for pressure amplification in the arterial system improved systolic BP prediction (r2=0.83). Dynamic calibration generated noninvasive BP fluctuations that reflect those invasively measured (systolic BP Pearson R=0.73, P<0.001; diastolic BP Pearson R=0.53, P<0.001). Static and dynamic analyses revealed a set of parameters with strong associations between catheter and cuff (Pearson R>0.5, P<0.001), encompassing magnitudes, timings, and pressure-time integrals but not slope-based parameters. CONCLUSIONS: This study demonstrated that the device and methods for peripheral waveform measurements presented here can be used for noninvasive estimation of central BP and a subset of aortic waveform features. These results serve as a benchmark for central cardiovascular assessment using suprasystolic BP cuff-based devices and contribute to preserving system dynamics in noninvasive measurements.

Development and web deployment of prediction model for pulmonary arterial pressure in chronic thromboembolic pulmonary hypertension using machine learning.

BACKGROUND AND PURPOSE: Mean pulmonary artery pressure (mPAP) is a key index for chronic thromboembolic pulmonary hypertension (CTEPH). Using machine learning, we attempted to construct an accurate prediction model for mPAP in patients with CTEPH. METHODS: A total of 136 patients diagnosed with CTEPH were included, for whom mPAP was measured. The following patient data were used as explanatory variables in the model: basic patient information (age and sex), blood tests (brain natriuretic peptide (BNP)), echocardiography (tricuspid valve pressure gradient (TRPG)), and chest radiography (cardiothoracic ratio (CTR), right second arc ratio, and presence of avascular area). Seven machine learning methods including linear regression were used for the multivariable prediction models. Additionally, prediction models were constructed using the AutoML software. Among the 136 patients, 2/3 and 1/3 were used as training and validation sets, respectively. The average of R squared was obtained from 10 different data splittings of the training and validation sets. RESULTS: The optimal machine learning model was linear regression (averaged R squared, 0.360). The optimal combination of explanatory variables with linear regression was age, BNP level, TRPG level, and CTR (averaged R squared, 0.388). The R squared of the optimal multivariable linear regression model was higher than that of the univariable linear regression model with only TRPG. CONCLUSION: We constructed a more accurate prediction model for mPAP in patients with CTEPH than a model of TRPG only. The prediction performance of our model was improved by selecting the optimal machine learning method and combination of explanatory variables.

Evaluating the accuracy of cerebrovascular computational fluid dynamics modeling through time-resolved experimental validation.

Accurate modeling of cerebral hemodynamics is crucial for better understanding the hemodynamics of stroke, for which computational fluid dynamics (CFD) modeling is a viable tool to obtain information. However, a comprehensive study on the accuracy of cerebrovascular CFD models including both transient arterial pressures and flows does not exist. This study systematically assessed the accuracy of different outlet boundary conditions (BCs) comparing CFD modeling and an in-vitro experiment. The experimental setup consisted of an anatomical cerebrovascular phantom and high-resolution flow and pressure data acquisition. The CFD model of the same cerebrovascular geometry comprised five sets of stationary and transient BCs including established techniques and a novel BC, the phase modulation approach. The experiment produced physiological hemodynamics consistent with reported clinical results for total cerebral blood flow, inlet pressure, flow distribution, and flow pulsatility indices (PI). The in-silico model instead yielded time-dependent deviations between 19-66% for flows and 6-26% for pressures. For cerebrovascular CFD modeling, it is recommended to avoid stationary outlet pressure BCs, which caused the highest deviations. The Windkessel and the phase modulation BCs provided realistic flow PI values and cerebrovascular pressures, respectively. However, this study shows that the accuracy of current cerebrovascular CFD models is limited.

