High Short-Term Blood Pressure Variability Predicts Long-Term Cardiovascular Mortality in Untreated Hypertensives But Not in Normotensives

A Bayesian Approach to Modeling Variance of Intensive Longitudinal Biomarker Data as a Predictor of Health Outcomes

Intensive longitudinal biomarker data are increasingly common in scientific studies that seek temporally granular understanding of the role of behavioral and physiological factors in relation to outcomes of interest. Intensive longitudinal biomarker data, such as those obtained from wearable devices, are often obtained at a high frequency typically resulting in several hundred to thousand observations per individual measured over minutes, hours, or days. Often in longitudinal studies, the primary focus is on relating the means of biomarker trajectories to an outcome, and the variances are treated as nuisance parameters, although they may also be informative for the outcomes. In this paper, we propose a Bayesian hierarchical model to jointly model a cross-sectional outcome and the intensive longitudinal biomarkers. To model the variability of biomarkers and deal with the high intensity of data, we develop subject-level cubic B-splines and allow the sharing of information across individuals for both the residual variability and the random effects variability. Then different levels of variability are extracted and incorporated into an outcome submodel for inferential and predictive purposes. We demonstrate the utility of the proposed model via an application involving bio-monitoring of hertz-level heart rate information from a study on social stress.

Assessment of blood pressure variability: characteristics and comparison of blood pressure measurement methods

Previous studies have reported that blood pressure variability (BPV) is associated with the risk of cardiovascular events independent of blood pressure (BP) levels. While there is little evidence from intervention trials examining whether suppressing BPV is useful in preventing cardiovascular disease, it is suggested that detection of abnormally elevated BPV may be useful in reducing cardiovascular events adding by complementing management of appropriate BP levels. Cuffless BP devices can assess beat-to-beat BPV. Although cuffless BP monitoring devices have measurement accuracy issues that need to be resolved, this is an area of research where the evidence is accumulating rapidly, with many publications on beat-to-beat BPV over several decades. Ambulatory BP monitoring (ABPM) can assess 24-hour BPV and nocturnal dipping patterns. Day-to-day BPV and visit-to-visit BPV are assessed by self-measured BP monitoring at home and office BP measurement, respectively. 24 h, day-to-day, and visit-to-visit BPV have been reported to be associated with cardiovascular prognosis. Although there have been several studies comparing whether ABPM and self-measured BP monitoring at home is the superior measurement method of BPV, no strong evidence has been accumulated that indicates whether ABPM or self-measured home BP is superior. ABPM and self-measured BP monitoring have their own advantages and complement each other in the assessment of BPV.

High versus low measurement frequency during 24-h ambulatory blood pressure monitoring - a randomized crossover study

Ambulatory blood pressure monitoring (ABPM) may be stressful and associated with discomfort, possibly influenced by the number of cuff inflations. We compared a low frequency (LF-ABPM) regimen with one cuff inflation per hour, with a high frequency (HF-ABPM) regimen performed according to current guidelines using three cuff-inflations per hour during daytime and two cuff-inflations during night time. In a crossover study, patients underwent ABPMs with both frequencies, in a randomized order, within an interval of a few days. Patients reported pain (visual analogue scale from 0 to 10) and sleep disturbances after each ABPM. The primary endpoint was the difference in mean 24 h systolic BP (SBP) between HF-ABPM and LF-ABPM. A total of 171 patients were randomized, and data from 131 (age 58 ± 14 years, 47% females, 24% normotensive, 53% mildly hypertensive, and 22% moderately-severely hypertensive) completing both ABPMs were included in the analysis. Mean SBP was 137.5 mmHg (95% CI, 134.8;140.2) for HF-ABPM and 138.2 mmHg (95%CI, 135.2;141.1) for LF-ABPM. The 95% limits of agreement were -15.3 mmHg and +14.0 mmHg. Mean 24 h SBP difference between HF-ABPM and LF-ABPM was -0.7 mmHg (95%CI, -2.0;0.6). Coefficients of variation were similar for LF-ABPM and HF-ABPM. Pain scores (median with interquartile range), for HF-ABPM and LF-ABPM were 1.5 (0.6;3.0) and 1.3 (0.6;2.9) during daytime, and 1.3 (0.4:3.4) and 0.9 (0.4;2.0) during nighttime (P < 0.05 for both differences). We conclude that LF-ABPM and HF-ABPM values are in good agreement without any clinically relevant differences in BP. Furthermore, LF-ABPM causes a relatively modest reduction in procedure-related pain.

Effect of blood pressure variability on hypertensive retinopathy

PURPOSE

This study intends to investigate the correlation between blood pressure variability (BPV) levels and the use of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) to measure retinal microvasculature in hypertensive patients.

METHODS

All individuals in the study had 24-hour ambulatory blood pressure monitoring and bilateral OCT and OCTA exams, and only data from the right eye were analyzed statistically.

RESULTS

The study included 170 individuals, with 60 in the control group. The experimental group was separated into two groups based on the average real variability (ARV) median, with 55 in the low ARV group and 55 in the high ARV group. The mean thicknesses of the Retinal Nerve Fiber Layer (RNFL), internal limiting membrane-retinal pigment epithelial cell layer (ILM-RPE), vessel density (VD), and perfusion density (PD) in the high-ARV group were substantially lower in the low-ARV and control groups (p＜0.05). Multiple linear regression analysis revealed that disease duration, age, and 24 h diastolic standard deviation all affected RNFL mean thickness (p＜0.05). VD and PD were influenced by disease duration, systolic-ARV, daytime systolic blood pressure, intraocular pressure(IOP), and best-corrected visual acuity (BCVA) (p＜0.05). And the change in VD was connected to best-corrected visual acuity.

CONCLUSION

Hypertensive retinopathy is related to BPV. In clinical practice, we can assess the degree of BPV and retinopathy in hypertensive patients to track the progression of hypertension-mediated organ damage (HMOD). Correction of BPV may help treat or postpone the progression of HOMD.

Comparison of Ambulatory and Home Blood Pressure Variability for Cardiovascular Prognosis and Biomarkers

BACKGROUND

Although blood pressure variability (BPV) is reported to be associated with cardiovascular prognoses, it has not been established whether ambulatory BPV (ABPV; ie, short-term 24-hour BPV) or home BPV (HBPV; day-to-day BPV) is a superior clinical marker.

