Differing effects of aging on central and peripheral blood pressures and pulse wave velocity: a direct intraarterial study

Cardiovascular outcomes according to on-treatment systolic blood pressure in older hypertensive patients: a multicenter cohort using a common data model

OBJECTIVE

In the growing population of older patients with hypertension, limited evidence supports an association between lowering systolic blood pressure (SBP) and decreased adverse events. We aimed to investigate cardiovascular outcomes according to on-treatment SBP in older hypertensive patients.

METHODS

This multicenter, retrospective study used data from the Korea University Medical Center database built on electronic health records from 2017 to 2022. Patients initiated on at least two antihypertensive drugs in combination were followed for three years. The patients were grouped by average on-treatment SBP in 10-mmHg increments from <110 to 160 mmHg or more. The primary outcome was a composite of all-cause death, myocardial infarction, stroke, and hospitalization due to heart failure.

RESULTS

A total of 6427 patients aged ≥75 years (mean age, 80 years) were identified. The incidence of the primary outcome was lowest in individuals with an SBP of 120-129 mmHg (14.0%, P  < 0.001), and the adjusted hazard ratio for the primary outcome showed a J-shaped relationship with on-treatment SBP. Achieving an SBP of 120-129 mmHg showed acceptable safety profiles, including electrolyte imbalance, acute kidney injury, new-onset atrial fibrillation, and new-onset dementia or Alzheimer's disease when compared to the group with SBP of 130-139 mmHg.

CONCLUSIONS

An average on-treatment SBP of less than 130 mmHg was associated with improved outcomes in older hypertensive patients without raising safety concerns. These findings support the target SBP of 130 mmHg in older patients, if tolerated.

Protective effects of blueberries on vascular function: A narrative review of preclinical and clinical evidence

Blueberries are rich in nutrients and (poly)phenols, popular with consumers, and a major agricultural crop with year-round availability supporting their use in food-based strategies to promote human health. Accumulating evidence indicates blueberry consumption has protective effects on cardiovascular health including vascular dysfunction (i.e., endothelial dysfunction and arterial stiffening). This narrative review synthesizes evidence on blueberries and vascular function and provides insight into underlying mechanisms with a focus on oxidative stress, inflammation, and gut microbiota. Evidence from animal studies supports beneficial impacts on vascular function. Human studies indicate acute and chronic blueberry consumption can improve endothelial function in healthy and at-risk populations and may modulate arterial stiffness, but that evidence is less certain. Results from cell, animal, and human studies suggest blueberry consumption improves vascular function through improving nitric oxide bioavailability, oxidative stress, and inflammation. Limited data in animals suggest the gut microbiome mediates beneficial effects of blueberries on vascular function; however, there is a paucity of studies evaluating the gut microbiome in humans. Translational evidence indicates anthocyanin metabolites mediate effects of blueberries on endothelial function, though this does not exclude potential synergistic and/or additive effects of other blueberry components. Further research is needed to establish the clinical efficacy of blueberries to improve vascular function in diverse human populations in a manner that provides mechanistic information. Translation of clinical research to the community/public should consider feasibility, social determinants of health, culture, community needs, assets, and desires, barriers, and drivers to consumption, among other factors to establish real-world impacts of blueberry consumption.

Influence of Belatacept- vs. CNI-Based Immunosuppression on Vascular Stiffness and Body Composition

Background: Arterial stiffness and phase angle (PhA) have gained importance as a diagnostic and prognostic parameter in the management of cardiovascular disease. There are few studies regarding the differences in arterial stiffness and body composition between renal transplant recipients (RTRs) receiving belatacept (BELA) vs. calcineurin inhibitors (CNI). Therefore, we investigated the differences in arterial stiffness and body composition between RTRs treated with different immunosuppressants, including BELA. Methods: In total, 325 RTRs were enrolled in the study (mean age 52.2 years, M −62.7%). Arterial stiffness was determined with an automated oscillometric device. All body composition parameters were assessed, based on bioelectrical impedance analysis (BIA), and laboratory parameters were obtained from the medical files of the patients. Results: We did not detect any significant difference in terms of arterial stiffness and PhA in RTRs undergoing different immunosuppressive regimens, based on CsA, Tac, or BELA. Age was an essential risk factor for greater arterial stiffness. The PhA was associated with age, BMI, time of dialysis before transplantation, and kidney graft function. Conclusion: No significant differences in arterial stiffness and PhA were observed in RTRs under different immunosuppressive regimens. While our data provide additional evidence for arterial stiffness and PhA in RTRs, more research is needed to fully explore these cardiovascular risk factors and the impact of different immunosuppressive regimens.

