Visit-to-visit Blood Pressure Variability and Arterial Stiffness: Which Came First: The Chicken or the Egg?

Significance of blood pressure variability in normotensive individuals as a risk factor of developing hypertension

PURPOSE

Visit-to-visit blood pressure variability is a strong predictor of the incidence of cardiovascular events and target organ damage due to hypertension. The present study investigated whether year-to-year blood pressure variability predicts the risk of hypertension in the Japanese general population.

MATERIALS AND METHODS

This study analysed 2806 normotensive individuals who participated in our physical check-up program for five years in a row from 2008 to 2013. The average, standard deviation, coefficient of variation, average real variability, and highest value of systolic blood pressure in the five consecutive visits were determined and used as baseline data. The participants were followed up for the next 6 years with the development of 'high blood pressure', an average blood pressure level of ≥140/90 mmHg or the use of antihypertensive medications, as the endpoint.

RESULT

During follow-up, 'high blood pressure' developed in 389 participants (13.9%, 29.5 per 1 000 person-years). The incidence increased across the quartiles of standard deviation and average real variability, while the average and highest systolic blood pressure had the most prominent impact on the development of 'high blood pressure'. Multivariate logistic regression analysis adjusted for possible risk factors indicated that the average, standard deviation, average real variability, and highest blood pressure, but not the coefficient of variation of systolic blood pressure, were significant predictors of 'high blood pressure'.

CONCLUSION

Increased year-to-year blood pressure variability predicts the risk of hypertension in the general normotensive population. The highest blood pressure in the preceding years may also be a strong predictor of the risk of hypertension.

Impact of seasonal blood pressure changes on visit-to-visit blood pressure variability and related cardiovascular outcomes

BACKGROUND

Visit-to-visit blood pressure (BP) variability associates with an increased risk of cardiovascular events. We investigated the role of seasonal BP modifications on the magnitude of BP variability and its impact on cardiovascular risk.

METHODS

In 25 390 patients included in the ONTARGET and TRANSCEND trials, the on-treatment systolic (S) BP values obtained by five visits during the first two years of the trials were grouped according to the month in which they were obtained. SBP differences between winter and summer months were calculated for BP variability quintiles (Qs), as quantified by the coefficient of variation (CV) of on-treatment mean SBP from the five visits. The relationship of BP variability with the risk of cardiovascular events and mortality was assessed by the Cox regression model.

RESULTS

SBP was approximately 4 mmHg lower in summer than in winter regardless of confounders. Winter/summer SBP differences contributed significantly to each SBP-CV quintile. Increase of SBP-CV from Q1 to Q5 was associated with a progressive increase in the adjusted hazard ratio (HR) of the primary endpoint of the trials, i.e. morbid and fatal cardiovascular events. This association was even stronger after removal of the effect of seasonality from the calculation of SBP-CV. A similar trend was observed for secondary endpoints.

CONCLUSIONS

Winter/summer SBP differences significantly contribute to visit-to-visit BP variability. However, this contribution does not participate in the adverse prognostic significance of visit-to-visit BP variations, which seems to be more evident after removal of the BP effects of seasonality from visit-to-visit BP variations.

Relationship between 24 h blood pressure variability and mortality in acute myocardial infarction patients

BACKGROUND

In recent years, the mortality of patients with AMI has not declined significantly. The relationship between blood pressure variability (BPV) and acute myocardial infarction (AMI) is unclear. We explored the relationship between 24-h BPV and mortality in patients with AMI.

HYPOTHESIS

The mortality of patients with AMI is related to BPV. We hope to provide therapeutic ideas for reducing the risk of death in patients with AMI.

METHODS

This is a retrospective cohort study. We extracted and analyzed data from the MIMIC-IV 2.0, which was established in 1999 under the auspices of the National Institutes of Health (America). The average real variability (ARV) was calculated for the first 24-h blood pressure measurement after patients with AMI were admitted to the intensive care unit (ICU). Patients were divided into four groups according to ARV quartiles. The outcomes were 30-day, 1-year, and 3-year all-cause mortalities. Data were analyzed using Cox regression, Kaplan-Meier curves, and restricted cubic spline (RCS) curves.

