Role of ambulatory blood pressure monitoring for the management of hypertension in Asian populations

Association between nocturnal blood pressure phenotype and adverse cardiovascular prognosis in patients with coronary heart disease and hypertension

Nocturnal blood pressure and nighttime dipping patterns are associated with the occurrence of cardiovascular events. However, there is few research on whether riser pattern is associated with the poor prognosis of patients with coronary heart disease (CHD) and hypertension independent of nighttime systolic blood pressure (SBP). This prospective and observational clinical study included 568 hospitalized patients with CHD and hypertension. All patients underwent 24-h ambulatory blood pressure (BP) monitoring during their hospitalization. Multivariate adjusted Cox proportional hazard models were utilized to examine the associations of nocturnal blood pressure and dipping status with primary endpoint events. Additionally, Harrell's C-statistics were employed to compare the discriminative ability of each model. During the 1-year follow-up period, 64 (11.3%) primary endpoint events were recorded, including 55 (9.7%) atherosclerotic cardiovascular disease (ASCVD) events. After adjusting for demographic and clinical risk variables, nighttime SBP was significantly related to the risk of incident primary endpoint events [per 20 mm Hg increase: hazard ratio (HR) = 1.775, 95% confidence interval (CI) 1.256-2.507]. The riser pattern group exhibited a significantly higher risk for primary endpoint events compared to the dipper pattern group, even after adjusting for office SBP (HR: 2.687, 95% CI: 1.015-7.110, p = .047). Furthermore, the addition of nighttime SBP or dipping status to the base model yielded statistically significant increments in C-statistic values (p = .036 and p = .007). However, adding both nighttime SBP and dipping status did not significantly enhance the model's performance in predicting the risk of primary endpoint events and ASCVD events according to the C-index (p = .053 and p = .054), which meant that the riser pattern group did not exhibit a significantly higher risk for primary endpoint events compared to the dipper pattern group after adjusting for nighttime SBP. In conclusion, nocturnal SBP and riser pattern demonstrated an association with adverse prognosis in patients with CHD and hypertension. Notably, nocturnal SBP proved to be a more reliable predictor than dipping status.

Cardiovascular Response to Intravenous Glucose Injection during Hemodialysis with Assessment of Entropy Alterations

BACKGROUND

The quality of autonomic blood pressure (BP) control can be assessed by the entropy of serial BP data. The aim of this study was to evaluate the effect of hemodialysis (HD) and glucose infusion (GI) on amplitude aware permutation entropy (AAPE) of hemodynamic variables during HD in chronic kidney disease patients with and without type-2 diabetes mellitus (DM).

METHODS

Twenty-one patients without DM (NDO) and ten with DM were studied. Thirty minutes after the start of HD, a 40% glucose solution was administered. Hemodynamic data were extracted from continuous recordings using the Portapres® system.

RESULTS

AAPE decreased during HD in all patients and all hemodynamic signals with the exception of AAPE of mean and diastolic BP in DM patients. GI led to an increase in AAPE for cardiac output in all patients, while AAPE for heart rate and ejection time increased only in DM studies, and AAPE for systolic, diastolic, and mean arterial pressure, as well as total peripheral resistance, increased only in NDO patients.

CONCLUSIONS

The reduction in entropy during HD indicates impaired autonomic control in response to external perturbations. This state is partially reversed by the infusion of glucose with differences in central and peripheral responsiveness in DM and NDO patients.

2022 Guidelines of the Taiwan Society of Cardiology and the Taiwan Hypertension Society for the Management of Hypertension