METHODS

We analyzed the associations of ABPV and HBPV with cardiovascular prognoses and biomarkers in 1314 hypertensive outpatients who underwent both home and ambulatory BP measurements in the J-HOP study (Japan Morning-Surge Home Blood Pressure). BPV was evaluated by the SD, coefficient of variation, and average real variability of the patients' 24-hour ambulatory and home systolic BP values.

RESULTS

During the median 7.0-year follow-up, 109 cardiovascular events occurred. All SD, coefficient of variation, and average real variability values of the HBPV were significantly associated with cardiovascular risk even after adjusting by average 24-hour ambulatory systolic BP and each ABPV value: 1 SD of hazard ratio (95% CI) for the SD, 1.36 (1.14-1.63); coefficient of variation, 1.38 (1.16-1.66); and average real variability 1.29 (1.10-1.51) of HBPV. The ABPV parameters did not exhibit comparable relationships. The cardiovascular risk spline curves showed a trend toward increased risks with increasing HBPV parameters. There were no differences between ABPV and HBPV in the relationships with B-type natriuretic peptide and the urine albumin-creatine ratio.

CONCLUSIONS

In this comparative analysis of ambulatory and home BP monitoring values in individuals with hypertension, ABPV was not significantly associated with cardiovascular prognosis adjusted by average BP level, and HBPV was suggested to have modest superiority in predicting cardiovascular prognosis compared with ABPV.

Amlodipine in the current management of hypertension

Hypertension is the leading cause of death worldwide, affecting 1.4 billion people. Treatment options include the widely used calcium channel blockers, among which amlodipine, a dihydropyridine, has unique characteristics that distinguish it from other drugs within this class. This review aims to provide an updated overview of the evidence supporting the use of amlodipine over the past 30 years and highlights its cardiovascular benefits in current hypertension management. Amlodipine has low renal clearance (7 mL/min/mg) and long half-life (35-50 h) and duration of action, which allows it to sustain its anti-hypertensive effect for more than 24 h following a single dose. Additionally, blood pressure (BP) control is maintained even when a dose has been missed, providing continuous protection in case of incidental noncompliance. It has proven to reduce BP variability and successfully lower BP. Amlodipine also controls BP in patients with a systolic/diastolic BP of 130/80 mm Hg or higher, diabetes, or chronic kidney disease without worsening glycemic or kidney function. Additionally, amlodipine is a wise choice for older adults due to its ability to control BP and protect against stroke and myocardial infarction. Side effects of amlodipine include edema, palpitations, dizziness, and flushing, which are more common with the higher dose of 10 mg. Amlodipine is cost effective and predicted to be cost saving when compared with usual care.

Cardiovascular variability, sociodemographics, and biomarkers of disease: the MIDUS study

Introduction: Like heart rate, blood pressure (BP) is not steady but varies over intervals as long as months to as short as consecutive cardiac cycles. This blood pressure variability (BPV) consists of regularly occurring oscillations as well as less well-organized changes and typically is computed as the standard deviation of multiple clinic visit-to-visit (VVV-BP) measures or from 24-h ambulatory BP recordings (ABPV). BP also varies on a beat-to-beat basis, quantified by methods that parse variation into discrete bins, e.g., low frequency (0.04-0.15 Hz, LF). However, beat-to-beat BPV requires continuous recordings that are not easily acquired. As a result, we know little about the relationship between LF-BPV and basic sociodemographic characteristics such as age, sex, and race and clinical conditions. Methods: We computed LF-BPV during an 11-min resting period in 2,118 participants in the Midlife in the US (MIDUS) study. Results: LF-BPV was negatively associated with age, greater in men than women, and unrelated to race or socioeconomic status. It was greater in participants with hypertension but unrelated to hyperlipidemia, hypertriglyceridemia, diabetes, elevated CRP, or obesity. LF-diastolic BPV (DBPV), but not-systolic BPV (SBPV), was negatively correlated with IL-6 and s-ICAM and positively correlated with urinary epinephrine and cortisol. Finally, LF-DBPV was negatively associated with mortality, an effect was rendered nonsignificant by adjustment by age but not other sociodemographic characteristics. Discussion: These findings, the first from a large, national sample, suggest that LF-BPV differs significantly from VVV-BP and ABPV. Confirming its relationship to sociodemographic risk factors and clinical outcomes requires further study with large and representative samples.

Short-term Blood Pressure Variability and Incident CKD in Patients With Hypertension: Findings From the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI) Study

RATIONALE & OBJECTIVE

The association between short-term blood pressure variability (BPV) and kidney outcomes is poorly understood. This study evaluated the association between short-term BPV and kidney disease outcomes in people with hypertension.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

1,173 hypertensive participants in the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (2013-2018) Study with estimated glomerular filtration rate (eGFR) ≥60mL/min/1.73m².

EXPOSURE

Short-term BPV assessed by average real variability (ARV).

OUTCOME

Composite kidney disease outcome (30% decline in eGFR from baseline, new occurrence of eGFR <60mL/min/1.73m², or onset of UACR >300mg/g).

ANALYTICAL APPROACH

Multivariable Cox regression analyses to evaluate the association between systolic and diastolic BP ARV (SBP-ARV and DBP-ARV) and outcomes.

RESULTS

During a median follow-up of 5.4 [4.1-6.5] years, 271 events of the composite kidney disease outcome occurred (46.5 per 1,000 person-years). Multivariable Cox analysis revealed that the highest SBP-ARV and DBP-ARV tertiles were associated with a higher risk of the composite kidney disease outcome than the lowest tertiles, independent of the 24-hour SBP or DBP levels (HR, 1.64 [95% CI, 1.16-2.33], and 1.60 [95% CI, 1.15-2.24] for SBP-ARV and DBP-ARV, respectively). These associations were consistent when SBP-ARV and DBP-ARV were treated as continuous variables (HR per 1.0-unit greater SBP-ARV, 1.03 [95% CI, 1.01-1.06]; HR per 1.0-unit greater DBP-ARV, 1.04 [95% CI, 1.01-1.08]). These associations were consistent, irrespective of subgroups (age, sex, 24-hour SBP or DBP, and moderate albuminuria). However, other measures of short-term BPV including SD, coefficient of variation, and dipping patterns were not associated with the composite kidney disease outcome.

LIMITATIONS

Observational study design, the use of single measurement of 24-hour BP, lack of information on changes in antihypertensive medication during the follow-up.