RESULTS

We enrolled 1291 patients with AMI, including 475 female. The patients were divided into four groups according to the qualities of diastolic blood pressure (DBP)-ARV. There were significant differences in the 30-day, 1-year and 3-year mortality among the four groups (p = .02, p < .001, p < .001, respectively). After adjustment for confounding factors, systolic blood pressure (SBP)-ARV could not predict AMI patient mortality (p > .05), while the highest DBP-ARV was associated strongly with increased 30-day mortality (HR: 2.291, 95% CI 1.260-4.168), 1-year mortality (HR: 1.933, 95% CI 1.316-2.840) and 3-year mortality (HR: 1.743, 95% CI 1.235-2.461). Kaplan-Meier curves demonstrated that, regardless of SBP or DBP, the long-term survival probabilities of patients in the highest ARV group were significantly lower than that of those in other groups. RCS curves showed that the death risk of patients with AMI first decreased and then increased with the increase in ARV when DBP-ARV < 8.04. The 30-day death risk first increased and then decreased, and the 1-year and 3-year death risks increased and then stabilized with ARV increase when DBP-ARV > 8.04.

CONCLUSION

This study showed that patients with AMI may have an increased risk of short- and long-term death if their DBP-ARV is higher or lower during the first 24-h in ICU.

Vascular function: a key player in hypertension

The major functions of the arterial system are to "efficiently deliver blood to the peripheral organs and maintain vascular homeostasis". Both the endothelial and medial layer contribute to the three major functions, namely, conversion of pulsatile to steady blood flow, appropriate distribution of blood flow to the target organs, and vascular protection and homeostasis. Vascular dysfunction contributes to the development of cardiovascular diseases through a combination of several mechanisms, including impaired coronary perfusion, cardiac systolic/diastolic dysfunction, microvascular damage, and abnormal hemodynamics in the arterial tree. The representative marker of endothelial function is flow-mediated vasodilatation and that of the medial layer function is pulse wave velocity, and that of the blood supply function of the arterial tree is the ankle-brachial pressure index. In hypertension, vascular dysfunction could also lead to the development of isolated systolic hypertension, isolated diastolic hypertension, and systolic/diastolic hypertension. Vascular dysfunction is involved in a vicious cycle with abnormal blood pressure variability. Furthermore, a vicious cycle may also exist between vascular dysfunction and hypertension. While the significances of vascular function tests to predict future cardiovascular events has been established in cases of hypertension, their usefulness in assessing the effectiveness of management of the vascular functions in hypertension on the cardiovascular outcomes has not yet been fully clarified. Thus, vascular dysfunction plays crucial roles in the pathophysiology of hypertension, and further research is warranted to establish strategies to improve vascular dysfunction in cases of hypertension. Vascular functions in the pathophysiology of hypertension. Vascular dysfunction and elevation of blood pressure are components of a vicious cycle even from their early stages, which including abnormal blood pressure variabilities. This vicious cycle is associated with hypertensive organ damage and also adverse cardiovascular outcomes. Strategies to break this vicious cycle have not yet been fully established.

Bidirectional association between SBP variability and arterial stiffness in patients with chronic kidney disease: findings from KNOW-CKD study

OBJECTIVE

Studies on the mutual relationship between blood pressure (BP) variability and arterial stiffness using time-dependent changes in arterial stiffness are scarce.

METHODS

In this prospective cohort of Korean patients with chronic kidney disease (CKD) G1-G5 without kidney replacement therapy, we studied the bidirectional association between visit-to-visit SBP variability (VVSV) and arterial stiffness in 1036 participants who underwent brachial-ankle pulse wave velocity (baPWV) measurement at baseline and year four. We constructed multivariable logistic regression models using two analytical sets. First, we determined the VVSV [standard deviation (SD)] of all SBP readings over 4 years, and then calculated the odds ratios (ORs) for arterial stiffness progression according to tertiles of VVSV. Arterial stiffness progression was defined as at least 75th percentile of the difference in baPWV between baseline and year four. Second, we analysed the ORs for at least 75th percentile of the 4-year VVSV according to tertiles of baseline baPWV.