Hypertension is the most important modifiable cause of cardiovascular (CV) disease and all-cause mortality worldwide. Despite the positive correlations between blood pressure (BP) levels and later CV events since BP levels as low as 100/60 mmHg have been reported in numerous epidemiological studies, the diagnostic criteria of hypertension and BP thresholds and targets of antihypertensive therapy have largely remained at the level of 140/90 mmHg in the past 30 years. The publication of both the SPRINT and STEP trials (comprising > 8,500 Caucasian/African and Chinese participants, respectively) provided evidence to shake this 140/90 mmHg dogma. Another dogma regarding hypertension management is the dependence on office (or clinic) BP measurements. Although standardized office BP measurements have been widely recommended and adopted in large-scale CV outcome trials, the practice of office BP measurements has never been ideal in real-world practice. Home BP monitoring (HBPM) is easy to perform, more likely to be free of environmental and/or emotional stress, feasible to document long-term BP variations, of good reproducibility and reliability, and more correlated with hypertension-mediated organ damage (HMOD) and CV events, compared to routine office BP measurements. In the 2022 Taiwan Hypertension Guidelines of the Taiwan Society of Cardiology (TSOC) and the Taiwan Hypertension Society (THS), we break these two dogmas by recommending the definition of hypertension as ≥ 130/80 mmHg and a universal BP target of < 130/80 mmHg, based on standardized HBPM obtained according to the 722 protocol. The 722 protocol refers to duplicate BP readings taken per occasion ("2"), twice daily ("2"), over seven consecutive days ("7"). To facilitate implementation of the guidelines, a series of flowcharts encompassing assessment, adjustment, and HBPM-guided hypertension management are provided. Other key messages include that: 1) lifestyle modification, summarized as the mnemonic S-ABCDE, should be applied to people with elevated BP and hypertensive patients to reduce life-time BP burden; 2) all 5 major antihypertensive drugs (angiotensin-converting enzyme inhibitors [A], angiotensin receptor blockers [A], β-blockers [B], calcium-channel blockers [C], and thiazide diuretics [D]) are recommended as first-line antihypertensive drugs; 3) initial combination therapy, preferably in a single-pill combination, is recommended for patients with BP ≥ 20/10 mmHg above targets; 4) a target hierarchy (HBPM-HMOD- ambulatory BP monitoring [ABPM]) should be considered to optimize hypertension management, which indicates reaching the HBPM target first and then keeping HMOD stable or regressed, otherwise ABPM can be arranged to guide treatment adjustment; and 5) renal denervation can be considered as an alternative BP-lowering strategy after careful clinical and imaging evaluation.

Utility of ambulatory blood pressure monitoring in detection of masked hypertension and risk of hypertension mediated organ damage in normotensive patients with type 2 diabetes mellitus

PURPOSE

In patients with diabetes, unrecognised hypertension is a serious problem risk factor for the development and progression of chronic complications. The study aimed to determine the prevalence of masked hypertension in normotensive diabetic patients, the factors affecting it, and its association with diabetes complications using ambulatory blood pressure monitoring (ABPM).

MATERIALS AND METHODS

A cross-sectional observational study was conducted on 150 normotensive diabetic patients. Patients were subjected to an interview and clinical examination to record demographic data, epidemiological data, and significant past history. ABPM was performed for each patient. Urine samples, echocardiogram, and ophthalmologic fundoscopy were done to check for diabetes-related complications.

RESULTS

The mean age of all participants was 56.7 ± 7.8 years. A total of 93 patients (62%) were males. 99 (66%) patients had masked hypertension. A total of 85 (56.7%) were non-dippers, 49 (32.7%) were dippers, 1 (0.7%) was extreme dipper and 15 (10%) were reverse dippers. Non-dipping and reverse dipping were associated with concentric left ventricular hypertrophy LVH (p < .001). Masked hypertension was associated with concentric LVH (p = .001) and nephropathy (p =.008) whereas, nocturnal hypertension was associated with concentric LVH (p = .001) and nephropathy (p =.003).

CONCLUSIONS

A single office blood pressure (BP) reading cannot rule out hypertension in patients with diabetes. Regardless of hypertension, clinicians should have all patients, especially patients with diabetes, undergo ABPM at least once. Masked hypertension, changes in nocturnal dipping and other phenomena that raise the risk of diabetes complications but cannot be measured by office BP can be measured by ABPM, and thus ABPM can provide a good prognostic benefit.