Asociación de la rigidez aórtica con calcificaciones vasculares abdominales y coronarias en pacientes con enfermedad renal crónica estadios 3 y 4 / Association of aortic stiffness with abdominal vascular and coronary calcifications in patients with stage 3 and 4 chronic kidney disease

Fundamento y objetivos: El aumento de la rigidez arterial central (aórtica) tiene repercusiones hemodinámicas con efectos nocivos cardiovasculares y renales. En la enfermedad renal crónica (ERC) puede existir un aumento de la rigidez aórtica secundaria a múltiples alteraciones metabólicas, entre ellas la calcificación de la pared vascular (CV). El objetivo de este estudio fue analizar la asociación de la rigidez aórtica y de la hemodinámica central con la presencia de CV en dos territorios: aorta abdominal (CAA) y arterias coronarias (CC). Material y métodos: Se incluyeron 87 pacientes con ERC estadios 3 y 4. Usando tonometría de aplanamiento se estudiaron la hemodinámica central y la rigidez aórtica. Esta se determinó mediante la velocidad de pulso carótida-femoral (Vpc-f). A partir de la Vpc-f se calculó el índice de la VPc-f (iVpc-f) que considera otras variables que influyen en la Vpc-f, como edad, presión arterial, sexo y frecuencia cardiaca. La presencia de CAA se valoró mediante radiografía lateral de columna lumbar calculándose el índice de Kauppila (iKauppila) y las CC mediante tomografía computarizada multidetección por el método de Agatston, calculándose su índice (iAgatston). Para el estudio de la asociación entre iVpc-f, iKauppila, iAgatston, presión aórtica central, parámetros clínicos y datos de laboratorio se usaron la regresión múltiple y la regresión logística. La capacidad discriminativa del iVpc-f para evaluar la presencia de CAA y CC se determinó mediante el área bajo la curva (ABC) de ROC (receiver-operating characteristic). Resultados: La Vpc-f y el iVpc-f fueron 11,3±2,6m/s y 10,6m/s, respectivamente. El iVpc-f fue mayor cuando la ERC coexistía con diabetes mellitus (DM). Se detectaron CAA y CC en el 77% y el 87%, respectivamente. La albuminuria (β=0,13, p=0,005) y el iKauppila (β=0,36, p=0,001) se asociaron de forma independiente con la magnitud del iVpc-f... (AU)

Rationale and objectives: Increased central (aortic) arterial stiffness has hemodynamic repercussions that affect the incidence of cardiovascular and renal disease. In chronic kidney disease (CKD) there may be an increase in aortic stiffness secondary to multiple metabolic alterations including calcification of the vascular wall (VC). The objective of this study was to analyze the association of central aortic pressures and aortic stiffness with the presence of VC in abdominal aorta (AAC) and coronary arteries (CAC). Materials and methods: We included 87 patients with CKD stage 3 and 4. Using applanation tonometry, central aortic pressures and aortic stiffness were studied. We investigated the association of aortic pulse wave velocity (Pvc-f) and Pvc-f adjusted for age, blood pressure, sex and heart rate (Pvc-f index) with AAC obtained on lumbar lateral radiography and CAC assessed by multidetector computed tomography. AAC and CAC were scored according to Kauppila and Agatston methods, respectively. For the study of the association between iPvc-f index, Kauppila score, Agatston score, central aortic pressures, clinical parameters and laboratory data, multiple and logistic regression were used. We investigated the diagnosis performance of the Pvc-f index for prediction of VC using receiver-operating characteristic (ROC). Results: Pvc-f and Pvc-f index were 11.3±2.6m/s and 10.6m/s, respectively. The Pvc-f index was higher when CKD coexisted with diabetes mellitus (DM). AAC and CAC were detected in 77% and 87%, respectively. Albuminuria (β=0.13, p=0.005) and Kauppila score (β=0.36, p=0.001) were independently associated with Pvc-f index. In turn, Pvc-f index (β=0.39, p=0.001), DM (β=0.46, p=0.01), and smoking (β=0.53; p=0.006) were associated with Kauppila score, but only Pvc-f index predicted AAC [OR: 3.33 (95% CI: 1.6–6.9; p=0.001)]. The Kauppila score was independently associated with the Agatston score (β=1.53, p=0.001)... (AU)

Does intradialytic oral nutrition impact hemodialysis patients' quality of life, appetite, and safety? a pilot study of a crossover clinical trial / ¿La nutrición oral intradialítica impacta en la calidad de vida, el apetito y la seguridadde los pacientes en hemodiálisis? Estudio piloto de un ensayo clínico cruzado

