Aortic valve calcification in chronic kidney disease

SNF472: a novel therapeutic agent for vascular calcification and calciphylaxis

Vascular calcification is a common complication in patients with chronic kidney disease (CKD) and is strongly associated with an increased risk of cardiovascular events and all-cause mortality. Calciphylaxis is a specific and life-threatening manifestation of vascular calcifications that usually affects individuals with advanced kidney function impairment or those undergoing dialysis. Currently, the treatment of vascular calcification and calciphylaxis in CKD lacks approved treatments and focuses on controlling risk factors. SNF472, the intravenous formulation of myo-inositol hexaphosphate, is a novel vascular calcification inhibitor currently undergoing phase 3 clinical trials, demonstrating its ability to directly inhibit the formation of calcium and phosphorus crystals, thereby blocking the production and deposition of ectopic calcium. The efficacy and safety of SNF472 in inhibiting vascular calcification have been confirmed in recent clinical studies. This review summarizes the results of studies related to SNF472 to provide a comprehensive overview of its mechanism of action, efficacy, safety, and ongoing clinical studies.

Progression of valve heart disease in a cohort of patients undergoing renal replacement therapy

INTRODUCTION

Cardiovascular disease is an important cause of death among patients with chronic kidney disease (CKD). Valve calcification is a predictor of cardiovascular mortality and coronary artery disease.

OBJECTIVE

To assess heart valve disease frequency, associated factors, and progression in CKD patients.

METHODS

We conducted a retrospective study on 291 CKD patients at Hospital das Clínicas de Pernambuco. Inclusion criteria were age ≥ 18 with CKD and valve disease, while those on conservative management or with missing data were excluded. Clinical and laboratory variables were compared, and patients were categorized by dialysis duration (<5 years; 5-10 years; >10 years). Statistical tests, including chi-square, Fisher's exact, ANOVA, and Kruskal-Wallis, were employed as needed. Simple and multivariate binary regression models were used to analyze valve disease associations with dialysis duration. Significance was defined as p < 0.05.

RESULTS

Mitral valve disease was present in 82.5% (240) of patients, followed by aortic valve disease (65.6%; 86). Over time, 106 (36.4%) patients developed valve disease. No significant association was found between aortic, pulmonary, mitral, or tricuspid valve disease and dialysis duration. Secondary hyperparathyroidism was the sole statistically significant factor for mitral valve disease in the regression model (OR 2.59 [95% CI: 1.09-6.18]; p = 0.031).

CONCLUSION

CKD patients on renal replacement therapy exhibit a high frequency of valve disease, particularly mitral and aortic valve disease. However, no link was established between dialysis duration and valve disease occurrence or progression.

Effect of an NHE3 inhibitor in combination with an NPT2b inhibitor on gastrointestinal phosphate absorption in Rodent models

Many of the pathological consequences of chronic kidney disease can be attributed to an elevation in serum phosphate levels. Current therapies focused on decreasing intestinal phosphate absorption to treat hyperphosphatemia are inadequate. The most effective therapeutic strategy may be to target multiple absorptive pathways. In this study, the ability of a novel inhibitor of the intestinal sodium hydrogen exchanger 3 (NHE3), LY3304000, which inhibits paracellular, diffusional uptake of phosphate, to work in combination with an inhibitor of the active transporter, sodium dependent phosphate cotransporter 2b (NPT2b), LY3358966, was explored. LY3304000 modestly inhibited the acute uptake of phosphate into plasma of rats, while surprisingly, it doubled the rate of phosphate uptake in mice, an animal model dominated by NPT2b mediated acute phosphate uptake. In rats, LY3004000 and LY3358966 work in concert to inhibit acute phosphate uptake. On top of LY3358966, LY3304000 further decreased the acute uptake of phosphate into plasma. Studies measuring the recovery of radiolabeled phosphate in the intestine demonstrated LY3304000 and LY3358966 synergistically inhibited the absorption of phosphate in rats. We hypothesize the synergism is because the NHE3 inhibitor, LY3304000, has two opposing effects on intestinal phosphate absorption in rats, first it decreases diffusion mediated paracellular phosphate absorption, while second, it simultaneously increases phosphate absorption through the NPT2b pathway. NHE3 inhibition decreases proton export from enterocytes and raises the cell surface pH. In vitro, NPT2b mediated phosphate transport is increased at higher pHs. The increased NPT2b mediated transport induced by NHE3 inhibition is masked in rats which have relatively low levels of NPT2b mediated phosphate transport, by the more robust inhibition of diffusion mediated phosphate absorption. Thus, the inhibition of NPT2b mediated phosphate transport in rats in the presence of NHE3 inhibition has an effect that exceeds its effect in the absence of NHE3 inhibition, leading to the observed synergism on phosphate absorption between NPT2b and NHE3 inhibition.