CONCLUSIONS

Short-term BPV is associated with the development of a composite kidney disease outcome in hypertensive patients.

Association of disrupted sleep with 24-hour blood pressure variability in caregivers

BACKGROUND

A growing body of research highlights the negative impact of caregiving on cardiovascular disease (CVD) risk.

OBJECTIVES

This study aimed to examine associations of psychological symptoms and sleep quality with 24-hour blood pressure variability (BPV), which is an independent predictor of CVD, among family caregivers of community-dwelling individuals with chronic illness.

METHODS

For this cross-sectional study, we assessed caregiving burden and depressive symptoms using questionnaires and 7-day sleep quality (i.e., number of awakenings, wake after sleep onset, sleep efficiency) using an actigraph. The participants carried out a 24-hour ambulatory BP monitoring for systolic and diastolic BPV over 24 h and during awake/sleep times. We performed Pearson's correlations and multiple linear regression.

RESULTS

The analytic sample consisted of 30 caregivers (25 female; mean age 62 years). The number of awakenings during sleep was positively correlated with systolic BPV-awake (r = 0.426, p = 0.019) and diastolic BPV-awake (r = 0.422, p = 0.020). Sleep efficiency was negatively correlated with diastolic BPV-awake (r = -0.368, p = 0.045). Caregiving burden and depressive symptoms were not correlated with BPV. After controlling for age and mean arterial pressure, the number of awakenings was significantly associated with increased systolic BPV-24 h (β = 0.194, p = 0.018) and systolic BPV-awake (β = 0.280, p = 0.002), respectively.

CONCLUSIONS

Caregivers' disrupted sleep may play a role in increased CVD risk. While these findings should be confirmed in large clinical studies, improving sleep quality would need to be considered in CVD prevention for caregivers.

Aerobic exercise improves central blood pressure and blood pressure variability among patients with resistant hypertension: results of the EnRicH trial

Central blood pressure (BP) and BP variability are associated with cardiovascular disease risk. However, the influence of exercise on these hemodynamic parameters is unknown among patients with resistant hypertension. The EnRicH (The Exercise Training in the Treatment of Resistant Hypertension) was a prospective, single-blinded randomized clinical trial (NCT03090529). Sixty patients were randomized to a 12-week aerobic exercise program or usual care. The outcome measures include central BP, BP variability, heart rate variability, carotid-femoral pulse wave velocity, and circulating cardiovascular disease risk biomarkers including high-sensitivity C-reactive protein, angiotensin II, superoxide dismutase, interferon gamma, nitric oxide, and endothelial progenitor cells. Central systolic BP decreased by 12.22 mm Hg (95% CI, -1.88 to -22.57, P = 0.022) as did BP variability by 2.85 mm Hg (95% CI, -4.91 to -0.78, P = 0.008), in the exercise (n = 26) compared to the control group (n = 27). Interferon gamma -4.3 pg/mL (95%CI, -7.1 to -1.5, P = 0.003), angiotensin II -157.0 pg/mL (95%CI, -288.1 to -25.9, P = 0.020), and superoxide dismutase 0.4 pg/mL (95%CI, 0.1-0.6, P = 0.009) improved in the exercise compared to the control group. Carotid-femoral pulse wave velocity, heart rate variability, high-sensitivity C-reactive protein, nitric oxide, and endothelial progenitor cells were not different between groups (P > 0.05). In conclusion, a 12-week exercise training program improved central BP and BP variability, and cardiovascular disease risk biomarkers in patients with resistant hypertension. These markers are clinically relevant as they are associated with target organ damage and increased cardiovascular disease risk and mortality.

Targeting autonomic nervous system as a biomarker of well-ageing in the prevention of stroke

Stroke prediction is a key health issue for preventive medicine. Atrial fibrillation (AF) detection is well established and the importance of obstructive sleep apneas (OSA) has emerged in recent years. Although autonomic nervous system (ANS) appears strongly implicated in stroke occurrence, this factor is more rarely considered. However, the consequences of decreased parasympathetic activity explored in large cohort studies through measurement of ANS activity indicate that an ability to improve its activity level and equilibrium may prevent stroke. In support of these observations, a compensatory neurostimulation has already proved beneficial on endothelium function. The available data on stroke predictions from ANS is based on many long-term stroke cohorts. These data underline the need of repeated ANS evaluation for the general population, in a medical environment, and remotely by emerging telemedicine digital tools. This would help uncovering the reasons behind the ANS imbalance that would need to be medically adjusted to decrease the risk of stroke. This ANS unbalance help to draw attention on clinical or non-clinical evidence, disclosing the vascular risk, as ANS activity integrates the cumulated risk from many factors of which most are modifiable, such as metabolic inadaptation in diabetes and obesity, sleep ventilatory disorders, hypertension, inflammation, and lack of physical activity. Treating these factors may determine ANS recovery through the appropriate management of these conditions. Natural aging also decreases ANS activity. ANS recovery will decrease global circulating inflammation, which will reinforce endothelial function and thus protect the vessels and the associated organs. ANS is the whistle-blower of vascular risk and the actor of vascular health. Such as, ANS should be regularly checked to help draw attention on vascular risk and help follow the improvements in response to our interventions. While today prediction of stroke relies on classical cardiovascular risk factors, adding autonomic biomarkers as HRV parameters may significantly increase the prediction of stroke.

Predictive Capacity of Beat-to-Beat Blood Pressure Variability for Cardioautonomic and Vascular Dysfunction in Early Metabolic Challenge

Diabetic patients present established cardiovascular disease at the onset of diagnostic metabolic symptoms. While premature autonomic and vascular deterioration considered risk factors for major cardiovascular complications of diabetes, present in initial stages of metabolic impairment, their early detection remains a significant challenge impeding timely intervention. In the present study, we examine the utility of beat-to-beat blood pressure variability (BPV) parameters in capturing subtle changes in cardiac autonomic and vascular control distinguishing between various risk categories, independent of the average BP. A rat model of mild hypercaloric (HC) intake was used to represent the insidious cardiovascular changes associated with early metabolic impairment. Invasive hemodynamics were used to collect beat-to-beat BP time series in rats of either sex with different durations of exposure to the HC diet. Linear (standard deviation and coefficient of variation) and nonlinear (approximate entropy, ApEn, and self-correlation of detrended fluctuation analysis, α) BPV parameters were calculated to assess the impact of early metabolic impairment across sexes and feeding durations. HC-fed male, but not female, rats developed increased fat:lean ratio as well as hyperinsulinemia. Unlike linear parameters, multivariate analysis showed that HC-fed rats possessed lower ApEn and higher α, consistent with early changes in heart rate variability and blunting of parasympathetic baroreceptor sensitivity, particularly in males. Moreover, logistic regression demonstrated the superiority of nonlinear parameters of diastolic BPV in predicting a prediabetic disease state. Our findings support the use of nonlinear beat-to-beat BPV for early detection of cardiovascular derangements in the initial stages of metabolic impairment.