Dosing Time Matters? Nighttime vs. Daytime Administration of Nifedipine Gastrointestinal Therapeutic System (GITS) or Amlodipine on Non-dipper Hypertension: A Randomized Controlled Trial of NARRAS

Background: Non-dipper hypertension is often characterized by a blunted decrease of nocturnal blood pressure (BP) and is associated with increased risk of target organ damage and cardiovascular (CV) events, while the optimal treatment strategy is yet to be established. This trial was designed to evaluate whether nocturnal BP reduction and arterial stiffness improvement differ from antihypertensive agents and time of administration. Methods: Young and middle-aged adults (18-65 years) with non-dipper hypertension were randomly assigned to nifedipine GITS (gastrointestinal therapeutic system) 30 mg or amlodipine besylate 5 mg once daily for 8 weeks, either taken in the morning or at night. Dose was doubled at 4-week if BP is not at goal. Twenty-four hour ambulatory BP monitoring (ABPM) and arterial stiffness were evaluated before and after 8 weeks of pharmacotherapy. The primary efficacy measure was the average nighttime systolic BP reduction. Results: A total of 98 non-dipper hypertensive patients (mean age 46.3 years) were randomized during Dec, 2016 and Dec, 2020, of whom 72 (73%) patients completed all ABPM and follow-up evaluations. Nighttime systolic BP significantly reduced at 8 weeks vs. baseline with nifedipine GITS or amlodipine, irrespective of dosing at nighttime (-9.9 vs -9.9 mmHg, P > 0.05) or daytime (-11.5 vs. -10.9 mmHg, P > 0.05). No difference was seen between these two agents, when combining the data of nighttime and daytime dosing together (-10.8 vs. -10.5 mmHg, respectively, P = 0.898). Daytime, 24-h systolic BP, diastolic BP at different time and pulse wave velocity reduced significantly and comparably, and recovery of dipping rhythm were similar among groups. Conclusion: Nighttime dosing of long-acting antihypertensive preparations, nifedipine GITS or amlodipine demonstrated similar effects on nocturnal BP reduction, dipping rhythm restoration and arterial elasticity improvement in younger subjects with non-dipper hypertension. These effects were comparable with morning dosing.

Patient preferences for ambulatory blood pressure monitoring devices: Wrist-type or arm-type?

BACKGROUND

Ambulatory blood pressure monitoring (ABPM) is important in evaluating average 24-hour blood pressure (BP) levels, circadian rhythm, sleeping BP and BP variability but many patients are reluctant to use standard ABPM devices.

METHODS

We compared two validated ABPM devices, the BPro tonometric wrist monitor and the A&D TM-2430 oscillometric upper arm monitor, for agreement of recordings and acceptability in 37 hypertensive patients (aged 55±9 years).

RESULTS

Successful BP measurements were less frequent with the wrist-type than the arm-type device during the sleeping (66.3% vs. 92.9%, P <0.01) and awake periods (56.2% vs. 86.5%, P <0.01). Comparable paired readings showed no significant difference in systolic BP but diastolic BP (DBP) values were higher with the wrist compared to the arm monitor (24-hour 89±13 vs. 85±14 mmHg, P <0.01) with similar differences awake and sleeping. Bland-Altman analysis showed some large discrepancies between individual arm and wrist monitor measurements. More patients found the wrist monitor more comfortable to use than the arm monitor.

CONCLUSIONS

Despite the difference in individual BP measurements and the systematic overestimation of DBP values with the BPro device, wrist monitors with good patient acceptability may be useful to facilitate ABPM in some patients to provide additional information about cardiovascular risk and response to antihypertensive therapies.