Cardiovascular Outcomes of Transcatheter Aortic Valve Implantation in Patients With Chronic Kidney Disease in Octogenarian Population

Limited data are available regarding in-hospital outcomes of transcatheter aortic valve implantation (TAVI) in the octogenarian population with chronic kidney disease (CKD). We sought to study the cardiovascular outcomes of TAVI in CKD hospitalization with different stages at the national cohort registry. We used the National Inpatient Sample database to compare TAVI CKD low-grade (LG) (stage I to IIIa, b) versus TAVI CKD high-grade (HG) (stage IV to V) in octogenarians. Outcomes such as inpatient mortality, cardiogenic shock, new permanent pacemaker implantation, acute kidney injury), sudden cardiac arrest, mechanical circulatory support, major bleeding, transfusion, and resource utilization were compared between the 2 cohorts. A total of 74,766 octogenarian patients (TAVI CKD-HG n = 12,220; TAVI CKD-LG n = 62,545) were included in our study. On matched analysis, TAVI CKD-HG had higher odds of in-hospital mortality (adjusted odds ratio [aOR] 2.18, 95% confidence interval [CI] 1.0-2.5, p <0.0001), cardiogenic shock (aOR 1.22, 95% CI 1.07 to 1.39, p = 0.0019), permanent pacemaker implantation (aOR 1.14, 95% CI 1.06 to 1.23, p = 0.0006), acute kidney injury (aOR 1.19, 95% CI 1.13 to 1.27, p <0.0001), sudden cardiac arrest (aOR 1.32, 95% CI 1.09 to 1.61, p = 0.004), major bleeding (aOR 1.1, 95% CI 1.006 to 1.22, p <0.0368) and higher rates of blood transfusion (aOR 1.62, 95% CI 1.5 to 1.75, p <0.0001) when compared with the TAVI CKD-LG cohort. However, there was no statistically significant difference in the odds of cerebrovascular accident and mechanical circulatory support use between the 2 groups.

Impact of arteriovenous fistula on flow states in the evaluation of aortic stenosis among ESKD patients on dialysis

INTRODUCTION

An arteriovenous fistula (AVF) in patients with end-stage kidney disease (ESKD) can influence flow states. We sought to evaluate if assessment of aortic stenosis (AS) by transthoracic echocardiographic (TTE) differs in the presence of AVF compared to other dialysis accesses in patients on dialysis.

METHODS

We identified consecutive ESKD patients on dialysis and concomitant AS from a single center between January 2000 and March 2021. We analyzed TTE parameters of AS severity (velocities, gradients, aortic valve area [AVA]) and hemodynamics (cardiac output [CO], valvuloarterial impedance [Zva]) and compared AS parameters in patients with AVF versus other dialysis access.