Effect of an Acute Resistance Training Bout and Long-Term Resistance Training Program on Arterial Stiffness: A Systematic Review and Meta-Analysis

Resistance training (RT) and exercise is useful for preventing cardiovascular disease, systolic hypertension and stroke, which are associated with the stiffening of the larger central arterial system. The aim of this systematic review was to (a) understand the changes in arterial stiffness (AS) in various parts of the body measurement after acute RT bout and long-term RT, and (b) to determine the impact of exercise intensity on these changes in healthy individuals. A systematic computerized search was performed according to the PRISMA in PubMed, Scopus and Google Scholar with final selection of 23 studies. An acute RT bout led to a temporary increase in pulse wave velocity (PWV) regardless of the measurement method or intensity. A long-term RT at above an 80% repetition maximum (RM) have an ambiguous effect on PWV. A low-intensity RT or whole-body vibration training program decreased carotid-femoral PWV and brachial-ankle PWV (d = 1.02) to between 0.7 ± 1.4 ms-1 (p < 0.05) and 1.3 ± 1.07 ms-1 (p < 0.05) and improved other cardiac functions. A long-term RT of moderate (60-80% 1RM) or low intensity (<60% one-repetition maximum (1RM)) can decrease AS. Low and moderate intensity RT is beneficial to reduce high AS to prevent cardiovascular diseases.

A systematic review of invasive, high-fidelity pressure studies documenting the amplification of blood pressure from the aorta to the brachial and radial arteries

It is commonly accepted that systolic blood pressure (SBP) is significantly higher in the brachial/radial artery than in the aorta while mean (MBP) and diastolic (DBP) pressures remain unchanged. This may have implications for outcome studies and for non-invasive devices calibration. We performed a systematic review of invasive high-fidelity pressure studies documenting BP in the aorta and brachial/radial artery. We selected articles published prior to July 2015. Pressure amplification (Amp = peripheral minus central pressure) was calculated (weighted mean). The six studies retained (n = 294, 76.5% male, mean age 63.5 years) mainly involved patients with suspected coronary artery disease (CAD). In two studies at the aortic/brachial level (n = 64), MBP and DBP were unchanged (MPAmp = 0.1 mmHg, DPAmp = -1.3 mmHg), while SBP increased (SPAmp = 4.2 mmHg; relative amplification = 3.1%). In four studies in which MBP was not documented (n = 230), brachial DBP remained unchanged and SBP increased (SPAmp = 6.6 mmHg; 4.9%). One of these four studies also reported radial SBP and DBP, not MBP (n = 12). Few high-fidelity pressure studies were found, and they have been performed mainly in elderly male patients with suspected CAD. Counter to expectations, the mean amplification of SBP from the aorta to brachial artery was < 5%. Further studies on SPAmp phenotypes (positive, null, negative) are advocated. Non-invasive device calibration assumptions were confirmed, namely unchanged MBP and DBP from the aorta to the brachial artery. Data did not allow for firm conclusions on the amount of BP changes from the aorta to the radial artery, and from the aorta to the brachial/radial arteries in other populations.

Subclinical Longitudinal Change in Ankle-Brachial Index With Aging in a Community-Dwelling Population Is Associated With Central Arterial Stiffening