Prognostic value of nocturnal blood pressure dipping on cardiovascular outcomes in Chinese patients with hypertension in primary care

Meta‐analyses showed that non‐dipping of nocturnal blood pressure on ambulatory blood pressure monitoring (ABPM) was associated with adverse cardiovascular prognosis. However, these prognostic studies were mainly conducted in Caucasian and Japanese populations. Whether this association applies to Chinese patients remained uninvestigated. A total of 1199 Chinese patients with hypertension undergoing ABPM between January 2012 and December 2014 were recruited retrospectively from five public hypertension referral clinics in Hong Kong. Patients were followed up for a mean 6.42 years for cardiovascular morbidity and mortality and all‐cause mortality. Time to event of different dipping patterns was compared by Kaplan‐Meier curves. Hazard ratios (HR) were obtained by Cox proportional hazard models with patient demographics and confounding factors adjusted in multivariate regression. A total of 163 end point events occurred in the period. Normal dipping was observed in 446 patients (37.2%), non‐dipping in 490 (40.9%), reverse dipping in 161 (13.4%), and extreme dipping in 102 (8.5%). Kaplan‐Meier analyses showed inferior survival in non‐dippers and reverse dippers for total cardiovascular events and coronary events but not cerebrovascular events. After adjusting for confounding factors, Cox regressions showed HRs 1.166 (CI 0.770‐1.764) and 1.173 (CI 0.681‐2.021) in non‐dippers and reverse dippers for total cardiovascular events, and HRs 1.320 (CI 0.814‐2.141) and 1.476 (CI 0.783‐2.784) for coronary events. Nocturnal blood pressure non‐dipping, and to a greater extent reverse dipping, demonstrated adverse cardiovascular prognosis in a cohort of Chinese patients with hypertension in Hong Kong. Further focused studies on cerebrovascular events and reverse dippers were warranted to refine risk stratification.

Guidance on ambulatory blood pressure monitoring: A statement from the HOPE Asia Network

Hypertension is an important public health issue due to its association with a number of serious diseases, including cardiovascular disease and stroke. The importance of evaluating hypertension taking into account different blood pressure (BP) profiles and BP variability (BPV) is increasingly being recognized, and is particularly relevant in Asian populations given the specific features of hypertension in the region (including greater salt sensitivity and a high rate of nocturnal hypertension). Ambulatory BP monitoring (ABPM) is the gold standard for diagnosing hypertension and assessing 24-hour BP and provides data on several important parameters that cannot be obtained using any other form of BP measurement. In addition, ABPM parameters provide better information on cardio- and cerebrovascular risk than office BP. ABPM should be used in all patients with elevated BP, particularly those with unstable office or home BP, or who are suspected to have white-coat or masked hypertension. ABPM is also an important part of hypertension diagnosis and monitoring in high-risk patients. ABPM needs to be performed using a validated device and good practice techniques, and has a role both in hypertension diagnosis and in monitoring the response to antihypertensive therapy to ensure strict BP control throughout the 24-hour period. Use of ABPM in clinical practice may be limited by cost and accessibility, and practical education of physicians and patients is essential. The ABPM evidence and practice points in this document are based on the Hypertension Cardiovascular Outcome Prevention and Evidence (HOPE) Asia Network expert panel consensus recommendations for ABPM in Asia.

Contributions of Anthropometrics and Lifestyle to Blood Pressure in Japanese University Students : Investigation by Annual Health Screening

Background : High blood pressure (BP) is a healthcare problem in young persons. There are racial differences in anthropometrics, dietary habit and lifestyle relating to BP. Therefore, this study investigated the relationship between anthropometrics, lifestyle and BP obtained in the Japanese university students. Materials and Methods : Participants were recruited in annual health screening including questionnaire, measurements of BP and anthropometrics calculating body mass index (BMI). Totally, 14,280 students (10,273 males and 4,007 females) were eligible. Multiple regression analyses were applied to predict contributors to high BP. Results : BMI was the most powerful contributor to high BP in many subgroups divided by gender and graduation (p < 0.001). In lifestyle, contribution of lack of exercise to high BPs was observed in the undergraduates. Smoking, drinking and breakfast skipping had no significant impact on high BP. However, smoking and drinking permeated and exercise habit declined after graduation. Prevalence of obesity (BMI ≥ 25 kg / m2) and hypertension ( ≥ 140 / 90 mmHg) increased in subgroups with advanced age (p < 0.001). Conclusion: BMI was found to be the most powerful contributor to high BPs. Health literacy to modify lifestyle is important to prevent hypertension for university students who are exposed to social trends of unhealthy lifestyle. J. Med. Invest. 67 : 174-181, February, 2020.

