Beneficial effects on arterial stiffness and pulse-wave reflection of combined enalapril and candesartan in chronic kidney disease--a randomized trial

Triiodothyronine and Protein Malnutrition Could Influence Pulse Wave Velocity in Pre-Dialysis Chronic Kidney Disease Patients

Cardiovascular diseases (CVD) are the first cause of chronic kidney disease (CKD) mortality. For personalized improved medicine, detecting correctable markers of CVD can be considered a priority. The aim of this study was the evaluation of the impact of nutritional, hormonal and inflammatory markers on brachial-ankle Pulse Wave Velocity (PWV) in pre-dialysis CKD patients. A cross-sectional observational study was conducted on 68 pre-dialysis CKD patients (median age of 69 years, 41.2% with diabetes mellitus, 52.9% male). Laboratory data were collected, including levels of prolactin, triiodothyronine, TGF α, IL-6, and IL-1β. The high values of brachial-ankle PWV were associated with reduced muscle mass (p = 0.001, r = -0.44), low levels of total cholesterol (p = 0.04, r = -0.26), triglycerides (p = 0.03, r = -0.31), triiodothyronine (p = 0.04, r = -0.24), and prolactin (p = 0.02, r = -0.27). High PWV was associated with advanced age (p < 0.001, r = 0.19). In the multivariate analysis, reduced muscle mass (p = 0.018), low levels of triiodothyronine (p = 0.002), and triglycerides (p = 0.049) were significant predictors of PWV, but age (p < 0.001) remained an important factor. In conclusion, reduced triiodothyronine together with markers of malnutrition and age were associated with PWV in pre-dialysis CKD patients.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for adults with early (stage 1 to 3) non-diabetic chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a long-term condition that occurs as a result of damage to the kidneys. Early recognition of CKD is becoming increasingly common due to widespread laboratory estimated glomerular filtration rate (eGFR) reporting, raised clinical awareness, and international adoption of the Kidney Disease Improving Global Outcomes (KDIGO) classifications. Early recognition and management of CKD affords the opportunity to prepare for progressive kidney impairment and impending kidney replacement therapy and for intervention to reduce the risk of progression and cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are two classes of antihypertensive drugs that act on the renin-angiotensin-aldosterone system. Beneficial effects of ACEi and ARB on kidney outcomes and survival in people with a wide range of severity of kidney impairment have been reported; however, their effectiveness in the subgroup of people with early CKD (stage 1 to 3) is less certain. This is an update of a review that was last published in 2011.

OBJECTIVES

To evaluate the benefits and harms of ACEi and ARB or both in the management of people with early (stage 1 to 3) CKD who do not have diabetes mellitus (DM).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 6 July 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and Embase, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting the effect of ACEi or ARB in people with early (stage 1 to 3) CKD who did not have DM were selected for inclusion. Only studies of at least four weeks duration were selected. Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out by two authors independently, using a standard data extraction form. The methodological quality of included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. When more than one study reported similar outcomes, data were pooled using the random-effects model. Heterogeneity was analysed using a Chi² test and the I² test. Results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach MAIN RESULTS: Six studies randomising 9379 participants with CKD stages 1 to 3 (without DM) met our inclusion criteria. Participants were adults with hypertension; 79% were male from China, Europe, Japan, and the USA. Treatment periods ranged from 12 weeks to three years. Overall, studies were judged to be at unclear or high risk of bias across all domains, and the quality of the evidence was poor, with GRADE rated as low or very low certainty. In low certainty evidence, ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo may make little or no difference to death (any cause) (2 studies, 8873 participants): RR 2.00, 95% CI 0.26 to 15.37; I² = 76%), total cardiovascular events (2 studies, 8873 participants): RR 0.97, 95% CI 0.90 to 1.05; I² = 0%), cardiovascular-related death (2 studies, 8873 participants): RR 1.73, 95% CI 0.26 to 11.66; I² = 54%), stroke (2 studies, 8873 participants): RR 0.76, 95% CI 0.56 to 1.03; I² = 0%), myocardial infarction (2 studies, 8873 participants): RR 1.00, 95% CI 0.84 to 1.20; I² = 0%), and adverse events (2 studies, 8873 participants): RR 1.33, 95% CI 1.26 to 1.41; I² = 0%). It is uncertain whether ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo reduces congestive heart failure (1 study, 8290 participants): RR 0.75, 95% CI 0.59 to 0.95) or transient ischaemic attack (1 study, 583 participants): RR 0.94, 95% CI 0.06 to 15.01; I² = 0%) because the certainty of the evidence is very low. It is uncertain whether ARB (losartan 50 mg) compared to placebo (1 study, 226 participants) reduces: death (any-cause) (no events), adverse events (RR 19.34, 95% CI 1.14 to 328.30), eGFR rate of decline (MD 5.00 mL/min/1.73 m2, 95% CI 3.03 to 6.97), presence of proteinuria (MD -0.65 g/24 hours, 95% CI -0.78 to -0.52), systolic blood pressure (MD -0.80 mm Hg, 95% CI -3.89 to 2.29), or diastolic blood pressure (MD -1.10 mm Hg, 95% CI -3.29 to 1.09) because the certainty of the evidence is very low. It is uncertain whether ACEi (enalapril 20 mg, perindopril 2 mg or trandolapril 1 mg) compared to ARB (olmesartan 20 mg, losartan 25 mg or candesartan 4 mg) (1 study, 26 participants) reduces: proteinuria (MD -0.40, 95% CI -0.60 to -0.20), systolic blood pressure (MD -3.00 mm Hg, 95% CI -6.08 to 0.08) or diastolic blood pressure (MD -1.00 mm Hg, 95% CI -3.31 to 1.31) because the certainty of the evidence is very low.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to determine the effectiveness of ACEi or ARB in patients with stage 1 to 3 CKD who do not have DM. The available evidence is overall of very low certainty and high risk of bias. We have identified an area of large uncertainty for a group of patients who account for most of those diagnosed as having CKD.

Vascular stiffness and healthy arterial aging in older patients with optimal blood pressure

INTRODUCTION

Pulse wave velocity is used to diagnose central arterial stiffness (CAS) and quantify healthy vascular aging (HVA).

OBJECTIVE

To evaluate the CAS and HVA in elderly patients with systemic blood pressure levels classified as optimal/normal.