RESULTS

The cohort included 94 patients with co-prevalent ESKD and AS; mean age 66 years, 71% male; 43% Black, 24% severe AS. Dialysis access: 53% AVF, 47% others. In the overall cohort, no significant differences were noted between AVF versus non-AVF in AVA/CO/Zva, but with notable subgroup differences. In mild AS, CO was significantly higher in AVF versus non-AVF (6.3 vs. 5.2 L/min; p = .04). In severe AS, Zva was higher in the AVF versus non-AVF (4.6 vs. 3.6 mm Hg/mL/m2 ). With increasing AS severity in the AVF group, CO decreased, coupled with increase in Zva, likely counterbalancing the net hemodynamic impact of the AVF.

CONCLUSION

Among ESKD patients with AS, TTE parameters of flow states and AS severity differed in those with AVF versus other dialysis accesses and varied with progression in severity of AS. Future longitudinal assessment of hemodynamic parameters in a larger cohort of co-prevalent ESRD and AS would be valuable.

Serum magnesium level and cardiac valve calcification in hemodialysis patients

INTRODUCTION

Cardiac valve calcification is closely related to cardiovascular disease. The aim of this study was to investigate the magnesium level and cardiac valve calcification in hemodialysis patients.

METHODS

A cross-sectional study was conducted in 105 maintenance hemodialysis patients with complete follow-up data from June 2020 to May 2021 in Beijing Tsinghua Changgung Hospital, Tsinghua University. Baseline data, including sex, age, primary disease, liver and kidney function, electrolytes and parathyroid hormone, were recorded. According to their echocardiograms, patients were divided into a cardiac valve calcification group and a noncardiac valve calcification group, and the correlations between valve calcification and clinical data were analyzed.

RESULTS

Of 105 patients under hemodialysis, 60 (56.6%) were male, with an average age of 62.1 ± 13.5 years and a mean dialysis duration of 58.8 ± 45.4 months. The majority of primary renal diseases were diabetic nephropathy (55, 51.9%). Approximately 64.8% of the 105 maintenance hemodialysis patients had cardiac valve calcification, and 35.2% were in the noncardiac valve calcification group. The independent t test and the chi-square test analysis showed that the cardiac valve calcification group had older age, higher smoking rate, diabetes mellitus, lower extremity arterial occlusion, coronary heart disease, and coronary artery calcification ratio but lower parathyroid hormone, serum calcium, serum magnesium, albumin, prealbumin, and high-density lipoprotein cholesterol levels (P < 0.05). Logistic regression analysis showed that age, diabetes mellitus, coronary artery calcification, lower serum magnesium, lower serum calcium, and lower parathyroid hormone levels were associated with valve calcification.

CONCLUSION

The presence of cardiac valve calcification was associated with age, calcium, phosphorus and lower magnesium level. These factors we should pay more attention in clinical practice.

Implications of Renal Disease in Patients Undergoing Structural Interventions

Percutaneous structural interventions have a major impact on the morbidity, mortality, and quality of life of patients by providing a lower-risk alternative to cardiac surgery. However, renal disease has a significant impact on outcomes of these interventions. This review explores the incidence, outcomes, pathophysiology, and preventative measures of acute kidney injury and chronic kidney disease on transcatheter aortic valve replacement, transcatheter mitral valve repair, and percutaneous balloon mitral valvuloplasty. Given the expanding indications for percutaneous structural interventions, further research is needed to identify ideal patients with chronic kidney disease or end-stage renal disease who would benefit from intervention.

Hypoxia-inducible factor activation promotes osteogenic transition of valve interstitial cells and accelerates aortic valve calcification in a mice model of chronic kidney disease

Introduction

Valve calcification (VC) is a widespread complication in chronic kidney disease (CKD) patients. VC is an active process with the involvement of in situ osteogenic transition of valve interstitial cells (VICs). VC is accompanied by the activation of hypoxia inducible factor (HIF) pathway, but the role of HIF activation in the calcification process remains undiscovered.