The HOPE Asia Network activity for "zero" cardiovascular events in Asia: Overview 2020

The impact of hypertension-related cardiovascular disease and target organ damage, and therefore the benefits of blood pressure (BP) control, is greater in Asian than in Western countries. Asia-specific features of hypertension and its effective management are important and active areas of research. The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was formed in 2016 and is now a member of the World Hypertension League. The main goal of the HOPE Asia Network is to improve the management of hypertension and organ protection toward achieving "zero" cardiovascular events in Asia. Considerable work has already been done on the journey to achieving this goal. We have shown that BP control status in Asia differs between countries, and even between regions within the same country. Several expert panel consensus recommendations and clinical guidance papers are available to support the use of home and ambulatory BP monitoring in the region. In addition, the AsiaBP@Home study prospectively investigated home BP control status across 15 specialist centers using the same validated device and measurement schedule. We have also proposed the concept of systemic hemodynamic atherothrombotic syndrome (SHATS), a vicious cycle of BP variability and vascular disease on cardiovascular events and organ damage, and suggested a SHATS score for risk stratification for clinical practice. This special issue of the journal collates Asia-specific resources and data, contributing to advances in hypertension management and cardiovascular disease prevention in the region.

Blood Pressure Measurement and Treatment Decisions

White-coat and masked hypertension are important hypertension phenotypes. Out-of-office blood pressure measurement is essential for the accurate diagnosis and monitoring of these conditions. This review summarizes literature related to the detection and diagnosis, prevalence, epidemiology, prognosis, and treatment of white-coat and masked hypertension. Cardiovascular risk in white-coat hypertension appears to be dependent on the presence of coexisting risk factors, whereas patients with masked hypertension are at increased risk of target organ damage and cardiovascular events. There is an unmet need for robust data to support recommendations around the use of antihypertensive treatment for the management of white-coat and masked hypertension.

Key Points of the 2019 Japanese Society of Hypertension Guidelines for the Management of Hypertension

The new 2019 Japanese Society of Hypertension (JSH) guidelines for the management of hypertension are now available; these update the previous guidelines published in 2014. The primary objective of the guideline is to provide all healthcare professionals with a standard management strategy and appropriate antihypertensive treatments to prevent hypertension-related target organ damage and cardiovascular events. The major changes in the new guideline relate to the definition of normal blood pressure (BP) and target BP. The terms 'normal BP' and 'high normal BP' used in the JSH 2014 guidelines are replaced with terms 'high normal BP' and 'elevated BP,' respectively. There was no change to the office BP diagnostic threshold for hypertension (140/90 mmHg). Recommended target office and home BP values for patients with hypertension aged <75 years and/or high-risk patients are <130/80 mmHg and <125/75 mmHg, respectively. Corresponding targets for elderly patients with hypertension (age≥75 years) are 140/90 and 135/85 mmHg, respectively. The goal is that these changes will contribute to reducing cardiovascular events, especially stroke and heart failure, in Japan. The dissemination of the JSH 2019 guidelines and implementation of a home BP-based approach by all general practitioners in Japan might be facilitated by digital hypertension management using health information technology.

Expert panel consensus recommendations for ambulatory blood pressure monitoring in Asia: The HOPE Asia Network

Hypertension is an important public health issue because of its association with a number of significant diseases and adverse outcomes. However, there are important ethnic differences in the pathogenesis and cardio-/cerebrovascular consequences of hypertension. Given the large populations and rapidly aging demographic in Asian regions, optimal strategies to diagnose and manage hypertension are of high importance. Ambulatory blood pressure monitoring (ABPM) is an important out-of-office blood pressure (BP) measurement tool that should play a central role in hypertension detection and management. The use of ABPM is particularly important in Asia due to the specific features of hypertension in Asian patients, including a high prevalence of masked hypertension, disrupted BP variability with marked morning BP surge, and nocturnal hypertension. This HOPE Asia Network document summarizes region-specific literature on the relationship between ABPM parameters and cardiovascular risk and target organ damage, providing a rationale for consensus-based recommendations on the use of ABPM in Asia. The aim of these recommendations is to guide and improve clinical practice to facilitate optimal BP monitoring with the goal of optimizing patient management and expediting the efficient allocation of treatment and health care resources. This should contribute to the HOPE Asia Network mission of improving the management of hypertension and organ protection toward achieving "zero" cardiovascular events in Asia.