METHODS

A total of 102 patients without comorbidities and with systolic pressure (SP) < 120 mmHg and diastolic pressure (DP) < 80 mmHg were selected from the EVOPIU database (Pulse Wave Velocity of Elderly Individuals in an Urban area of Brazil). The carotid-femoral pulse wave velocity (c-fPWV) and the central and peripheral pressures were evaluated in all patients. The patients were divided into four groups: G1: (n = 19, with c-fPWV < 7.6 m/s, without medication), G2 (n = 26, c-fPWV ≥ 7.6 m/s; without medication), G3 (n = 25, c-fPWV < 7.6 m/s with antihypertensive medication), and G4 (n = 32, c-fPWV ≥ 7.6 m/s with antihypertensive medication).

RESULTS

In our sample, 56.7% of patients had c-fPWV ≥ 7.6 m/s. The central systolic pressure in G1 [99 (10) mmHg] was lower than that found in the other three groups [vs. 112 (14) mmHg, 111 (15), 112 (20) mmHg; P < 0.05)].

CONCLUSION

Older people with optimal arterial blood pressure do not necessarily have HVA and could have c-fPWV values close to the limits established for CAS diagnosis.

Rigidez vascular e envelhecimento arterial saudável em pacientes idosos com pressão arterial ideal

RESUMO Introdução: A velocidade da onda de pulso é usada para diagnosticar a rigidez arterial central (RAC) e quantificar o envelhecimento vascular saudável (EVS). Objetivo: Avaliar a RAC e o EVS em pacientes idosos com níveis pressóricos sistêmicos classificados como ideais/normais. Métodos: Um total de 102 pacientes sem comorbidades e com pressão sistólica (PS) < 120 mmHg e pressão diastólica (PD) < 80 mmHg foram selecionados do banco de dados EVOPIU (Estudo da Velocidade de Onda de Pulso em Idosos em área Urbana no Brasil). Foram avaliadas a velocidade da onda de pulso carotídeo-femoral (VOPcf) e as pressões central e periférica em todos os pacientes. Os pacientes foram divididos em quatro grupos: G1: (n = 19; com VOPcf < 7,6 m/s; sem medicação), G2 (n = 26; VOPcf ≥ 7,6 m/s; sem medicação), G3 (n = 25; VOPcf < 7,6 m/s com medicação anti-hipertensiva), e G4 (n = 32; VOPcf ≥ 7,6 m/s com medicação anti-hipertensiva). Resultados: Em nossa amostra, 56,7% dos pacientes apresentaram VOPcf ≥ 7,6 m/s. A pressão sistólica central no G1 [99 (10) mmHg] foi inferior à encontrada nos outros três grupos [vs. 112 (14) mmHg, 111 (15), 112 (20) mmHg; P < 0,05)]. Conclusão: Pessoas idosas com pressão arterial ideal não necessariamente têm EVS e podem apresentar valores de VOPcf próximos aos limites estabelecidos para o diagnóstico de RAC.

Effects of enhanced versus reduced vasodilating treatment on brachial and central blood pressure in patients with chronic kidney disease: a randomized controlled trial

BACKGROUND

Blood pressure (BP) control is important in chronic kidney disease (CKD), but a reduction in brachial BP may not mirror changes in central aortic BP (cBP) during antihypertensive medication. We hypothesize that a fall in cBP is better reflected during enhanced vasodilation treatment (EVT) compared with reduced vasodilation treatment (RVT) because of different hemodynamic actions of these interventions.

METHODS

Eighty-one hypertensive CKD stage 3-4 patients (mean measured glomerular filtration rate 36 ml/min per 1.73 m2) were randomized to either EVT based on renin--angiotensin blockade and/or amlodipine or RVT based on nonvasodilating β-blockade (metoprolol). Before randomization and following 18 months of treatment, we performed 24-h ambulatory BP measurements (ABPM) and radial artery pulse wave analysis for estimation of cBP and augmentation index (AIx). Forearm resistance (Rrest) was determined by venous occlusion plethysmography and arterial stiffness by carotid--femoral pulse wave velocity (PWV). Matched healthy controls were studied once for comparison.

RESULTS

Compared with controls, CKD patients had elevated ABPM, cBP and PWV. Although ABPM remained unchanged from baseline to follow-up in both treatment groups, cBP decreased 4.7/2.9 mmHg (systolic/diastolic) during EVT and increased 5.1/1.5 mmHg during RVT (Δ=9.8/4.4 mmHg, P=0.02 for SBP, P = 0.05 for DBP). At follow-up, the difference between systolic cBP and 24-h ABPM (ΔBPsyst) was negatively associated with heart rate and positively associated with AIx and Rrest (all P < 0.01) but not PWV (P = 0.32).

CONCLUSION

In CKD patients, EVT and RVT have opposite effects on cBP and the difference between cBP and ambulatory BP is larger for EVT than RVT.

KCNJ5 Somatic Mutations in Aldosterone-Producing Adenoma Are Associated with a Greater Recovery of Arterial Stiffness

Simple Summary

Primary aldosteronism (PA) is the most common form of secondary hypertension and induces various cardiovascular injuries. Aldosterone-producing adenoma (APA) is one of the major forms of PA. The occurrence of APA is closely correlated with somatic mutations, including KCNJ5. We described here the impact of KCNJ5 somatic mutations on arterial stiffness excluding the influence of age, sex, and blood pressure status. We found KCNJ5 mutation carriers had similar arterial stiffness before surgery, but greater improvement of arterial stiffness after adrenalectomy compared with non-carriers. Hence, APA patients with KCNJ5 mutations had a greater improvement in arterial stiffness after adrenalectomy than those without mutations.

Abstract

Primary aldosteronism is the most common form of secondary hypertension and induces various cardiovascular injuries. In aldosterone-producing adenoma (APA), the impact of KCNJ5 somatic mutations on arterial stiffness excluding the influence of confounding factors is uncertain. We enrolled 213 APA patients who were scheduled to undergo adrenalectomy. KCNJ5 gene sequencing of APA was performed. After propensity score matching (PSM) for age, sex, body mass index, blood pressure, number of hypertensive medications, and hypertension duration, there were 66 patients in each group with and without KCNJ5 mutations. The mutation carriers had a higher aldosterone level and lower log transformed brachial–ankle pulse wave velocity (baPWV) than the non-carriers before PSM, but no difference in log baPWV after PSM. One year after adrenalectomy, the mutation carriers had greater decreases in log plasma aldosterone concentration, log aldosterone–renin activity ratio, and log baPWV than the non-carriers after PSM. Only the mutation carriers had a significant decrease in log baPWV after surgery both before and after PSM. KCNJ5 mutations were not correlated with baseline baPWV after PSM but were significantly correlated with ∆baPWV after surgery both before and after PSM. Conclusively, APA patients with KCNJ5 mutations had a greater regression in arterial stiffness after adrenalectomy than those without mutations.