Methods and result

Using in vitro and in vivo approaches we addressed the role of HIF activation in osteogenic transition of VICs and CKD-associated VC. Elevation of osteogenic (Runx2, Sox9) and HIF activation markers (HIF-1α and HIF-2α) and VC occurred in adenine-induced CKD mice. High phosphate (Pi) induced upregulation of osteogenic (Runx2, alkaline-phosphatase, Sox9, osteocalcin) and hypoxia markers (HIF-1α, HIF-2α, Glut-1), and calcification in VICs. Down-regulation of HIF-1α and HIF-2α inhibited, whereas further activation of HIF pathway by hypoxic exposure (1% O₂) or hypoxia mimetics [desferrioxamine, CoCl₂, Daprodustat (DPD)] promoted Pi-induced calcification of VICs. Pi augmented the formation of reactive oxygen species (ROS) and decreased viability of VICs, whose effects were further exacerbated by hypoxia. N-acetyl cysteine inhibited Pi-induced ROS production, cell death and calcification under both normoxic and hypoxic conditions. DPD treatment corrected anemia but promoted aortic VC in the CKD mice model.

Discussion

HIF activation plays a fundamental role in Pi-induced osteogenic transition of VICs and CKD-induced VC. The cellular mechanism involves stabilization of HIF-1α and HIF-2α, increased ROS production and cell death. Targeting the HIF pathways may thus be investigated as a therapeutic approach to attenuate aortic VC.

Screening of immune-related secretory proteins linking chronic kidney disease with calcific aortic valve disease based on comprehensive bioinformatics analysis and machine learning

BACKGROUND

Chronic kidney disease (CKD) is one of the most significant cardiovascular risk factors, playing vital roles in various cardiovascular diseases such as calcific aortic valve disease (CAVD). We aim to explore the CKD-associated genes potentially involving CAVD pathogenesis, and to discover candidate biomarkers for the diagnosis of CKD with CAVD.

METHODS

Three CAVD, one CKD-PBMC and one CKD-Kidney datasets of expression profiles were obtained from the GEO database. Firstly, to detect CAVD key genes and CKD-associated secretory proteins, differentially expressed analysis and WGCNA were carried out. Protein-protein interaction (PPI), functional enrichment and cMAP analyses were employed to reveal CKD-related pathogenic genes and underlying mechanisms in CKD-related CAVD as well as the potential drugs for CAVD treatment. Then, machine learning algorithms including LASSO regression and random forest were adopted for screening candidate biomarkers and constructing diagnostic nomogram for predicting CKD-related CAVD. Moreover, ROC curve, calibration curve and decision curve analyses were applied to evaluate the diagnostic performance of nomogram. Finally, the CIBERSORT algorithm was used to explore immune cell infiltration in CAVD.

RESULTS

The integrated CAVD dataset identified 124 CAVD key genes by intersecting differential expression and WGCNA analyses. Totally 983 CKD-associated secretory proteins were screened by differential expression analysis of CKD-PBMC/Kidney datasets. PPI analysis identified two key modules containing 76 nodes, regarded as CKD-related pathogenic genes in CAVD, which were mostly enriched in inflammatory and immune regulation by enrichment analysis. The cMAP analysis exposed metyrapone as a more potential drug for CAVD treatment. 17 genes were overlapped between CAVD key genes and CKD-associated secretory proteins, and two hub genes were chosen as candidate biomarkers for developing nomogram with ideal diagnostic performance through machine learning. Furthermore, SLPI/MMP9 expression patterns were confirmed in our external cohort and the nomogram could serve as novel diagnosis models for distinguishing CAVD. Finally, immune cell infiltration results uncovered immune dysregulation in CAVD, and SLPI/MMP9 were significantly associated with invasive immune cells.

CONCLUSIONS

We revealed the inflammatory-immune pathways underlying CKD-related CAVD, and developed SLPI/MMP9-based CAVD diagnostic nomogram, which offered novel insights into future serum-based diagnosis and therapeutic intervention of CKD with CAVD.