Early morning-Best time window of hourly 24-hour ambulatory blood pressure in relation to hypertensive organ damage: The Japan Morning Surge-Home Blood Pressure study

The correlations between organ damage and hourly ambulatory blood pressure (BP) have not been established. The patients were 1464 participants of the Japan Morning Surge-Home Blood Pressure (J-HOP) study participants who underwent ambulatory BP monitoring. The hourly systolic BP (SBP) at x o'clock was defined as the average of SBP values measured at times x - 30 minutes, x, and x + 30 minutes. The mean age was 64.8 ± 11.6 years. The percentage of male participants was 47.8%. The left ventricular mass index (LVMI) was significantly associated with SBP at 6 o'clock (r = 0.166, P < 0.001). The carotid intima-media thickness was significantly associated with SBP at 5 o'clock (r = 0.196, P < 0.001). After adjustment for age, sex, smoking, hyperlipidemia, diabetes mellitus, antihypertensive drug use, clinic SBP, and 24-hour ambulatory SBP, the correlations of the LVMI and hourly SBP at 6 o'clock remained significant (beta coefficient = 0.125, P < 0.01). In conclusion, morning ambulatory systolic BP especially at 5 and 6 o'clock was independently associated with organ damage.

Controversies in the 2017 ACC/AHA Hypertension Guidelines: Who Can Be Eligible for Treatments Under the New Guidelines? - An Asian Perspective

Until the 2017 ACC/AHA Hypertension Guidelines were released, the target blood pressure (BP) for adults with hypertension (HTN) was 140/90 mmHg in most of the guidelines. The new 2018 ESC/ESH, Canadian, Korean, Japan, and Latin American hypertension guidelines have maintained the <140/90 mmHg for the primary target in the general population and encourage reduction to <130/80 if higher risk. This is more in keeping with the 2018 American Diabetes Association guidelines. However, the 2017 ACC/AHA guidelines classify HTN as BP ≥130/80 mmHg and generally recommend target BP levels below 130/80 mmHg for hypertensive patients independently of comorbid disease or age. Although the new guidelines mean that more people (nearly 50% of adults) will be diagnosed with HTN, the cornerstone of therapy is still lifestyle management unless BP cannot be lowered to this level; thus, more people will require BP-lowering medications. To date, there have been many controversies about the definition of HTN and the target BP. Targeting an intensive systolic BP goal can increase the adverse effects of multiple medications and the cardiovascular disease risk by excessively lowering diastolic BP, especially in patients with high risk, including those with diabetes, chronic kidney disease, heart failure, and coronary artery disease, and the elderly. In this review, we discuss these issues, particularly regarding the optimal target BP.

Effects of a Community Population Health Initiative on Blood Pressure Control in Latinos

Background

Hypertension remains one of the most important, modifiable cardiovascular risk factors. Yet, the largest minority ethnic group (Hispanics/Latinos) often have different health outcomes and behavior, making hypertension management more difficult. We explored the effects of an American Heart Association–sponsored population health intervention aimed at modifying behavior of Latinos living in Texas.

Methods and Results

We enrolled 8071 patients, and 5714 (65.7%) completed the 90‐day program (58.5 years ±11.7; 59% female) from July 2016 to June 2018. Navigators identified patients with risk factors; initial and final blood pressure (BP) readings were performed in the physician's office; and interim home measurements were recorded telephonically. The intervention incorporated home BP monitoring, fitness and nutritional counseling, and regular follow‐up. Primary outcomes were change in systolic BP and health‐related quality of life. Using a univariate paired‐samples pre–post design, we found an average 5.5% (7.6‐mm Hg) improvement in systolic BP (139.1 versus 131.5, t=10.32, P<0.001). Quality of life measured by the European quality of life 5‐dimension visual analog scale improved from 0.79 to 0.82 (t=31.03, P<0.001). After multivariate regression analyses, improvements in quality of life and overall body mass index were significantly associated with reductions in systolic BP.