Background Aging is associated with a modest decline in ankle-brachial index (ABI); however, the underpinnings of this decline are not fully understood. The greater systolic ankle than brachial blood pressure, a normal ABI implies, is partially attributed to lower central than peripheral arterial stiffness. Hence, we examined the hypothesis that the age-associated decline in ABI is associated with central arterial stiffening with aging, assessed by pulse wave velocity. Methods and Results We analyzed longitudinal data from 974 participants aged 27 to 95 years from the Baltimore Longitudinal Study of Aging who were free of clinically significant cardiovascular disease. Participants had an average of 4 visits with a 6.8-year average follow-up time. Linear mixed-effects models showed that the average ABI decline beyond the age of 70 years was 0.03 per decade. In multiple regression analysis, the ABI rate of change was inversely associated with initial age (standardized β=-0.0711, P=0.0282), independent of peripheral disease factors and baseline ABI. After adjustment, the pulse wave velocity rate of change was inversely associated with ABI rate of change (standardized β=-0.0993, P=0.0040), rendering the association of the latter with initial age nonsignificant (standardized β=-0.0265, P=0.5418). Conclusions A modest longitudinal decline in ABI beyond the age of 70 years was shown to be independent of traditional risk factors for peripheral arterial disease but was accounted for by an increase in pulse wave velocity. A modest decline in ABI with aging might be a manifestation of changes in central hemodynamics and not necessarily attributable to peripheral flow-limiting factors.

Ventricular Stiffness and Ventricular-Arterial Coupling in Heart Failure: What Is It, How to Assess, and Why?

The heart and blood vessels are constantly interfering with each other in a closed system. For a few decades, the concept of ventricular-arterial coupling has been considered as a key pathogenesis of heart failure especially in heart failure with preserved ejection fraction.

Impact of immunosuppressive therapy on arterial stiffness in kidney transplantation: are all treatments the same?

Arterial stiffness is a biologic process related to ageing and its relationship with cardiovascular risk is well established. Several methods are currently available for non-invasive measurement of arterial stiffness that provide valuable information to further assess patients’ vascular status in real time. In kidney transplantation recipients, several factors could accelerate the stiffness process, such as the use of calcineurin inhibitors (CNIs), the presence of chronic kidney disease and other classical cardiovascular factors, which would explain, at least in part, the high cardiovascular mortality and morbidity. Despite the importance of arterial stiffness as a biomarker of cardiovascular risk, and unlike other cardiovascular risk factors (e.g. left ventricular hypertrophy), only a few clinical trials or retrospective studies of kidney recipients have evaluated its impact. In this review we describe the clinical impact of arterial stiffness as a prognostic marker of cardiovascular disease and the effects of different immunosuppressive regimens on its progression, focusing on the potential benefits of CNI-sparing protocols and supporting the rationale for individualization of immunosuppression in patients with lower arterial elasticity. Among the immunosuppressive drugs, a belatacept-based regimen seems to offer better vascular protection compared with CNIs, although further studies are needed to confirm the preliminary positive results.

Influence of the central-to-peripheral arterial stiffness gradient on the timing and amplitude of wave reflections

In individuals with compliant aortas, peripheral muscular artery stiffness exceeds central elastic artery stiffness. With aging, central stiffness increases with little change in peripheral stiffness, resulting in a reversal of the normal stiffness gradient. This reversal may reduce the wave reflection amplitude due to the movement of the major 'effective' reflection site further from the heart. To test this phenomenon, we investigated the relationship among arterial stiffness gradients (normal and reversed), wave reflection amplitude and reflection site distance. Subjects aged ⩾50 years were recruited from the Anglo-Cardiff Collaborative Trial. Central stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). In Study 1, peripheral PWV was also measured in the arm (carotid-radial pulse wave velocity) and, in Study 2, in the leg (femoral-dorsalis pedis). Reflection site distance was calculated from cfPWV and the reflected wave Tr. Subjects were dichotomized into those with a normal stiffness gradient (peripheral >central PWV) or a reversed gradient (peripheral Collapse

Key Words

• arterial stiffness gradient
• augmentation index
• pulse wave velocity
• wave reflection
• central pulse pressure

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MESH Headings

• Aged
• Aorta/physiology
• Arm/blood supply
• Blood Pressure/physiology
• Carotid Arteries/physiology
• Female
• Femoral Artery/physiology
• Humans
• Leg/blood supply
• Male
• Middle Aged
• Pulsatile Flow/physiology
• Pulse Wave Analysis
• Vascular Stiffness/physiology

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Grants

• FS/07/001/21990 British Heart Foundation
• FS/12/8/29377 British Heart Foundation

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Affiliation(s)

Stacey S Hickson Division of Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, UK
Wilmer W Nichols Division of Cardiovascular Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
Yasmin Division of Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, UK
Barry J McDonnell Department of Biomedical Sciences, School of Health Sciences, Cardiff Metropolitan University, Cardiff, UK
John R Cockcroft Department of Cardiology, Wales Heart Research Institute, Cardiff University, Cardiff, UK
Ian B Wilkinson Division of Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, UK
Carmel M McEniery Division of Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, UK