Calcific aortic valve disease: mechanisms, prevention and treatment

Calcific aortic valve disease (CAVD) is the most common disorder affecting heart valves and is characterized by thickening, fibrosis and mineralization of the aortic valve leaflets. Analyses of surgically explanted aortic valve leaflets have shown that dystrophic mineralization and osteogenic transition of valve interstitial cells co-occur with neovascularization, microhaemorrhage and abnormal production of extracellular matrix. Age and congenital bicuspid aortic valve morphology are important and unalterable risk factors for CAVD, whereas additional risk is conferred by elevated blood pressure and plasma lipoprotein(a) levels and the presence of obesity and diabetes mellitus, which are modifiable factors. Genetic and molecular studies have identified that the NOTCH, WNT-β-catenin and myocardin signalling pathways are involved in the control and commitment of valvular cells to a fibrocalcific lineage. Complex interactions between valve endothelial and interstitial cells and immune cells promote the remodelling of aortic valve leaflets and the development of CAVD. Although no medical therapy is effective for reducing or preventing the progression of CAVD, studies have started to identify actionable targets.

Aortic Stenosis and Aortic Valve Replacement among Patients with Chronic Kidney Disease: A Narrative Review

BACKGROUND

Aortic stenosis (AS) can present with dyspnea, angina, syncope, and palpitations, and this presents a diagnostic challenge as chronic kidney disease (CKD) and other commonly found comorbid conditions may present similarly. While medical optimization is an important aspect in management, aortic valve replacement (AVR) by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) is the definitive treatment. Patients with concomitant CKD and AS require special consideration as it is known that CKD is associated with progression of AS and poor long-term outcomes.

AIMS AND OBJECTIVES

The aim of the study was to summarize and review the current existing literature on patients with both CKD and AS regarding disease progression, dialysis methods, surgical intervention, and postoperative outcomes.

CONCLUSION

The incidence of AS increases with age but has also been independently associated with CKD and furthermore with hemodialysis (HD). Regular dialysis with HD versus peritoneal dialysis (PD) and female gender have been associated with progression of AS. Management of AS is multidisciplinary and requires planning and interventions by the heart-kidney team to decrease the risk of further inducing kidney injury among high-risk population. Both TAVR and SAVR are effective interventions for patients with severe symptomatic AS, but TAVR has been associated with better short-term renal and cardiovascular outcomes.

IMPLICATIONS FOR PRACTICE

Special consideration must be given to patients with both CKD and AS. The choice of whether to undergo HD versus PD among patients with CKD is multifactorial, but studies have shown benefit regarding AS progression among those who undergo PD. The choice regarding AVR approach is likewise the same. TAVR has been associated with decreased complications among CKD patients, but the decision is multifactorial and requires a comprehensive discussion with the heart-kidney team as many other factors play a role in the decision including preference, prognosis, and other risk factors.

Preoperative hypomagnesemia as a possible predictive factor for postoperative increase of transvalvular pressure gradient in hemodialysis patients treated with transcatheter aortic valve implantation

BACKGROUND

Patients undergoing maintenance hemodialysis (HD) with severe aortic stenosis are at a high risk for bioprosthetic valve dysfunction after transcatheter aortic valve implantation (TAVI). Currently, preoperative factors that predict the occurrence of valve dysfunction after TAVI on HD patients remain to be elucidated. The aim of this study is to analyze the association between preoperative clinical factors and valve stenosis after TAVI on HD patients.

METHODS

Twenty-four of HD patients who underwent TAVI at our institution between April 2012 and January 2016 were analyzed. The mean aortic transvalvular pressure gradient (MPG) and effective orifice area index (EOAi) were assessed by serial echocardiography. Associations between preoperative clinical factors and time-series changes in MPG were examined using mixed-effects linear regression model for repeated measures.