Associations of Long-Term Visit-to-Visit Blood Pressure Variability With Subclinical Kidney Damage and Albuminuria in Adulthood: a 30-Year Prospective Cohort Study

BACKGROUND

Recent evidence indicates that long-term visit-to-visit blood pressure variability (BPV) may be associated with risk of cardiovascular disease. We, therefore, aimed to determine the potential associations of long-term BPV from childhood to middle age with subclinical kidney damage (SKD) and albuminuria in adulthood.

METHODS

Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, which recruited children and adolescents aged 6 to 18 years at baseline, we assessed BPV by SD and average real variability (ARV) for 30 years (6 visits). Presence of SKD was defined as estimated glomerular filtration rate between 30 and 60 mL/min per 1.73 m² or elevated urinary albumin-to creatinine ratio at least 30 mg/g. Albuminuria was defined as urinary albumin-to creatinine ratio ≥30 mg/g.

RESULTS

During 30 years of follow-up, of the 1771 participants, 204 SKD events occurred. After adjustment for demographic, clinical characteristics, and mean BP during 30 years, higher SD_SBP , ARV_SBP , SD_DBP , ARV_DBP , SD_MAP , ARV_MAP , and ARV_PP were significantly associated with higher risk of SKD. When we used cumulative exposure to BP from childhood to adulthood instead of mean BP as adjustment factors, results were similar. In addition, greater long-term BPV was also associated with the risk of albuminuria. Long-term BPV from childhood to middle age was associated with higher risk of SKD and albuminuria in adulthood, independent of mean BP or cumulative exposure to BP during follow-up.

CONCLUSIONS

Identifying long-term BPV from early age may assist in predicting kidney disease and cardiovascular disease in later life.

Association between Short-Term Blood Pressure Variability and Intracranial Atherosclerotic Plaque Vulnerability: A High-Resolution Magnetic Resonance Imaging Study

Aim: short-term blood pressure variability (BPV) as a risk factor of atherosclerosis and cardiovascular events has been investigated. However, its association with atherosclerotic plaque vulnerability remains unknown. The objective of this study was to determine the association between short-term BPV and intracranial atherosclerotic plaque vulnerability.

Methods: this is a cross-sectional analysis of 267 ischemic stroke patients with symptomatic intracranial atherosclerosis (mean age, 65±12 years old; 60.3% male), which were prospectively recruited in a comprehensive stroke center. Systolic and diastolic BP SD, CV, and BP variability ratio (BPVR) from 24 hours, daytime, and nighttime were calculated from 24-h ambulatory blood pressure monitoring, intracranial atherosclerotic plaque burden and vulnerability were evaluated by high-resolution magnetic resonance vessel wall imaging. Logistic regression analysis was used to locate the correlation between short-term BPV and plaque vulnerability.

Results: a total of 36.3% subjects presented with intraplaque hemorrhage (IPH) in this study. Multivariate logistic regression suggested that nighttime diastolic BP CV and 24-h BPVR were associated with intracranial IPH independently after adjusted for cardiovascular risk factors, odds ratio (OR) and 95% confidence interval (CI) for per SD BPV changes were 1.418 (1.051, 1.914) and 0.731 (0.548, 0.976), respectively, and this association also independent of atherosclerosis burden and 24-h mean systolic BP level. Further subgroup analysis by age and hypertension history demonstrated that the statistical correlation could only establish in the elder, and subjects with hypertension.

Conclusion: nighttime diastolic BP CV and 24-h BPVR were associated with intracranial IPH independently, especially in the elderly and subjects with hypertension.

Acupuncture for Hypertension in Animal Models: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this study was to summarize and evaluate the efficacy of acupuncture in hypertension animal study.

METHODS

Studies were searched from six databases, including Medline, Embase, Chinese National Knowledge Infrastructure, Wanfang Data, VIP information database, and Chinese Biomedical Literature Database. Study quality of each included study was evaluated according to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines, and the risk of bias was evaluated by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were selected as outcomes. Meta-analyses were performed using Stata 12.0 software. The effect size was calculated by combining SBP/DBP/MAP data with the random effects model, respectively.

RESULTS

67 studies containing 1522 animals were included. According to the ARRIVE guideline, 8 items were assessed as poor and 4 items were assessed as excellent. According to the SYRCLE tool, all studies were judged as having high risk of bias. Compared with the hypertension group, the pooled results showed significant antihypertension effects of acupuncture for SBP, DBP, and MAP. Similarly, compared with the sham-acupuncture group, the pooled results showed significant antihypertension effects of acupuncture for SBP, DBP, and MAP.

CONCLUSION

Although pooled data suggested that the acupuncture group was superior to the hypertension group or sham-acupuncture group for SBP/DBP/MAP, the presentation of poor methodological quality, high risk of bias, and heterogeneity deserves cautious interpretation of the results.

Impact of home blood pressure variability on cardiovascular outcome in patients with arterial stiffness: Results of the J-HOP study

This study sought to investigate whether the relation between increased blood pressure (BP) variability and increased arterial stiffness confers a risk for cardiovascular disease (CVD) events. We analyzed 2648 patients from a practitioner‐based population (mean ± SD age 64.9 ± 11.4 years: 75.8% taking antihypertensive medication) with at least one cardiovascular risk factor who underwent home BP monitoring in the Japan Morning Surge‐Home Blood Pressure Study. The standard deviation (SD_SBP), coefficient of variation (CV_SBP), and average real variability (ARV_SBP) were assessed as indexes of day‐by‐day home systolic BP (SBP) variability. The authors assessed arterial stiffness by brachial‐ankle pulse wave velocity (baPWV) and divided patients into lower (< 1800 cm/s, n = 1837) and higher (≥1800 cm/s, n = 811) baPWV groups. During a mean follow‐up of 4.4 years, 95 cardiovascular events occurred (8.1 per 1000 person‐years). In Cox proportional hazard models adjusted for traditional cardiovascular risk factors including average home SBP, the highest quartiles of SD_SBP (hazard ratio [HR], 2.30; 95% confidence interval [CI], 1.23‐4.32), CV_SBP (HR, 2.89; 95%CI, 1.59‐5.26) and ARV_SBP (HR, 2.55; 95%CI, 1.37‐4.75) were predictive of CVD events compared to the other quartiles in the higher baPWV group. Moreover, 1SD increases in SD_SBP (HR, 1.44; 95%CI, 1.13‐1.82), CV_SBP (HR, 1.49; 95%CI, 1.16‐1.90) and ARV_SBP (HR, 1.37; 95%CI, 1.09‐1.73) were also predictive of CVD events. These associations remained even after N‐terminal pro‐brain natriuretic peptide was added to the models. However, these associations were not observed in the lower baPWV group. We conclude that arterial stiffness contributes to the association between home BP variability and CVD incidence.