Cardiovascular Risk Assessment Using Ultrasonographic Surrogate Markers of Atherosclerosis and Arterial Stiffness in Patients With Chronic Renal Impairment: A Narrative Review of the Evidence and a Critical View of Their Utility in Clinical Practice

PURPOSE OF THE REVIEW

Validated tools to improve cardiovascular disease (CVD) risk assessment and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) are lacking. Noninvasive measures of arteriosclerosis and subclinical atherosclerosis such as pulse wave velocity (PWV) and carotid intima-media thickness (cIMT), respectively, have emerged as promising risk stratification tools and potential modifiable biomarkers. Their wide use as surrogate markers in clinical research studies is based on the strong pathophysiological links with CVD. However, whether their effect as risk stratification or intervention targets is superior to established clinical approaches is uncertain. In this review, we examine the evidence on the utility of PWV, cIMT, and plaque assessment in routine practice and highlight unanswered questions from the clinician's perspective.

SOURCES OF INFORMATION

Electronic databases PubMed and Google Scholar were searched until February 2020.

METHODS

This narrative review is based on peer-reviewed meta-analyses, national and international societies' guidelines, and on focused critical review of recent original studies and landmark studies in the field.

KEY FINDINGS

Although patients with CKD are considered in the high-risk CVD groups, there is still need for tools to improve risk stratification and individualized management strategies within this group of patients. Carotid intima-media thickness is associated with all-cause mortality, CVD mortality, and events in CKD and hemodialysis cohorts. However, the evidence that measurement of cIMT has a clinically meaningful role over and above existing risk scores and management strategies is limited. Plaque assessment is a better predictor than cIMT in non-CKD populations and it has been incorporated in recent nonrenal-specific guidelines. In the CKD population, one large observational study provided evidence for a potential role of plaque assessment in CKD similar to the non-CKD studies; however, whether it improves prediction and outcomes in CKD is largely understudied. Pulse wave velocity as a marker of arterial stiffness has a strong pathophysiological link with CVD in CKD and numerous observational studies demonstrated associations with increased cardiovascular risk. However, PWV did not improve CVD reclassification of dialysis patients when added to common risk factors in a reanalysis of ESRD cohorts with available PWV data. Therapeutic strategies to regress PWV, independently from blood pressure reduction, have not been studied in well-conducted randomized trials.

LIMITATIONS

This study provides a comprehensive review based on extensive literature search and critical appraisal of included studies. Nevertheless, formal systematic literature review and quality assessment were not performed and the possibility of selection bias cannot be excluded.

IMPLICATIONS

Larger, prospective, randomized studies with homogeneous approach, designed to answer specific clinical questions and taking into consideration special characteristics of CKD and dialysis, are needed to study the potentially beneficial role of cIMT/plaque assessment and PWV in routine practice.

Vitamin K Supplementation to Improve Vascular Stiffness in CKD: The K4Kidneys Randomized Controlled Trial

BACKGROUND

Vascular calcification, a risk factor for cardiovascular disease, is common among patients with CKD and is an independent contributor to increased vascular stiffness and vascular risk in this patient group. Vitamin K is a cofactor for proteins involved in prevention of vascular calcification. Whether or not vitamin K supplementation could improve arterial stiffness in patients with CKD is unknown.

METHODS

To determine if vitamin K supplementation might improve arterial stiffness in patients in CKD, we conducted a parallel-group, double-blind, randomized trial in participants aged 18 or older with CKD stage 3b or 4 (eGFR 15-45 ml/min per 1.73 m²). We randomly assigned participants to receive 400 μg oral vitamin K2 or matching placebo once daily for a year. The primary outcome was the adjusted between-group difference in carotid-femoral pulse wave velocity at 12 months. Secondary outcomes included augmentation index, abdominal aortic calcification, BP, physical function, and blood markers of mineral metabolism and vascular health. We also updated a recently published meta-analysis of trials to include the findings of this study.

RESULTS

We included 159 randomized participants in the modified intention-to-treat analysis, with 80 allocated to receive vitamin K and 79 to receive placebo. Mean age was 66 years, 62 (39%) were female, and 87 (55%) had CKD stage 4. We found no differences in pulse wave velocity at 12 months, augmentation index at 12 months, BP, B-type natriuretic peptide, or physical function. The updated meta-analysis showed no effect of vitamin K supplementation on vascular stiffness or vascular calcification measures.

CONCLUSIONS

Vitamin K2 supplementation did not improve vascular stiffness or other measures of vascular health in this trial involving individuals with CKD.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Vitamin K therapy to improve vascular health in patients with chronic kidney disease, ISRCTN21444964 (www.isrctn.com).

Vascular age is associated with the risk of dialysis or death in chronic kidney disease

AIM

Increased arterial stiffness is associated with progressive renal deterioration and poor clinical outcomes in patients with chronic kidney disease (CKD). Assessment of vascular age as derived from arterial stiffness parameters might be an important clinical marker of cardiovascular risks. The aim of the present study is to evaluate whether the difference (△age) between vascular age and chronological age can predict the risk of reaching dialysis or death in patients with known CKD.

METHODS

This longitudinal study enrolled 94 male Chinese CKD patients, aged 40-62 years. Vascular age was calculated by brachial-ankle pulse wave velocity, and measured by an ankle-brachial index-form device. The study endpoints were the commencement of renal replacement therapy or death.

RESULTS

After a stepwise multivariate analysis, △age was associated independently with increased urine protein-to-creatinine ratio (β = 0.32; P = 0.001) and decreased baseline estimated glomerular filtration rate (β = -0.24; P = 0.008). During a median follow-up period of 62 (interquartile range = 55-66) months, the 4-year cumulative incidence of reaching the study endpoint in patients with △age = 0 and △age > 0 year was 4.9% and 25%, respectively (log-rank test, P = 0.009). Multivariate forward Cox regression analysis identified that higher △age (hazard ratio (HR) = 1.05; P = 0.027), lower baseline estimated glomerular filtration rate (HR = 0.93; P < 0.001), and history of cardiovascular disease (HR = 5.90; P = 0.031) were independently associated with progression to commencement of dialysis or death.

CONCLUSION

Thus, the assessment of the difference between vascular age and chronological age may provide an alternative method to identify CKD patients at a high risk of progression to dialysis or death.