Introduction: due to the catabolic characteristics of hemodialysis (HD), patients should consume foods or supplements during this treatment to meet their energy requirements and maintain a neutral nitrogen balance; however, there are some outcomes in which the effect of intradialytic oral nutrition (ION) is scarcely known. Objectives: this study aims to evaluate the effect of two types of ION (liquid and solid) on Quality of Life (QoL), appetite, and safety in HD patients. Methods: a pilot randomized, crossover clinical trial was performed in 18 patients on chronic HD. One group received ION for 18 HD sessions, after the crossover continued for 18 more sessions in the control group, and vice versa. We recorded QoL, appetite, systolic blood pressure (SBP), and intradialytic hypotension (IH) events. Results: clinical improvement was observed for most QoL components. Regardless of the consistency of supplementation, SBP increased to 4.10 mmHg. Both study groups reported a “very good-to-good” appetite. Conclusion: favorable clinical changes were observed in QoL scores during the study. Five of six IH events were reported for patients in the ION group, and SBP increased within the safe range (≤ 10 mmHg); appetite remained stable in both groups. Therefore, we concluded that this strategy, regardless of implementation consistency, is safe to be used in stable patients.(AU)

Introducción: debido a las características catabólicas de la hemodiálisis (HD), los pacientes deben consumir alimentos o suplementos durante este tratamiento para cubrir sus requerimientos energéticos y mantener un balance nitrogenado neutro; sin embargo, existen algunos desenlaces en los que el efecto de la nutrición oral intradialítica (NOID) es poco conocido.Objetivo: este estudio tiene como objetivo evaluar el efecto de dos tipos de NOID (líquido y sólido) sobre la calidad de vida, el apetito y la seguridad en pacientes en HD. Métodos: se realizó un estudio piloto en forma de ensayo clínico aleatorizado y cruzado con 18 pacientes en HD crónica. Un grupo recibió NOID durante 18 sesiones de HD, después del cruzamiento continuaron durante 18 sesiones más en el grupo de control, y viceversa. Se registraron la calidad de vida, el apetito, la presión arterial sistólica (PAS) y la hipotensión intradialítica (HI).Resultados: se observó mejoría clínica en la mayoría de los componentes de la calidad de vida. Independientemente de la consistencia de la suplementación, la PAS aumentó hasta 4,10 mmHg. Ambos grupos de estudio informaron de un apetito "muy bueno-bueno". Conclusiones: se observaron cambios clínicos favorables en las puntuaciones de calidad de vida durante el estudio. Cinco de seis eventos de HI se reportaron en pacientes del grupo de NOID y la PAS aumentó dentro del rango seguro (≤ 10 mmHg); el apetito se mantuvo estable en ambos grupos. Por lo tanto, se puede concluir que esta estrategia, independientemente de la consistencia implementada, es segura para ser utilizada en pacientes estables.(AU)

Novel theory and potential applications of central diastolic pressure decay time constant.

Central aortic diastolic pressure decay time constant ( τ ) is according to the two-element Windkessel model equal to the product of total peripheral resistance ( R ) times total arterial compliance ( C ). As such, it is related to arterial stiffness, which has considerable pathophysiological relevance in the assessment of vascular health. This study aimed to investigate the relationship of the constant τ with the product T MBP cPP , given by heart period ( T ) times the ratio of mean blood pressure (MBP) to central pulse pressure ( cPP ). The relationship was derived by performing linear fitting on an in silico population of n1 = 3818 virtual subjects, and was subsequently evaluated on in vivo data (n2 = 2263) from the large Asklepios study. The resulted expression was found to be τ = k ' T MBP cPP , with k ' = 0.7 (R2 = 0.9). The evaluation of the equation on the in vivo human data reported high agreement between the estimated and reference τ values, with a correlation coefficient equal to 0.94 and a normalized RMSE equal to 5.5%. Moreover, the analysis provided evidence that the coefficient k ' is age- and gender-independent. The proposed formula provides novel theoretical insights in the relationship between τ and central blood pressure features. In addition, it may allow for the evaluation of τ without the need for acquiring the entire central blood pressure wave, especially when an approximation of the cPP is feasible. This study adds to the current literature by contributing to the accessibility of an additional biomarker, such as the central diastolic pressure decay time constant, for the improved assessment of vascular ageing.

Prehospital invasive arterial blood pressure monitoring in critically ill patients attended by a UK helicopter emergency medical service- a retrospective observational review of practice.