Impact of dietary intake of sodium and potassium on short-term blood pressure variability

BACKGROUND

Dietary Approaches to Stop Hypertension (DASH)-Sodium trial showed that dietary sodium and potassium affect blood pressure (BP). We aimed to investigate whether dietary sodium and potassium affect short-term BP variability (BPV) in addition to BP.

METHODS

A total of 343 participants from the DASH-Sodium trial (age 48.4 ± 9.7, 42.5% men) and 323 individuals from the Jackson Heart Study (JHS) (age 56.7 ± 11.2, 30.7% men) with satisfactory ambulatory BP monitoring records and 24-h urine collection were included. Average real variability (ARV) was calculated as a measure of short-term BPV.

RESULTS

By estimating dietary intake from urinary excretion, we observed that higher urinary sodium-to-potassium ratio was significantly associated with higher diastolic ARV in both studies. Among the DASH-Sodium trial, potassium-rich DASH diet alone had insignificant effect on both systolic (-0.1 ± 1.7 mmHg, P = 0.343) or diastolic ARV (-0.2 ± 1.5 mmHg, P = 0.164), whereas combined DASH diet and low sodium intake significantly reduced both systolic (8.5 ± 1.6 vs. 8.9 ± 1.7 mmHg, P = 0.032) and diastolic ARV (7.5 ± 1.5 vs. 7.8 ± 1.6 mmHg, P = 0.025) as compared with control diet and high sodium intake. As the reduction of systolic ARV was majorly derived from the change of mean SBP, diastolic ARV was significantly determined by urinary sodium-to-potassium ratio (β coefficient ± standard error: 0.012 ± 0.004; P = 0.006) after adjusting for age, sex, smoking, mean DBP, BMI, and race.

CONCLUSION

Dietary sodium and potassium can jointly modulate short-term BPV in addition to BP. Combined DASH diet and low sodium intake may reduce systolic and diastolic ARV via different mechanisms.

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.

Coconut Oil Supplementation Does Not Affect Blood Pressure Variability and Oxidative Stress: A Placebo-Controlled Clinical Study in Stage-1 Hypertensive Patients

Exploring an alternative to improve the clinical management of hypertension, we tested the hypothesis that food supplementation with coconut oil (EVCO), alone or combined with aerobic exercise training, could exert an antihypertensive effect (primary outcome) in patients with stage 1 hypertension. Forty-five hypertensive volunteers of both genders participated in a placebo-controlled clinical trial. The volunteers were submitted to 24-hour ambulatory blood pressure monitoring, analysis of blood pressure variability (BPV), measurement of serum malondialdehyde (MDA) and nutritional assessment. Results indicate that EVCO consumption had no adverse effects. The supplementation did not increase the caloric intake compared with placebo, and the dietary constituents were similar between groups, except for the saturated fats, especially lauric acid. The analysis of blood pressure indicated absence of antihypertensive effect of EVCO alone or combined with physical training. Furthermore, no effects on blood pressure variability and oxidative stress were observed in the supplemented hypertensive patients. Thus, despite the results observed in pre-clinical studies, the current clinical study did not provide evidence to support the use of coconut oil as an adjuvant in the management of hypertension in humans.

Association between renin-angiotensin-aldosterone system inhibitors and risk of dementia: A meta-analysis

OBJECTIVE

To evaluate the association of all RAAS inhibitors, ACE inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) on dementia onset (any dementia, Alzheimer's disease and vascular dementia) using a meta-analytic approach.

METHODS

A systematic MEDLINE search was carried out to identify all observational studies published up to the 30th September 2020 evaluating the association between RAAS inhibitors and risk of dementia. Studies were included if original investigations considering incident dementia cases, with ACEIs and/or ARBs as exposure and other antihypertensives (AHs) use as reference, and if reporting association estimates and relative variability measures. Random effect pooled relative risks (pRR) and the corresponding 95% confidence intervals (95%CI) were calculated according to DerSimonian and Laird's (DL) or to Hartung Knapp Sidik Jonkman (HKSJ) method depending on the number of studies and between-studies heterogeneity. A linear mixed meta-regression model (MM) was applied to take into account correlation among association estimates from the same study.

RESULTS

15 studies were included in the meta-analysis. ARBs but not ACEIs' use led to a significant reduction of the risk of any dementia (pRR 0.78, 95%CI_MM 0.70-0.87) and Alzheimer's disease (pRR 0.73, 95%CI_MM 0.60-0.90). Moreover, when compared to ACEIs, ARBs reduced of 14% the risk of any dementia (pRR 0.86, 95%CI_DL 0.79-0.94).

CONCLUSIONS

ARBs but not ACEIs led to a reduction in the risk of any dementia. The difference between ARBs and ACEIs in terms of preventive effectiveness could be due to distinct profiles of antagonism towards independent receptor pathways or to differential influences on amyloid metabolism.

Blood pressure variability and target organ damage regression in hypertension

The study by Triantafyllidi et al. supports the view that regression of subclinical cardiac damage requires an effective 24‐hour blood pressure (BP) control along with a reduction in BP variability and suggests that the assessment of BPV and its modifications during the course of therapy may be an useful approach in predicting the beneficial effects of treatment on cardiac structure. However, some aspects and limitations of this study require caution in drawing firm conclusions. So, further investigation is needed to determine if reduction of BPV is actually associated with a regression in cardiac and extracardiac organ damage to identify which which classes of antihypertensive drugs are most effective in reducing BPV, and to elucidate whether those treatments provide additional clinical benefit, independent of the conventional BP targets.