RESULTS

Three patients developed severe structural valve deterioration with calcific valve stenosis requiring reoperation. A multivariate linear mixed-effects model showed that lower serum magnesium (sMg) levels were associated with the increase of MPG after TAVI (beta-coefficient = 0.019, p = 0.03). No correlation was observed with serum calcium, phosphorus, or intact parathyroid hormone. Time-series changes of MPG and EOAi had significant difference between lower and higher sMg group. All 3 of the patients who underwent reoperation showed lower preoperative sMgs.

CONCLUSION

Among bone-mineral metabolism markers, preoperative hypomagnesemia was associated with the increase of MPG after TAVI, suggesting that hypomagnesemia could predict post-TAVI valve dysfunction in HD patients. Further studies with larger sample sizes are warranted.

Association of serum levels of calcium, phosphate, and vitamin D with risk of developing aortic stenosis: the UK Biobank cohort

AIMS

This study was aimed to investigate the associations of serum calcium, phosphate, and vitamin D levels with the risk of developing aortic stenosis (AS).

METHODS AND RESULTS

We included 296 415 participants who were free of prior diagnosis of any valvular heart disease from the UK Biobank. Serum levels of phosphate, calcium, and vitamin D were measured. Incidental AS was determined by the records of hospital data. Cox regression was used to examine the association of serum mineral levels with incidental AS after adjustment for potential confounders. The mean age was 56.4 years (SD 8.14) and 53.3% of participants were women. During an average follow-up of 8.1 years, 1232 individuals developed AS. After adjustment, each 0.5-unit increase in serum phosphate level was associated with a 50% increase of AS risk (hazard ratio 1.50, 95% confidence interval 1.26-1.80). We observed no association of serum calcium and vitamin D levels with AS.

CONCLUSION

Increased serum phosphate level, but not calcium or vitamin D, was associated with a higher risk of incident AS, this association did not differed substantially between patients with and without decreased kidney function. This finding implied that phosphate may be a potential interventional target for AS.

Hyperphosphatemia is associated with cardiac valve calcification in chronic hypoparathyroidism

PURPOSE

To evaluate the association between metabolic abnormalities and cardiovascular risk factors in patients with chronic hypoparathyroidism (HPP).

PATIENTS AND METHODS

Patients 18 years and older, glomerular filtration > 30 mL/min/1.73 m² and no documented coronary artery disease were selected. Serum calcium, phosphorus, glucose, lipids, PTH, 25(OH)D and FGF23 were measured. Cardiovascular risk was estimated by the European Society of Cardiology (ESC) calculator. Transthoracic echocardiogram and carotid ultrasound were performed to detect carotid plaques (CP), carotid intima-media thickness (IMT), cardiac valve calcification (CVC), and left ventricular hypertrophy (LVH).

RESULTS

Thirty-seven patients (94.6% female), aged 56.0 ± 13.5 years and HPP duration 7.0 (4.0; 11.3) years, were included. Fifteen were classified as low cardiovascular risk, 9 as intermediate risk, 9 as high risk and none as very high risk. The prevalence of CP, CVC and LVH was 24.3%, 24.3% and 13.5%, respectively. IMT values were within normal ranges in all cohort. FGF23 were not associated with CP, IMT, CVC or LVH. After logistic regression, phosphorus was the only significant metabolic variable impacting CVC in univariate analysis (OR 2.795; 95% CI 1.132-6.905; p = 0.026), as well as in the multivariate analysis (OR 3.572; 95% CI 1.094-11.665; p = 0.035). Analysis by ROC curve showed serum phosphorus > 5.05 mg/dL (AUC 0.748; CI 0.584-0.877; p = 0.05) as the best cutoff point associated with valve heart calcification (sensitivity 78%; negative predictive value 91.3%).

CONCLUSION

Hyperphosphatemia was associated with CVC in HPP patients. Further studies are needed to investigate whether the control of hyperphosphatemia may reduce cardiovascular risk in this population.