Chronic Kidney Disease and Pulse Wave Velocity: A Narrative Review

Chronic kidney disease (CKD) is associated with excess cardiovascular mortality, resulting from both traditional and nontraditional, CKD-specific, cardiovascular risk factors. Nontraditional risk factors include the entity Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) which is characterised by disorders of bone and mineral metabolism, including biochemical abnormalities of hyperphosphatemia and hyperparathyroidism, renal osteodystrophy, and vascular calcification. Increased arterial stiffness in the CKD population can be attributed amongst other influences to progression of vascular calcification, with significant resultant contribution to the cardiovascular disease burden. Pulse wave velocity (PWV) measured over the carotid-femoral arterial segments is the noninvasive gold-standard technique for measurement of aortic stiffness and has been suggested as a surrogate cardiovascular end-point. A PWV value of 10 m/s or greater has been recommended as a suitable cut-off for an increased risk of cardiovascular mortality. CKD is a risk factor for an excessive rate of increase in aortic stiffness, reflected by increases in PWV, and increased aortic PWV in CKD shows faster progression than for individuals with normal kidney function. Patients with varying stages of CKD, as well as those on dialysis or with a kidney transplant, have different biological milieu which influence aortic stiffness and associated changes in PWV. This review discusses the pathophysiology of arterial stiffness with CKD and outlines the literature on PWV across the spectrum of CKD, highlighting that determination of arterial stiffness using aortic PWV can be a useful diagnostic and prognostic tool for assessing cardiovascular disease in the CKD population.

Potential Role of Antihypertensive Medications in Preventing Excessive Arterial Stiffening

PURPOSE OF REVIEW

Increased arterial stiffness, an abnormal structural and functional change in the vascular wall, is a precursor for hypertension, coronary heart disease, stroke, and associated cardiovascular disease (CVD). The aim of this paper is to review the etiology of arterial stiffening and potential therapeutic approaches to modulate arterial fibrosis and stiffness.

RECENT FINDINGS

The Framingham Heart Study demonstrated that arterial stiffness is an independent predictor of CVD and related morbidity and mortality. Dysfunction of endothelial cells, vascular smooth muscle cells, extracellular matrix, and other functional elements of the vessel wall contribute to underlying pathophysiology of increased arterial stiffness. An activated renin-angiotensin-aldosterone system, oxidative stress, abnormal peri-vascular adipose tissue, inflammation, and increased sympathetic nervous system activity are associated with the development and progression of arterial fibrosis, stiffening, and associated CVD. In this review, we will discuss the structural and function changes and mechanisms of the vessel wall in arterial stiffness and provide potential therapeutic strategies.

Vascular dysfunction in children and young adults with autosomal dominant polycystic kidney disease

Background

Adults with autosomal dominant polycystic kidney disease (ADPKD) exhibit vascular dysfunction, as evidenced by impaired endothelium-dependent dilation (EDD) and stiffening of the large elastic arteries. However, it is unknown whether vascular dysfunction begins earlier in the course of ADPKD. The aim of the study was to assess EDD and arterial stiffness in children and young adults with ADPKD.

Methods

Fifteen children and young adults 6–22 years of age with ADPKD and normal renal function were prospectively recruited for participation in a cross-sectional study. Fifteen healthy controls were enrolled to match cases for age and sex. The primary outcomes were EDD, measured as brachial artery flow-mediated dilation (FMDBA), and arterial stiffness, measured as carotid-femoral pulse wave velocity (CFPWV).

Results

ADPKD cases were more likely to be taking an angiotensin-converting enzyme inhibitor, but otherwise did not differ from controls in clinical characteristics, including blood pressure. FMDBA was 25% lower in children and young adults with ADPKD (7.7 ± 0.9%, mean ± SE) when compared with matched controls (10.2 ± 0.8%) (P < 0.05). CFPWV was 14% higher in children and young adults with ADPKD (544 ± 23 cm/s) when compared with matched controls (478 ± 17 cm/s) (P < 0.05). Secondary measures of arterial stiffness, carotid augmentation index and carotid systolic blood pressure were also increased in cases when compared with controls (P < 0.05).

Conclusions

Impaired EDD and increased arterial stiffness, important independent predictors of future cardiovascular events and mortality, are evident very early in the course of ADPKD in the presence of normal kidney function. Novel interventions to reduce vascular dysfunction in children and young adults with ADPKD should be evaluated, as childhood and young adulthood may represent a critical therapeutic window to reduce future cardiovascular risk in patients with ADPKD.

Arterial stiffness, cognitive impairment and dementia: confounding factor or real risk?

Large artery stiffness is a frequent condition that arises with ageing, and is accelerated by the presence of co-morbidities like hypertension, obesity and diabetes. Although epidemiological studies have indicated an association between arterial stiffness, cognitive impairment and dementia, the precise effects of stiff arteries on the brain remains obscure. This is because, in humans, arterial stiffness is often accompanied by other factors such as age, high blood pressure, atherosclerosis and inflammation, which could themselves damage the brain independently of stiffness. Therefore, the question remains: is arterial stiffness a true risk for cognitive decline? Or, is it a confounding factor? In this review, we provide an overview of arterial stiffness and its impact on brain function based on human and animal studies. We summarize the evidence linking arterial stiffness to cognitive dysfunction and dementia, and discuss the role of new animal models to better understand the mechanisms by which arterial stiffness affects the brain. We close with an overview of treatments to correct stiffness and discuss the challenges to translate them to real patient care. This article is part of the Special Issue "Vascular Dementia".

Arterial stiffness and stroke: de-stiffening strategy, a therapeutic target for stroke

Stroke is the second leading cause of mortality and morbidity worldwide. Early intervention is of great importance in reducing disease burden. Since the conventional risk factors cannot fully account for the pathogenesis of stroke, it is extremely important to detect useful biomarkers of the vascular disorder for appropriate intervention. Arterial stiffness, a newly recognised reliable feature of arterial structure and function, is demonstrated to be associated with stroke onset and serve as an independent predictor of stroke incidence and poststroke functional outcomes. In this review article, different measurements of arterial stiffness, especially pressure wave velocity, were discussed. We explained the association between arterial stiffness and stroke occurrence by discussing the secondary haemodynamic changes. We reviewed clinical data that support the prediction role of arterial stiffness on stroke. Despite the lack of long-term randomised double-blind controlled therapeutic trials, it is high potential to reduce stroke prevalence through a significant reduction of arterial stiffness (which is called de-stiffening therapy). Pharmacological interventions or lifestyle modification that can influence blood pressure, arterial function or structure in either the short or long term are promising de-stiffening therapies. Here, we summarised different de-stiffening strategies including antihypertension drugs, antihyperlipidaemic agents, chemicals that target arterial remodelling and exercise training. Large and well-designed clinical trials on de-stiffening strategy are needed to testify the prevention effect for stroke. Novel techniques such as modern microscopic imaging and reliable animal models would facilitate the mechanistic analyses in pathophysiology, pharmacology and therapeutics.