Beat-to-beat blood pressure variability: an early predictor of disease and cardiovascular risk

Blood pressure (BP) varies on the long, short and very-short term. Owing to the hidden physiological and pathological information present in BP time-series, increasing interest has been given to the study of continuous, beat-to-beat BP variability (BPV) using invasive and noninvasive methods. Different linear and nonlinear parameters of variability are employed in the characterization of BP signals in health and disease. Although linear parameters of beat-to-beat BPV are mainly measures of dispersion, such as standard deviation (SD), nonlinear parameters of BPV quantify the degree of complexity/irregularity- using measures of entropy or self-similarity/correlation. In this review, we summarize the value of linear and nonlinear parameters in reflecting different information about the pathophysiology of changes in beat-to-beat BPV independent of or superior to mean BP. We then provide a comparison of the relative power of linear and nonlinear parameters of beat-to-beat BPV in detecting early and subtle differences in various states. The practical advantage and utility of beat-to-beat BPV monitoring support its incorporation into routine clinical practices.

Short-Term but not Long-Term Blood Pressure Variability Is a Predictor of Adverse Cardiovascular Outcomes in Young Untreated Hypertensives

BACKGROUND

Whether blood pressure variability (BPV) measured with ambulatory monitoring (short-term BPV) or computed from office visits (long-term BPV) are related to each other and carry similar prognostic information is not well known. We investigated the independent determinants of short-term and long-term BPVs and their predictive capacity for the development of major adverse cardiovascular and renal events (MACEs) in a cohort of young hypertensive participants.

METHODS

Long-term BPV was calculated as visit-to-visit SD and average real variability from office blood pressure (BP) measured during 7 visits, within 1 year. Short-term BPV was calculated as weighted 24-hour SD and coefficient of variation. Hazard ratios (HRs) for risk of MACE were computed from multivariable Cox regressions.

RESULTS

1,167 participants were examined; mean age was 33.1 ± 8.5 years. Variables independently associated with 24-hour systolic SD were 24-hour systolic BP, low physical activity, smoking, baseline office pulse pressure, systolic BP dipping, and diastolic white coat effect, while those associated with long-term BPV were mean systolic BP, age, female gender, and baseline office heart rate. During a median follow-up of 17.4 years 75 MACEs occurred. In Cox analysis only short-term BPV resulted a significant predictor of MACE (HR, 1.31 (1.07-1.59); P = 0.0086), while no index of long-term BPV was independently associated with outcome.

CONCLUSIONS

In young hypertensive subjects only short-term BPV resulted a significant predictor of MACE on top of traditional ambulatory BP monitoring parameters. Whether reduction of short-term BPV with therapy may reduce the cardiovascular risk independently from the effects on 24-hour BP is a matter for future research.

2020 Consensus summary on the management of hypertension in Asia from the HOPE Asia Network

Hypertension professionals from Asia have been meeting together for the last decade to discuss how to improve the management of hypertension. Based on these education and research activities, the Hypertension, brain, cardiovascular and renal Outcome Prevention and Evidence in Asia (HOPE Asia) Network was officially established in June 2018 and includes experts from 12 countries/regions across Asia. Among the numerous research and review papers published by members of the HOPE Asia Network since 2017, publications in three key areas provide important guidance on the management of hypertension in Asia. This article highlights key consensus documents, which relate to the Asian characteristics of hypertension, home blood pressure monitoring (HBPM), and ambulatory blood pressure monitoring (ABPM). Hypertension and hypertension-related diseases are common in Asia, and their characteristics differ from those in other populations. It is essential that these are taken into consideration to provide the best opportunity for achieving "perfect 24-hour blood pressure control", guided by out-of-office (home and ambulatory) blood pressure monitoring. These region-specific consensus documents should contribute to optimizing individual and population-based hypertension management strategies in Asian country. In addition, the HOPE Asia Network model provides a good example of the local interpretation, modification, and dissemination of international best practice to benefit specific populations.

Prognostic value of average real variability of systolic blood pressure in elderly treated hypertensive patients

OBJECTIVE

The independent prognostic significance of ambulatory blood pressure variability in the elderly is incompletely clear. We investigated the prognostic value of average real variability of 24-hour blood pressure in elderly treated hypertensive patients.

METHODS

The occurrence of a combined end-point including stroke, coronary events, heart failure requiring hospitalization and peripheral revascularization was evaluated in 757 elderly treated hypertensive patients. According to tertiles of average real variability of 24-hour systolic blood pressure patients were classified as having low (≤8.66 mmHg; n = 252), medium (8.67-10.05 mmHg; n = 252) or high (>10.05 mmHg; n = 253) average real variability.

RESULTS

During the follow-up (6.9 ± 3.4 years, range 0.4-12.9 years), 195 events occurred. The event rate of the population was 3.74 per 100 patient-years. After adjustment for age, sex, previous events, diabetes, estimated glomerular filtration rate, left ventricular hypertrophy, left atrial enlargement, asymptomatic left ventricular systolic dysfunction at baseline, 24-hour systolic blood pressure, non-dipping and dipping with high morning surge of blood pressure, patients with high average real variability were at higher cardiovascular risk than those with low average real variability (hazard ratio 1.64, 95% confidence interval 1.12-2.40).

CONCLUSIONS

In elderly treated hypertensive patients, high average real variability of 24-hour systolic blood pressure is associated with higher cardiovascular risk independently of other risk markers, average 24-hour systolic blood pressure and circadian blood pressure changes.

Correlation between blood pressure variability and subclinical target organ damage in patients with essential hypertension

High blood pressure (BP) variability is associated with the increased risk of cardiovascular and renal damage together with increased cardiovascular mortality. The aim of our study was to investigate the relationship between BP variability and subclinical target organ damage (TOD) in patients with controlled essential hypertension. One hundred patients with controlled essential hypertension were randomly selected from outpatient clinic of Beni-Suef University hospital. All patients were subjected to full history taking, physical examination, three separate office BP measurements for assessment of long-term BP variability, ambulatory BP monitoring for short-term variability, and finally different investigations for subclinical TOD. We had 73 patients with subclinical TOD. Long-term visit-to-visit variability was evaluated by measuring SD (standard deviation) and CV (coefficient of variance) of systolic and diastolic BP. None of the parameters of long-term BP variability were significantly higher among patients with TOD compared with those without TOD. For short-term variability evaluated by ambulatory BP monitoring, average real variability (ARV) was the only parameter that had a significant consistent association with TOD in contrast to SD and CV. Finally, Daytime systolic ARV, nighttime diastolic ARV, and age were independent predictors of TOD (P values = 0.014, 0.018, 0.047, and 0.02, respectively). We concluded that ARV could be an appropriate index of BP variability and a more useful predictor of TOD in contrast to other parameters of BP variability.