The tyrosine kinase inhibitor nilotinib targets discoidin domain receptor 2 in calcific aortic valve stenosis

Background and Purpose

Tyrosine kinase inhibitors (TKI) used to treat chronic myeloid leukaemia (CML) have been associated with cardiovascular side effects, including reports of calcific aortic valve stenosis. The aim of this study was to establish the effects of first and second generation TKIs in aortic valve stenosis and to determine the associated molecular mechanisms.

Experimental Approach

Hyperlipidemic APOE*3Leiden.CETP transgenic mice were treated with nilotinib, imatinib or vehicle. Human valvular interstitial cells (VICs) were isolated and studied in vitro. Gene expression analysis was perfromed in aortic valves from 64 patients undergoing aortic valve replacement surgery.

Key Results

Nilotinib increased murine aortic valve thickness. Nilotinib, but not imatinib, promoted calcification and osteogenic activation and decreased autophagy in human VICs. Differential tyrosine kinase expression was detected between healthy and calcified valve tissue. Transcriptomic target identification revealed that the discoidin domain receptor DDR2, which is preferentially inhibited by nilotinib, was predominantly expressed in human aortic valves but markedly downregulated in calcified valve tissue. Nilotinib and selective DDR2 targeting in VICs induced a similar osteogenic activation, which was blunted by increasing the DDR2 ligand, collagen.

Conclusions and Implications

These findings suggest that inhibition of DDR2 by nilotinib promoted aortic valve thickening and VIC calcification, with possible translational implications for cardiovascular surveillance and possible personalized medicine in CML patients.

Factors associated with aortic valve stenosis in Japanese patients with end-stage kidney disease

Background

Aortic valve stenosis (AS) has a high prevalence and poor prognosis in patients who receive maintenance dialysis. However, few large-scale observational studies in Japan have investigated patients with AS who underwent dialysis. In this study, we investigated the prevalence and factors associated with AS in Japanese patients who underwent dialysis.

Methods

In this cross-sectional analysis, we enrolled patients who underwent dialysis and transthoracic echocardiography between July 1, 2017 and June 30, 2018. Patients with a maximum aortic jet velocity (Vmax) ≥ 2.0 m/s, pressure gradient (PG) between the left ventricle and ascending aorta (mean PG) ≥ 20 mmHg, or aortic valve area (AVA) ≤ 1.0 cm² were categorized into the AS group (G1). Patients with Vmax ≥ 3.0 m/s, mean PG ≥ 20 mmHg, or AVA ≤ 1.0 cm² were categorized into the moderate and severe AS groups (G2). We performed multivariate logistic regression analysis and compared G1 and G2 with the non-AS group to determine the risk factors for AS. We also investigated the risk factors for aortic valve calcification, which is a pre-stage for AS.

Results

Of the 2,786 patients investigated, 555 (20.0%) and 193 (6.9%) were categorized into G1 and G2, respectively. Multivariate logistic regression analysis revealed that age, long-term dialysis, and elevated serum phosphorus levels were associated with AS in both the groups (p < 0.05). These factors were converted into ordinal categories, and a multivariate logistic regression analysis was performed. Patients with serum phosphorus levels measuring 5.0–5.9 mg/dL and > 6.0 mg/dL showed a higher risk of AS than those with serum phosphorus levels measuring < 4.0 mg/dL (odds ratio 2.24, p = 0.01 and odds ratio 2.66, p = 0.005, respectively). Aortic valve calcification was associated with age, long-term dialysis, diabetes mellitus, administration of vitamin D receptor activators, elevated serum calcium levels, and anemia (p < 0.05 for all).

Conclusions

Patients on dialysis showed a high prevalence of AS, which was associated with age, long-term dialysis, and elevated serum phosphorus levels.

Trial registration

UMIN000026756, registered on March 29, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02758-y.