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Peripheral Arterial Stiffness in Primary Aldosteronism

Aldosterone overproduction increases arterial wall stiffness by accumulation of different types of collagen fibres and growth factors. Our previous studies showed that central (aortic) arterial stiffness is increased in primary aldosteronism (PA) independently of concomitant hypertension and that these changes might be reversible after successful adrenalectomy. There is limited data available on the potential impact of mineralocorticoid overproduction on the deterioration of peripheral arterial stiffness. The current study was thus aimed at investigating the effect of aldosterone overproduction on peripheral arterial stiffness assessed by peripheral (femoral-ankle) pulse wave velocity (PWV) in PA patients compared with essential hypertension (EH) patients. Forty-nine patients with confirmed PA and 49 patients with EH were matched for age, blood pressure, body mass index, lipid profile, and fasting glucose. PWV was obtained using the Sphygmocor applanation tonometer. Both peripheral and central PWV were significantly higher in PA patients compared to EH patients, while clinical blood pressures were similar. Plasma aldosterone level was the main predictor of peripheral PWV in PA. Our data indicate aldosterone overproduction in PA does not preferentially affect central arterial system. Fibroproliferative effect of higher aldosterone levels lead to alteration of central-elastic as well as peripheral-muscular arteries with subsequent increase in its stiffness.

Tube-load model parameter estimation for monitoring arterial hemodynamics

A useful model of the arterial system is the uniform, lossless tube with parametric load. This tube-load model is able to account for wave propagation and reflection (unlike lumped-parameter models such as the Windkessel) while being defined by only a few parameters (unlike comprehensive distributed-parameter models). As a result, the parameters may be readily estimated by accurate fitting of the model to available arterial pressure and flow waveforms so as to permit improved monitoring of arterial hemodynamics. In this paper, we review tube-load model parameter estimation techniques that have appeared in the literature for monitoring wave reflection, large artery compliance, pulse transit time, and central aortic pressure. We begin by motivating the use of the tube-load model for parameter estimation. We then describe the tube-load model, its assumptions and validity, and approaches for estimating its parameters. We next summarize the various techniques and their experimental results while highlighting their advantages over conventional techniques. We conclude the review by suggesting future research directions and describing potential applications.

Arterial-cardiac interaction: the concept and implications

Vascular stiffening of the large arteries is a common feature of human aging. Increased aortic stiffness with age may contribute to pathological changes in the left ventricle and this can induce ventricular stiffening. Vascular-ventricular stiffening combined with abnormal arterial-cardiac interaction is considered an important pathophysiology of heart failure with a preserved ejection fraction. Here, I briefly review the concept and implications of arterial-cardiac interaction and this will pave the way to understanding and controlling heart failure with a preserved ejection fraction, which is more prevalent in the elderly.

Arterial stiffness, its assessment, prognostic value, and implications for treatment

Arterial stiffness has been known as a sign of cardiovascular risk since the 19th century. Despite this, accurate measurement and clinical utility have only emerged in recent times. Arterial stiffness and its hemodynamic consequences are now established as predictors of adverse cardiovascular outcome. They are easily and reliably measured using a range of noninvasive techniques, which can be used readily by risk assessment facilities or individual practitioners. The techniques described in this review are based on the pulsatility of the cardiovascular system, utilizing the timing of pulse travel along major arteries and the magnitude of wave reflection. These have enabled better understanding of the ill effects of arterial stiffening, not only on large arteries and the left ventricle, but also on tiny arteries in highly perfused organs such as brain and kidneys. Treatment options, which directly target the consequences of arterial stiffening, as opposed to arbitrary reduction of brachial blood pressure, have proved clinical superiority; optimal therapy entails use of angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, and calcium-channel blockers, as well as vasodilating β-blockers. Arterial stiffness will undoubtedly contribute to cardiovascular assessment and management in future clinical practice. Reviews such as this will hopefully increase awareness of the mounting evidence underlying this transition, and the relevant theory and methodology. As we begin the second decade of the 21st century, we are finally collectively coming to realize what pioneers such as Osler, Roy, Bramwell and Hill foresaw in the 19th and 20th centuries.