Therapeutic Modulation of Aortic Stiffness

Aortic stiffness (AS) is an important predictor of cardiovascular morbidity in humans. The present review discusses the possible pathophysiological mechanisms of AS and focuses on a survey of different therapeutic modalities for decreasing AS. The influence of several nonpharmacological interventions is described: decrease body weight, diet, aerobic exercise training, music, and continuous positive airway pressure therapy. The effects of different pharmacological drug classes on AS are also discussed: antihypertensive drugs-renin-angiotensin-aldosterone system drugs, beta-blockers, alpha-blockers, diuretics, and calcium channel blockers (CCBs)-advanced glycation end product cross-link breakers, statins, oral anti-diabetics, anti-inflammatory drugs, vitamin D, antioxidant vitamins, and endothelin-1 receptor antagonists. All of these have shown some effect in decreasing AS.

The reverse remodeling of the aorta in patients after renal transplantation - the value of aortic stiffness index: prospective echocardiographic study

BACKGROUND

Atherosclerosis is regarded as a combination of two major separate diseases: atherosis and sclerosis. Sclerotic component depends on deterioration of elastic properties of the aortic wall and is called aortic stiffness. The most valuable, non-invasive method of aortic stiffness assessment is echocardiography, which allows to calculate the aortic stiffness index (ASI). ASI is an independent predictor of all-cause and cardiovascular mortality in different groups of patients. The main aim of study was the assessment of the aortic reverse remodeling in patients with end-stage renal disease (ESRD) after renal transplantation (RT).

METHODS

Study group involved 42 patients aged 43.3 ± 12.6 years, including 19 women aged 49.9 ± 10.9 years and 23 men aged 41.5 ± 12.91 years, who have undergone RT from non-related renal transplant donors, The study protocol has been consisted of 5 stages: 1 week after RT, 3 months after RT, 6 months after RT, 1 year after RT and 3 years after RT. The echocardiographic examination was performed and measurements of Ao_max, Ao_min were done. On the base of obtained parameters ASI, aortic distensibility (AD) and aortic strain (AS) were calculated according to adequate formulas.

RESULTS

The improvement of indices characterizing the elastic properties of aorta were noted. These changes attained the statistically significant level only at the end of the observation. ASI just after RT was equal - 4.65 ± 1.58, three months after RT - 4.54 ± 1.49, six months after RT - 4.59 ± 1.61, one year after RT - 4.35 ± 1.21 and three years after RT - 3.35 ± 1.29, while AD reached respectively - 6.55 ± 3.76 cm²/dyn^-110^-6 just after RT, - 6.38 ± 3.42 cm²/dyn^-110^-6 three months after RT, - 6.53 ± 3.60 cm²/dyn^-110^-6 six months after RT, - 6.48 ± 2.79 cm²/dyn^-110^-6 one year after RT and - 8.03 ± 3.95 cm²/dyn^-110^-6 three years after RT. Noted AS values were equal - 6.61 ± 4.05%, just after RT, - 6.40 ± 3.58% three months after RT, - 6.56 ± 3.76%, six months after RT, - 6.45 ± 2.80% one year after RT, - 8.01 ± 3.97%. and three years after RT. The exact analysis of parameters concerning aortic function showed that to achieve ASI, AD and AS improvement, long time was needed, because the most significant changes of these indices were observed only between 1 year and 3 years after RT.

CONCLUSIONS

There is a relationship between renal transplantation and improvement of the aortic elastic properties. The recovery of the renal function allows to initiate the reparative processes leading to at least partial restitution of the structure and features of the aorta, which is called reverse remodelling. Improvement of aortic wall elastic properties after renal transplantation is a continuous and prolonged process.

IL-1 Inhibition and Vascular Function in CKD

Vascular endothelial dysfunction and increased arterial stiffness contribute to increased cardiovascular risk in patients with CKD who exhibit chronic systemic inflammation. Because chronic inflammation contributes to vascular dysfunction, blocking inflammation may reduce cardiovascular risk in patients with CKD. In a two-site, double-blind trial, we randomized 42 adult patients with stage 3-4 CKD who were already receiving optimal background therapy to receive either IL-1 trap rilonacept or placebo for 12 weeks. Coprimary end points included change in brachial artery flow-mediated dilation (FMD_BA) and aortic pulse-wave velocity (aPWV) after 4, 8, and 12 weeks. Exploratory end points included change in high-sensitivity C-reactive protein (hsCRP), FMD_BA after acute ascorbic acid infusion, and vascular endothelial cell protein expression of NADPH oxidase. Participants were 63±11 (mean±SD) years of age and 24% were women; mean eGFR was 38±13 ml/min per 1.73 m² Compared with placebo, rilonacept improved FMD_BA (baseline: 3.36%±2.06% [mean±SD], 12 weeks: 2.45%±2.29% with placebo and baseline: 3.75%±3.12%, 12 weeks: 4.86%±3.20% with rilonacept; P<0.01), without changing aPWV (P=0.56). Rilonacept also reduced hsCRP levels (median [interquartile range]) (baseline: 4.60 [1.90-8.22] mg/L, 12 weeks: 2.16 [0.92-7.38] mg/L; P<0.01) and endothelial cell NADPH oxidase expression (P<0.05). Acute infusion of ascorbic acid to inhibit superoxide production associated with a nonsignificant trend toward increased FMD_BA in the placebo group (P=0.07) but not the rilonacept group (P=0.56). Rilonacept was well tolerated (five adverse events versus two with placebo). In conclusion, treatment with an IL-1 trap improved FMD_BA without changing aPWV and reduced systemic inflammation in patients with CKD.

Impact of Antihypertensive Agents on Central Systolic Blood Pressure and Augmentation Index: A Meta-Analysis

BACKGROUND

New evidence suggests that central systolic blood pressure (cSBP) and augmentation index (AI) are superior predictors of adverse cardiovascular outcomes compared to peripheral systolic BP (pSBP). We performed a meta-analysis assessing the impact of antihypertensives on cSBP and AI.