RESULTS

Compared with the lowest tertile of VVSV (SD), the ORs [95% confidence interval (95% CI)] for arterial stiffness progression were 1.42 (0.96-2.10) and 1.64 (1.11-2.43) for the middle and highest tertiles, respectively. In the second analysis based on tertiles of baseline baPWV, the ORs for at least 75th percentile of VVSV (SD) were 1.41 (95% CI, 0.95-2.10) and 1.64 (95% CI, 1.04-2.61) for the middle and highest tertiles, respectively. This association was similar in both analytical models when VVSV and baPWV were treated as continuous variables.

CONCLUSION

There is a bidirectional relationship between BP variability and arterial stiffness in patients with CKD.

Apitherapy combination improvement of blood pressure, cardiovascular protection, and antioxidant and anti-inflammatory responses in dexamethasone model hypertensive rats

Hypertension-induced ventricular and vascular remodeling causes myocardial infarction, heart failure, and sudden death. Most available pharmaceutical products used to treat hypertension lead to adverse effects on human health. Limited data is available on apitherapy (bee products) combinations for treatment of hypertension. This study aims to evaluate the antihypertensive effects of combinations of natural apitherapy compounds used in the medical sector to treat a variety of diseases. Rats were assigned into six groups consisting of one control group and five hypertensive groups where hypertension (blood pressure > 140/90) was induced with dexamethasone. One of these groups was used as a hypertension model, while the remaining four hypertensive groups were treated with a propolis, royal jelly, and bee venom combination (PRV) at daily oral doses of 0.5, 1.0, and 2.0 mg/kg, and with losartan 10 mg/kg. The PRV combination at all doses decreased arterial blood pressure below the suboptimal value (p < 0.001), and PRV combination treatment improved dexamethasone-induced-ECG changes. The same treatment decreased angiotensin-II, endothelin-1, and tumor growth factor β serum levels in hypertensive rats. Additionally, PRV combination improved histopathological structure, and decreased serum levels of NF-kB and oxidative stress biomarkers. We concluded that PRV combination therapy may be used as a potential treatment for a variety of cardiovascular diseases.

Blood pressure variability and the development of hypertensive organ damage in the general population

Increasing blood pressure variability (BPV) has been reported to be a strong predictor of cardiovascular events in patients with hypertension. However, the effects of BPV in the general population have not been intensively studied. The present study was designed to investigate a possible relationship between year-to-year BPV and hypertensive target organ damage (TOD) in a relatively low-risk general population. A total of 5489 consecutive patients (mean age 58.6 ± 10.7 years) who visited our hospital for an annual physical checkup for five consecutive years during 2008-2013 were enrolled in this study. The average systolic and diastolic blood pressures and pulse pressure were calculated, as well as standard deviation, coefficient of variation, and average real variability in blood pressures. Cross-sectional analysis was conducted and subjects without TOD at baseline (n = 3115) were followed up (median 1827 days) with the endpoint of TOD, defined as left ventricular hypertrophy on electrocardiogram or declining glomerular filtration rate. At baseline, BPV was closely associated with TOD. During follow-up, left ventricular hypertrophy and declining glomerular filtration rate developed in 189 and 400 subjects, respectively. Although the standard deviation for systolic blood pressure and pulse pressure predicted future development of TOD in a univariate analysis, BPV was not a significant determinant of incident TOD in adjusted Cox hazard models. These results suggest that year-to-year BPV is a marker of the presence of TOD in the general population but does not independently predict future TOD.