BACKGROUND: Accurate haemodynamic monitoring in the prehospital setting is essential. Non-invasive blood pressure measurement is susceptible to vibration and motion artefact, especially at extremes of hypotension and hypertension: invasive arterial blood pressure (IABP) monitoring is a potential solution. This study describes the largest series to date of cases of IABP monitoring being initiated prehospital. METHODS: This retrospective observational study was conducted at East Anglian Air Ambulance (EAAA), a UK helicopter emergency medical service (HEMS). It included all patients attended by EAAA who underwent arterial catheterisation and initiation of IABP monitoring between 1st February 2015 and 20th April 2023. The following data were retrieved for all patients: sex; age; aetiology (medical cardiac arrest, other medical emergency, trauma); site of arterial cannulation; operator role (doctor/paramedic); time of insertion and, where applicable, times of pre-hospital emergency anaesthesia, and return of spontaneous circulation following cardiac arrest. Descriptive analyses were performed to characterise the sample. RESULTS: 13,556 patients were attended: IABP monitoring was initiated in 1083 (8.0%) cases, with a median age 59 years, of which 70.8% were male. 546 cases were of medical cardiac arrest: in 22.4% of these IABP monitoring was initiated during cardiopulmonary resuscitation. 322 were trauma cases, and the remaining 215 were medical emergencies. The patients were critically unwell: 981 required intubation, of which 789 underwent prehospital emergency anaesthesia; 609 received vasoactive medication. In 424 cases IABP monitoring was instituted en route to hospital. CONCLUSION: This study describes over 1000 cases of prehospital arterial catheterisation and IABP monitoring in a UK HEMS system and has demonstrated feasibility at scale. The high-fidelity of invasive arterial blood pressure monitoring with the additional benefit of arterial blood gas analysis presents an attractive translation of in-hospital critical care to the prehospital setting.

Gender Differences in Cardiac Organ Damage in Arterial Hypertension: Assessing the Role of Drug Nonadherence.

INTRODUCTION: Cardiac organ damage like left ventricular (LV) hypertrophy and left atrial (LA) enlargement is more prevalent in women than men with hypertension, but the mechanisms underlying this gender difference remain unclear. METHODS: We tested the association of drug nonadherence with the presence of LV hypertrophy and LA enlargement by echocardiography in 186 women and 337 men with uncontrolled hypertension defined as daytime systolic blood pressure (BP) ≥ 135mmHg despite the prescription of at least two antihypertensive drugs. Drug adherence was assessed by measurements of serum drug concentrations interpreted by an experienced pharmacologist. Aldosterone-renin-ratio (ARR) was measured on actual medication. RESULTS: Women had a higher prevalence of LV hypertrophy (46% vs. 33%) and LA enlargement (79% vs 65%, both p < 0.05) than men, while drug nonadherence (8% vs. 9%, p > 0.514) did not differ. Women were older and had lower serum renin concentration and higher ARR than men, while 24-h systolic BP (141 ± 9 mmHg vs. 142 ± 9 mmHg), and the prevalences of obesity (43% vs. 50%) did not differ (all p > 0.10). In multivariable analyses, female gender was independently associated with a two-fold increased risk of LV hypertrophy (OR 2.01[95% CI 1.30-3.10], p = 0.002) and LA enlargement (OR 1.90 [95% CI 1.17-3.10], p = 0.010), while no association with drug nonadherence was found. Higher ARR was independently associated with LV hypertrophy in men only (OR 2.12 [95% CI 1.12-4.00] p = 0.02). CONCLUSIONS: Among patients with uncontrolled hypertension, the higher prevalence of LV hypertrophy and LA enlargement in women was not explained by differences in drug nonadherence. REGISTRATION: URL:  https://www. CLINICALTRIALS: gov ; Unique identifier: NCT03209154.

Finger cuff versus invasive and noninvasive arterial pressure measurement in pregnant patients with obesity.