The impact of systolic and diastolic blood pressure variability on mortality is age dependent: Data from the Dublin Outcome Study

Background

Twenty-four-hour blood pressure variability (BPV) is independently related to cardiovascular outcomes, but limited and conflicting evidence is available on the relative prognostic importance of systolic and diastolic BPV. The aim of this study was to verify the hypothesis that the association of systolic and diastolic blood pressure variability over 24 h with cardiovascular mortality in untreated subjects is affected by age.

Design and methods

The study included 9154 untreated individuals assessed for hypertension between 1982 and 2002 in the frame of the Dublin Outcome Study, in which 24 h ambulatory blood pressure monitoring was obtained (age 54.1 ± 14.3 years, 47% males). The association of short-term systolic and diastolic blood pressure variability with cardiovascular and all-cause mortality in the entire sample and separately in younger and older age subgroups was assessed over a median follow-up period of 6.3 years.

Results

Diastolic BPV was directly and independently related to cardiovascular mortality (adjusted hazard ratio (adjHR) for daytime standard deviation 1.16 (95% confidence interval 1.08–1.26)) with no significant differences among age groups. Conversely, systolic BPV was independently associated with cardiovascular mortality only in younger (<50 years) subjects (adjHR for daytime standard deviation 1.72 (95% confidence interval 1.33–2.23)), superseding the predictive value of diastolic BPV in this group.

Conclusions

Diastolic short-term BPV independently predicts cardiovascular mortality in hypertensive subjects at all ages, while systolic BPV seems a particularly strong predictor in young adults. If confirmed, these findings might improve the understanding of the prognostic value of BPV, with new perspectives for its possible clinical application.

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.

Increased Nighttime Pulse Pressure Variability but Not Ambulatory Blood Pressure Levels Predicts 14-Year All-Cause Mortality in Patients on Hemodialysis

Increased short-term blood pressure (BP) variability is associated with adverse cardiovascular outcomes in patients with hypertension. The present study investigated the long-term prognostic significance of the short-term blood pressure variability in patients on hemodialysis. A total of 149 patients (53.0% male; mean age: 54.5±15.1 years) receiving regular hemodialysis for >6 months were enrolled. They completed a 44-hour (excluding the hemodialysis session) ambulatory BP monitoring and comprehensive hemodynamic assessments, including carotid-femoral pulse wave velocity and pressure waveform decomposition (forward and backward wave amplitude). Blood pressure variability parameters, including average real variability (ARV) of systolic BP, diastolic BP, and pulse pressure (ARVp) during daytime, nighttime, and overall 44 hours were calculated. During a median follow-up of 14 years, 78 deaths (52.4%) were confirmed. In multivariable Cox regression analysis, none of the ambulatory BP parameters were predictive of mortality. In contrast, nighttime ARVp was consistently and significantly associated with all-cause mortality in multivariable Cox models adjusting for age, sex, albumin, hemodialysis treatment adequacy, and 44-hour systolic BP (continuous variable analysis, per 1-SD, hazard ratio=1.348; 95% CI, 1.029-1.767; categorical variable analysis, ≥8.5 versus <8.5 mm Hg; hazard ratio=1.825; 95% CI, 1.074-3.103). Forward wave amplitude and 44-hour systolic BP were identified as the 2 most important determinants of nighttime ARVp. Addition of nighttime ARVp to the base model significantly improved prediction of all-cause mortality (Net reclassification improvement =0.198; P=0.0012). In hemodialysis patients, increased short-term nighttime pulse pressure variability but not ambulatory BP levels were significantly predictive of long-term all-cause mortality.

Long-term incidence and risk factors of cardiovascular events in Asian populations: systematic review and meta-analysis of population-based cohort studies

BACKGROUND

Scientific studies on cardiovascular disease (CVD) burden and risk factors are predominantly based on short-term risk in Westerner populations, and such information may not be applicable to Asian populations, especially over the longer term. This review aims to estimate the long-term (>10 years) CVD burden, including coronary heart disease (CHD) and stroke, as well as associated risk factors in Asian populations.

METHODS

PubMed, Embase and Web of Science were systematically searched, and hits screened on: Asian adults, free of CVD at baseline; cohort study design (follow-up >10 years). Primary outcomes were fatal and non-fatal CVD events. Pooled estimates and between-study heterogeneity were calculated using random effects models, Q and I² statistics.

RESULTS

Overall, 32 studies were eligible for inclusion (follow-up: 11-29 years). The average long-term rate of fatal CVD is 3.68 per 1000 person-years (95% CI 2.84-4.53), the long-term cumulative risk 6.35% (95% CI 4.69%-8.01%, mean 20.13 years) and the cumulative fatal stroke/CHD risk ratio 1.5:1. Important risk factors for long-term fatal CVD (RR, 95% CI) were male gender (1.49, 1.36-1.64), age over 60/65 years (7.55, 5.59-10.19) and current smoking (1.68, 1.26-2.24). High non-HDL-c, and β- and γ-tocopherol serum were associated only with CHD (HR 2.46 [95% CI 1.29-4.71] and 2.47 [1.10-5.61] respectively), while stage 1 and 2 hypertensions were associated only with fatal stroke (2.02 [1.19-3.44] and 2.89 [1.68-4.96] respectively).

CONCLUSIONS

Over a 10 year + follow-up period Asian subjects had a higher risk of stroke than CHD. Contrary to CVD prevention in Western countries, strategies should also consider stroke instead of CHD only.