Stem Cell Based Approaches to Modulate the Matrix Milieu in Vascular Disorders

The extracellular matrix (ECM) represents a complex and dynamic framework for cells, characterized by tissue-specific biophysical, mechanical, and biochemical properties. ECM components in vascular tissues provide structural support to vascular cells and modulate their function through interaction with specific cell-surface receptors. ECM–cell interactions, together with neurotransmitters, cytokines, hormones and mechanical forces imposed by blood flow, modulate the structural organization of the vascular wall. Changes in the ECM microenvironment, as in post-injury degradation or remodeling, lead to both altered tissue function and exacerbation of vascular pathologies. Regeneration and repair of the ECM are thus critical toward reinstating vascular homeostasis. The self-renewal and transdifferentiating potential of stem cells (SCs) into other cell lineages represents a potentially useful approach in regenerative medicine, and SC-based approaches hold great promise in the development of novel therapeutics toward ECM repair. Certain adult SCs, including mesenchymal stem cells (MSCs), possess a broader plasticity and differentiation potential, and thus represent a viable option for SC-based therapeutics. However, there are significant challenges to SC therapies including, but not limited to cell processing and scaleup, quality control, phenotypic integrity in a disease milieu in vivo, and inefficient delivery to the site of tissue injury. SC-derived or -inspired strategies as a putative surrogate for conventional cell therapy are thus gaining momentum. In this article, we review current knowledge on the patho-mechanistic roles of ECM components in common vascular disorders and the prospects of developing adult SC based/inspired therapies to modulate the vascular tissue environment and reinstate vessel homeostasis in these disorders.

Visit-to-visit office blood pressure variability combined with Framingham risk score to predict all-cause mortality: A post hoc analysis of the systolic blood pressure intervention trial

We aim to determine if visit‐to‐visit blood pressure variability (BPV) adds prognostic value for all‐cause mortality independently of the Framingham risk score (FRS) in the systolic blood pressure intervention trial (SPRINT). We defined BPV as variability independent of the mean (VIM) and the difference of maximum minus minimum (MMD) of the systolic blood pressure (SBP). Multivariable Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI). Based on FRS stratification, there were 1035, 2911, and 4050 participants in the low‐, intermediate‐, and high‐risk groups, respectively. During the trial, 230 deaths occurred since the 12th month with an average follow‐up of 2.5 years. In continuous analysis, 1‐SD increase of SBP VIM and MMD were significantly associated with all‐cause mortality (HR 1.18, 95% CI 1.05–1.32, p = .005; and HR 1.21, 95% CI 1.09–1.35, p < .001, respectively). In category analysis, the highest quintile of BPV compared with the lowest quintile had significantly higher risk of all‐cause mortality. Cross‐tabulation analysis showed that the 3rd tertile of SBP VIM in the high‐risk group had the highest HR of all‐cause mortality in total population (HR 4.99; 95% CI 1.57–15.90; p = .007), as well as in intensive‐therapy group (HR 7.48; 95% CI 1.01–55.45; p = .05) analyzed separately. Cross‐tabulation analysis of SBP MMD had the same pattern as VIM showed above. In conclusion, visit‐to‐visit BPV was an independent predictor of all‐cause mortality, when accounting for conventional risk factors or FRS. BPV combined with FRS conferred an increased risk for all‐cause mortality in the SPRINT trial.

Association of 1-Year Blood Pressure Variability With Long-term Mortality Among Adults With Coronary Artery Disease: A Post Hoc Analysis of a Randomized Clinical Trial

Importance

Accumulating evidence indicates that higher blood pressure (BP) variability from one physician office visit to the next (hereafter referred to as visit-to-visit BP variability) is associated with poor outcomes. Short-term measurement (throughout 1 year) of visit-to-visit BP variability in high-risk older patients may help identify patients at increased risk of death.

Objective

To evaluate whether short-term visit-to-visit BP variability is associated with increased long-term mortality risk.

Design, Setting, and Participants

The US cohort of the International Verapamil SR-Trandolapril Study (INVEST), a randomized clinical trial of 16 688 patients aged 50 years or older with hypertension and coronary artery disease, was conducted between September 2, 1997, and December 15, 2000, with in-trial follow-up through February 14, 2003. The study evaluated a calcium antagonist (sustained-release verapamil plus trandolapril) vs β-blocker (atenolol plus hydrochlorothiazide) treatment strategy. Blood pressure measurement visits were scheduled every 6 weeks for the first 6 months and biannually thereafter. Statistical analysis was performed from September 2, 1997, to May 1, 2014.

Exposures

Visit-to-visit systolic BP (SBP) and diastolic BP variability during the first year of enrollment using 4 different BP variability measures: standard deviation, coefficient of variation, average real variability, and variability independent of the mean.

Main Outcomes and Measures

All-cause death, assessed via the US National Death Index, beginning after the exposure assessment period through May 1, 2014.