BACKGROUND: Pregnant patients with obesity may have compromised noninvasive blood pressure (NIBP) measurement. We assessed the accuracy and trending ability of the ClearSight™ finger cuff (FC) with invasive arterial monitoring (INV) and arm NIBP, in obese patients having cesarean delivery. METHODS: Participants were aged ≥18 years, ≥34 weeks gestation, and body mass index (BMI) ≥ 40 kg m-2. FC, INV, and NIBP measurements were obtained across 5-min intervals. The primary outcome was agreement of FC measurements with those of the reference standard INV, using modified Bland-Altman plots. Secondary outcomes included comparisons between FC and NIBP and NIBP versus INV, with four-quadrant plots performed to report discordance rates and evaluate trending ability. RESULTS: Twenty-three participants had a median (IQR) BMI of 45 kg m-2 (44-48). When comparing FC and INV the mean bias (SD, 95% limits of agreement) for systolic blood pressure (SBP) was 16 mmHg (17, -17.3 to 49.3 mmHg), for diastolic blood pressure (DBP) -0.2 mmHg (10.5, -20.7 to 20.3), and for mean arterial pressure (MAP) 5.2 mmHg (11.1, -16.6 to 27.0 mmHg). Discordance occurred in 54 (26%) pairs for SBP, 41 (23%) for DBP, and 41 (21.7%) for MAP. Error grid analysis showed 92.1% of SBP readings in Zone A (no-risk zone). When comparing NIBP and INV, the mean bias (95% limits of agreement) for SBP was 13.0 mmHg (16.7, -19.7 to 29.3), for DBP 5.9 mmHg (11.9, -17.4 to 42.0), and for MAP 8.2 mmHg (11.9, -15.2 to 31.6). Discordance occurred in SBP (84 of 209, 40.2%), DBP (74 of 187, 39.6%), and MAP (63 of 191, 33.0%). CONCLUSIONS: The FC and NIBP techniques were not adequately in agreement with INV. Trending capability was better for FC than NIBP. Clinically important differences may occur in the setting of the perfusion-dependent fetus.

Short-term vascular responses to spring and fall daylight savings time shifts.

Daylight saving time (DST) is a Western biannual time transition, setting the clock back 1 h in the fall and forward 1 h in the spring. There is an epidemiological link between DST and acute myocardial infarction risk in the first week following the spring shift; however, the mechanisms underlying the effect of DST on cardiovascular function remain unclear. The purpose of this study was to explore the short-term cardiovascular changes induced by fall and spring shifts in DST in a convenience sample of healthy adults. We hypothesized that spring, but not fall, DST shifts would acutely increase central pulse wave velocity, the gold standard measurement of central arterial stiffness. Twenty-one individuals (fall: n = 10; spring: n = 11) participated in four visits, occurring 1 wk before and at +1, +3, and +5 days after spring and fall time transitions. Central, brachial, and radial pulse wave velocity as well as carotid augmentation index were assessed with applanation tonometry. Sleep quality and memory function were assessed via questionnaire and the Mnemonic Similarities Task, respectively. Neither fall or spring transition resulted in changes to cardiovascular variables (carotid-femoral pulse wave velocity, carotid-brachial pulse wave velocity, carotid-radial pulse wave velocity, heart rate, mean arterial pressure, or augmentation index), sleep quality, or cognitive function (all P > 0.05). Our findings do not provide evidence that DST shifts influence cardiovascular outcomes in healthy adults. This study emphasizes the need for further research to determine the mechanisms of increased cardiovascular disease risk with DST that help explain epidemiological trends.NEW & NOTEWORTHY The debate of whether to abolish daylight savings time (DST) is, in part, motivated by the population-level increase in all-cause mortality and incidence of cardiovascular events following DST; however, there is an absence of data to support a physiological basis for risk. We found no changes in pulse wave velocity or augmentation index during the subacute window of DST. Large multisite trials are necessary to address the small, but meaningful, effects brought on by a societal event.

Blood pressure trends following birth in infants born under 25 weeks' gestational age: a retrospective cohort study.