METHODS

PubMed, Cochrane Library, and CINAHL were searched until September 2014 to identify eligible articles. A DerSimonian and Laird random-effects model was used to calculate the weighted mean difference (WMD) and its 95% confidence interval (CI). Fifty-two and 58 studies incorporating 4,381 and 3,716 unique subjects were included for cSBP and AI analysis, respectively.

RESULTS

Overall, antihypertensives reduced pSBP more than cSBP (WMD 2.52 mm Hg, 95% CI 1.35 to 3.69; I (2) = 21.9%). β-Blockers (BBs) posed a significantly greater reduction in pSBP as compared to cSBP (WMD 5.19 mm Hg, 95% CI 3.21 to 7.18). α-Blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, renin-angiotensin aldosterone system inhibitors and nicorandil reduced cSBP and pSBP in a similar manner. The overall reduction in AI from baseline was 3.09% (95% CI 2.28 to 3.90; I (2) = 84.5%). A significant reduction in AI was seen with angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, renin-angiotensin aldosterone system inhibitors, BBs, α-blockers (ABs), nicorandil, and moxonidine reduced AI nonsignificantly.

CONCLUSIONS

BBs are not as beneficial as the other antihypertensives in reducing cSBP and AI.

Effects of different types of antihypertensive agents on arterial stiffness: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This system review and meta-analysis was conducted to systematically review and analyze the clinical benefits of different antihypertensive agents in improving arterial stiffness in hypertensive patients.

METHODS

PubMed database was searched for randomized controlled trials (RCTs) evaluating the effects of angiotensin receptor blockers (ARB) or other types of antihypertensive agents on pulse wave velocity (PWV). The main indicators were the improvements of PWV and augmentation index (AI) before and after randomized treatments with antihypertensive agents. For the studies that only provided the mean and standard deviation of the indicators before and after randomization, the standardized mean difference (SMD) method was directly applied to combine the mean and standard deviation of various indicators after the treatment. For the studies provided the mean and standard deviation of the changes of the indicators, the weighted mean difference (MD) method was applied to combine the mean and standard deviation of the therapeutic effect.

RESULTS

Ten RCT studies were included and the sample sizes range from 40 to 201 (total: 938). Four studies provided the changes of PWV before and after randomization, the pooled analysis showed that the changes of PWV in ARB group were not significantly higher than other antihypertensive agents [MD: 125.76, 95% confidence interval (CI): -78.70 to 330.23, P=0.23]; 4 studies provided the PWV values before and after randomization, the PWV values in ARB group were not significantly superior (SMD: 0.04, 95% CI: -0.16 to 0.24, P=0.71). Three studies provided the changes of AI before and after randomization, the ability of ARB to lower the level of the AI was superior to other antihypertensive agents (MD: 8.94, 95% CI: 2.18-5.71, P=0.01); 2 studies provided the AI value after randomization, the abilities of ARB and other anti-hypertensive agents to improve the AI were similar (SMD: 0.03, 95% CI: -1.20 to 1.26, P=0.06).

CONCLUSIONS

The effect of ARB on the improvement of the PWV level is not superior to other types of antihypertensive agents, but ARB is superior to other types of antihypertensive agents for improving the AI level. Overall, to improve of arterial stiffness, ARB maybe is superior to other antihypertensive agents.

Serum Mimecan Is Associated With Arterial Stiffness in Hypertensive Patients

Background

Mimecan plays an important role in endothelial and vascular smooth muscle cell integrity and may be involved the pathology of arterial stiffness. However, the role of mimecan in arterial stiffness in patients with hypertension is not well defined.

Methods and Results

A total of 116 hypertension patients and 54 healthy controls were enrolled in the investigation. Hypertensive patients were divided into 2 groups: the with arterial stiffness group (brachial-ankle pulse wave velocity [baPWV] ≥1400 cm/s; n=83) and the without arterial stiffness group (baPWV <1400 cm/s; n=33). A noninvasive measure of vascular stiffness was performed using pulse wave velocity (PWV) measurement of baPWV. Hypertensive patients had higher baPWV, mimecan, and endothelin 1 (ET-1) than healthy controls. The arterial stiffness group had higher mimecan and endothelin 1 (ET-1) and lower ankle-brachial pressure index (ABI) than those without stiffness. In hypertensive patients, mimecan was inversely correlated with ABI (P<0.05) and positively correlated with baPWV, ET-1, and total cholesterol. On multivariable logistic regression analysis, diastolic blood pressure, mimecan, ET-1, and creatinine were independent predictors of arterial stiffness in hypertensive patients (P<0.05).

Conclusions

Mimecan levels are higher in hypertensive patients than in healthy controls. Increased plasma mimecan levels are independently associated with increased arterial stiffness as assessed by baPWV.

Effects of AP39, a novel triphenylphosphonium derivatised anethole dithiolethione hydrogen sulfide donor, on rat haemodynamic parameters and chloride and calcium Cav3 and RyR2 channels

H2S donor molecules have the potential to be viable therapeutic agents. The aim of this current study was (i) to investigate the effects of a novel triphenylphosphonium derivatised dithiolethione (AP39), in the presence and absence of reduced nitric oxide bioavailability and (ii) to determine the effects of AP39 on myocardial membrane channels; CaV3, RyR2 and Cl(-). Normotensive, L-NAME- or phenylephrine-treated rats were administered Na2S, AP39 or control compounds (AP219 and ADT-OH) (0.25-1 µmol kg(-1)i.v.) and haemodynamic parameters measured. The involvement of membrane channels T-type Ca(2+) channels CaV3.1, CaV3.2 and CaV3.3 as well as Ca(2+) ryanodine (RyR2) and Cl(-) single channels derived from rat heart sarcoplasmic reticulum were also investigated. In anaesthetised Wistar rats, AP39 (0.25-1 µmol kg(-1) i.v) transiently decreased blood pressure, heart rate and pulse wave velocity, whereas AP219 and ADT-OH and Na2S had no significant effect. In L-NAME treated rats, AP39 significantly lowered systolic blood pressure for a prolonged period, decreased heart rate and arterial stiffness. In electrophysiological studies, AP39 significantly inhibited Ca(2+) current through all three CaV3 channels. AP39 decreased RyR2 channels activity and increased conductance and mean open time of Cl(-) channels. This study suggests that AP39 may offer a novel therapeutic opportunity in conditions whereby (•)NO and H2S bioavailability are deficient such as hypertension, and that CaV3, RyR2 and Cl(-) cardiac membrane channels might be involved in its biological actions.