Conclusions

A noninvasive, population health initiative that encourages routine engagement in patients’ own BP control was associated with improvements in systolic BP and quality of life for this largely Latino community.

A Novel Minimally Occlusive Cuff Method Utilizing Ultrasound Vascular Imaging for Stress-Free Blood Pressure Measurement: A-Proof-of-Concept Study

OBJECTIVE

Occlusive cuff inflation in ambulatory blood pressure (BP) monitoring disturbs the daily life of the user and affects efficacy of monitoring. To overcome this limitation, we have developed a novel minimally occlusive cuff method for stress-free measurement of BP. This study aimed to experimentally evaluate the reliability of this method.

METHODS

In this method, a thin plate-type ultrasound probe placed between the cuff and the skin is used to measure the ultrasonic dimension of the artery. Analyzing the arterial dimension and the cuff pressure measured during mild cuff inflation (cuff pressure <50 mmHg) allows estimation of systolic BP (SBP_e) and diastolic BP (DBP_e). We evaluated this method in six anesthetized dogs by attaching the cuff with the probe to the right thigh to get SBP_e and DBP_e. We measured reference SBP and DBP using an intra-arterial catheter and determined the pulse arrival time (PAT), commonly employed in cuffless BP monitoring. BP was perturbed by infusing noradrenaline or nitroprusside.

RESULTS

DBP_e correlated tightly with DBP with a coefficient of determination (R²) of 0.85 ± 0.08, and predicted DBP with a mean ± standard deviation of error of 3.9 ± 7.9 mmHg after one-time calibration. Reciprocal of PAT correlated poorly with DBP (R² = 0.49 ± 0.17), and predicted DBP less accurately than this method. SBP_e correlated well with SBP (R² = 0.78 ± 0.08).

CONCLUSION

This method reliably tracks BP changes without occlusive cuff inflation. Once calibrated, this method measures DBP accurately.

SIGNIFICANCE

This method has the potential for stress-free BP measurement in ambulatory BP monitoring.

Blood pressure and heart rate variability are linked with hyperphosphatemia in chronic kidney disease patients

Hyperphosphatemia is a common complication of chronic kidney disease (CKD) and is associated with cardiovascular disease (CVD), which has contributed to an increase in mortality of CKD patients. The onset of CVD often varies by time-of-day. Acute myocardial infarction or ventricular arrhythmia occurs most frequently during early morning. Blood pressure (BP) and heart rate circadian rhythms account for the diurnal variations in CVD. Preservation of normal circadian time structure from the cardiomyocyte level to the whole organ system is essential for cardiovascular health and CVD prevention. Independent risk factors, such as reduced heart rate variability (HRV) and increased BP variability (BPV), are particularly prevalent in patients with CKD. Analysis of HRV is an important clinical tool for characterizing cardiac autonomic status, and reduced HRV has prognostic significance for various types of CVD. Circadian BP rhythms are classified as extreme dipper, dipper, non-dipper or riser. It has been reported that nocturnal riser BP pattern contributes to cardiovascular threats. Previous studies have indicated that the circadian rhythm of serum phosphate in CKD patients is consistent with the general population, with the highest diurnal value observed in the early morning hours, followed by a progressive decrease to the lowest value of the day, which occurs around 11:00 am. Rhythm abnormalities have become the main therapeutic target for treating CVD in CKD patients. It has been reported that high levels of serum phosphate are associated with reduced HRV and increased BPV in CKD patients. However, the mechanisms related to interactions between hyperphosphatemia, HRV and BPV have not been fully elucidated. This review focuses on the evidence and discusses the potential mechanisms related to the effects of hyperphosphatemia on HRV and BPV.