Results

For the present post hoc analysis, long-term mortality data were available on 16 688 patients (9001 women [54%]; mean [SD] age, 66.5 [9.9] years; 45% White patients, 16% Black patients, and 37% Hispanic patients). During a mean (SD) follow-up of 10.9 (4.2) years, 5058 patients (30%) died. All 4 variability measures for SBP were significantly associated with long-term mortality after adjustment for baseline demographic characteristics and comorbidities. After comparison of lowest vs highest variability measure quintiles, the magnitude of the association with death remained statistically significant even after adjustment for baseline demographic characteristics and comorbidities (average real variability: adjusted hazard ratio [aHR], 1.18; 95% CI, 1.08-1.30; standard deviation: aHR, 1.14; 95% CI, 1.04-1.24; coefficient of variation: aHR, 1.15; 95% CI, 1.06-1.26; variability independent of the mean: aHR, 1.15; 95% CI, 1.05-1.25). The signal was stronger in women compared with men. Associations of diastolic BP variability measures with death were weaker than for SBP and were not significant after adjustment.

Conclusions and Relevance

This study suggests that, in a large population of older patients with hypertension and coronary artery disease, short-term visit-to-visit SBP variability was associated with excess long-term mortality, especially for women. Efforts to identify and minimize visit-to-visit SBP variability may be important in reducing excess mortality later in life.

Trial Registration

ClinicalTrials.gov Identifier: NCT00133692.

Pregnancy Outcomes and Blood Pressure Visit-to-Visit Variability and Level in Three Less-Developed Countries

[Figure: see text].

Association Between Visit-to-Visit Blood Pressure Variability in Early Adulthood and Myocardial Structure and Function in Later Life

Importance

Long-term blood pressure (BP) variability has emerged as a reproducible measure that is associated with heart failure independent of systemic BP. Visit-to-visit BP variability may be associated with the risk of heart failure early in the life course and thus may be reflected in subclinical alterations in cardiac structure and function.

Objective

To evaluate the association between visit-to-visit BP variability in early adulthood and myocardial structure and function in middle age.

Design, Setting, and Participants

This cohort study used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a community-based cohort study of 5115 participants aged 18 to 30 years at baseline (year 0; March 25, 1985, to June 7, 1986) and followed up over a 30-year interval. A total of 2400 CARDIA study participants underwent evaluation at 4 field sites (Birmingham, Alabama; Oakland, California; Chicago, Illinois; and Minneapolis, Minnesota). Blood pressure was measured at 8 visits over a 25-year interval and participants received echocardiograms at year 25 (June 1, 2010, to August 31, 2011). Data analysis was conducted from June 7, 1986, to August 31, 2011.

Exposures

Visit-to-visit systolic and diastolic BP variability measures included SD, average real variability, and variability independent of the mean.

Main Outcomes and Measures

Echocardiographic indices of myocardial structure, systolic function, and diastolic function at the year 25 examination.

Results

Of the 2400 participants, 1024 were men (42.7%) and 976 were African American (40.7%); mean (SD) age at the year 25 examination was 50.4 (3.6) years. Per 1-SD increment, greater visit-to-visit systolic BP variability independent of the mean was associated with higher left-ventricular (LV) mass index (β [SE], 2.66 [0.4] g/m2, P < .001), worse diastolic function (early peak diastolic mitral annular velocity [é]) (β [SE], -0.40 [0.1] cm/s, P < .001), higher LV filling pressures (mitral inflow velocity to early diastolic mitral annular velocity [E/é]) β [SE], 0.37 [0.1] cm/s, P < .001), and worse global longitudinal strain (β [SE], 0.17 [0.1], P = .002). Similarly, greater visit-to-visit diastolic BP variability was associated with higher LV mass index (β [SE], 3.21 [0.5] g/m2, P < .001), worse diastolic function (é: β [SE], -0.24 [0.1] cm/s [P < .001]; E/é: β [SE], 0.23 [0.1] cm/s [P < .001]), and worse global longitudinal strain (β [SE], 0.13 [0.1], P = .02). The findings remained consistent when other BP variability measures were used (SD and average real variability).

Conclusions and Relevance

In this cohort study using data from the CARDIA study, greater visit-to-visit systolic and diastolic BP variability have been associated with adverse alterations in cardiac structure as well as systolic and diastolic function independent of mean BP levels.