Vascular stiffening in pulmonary hypertension: cause or consequence? (2013 Grover Conference series)

Recent studies have indicated that systemic arterial stiffening is a precursor to hypertension and that hypertension, in turn, can perpetuate arterial stiffening. Pulmonary artery (PA) stiffening is also well documented to occur in pulmonary hypertension (PH), and there is evidence that pulmonary vascular stiffness (PVS) may be a better predictor of outcome than pulmonary vascular resistance (PVR). We have hypothesized that the decreased flow-damping function of elastic PAs in PH likely initiates and/or perpetuates dysfunction of pulmonary microvasculature. Recent studies have shown that large-vessel stiffening increases flow pulsatility in the distal pulmonary vasculature, leading to endothelial dysfunction within a proinflammatory, vasoconstricting, and profibrogenic environment. The intricate role of stiffening-stimulated high pulsatile flow in endothelial cell dysfunction includes stepwise molecular events underlying PA hypertrophy, inflammation, endothelial-mesenchymal transition, and fibrosis. In addition to contributing to microenvironmental alterations of the distal vasculature, disordered proximal-distal PA coupling likely also plays a role in increasing ventricular afterload, ultimately causing right ventricle (RV) dysfunction and death. Current therapeutic treatments do not provide a realistic approach to destiffening arteries and, thus, to potentially abrogating the effects of high pulsatile flow on the distal pulmonary vasculature or the increased work imposed by stiffening on the RV. Scrutinizing the effect of PA stiffening on high pulsatile flow-induced cellular and molecular changes, and vice versa, might lead to important new therapeutic options that abrogate PA remodeling and PH development. With a clear understanding that PA stiffening may contribute to the progression of PH to an irreversible state by contributing to chronic microvascular damage in lungs, future studies should be aimed first at defining the underlying mechanisms leading to PA stiffening and then at improved treatment approaches based on these findings.

Effects of blood pressure and sex on the change of wave reflection: evidence from Gaussian fitting method for radial artery pressure waveform

An early return of the reflected component in the arterial pulse has been recognized as an important indicator of cardiovascular risk. This study aimed to determine the effects of blood pressure and sex factor on the change of wave reflection using Gaussian fitting method. One hundred and ninety subjects were enrolled. They were classified into four blood pressure categories based on the systolic blood pressures (i.e., ≤110, 111–120, 121–130 and ≥131 mmHg). Each blood pressure category was also stratified for sex factor. Electrocardiogram (ECG) and radial artery pressure waveforms (RAPW) signals were recorded for each subject. Ten consecutive pulse episodes from the RAPW signal were extracted and normalized. Each normalized pulse episode was fitted by three Gaussian functions. Both the peak position and peak height of the first and second Gaussian functions, as well as the peak position interval and peak height ratio, were used as the evaluation indices of wave reflection. Two-way ANOVA results showed that with the increased blood pressure, the peak position of the second Gaussian significantly shorten (P<0.01), the peak height of the first Gaussian significantly decreased (P<0.01) and the peak height of the second Gaussian significantly increased (P<0.01), inducing the significantly decreased peak position interval and significantly increased peak height ratio (both P<0.01). Sex factor had no significant effect on all evaluation indices (all P>0.05). Moreover, the interaction between sex and blood pressure factors also had no significant effect on all evaluation indices (all P>0.05). These results showed that blood pressure has significant effect on the change of wave reflection when using the recently developed Gaussian fitting method, whereas sex has no significant effect. The results also suggested that the Gaussian fitting method could be used as a new approach for assessing the arterial wave reflection.

Arterial stiffness and cardiovascular therapy

The world population is aging and the number of old people is continuously increasing. Arterial structure and function change with age, progressively leading to arterial stiffening. Arterial stiffness is best characterized by measurement of pulse wave velocity (PWV), which is its surrogate marker. It has been shown that PWV could improve cardiovascular event prediction in models that included standard risk factors. Consequently, it might therefore enable better identification of populations at high-risk of cardiovascular morbidity and mortality. The present review is focused on a survey of different pharmacological therapeutic options for decreasing arterial stiffness. The influence of several groups of drugs is described: antihypertensive drugs (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, beta-blockers, diuretics, and nitrates), statins, peroral antidiabetics, advanced glycation end-products (AGE) cross-link breakers, anti-inflammatory drugs, endothelin-A receptor antagonists, and vasopeptidase inhibitors. All of these have shown some effect in decreasing arterial stiffness. Nevertheless, further studies are needed which should address the influence of arterial stiffness diminishment on major adverse cardiovascular and cerebrovascular events (MACCE).

Modelling arterial pressure waveforms using Gaussian functions and two-stage particle swarm optimizer

Changes of arterial pressure waveform characteristics have been accepted as risk indicators of cardiovascular diseases. Waveform modelling using Gaussian functions has been used to decompose arterial pressure pulses into different numbers of subwaves and hence quantify waveform characteristics. However, the fitting accuracy and computation efficiency of current modelling approaches need to be improved. This study aimed to develop a novel two-stage particle swarm optimizer (TSPSO) to determine optimal parameters of Gaussian functions. The evaluation was performed on carotid and radial artery pressure waveforms (CAPW and RAPW) which were simultaneously recorded from twenty normal volunteers. The fitting accuracy and calculation efficiency of our TSPSO were compared with three published optimization methods: the Nelder-Mead, the modified PSO (MPSO), and the dynamic multiswarm particle swarm optimizer (DMS-PSO). The results showed that TSPSO achieved the best fitting accuracy with a mean absolute error (MAE) of 1.1% for CAPW and 1.0% for RAPW, in comparison with 4.2% and 4.1% for Nelder-Mead, 2.0% and 1.9% for MPSO, and 1.2% and 1.1% for DMS-PSO. In addition, to achieve target MAE of 2.0%, the computation time of TSPSO was only 1.5 s, which was only 20% and 30% of that for MPSO and DMS-PSO, respectively.

Regression of vascular calcification in chronic kidney disease - feasible or fantasy? a review of the clinical evidence

The complex relationships between cardiovascular, renal, and bone disease are increasingly recognized but not yet clearly understood. Vascular calcification (VC) represents a common end point between these interlinked systems. It is highly prevalent in chronic kidney disease (CKD) and may be responsible for some of the excess cardiovascular events seen in this condition. There is much interest in developing therapeutic agents to stop its development or reverse its progression. Traditionally considered to be due to abnormalities in calcium and phosphate metabolism alone, VC is now known to be the product of active, dynamic processes within the vessel wall. Primary prevention of VC is possible through successful prevention or reversal of progressive renal dysfunction, hypertension and hyperlipidaemia, but is challenging given the increasing global prevalence of these risk factors. Secondary prevention of VC through tight control of calcium and phosphate, can be achieved by dietary or pharmacological means. Both the modification of haemodialysis duration or methods and the use of renal transplantation have an effect. Novel drugs such as cinacalcet were hoped to halt calcification but results have been mixed, and no intervention has yet been shown to reverse calcification reliably. A new range of experimental targets involved in the putative mediatory pathways between bone and vascular disease has emerged. Aiming to manipulate the active mechanisms involved in calcium deposition, these hold hope for reversal of calcification, but are still theoretical or in early animal or human experimentation.