Morning surge in blood pressure and blood pressure variability in Asia: Evidence and statement from the HOPE Asia Network

Hypertension is a major risk factor for cardiovascular and cerebrovascular diseases. To effectively prevent end-organ damage, maintain vascular integrity and reduce morbidity and mortality, it is essential to decrease and adequately control blood pressure (BP) throughout each 24-hour period. Exaggerated early morning BP surge (EMBS) is one component of BP variability (BPV), and has been associated with an increased risk of stroke and cardiovascular events, independently of 24-hour average BP. BPV includes circadian, short-term and long-term components, and can best be documented using out-of-office techniques such as ambulatory and/or home BP monitoring. There is a large body of evidence linking both BPV and EMBS with increased rates of adverse cardio- and cerebrovascular events, and end-organ damage. Differences in hypertension and related cardiovascular disease rates have been reported between Western and Asian populations, including a higher rate of stroke, higher prevalence of metabolic syndrome, greater salt sensitivity and more common high morning and nocturnal BP readings in Asians. This highlights a need for BP management strategies that take into account ethnic differences. In general, long-acting antihypertensives that control BP throughout the 24-hour period are preferred; amlodipine and telmisartan have been shown to control EMBS more effectively than valsartan. Home and ambulatory BP monitoring should form an essential part of hypertension management, with individualized pharmacotherapy to achieve optimal 24-hour BP control particularly the EMBS and provide the best cardio- and cerebrovascular protection. Future research should facilitate better understanding of BPV, allowing optimization of strategies for the detection and treatment of hypertension to reduce adverse outcomes.

Blood pressure regulation determined by ambulatory blood pressure profiles in children and adolescents with type 1 diabetes mellitus: Impact on diabetic complications

BACKGROUND

The combination of high blood pressure and hyperglycemia contributes to the development of diabetic complications. Ambulatory monitoring of blood pressure (ABPM) is seen as standard to assess blood pressure (BP) regulation.

OBJECTIVE

We evaluated 24-hour BP regulation in 3529 children with type 1 diabetes, representing 5.6% of the patients <20 years of age documented in the DPV registry, and studied the influence of BP parameters including pulse pressure (PP) and blood pressure variability (BPV) on microalbuminuria (MA) and diabetic retinopathy (DR).

RESULTS

BP was increased in this selected cohort of children with diabetes compared to healthy German controls (standard deviation score (SDS) day: systolic BP (SBP) +0.06, mean arterial pressure (MAP) +0.08, PP +0.3; night: SBP +0.6, diastolic BP +0.6, MAP +0.8), while daytime diastolic BP (SDS -0.2) and dipping of SBP and MAP were reduced (SBP -1.1 SDS, MAP 12.4% vs 19.4%), PP showed reverse dipping (-0.7 SDS). Children with microvascular complications had by +0.1 to +0.75 SDS higher BP parameters, except of nocturnal PP in MA and diurnal and nocturnal PP in DR. Reverse dipping of PP was more pronounced in the children with MA (-5.1% vs -0.8%) and DR (-2.6% vs -1.0%). BP alteration was stronger in girls and increased with age.

CONCLUSION

There is an early and close link between 24-hour blood pressure regulation and the development of diabetic complications not only for systolic, diastolic, and mean arterial BP but also for the derived BP parameter PP and BPV in our selected patients.

24-Hour Blood Pressure Variability Assessed by Average Real Variability: A Systematic Review and Meta-Analysis

BACKGROUND

Although 24-hour blood pressure (BP) variability (BPV) is predictive of cardiovascular outcomes independent of absolute BP levels, it is not regularly assessed in clinical practice. One possible limitation to routine BPV assessment is the lack of standardized methods for accurately estimating 24-hour BPV. We conducted a systematic review to assess the predictive power of reported BPV indexes to address appropriate quantification of 24-hour BPV, including the average real variability (ARV) index.

METHODS AND RESULTS

Studies chosen for review were those that presented data for 24-hour BPV in adults from meta-analysis, longitudinal or cross-sectional design, and examined BPV in terms of the following issues: (1) methods used to calculate and evaluate ARV; (2) assessment of 24-hour BPV determined using noninvasive ambulatory BP monitoring; (3) multivariate analysis adjusted for covariates, including some measure of BP; (4) association of 24-hour BPV with subclinical organ damage; and (5) the predictive value of 24-hour BPV on target organ damage and rate of cardiovascular events. Of the 19 assessed studies, 17 reported significant associations between high ARV and the presence and progression of subclinical organ damage, as well as the incidence of hard end points, such as cardiovascular events. In all these cases, ARV remained a significant independent predictor (P<0.05) after adjustment for BP and other clinical factors. In addition, increased ARV in systolic BP was associated with risk of all cardiovascular events (hazard ratio, 1.18; 95% confidence interval, 1.09-1.27). Only 2 cross-sectional studies did not find that high ARV was a significant risk factor.

CONCLUSIONS

Current evidence suggests that ARV index adds significant prognostic information to 24-hour ambulatory BP monitoring and is a useful approach for studying the clinical value of BPV.

Hemodynamic Determinants of the Short-Term Blood Pressure Variability: Differential Roles of Arterial Stiffness and Wave Reflection

BACKGROUND

A high 24-hour ambulatory diastolic (DBP) but not systolic (SBP) blood pressure variability (BPV) is significantly predictive of long-term cardiovascular mortality in untreated hypertensive subjects, independent of office or 24-hour SBP. The present study was aimed to investigate hemodynamic factors that are independently associated with systolic and diastolic BPV from the 24-hour ambulatory blood pressure monitoring (ABPM).

METHODS

A cohort of 624 normotensive and 633 untreated hypertensive participants with baseline ABPM was drawn from a community-based survey. BPV was assessed by the read-to-read average real variability of the 24-hour SBP and DBP (ARVs and ARVd, respectively). Hemodynamic variables including total peripheral resistance (TPR), carotid-femoral pulse wave velocity (cf-PWV), and amplitudes of the decomposed forward (Pf) and backward (Pb) carotid pressure waves were analyzed.

RESULTS

In multivariable analyses, hemodynamic variables independently associated with 24-hour SBP were 24-hour heart rate (HR), TPR, cf-PWV, Pf, and Pb (model r2 = 0.535). Hemodynamic factors independently associated with ARV were 24-hour HR, Pf, and Pb for ARVs, and 24-hour HR, cf-PWV, Pf, and Pb for ARVd (model R2 = 0.345 and 0.220, respectively). Addition of 24-hour SBP to the ARV models only slightly improved variance explained by the models (R2 = 0.383 and 0.224, respectively). Pb accounted for >50% of total variance of ARVs and ARVd, whereas cf-PWV was a minor determinant of ARVd (<5% of total variance).

CONCLUSIONS

ARVd was associated with fewer hemodynamic variables than to 24-hour SBP. Among those hemodynamic variables wave reflection but not arterial stiffness had the dominant independent association with ARV.