OBJECTIVE: The aim of our study was to describe postnatal blood pressure (BP) trends and evaluate relevant dynamics and outcomes for a subgroup of extremely preterm (EPT) infants. DESIGN: Retrospective observational cohort study. SETTING: Patients admitted to Karolinska University Hospital Stockholm. PATIENTS: EPT infants born between 22+0 and 24+6 weeks' gestational age (GA) undergoing invasive, continuous BP monitoring through an umbilical arterial catheter. MAIN OUTCOME MEASURES: Physiological BP trends, the influence of cardiovascular active interventions and fluid boluses on BP, and relevant adverse outcomes, including intraventricular haemorrhage (IVH), necrotising enterocolitis (NEC) and death, were mapped over the first week of life. RESULTS: We included 125 infants between January 2009 and November 2021. Mean BP values were 31 mm Hg, 32 mm Hg and 35 mm Hg, at 3 hours, 24 hours and 48 hours, respectively. A pronounced BP dip and nadir were observed around 20 hours, with a mean BP value of 32 mm Hg. 84% received fluid boluses within the first week of life; however, we could not observe any noteworthy change in BP following administration. Only 8% of patients received cardiovascular active drugs, which were too few to infer drug-specific effects. Overall, 48% developed IVH, 15% developed NEC and 25% died. CONCLUSIONS: Approximating clinically acceptable mean BP values using GA gives underestimations in these infants. The postnatal BP dip should be regarded as a physiological phenomenon and not automatic grounds for interventions which may momentarily stabilise BP but have no appreciable short-term or long-term effects. Further studies are warranted for improved understanding of clinically relevant trends and outcomes.

Influence of a Decrease in Blood Viscosity on Arterial Pressure in Normotensive and Spontaneously Hypertensive Rats.

We investigated the effect of a decrease in blood viscosity on the mean BP during isovolumic hemodilution and vasodilating activity of the endothelium in normotensive Wistar rats and spontaneously hypertensive rats (SHR). Blood viscosity was reduced by isovolumic hemodilution (replacement of 10% of circulating blood with an equal volume of plasma). Hemodilution caused the same reduction in blood viscosity by 16% in both groups of rats. In Wistar rats, a decrease in blood viscosity did not significantly change in the mean BP; no significant correlations between blood viscosity and mean BP were observed before and after hemodilution. In SHR, a decrease in blood viscosity led to a significant decrease in the mean BP by 18%. Correlations were found between the mean BP and blood viscosity in SHR before (r=0.63; p=0.028) and after (r=0.71; p=0.009) isovolumic hemodilution. In SHR, a decrease in the index of vasodilating activity of the endothelium due to a decrease in the vasodilatory response to intravenous administration of the endothelium-dependent vasodilator acetylcholine was revealed. In SHR, BP passively follows the change, in this case, the decrease in blood viscosity, which attests to impaired BP regulation in response to changes in shear stress on the vascular endothelium caused by the development of endothelial dysfunction in hypertensive animals.

Mean Arterial Pressure (MAP) Trial: study protocol for a multicentre, randomized, controlled trial to compare three different strategies of mean arterial pressure management during cardiopulmonary bypass.

BACKGROUND: One of the main goals of cardiopulmonary bypass (CPB) is targeting an adequate mean arterial pressure (MAP) during heart surgery, in order to maintain appropriate perfusion pressures in all end-organs. As inheritance of early studies, a value of 50-60 mmHg has been historically accepted as the "gold standard" MAP. However, in the last decades, the CPB management has remarkably changed, thanks to the evolution of technology and the availability of new biomaterials. Therefore, as highlighted by the latest European Guidelines, the current management of CPB can no longer refer to those pioneering studies. To date, only few single-centre studies have compared different strategies of MAP management during CPB, but with contradictory findings and without achieving a real consensus. Therefore, what should be the ideal strategy of MAP management during CPB is still on debate. This trial is the first multicentre, randomized, controlled study which compares three different strategies of MAP management during the CPB. METHODS: We described herein the methodology of a multicentre, randomized, controlled trial comparing three different approaches to MAP management during CPB in patients undergoing elective cardiac surgery: the historically accepted "standard MAP" (50-60 mmHg), the "high MAP" (70-80 mmHg) and the "patient-tailored MAP" (comparable to the patient's preoperative MAP). It is the aim of the study to find the most suitable management in order to obtain the most adequate perfusion of end-organs during cardiac surgery. For this purpose, the primary endpoint will be the peak of serum lactate (Lmax) released during CPB, as index of tissue hypoxia. The secondary outcomes will include all the intraoperative parameters of tissue oxygenation and major postoperative complications related to organ malperfusion. DISCUSSION: This trial will assess the best strategy to target the MAP during CPB, thus further improving the outcomes of cardiac surgery. TRIAL REGISTRATION: NCT05740397 (retrospectively registered; 22/02/2023).