Dual renin-angiotensin system inhibition for prevention of renal and cardiovascular events: do the latest trials challenge existing evidence?

Circulatory and tissue renin-angiotensin systems (RAS) play a central role in cardiovascular (CV) and renal pathophysiology, making RAS inhibition a logical therapeutic approach in the prevention of CV and renal disease in patients with hypertension. The cardio- and renoprotective effects observed with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) monotherapy, together with the availability of a direct renin inhibitor (DRI), led to the investigation of the potential benefits of dual RAS inhibition. In small studies, ARB and ACE inhibitor combinations were shown to be beneficial in patients with CV or renal disease, with improvement in surrogate markers. However, in larger outcome trials, involving combinations of ACE inhibitors, ARBs or DRIs, dual RAS inhibition did not show reduction in mortality in patients with diabetes, heart failure, coronary heart disease or after myocardial infarction, and was in fact, associated with increased harm. A recent meta-analysis of all major trials conducted over the past 22 years involving dual RAS inhibition has clearly shown that the risk-benefit ratio argues against the use of dual RAS inhibition. Hence, the recent evidence clearly advocates against the use of dual RAS inhibition, and single RAS inhibition appears to be the most suitable approach to controlling blood pressure and improving patient outcomes.

Impact of multiple cardiovascular risk factors on carotid intima-media thickness and elasticity

Background

Carotid intima-media thickness (IMT) and elasticity have been shown to be independent predictors of cardiovascular disease (CVD). Cardiovascular risk factors (CVRFs) includes hypertension, dyslipidemia, diabetes, overweight and smoking. The objective was to investigate whether the clustering of three or more components of CVRFs has a greater impact on carotid IMT and elasticity than individual components of CVRFs.

Methods

One hundred and seventy-three participants without clinical CVD were classified as the multiple CVRFs patients with three or more CVRFs (n  = 55) and control group with two or less CVRFs (n  = 118). Carotid IMT and elastic modulus were measured by B-mode ultrasound and vessel texture matching method (VTMM), respectively.

Results

The multiple CVRFs conferred a disproportionate increase in carotid IMT (43%, p<0.0001) and elastic modulus (60%, p<0.0001), compared with control group. Multiple regression models, which included age, gender, as well as each individual component of CVRFs as continuous variables, showed that multiple CVRFs was an independent determinant of both IMT (p  = 0.042) and elasticity (p  = 0.008). In the analysis of variance adjusted with age, subjects with single, double, and multiple CVRFs, increased by 8.1%, 42.2%, and 66% for IMT, 54.6%, 94.3%, and 125.2% for elastic modulus, respectively, compared to subjects without CVRFs.

Conclusions

The clustering of multiple CVRFs has a greater impact on carotid IMT and elasticity than individual components of CVRFs. This suggests that the components of CVRFs interact to synergistically impact carotid IMT and elasticity.

Eplerenone attenuates pulse wave reflection in chronic kidney disease stage 3-4--a randomized controlled study

Background

Patients with chronic kidney disease (CKD) have high cardiovascular mortality and morbidity associated with increased arterial stiffness. Plasma aldosterone levels are increased in CKD, and aldosterone has been found to increase vascular inflammation and fibrosis. It was hypothesized that aldosterone receptor inhibition with eplerenone could reduce arterial stiffness in CKD stage 3–4.

Study Design

The design was randomized, open, parallel group. Measurements of arterial stiffness markers were undertaken at weeks 1 and 24.

Intervention

24 weeks of add-on treatment with 25–50 mg eplerenone or standard medication.

Outcomes

Primary outcome parameter was carotid-femoral pulse wave velocity (cfPWV). Secondary outcomes were augmentation index (AIx), ambulatory arterial stiffness index (AASI) and urinary albumin excretion.

Results

Fifty-four CKD patients (mean eGFR 36 mL/min/1.73 m², SD 11) were randomized. Forty-six patients completed the trial. The mean difference in cfPWV changes between groups was 0.1 m/s (95%CI: −1.0, 1.3), P = 0.8. The mean difference in AIx changes between groups was 4.4% (0.1, 8.6), P = 0.04. AASI was unchanged in both groups. The ratio of change in urinary albumin excretion in the eplerenone group compared to the control was 0.61 (0.37, 1.01), P = 0.05. Four patients were withdrawn from the eplerenone group including three because of possible side effects; one was withdrawn from the control group. Mild hyperkalemia was seen on three occasions and was easily managed.

Limitations

The full planned number of patients was not attained. The duration of the trial may have been too short to obtain full effect of eplerenone on the arteries.

Conclusions

Add-on treatment with eplerenone in CKD stage 3–4 did not significantly reduce cfPWV. There may be beneficial vascular effects leading to attenuated pulse wave reflection. Treatment was well-tolerated.

Trial Registration

ClinicalTrials.govNCT01100203

Arterial Stiffness

Stiffness of large arteries has been long recognized as a significant determinant of pulse pressure. However, it is only in recent decades, with the accumulation of longitudinal data from large and varied epidemiological studies of morbidity and mortality associated with cardiovascular disease, that it has emerged as an independent predictor of cardiovascular risk. This has generated substantial interest in investigations related to intrinsic causative and associated factors responsible for the alteration of mechanical properties of the arterial wall, with the aim to uncover specific pathways that could be interrogated to prevent or reverse arterial stiffening. Much has been written on the haemodynamic relevance of arterial stiffness in terms of the quantification of pulsatile relationships of blood pressure and flow in conduit arteries. Indeed, much of this early work regarded blood vessels as passive elastic conduits, with the endothelial layer considered as an inactive lining of the lumen and as an interface to flowing blood. However, recent advances in molecular biology and increased technological sophistication for the detection of low concentrations of biochemical compounds have elucidated the highly important regulatory role of the endothelial cell affecting vascular function. These techniques have enabled research into the interaction of the underlying passive mechanical properties of the arterial wall with the active cellular and molecular processes that regulate the local environment of the load-bearing components. This review addresses these emerging concepts.