Towards Personalized Therapy of Aortic Stenosis

Calcific aortic stenosis (CAS) is the most common cause of acquired valvular heart disease in adults with no available pharmacological treatment to inhibit the disease progression to date. This review provides an up-to-date overview of current knowledge of molecular mechanisms underlying CAS pathobiology and the related treatment pathways. Particular attention is paid to current randomized trials investigating medical treatment of CAS, including strategies based on lipid-lowering and antihypertensive therapies, phosphate and calcium metabolism, and novel therapeutic targets such as valvular oxidative stress, coagulation proteins, matrix metalloproteinases, and accumulation of advanced glycation end products.

Calcific aortic valve disease: from molecular and cellular mechanisms to medical therapy

Calcific aortic valve disease (CAVD) is a highly prevalent condition that comprises a disease continuum, ranging from microscopic changes to profound fibro-calcific leaflet remodelling, culminating in aortic stenosis, heart failure, and ultimately premature death. Traditional risk factors, such as hypercholesterolaemia and (systolic) hypertension, are shared among atherosclerotic cardiovascular disease and CAVD, yet the molecular and cellular mechanisms differ markedly. Statin-induced low-density lipoprotein cholesterol lowering, a remedy highly effective for secondary prevention of atherosclerotic cardiovascular disease, consistently failed to impact CAVD progression or to improve patient outcomes. However, recently completed phase II trials provide hope that pharmaceutical tactics directed at other targets implicated in CAVD pathogenesis offer an avenue to alter the course of the disease non-invasively. Herein, we delineate key players of CAVD pathobiology, outline mechanisms that entail compromised endothelial barrier function, and promote lipid homing, immune-cell infiltration, and deranged phospho-calcium metabolism that collectively perpetuate a pro-inflammatory/pro-osteogenic milieu in which valvular interstitial cells increasingly adopt myofibro-/osteoblast-like properties, thereby fostering fibro-calcific leaflet remodelling and eventually resulting in left ventricular outflow obstruction. We provide a glimpse into the most promising targets on the horizon, including lipoprotein(a), mineral-binding matrix Gla protein, soluble guanylate cyclase, dipeptidyl peptidase-4 as well as candidates involved in regulating phospho-calcium metabolism and valvular angiotensin II synthesis and ultimately discuss their potential for a future therapy of this insidious disease.

PPAR-Gamma Activation May Inhibit the In Vivo Degeneration of Bioprosthetic Aortic and Aortic Valve Grafts under Diabetic Conditions

BACKGROUND

We aimed to examine the anti-calcification and anti-inflammatory effects of pioglitazone as a PPAR-gamma agonist on bioprosthetic-valve-bearing aortic grafts in a rat model of diabetes mellitus (DM).

METHODS

DM was induced in male Wistar rats by high-fat diet with an intraperitoneal streptozotocin (STZ) injection. The experimental group received additional pioglitazone, and controls received normal chow without STZ (n = 20 each group). Cryopreserved aortic donor grafts including the aortic valve were analyzed after 4 weeks and 12 weeks in vivo for analysis of calcific bioprosthetic degeneration.

RESULTS

DM led to a significant media proliferation at 4 weeks. The additional administration of pioglitazone significantly increased circulating adiponectin levels and significantly reduced media thickness at 4 and 12 weeks, respectively (p = 0.0002 and p = 0.0107, respectively). Graft media calcification was highly significantly inhibited by pioglitazone after 12 weeks (p = 0.0079). Gene-expression analysis revealed a significant reduction in relevant chondro-osteogenic markers osteopontin and RUNX-2 by pioglitazone at 4 weeks.

CONCLUSIONS

Under diabetic conditions, pioglitazone leads to elevated circulating levels of adiponectin and to an inhibition of bioprosthetic graft degeneration, including lower expression of chondro-osteogenic genes, decreased media proliferation, and inhibited graft calcification in a small-animal model of DM.

Prognosis of hemodialysis patients with progressive aortic stenosis: a prospective cohort study

Background

Whether progressive mild to moderate aortic stenosis in hemodialysis patients influences their prognosis has not been elucidated. This prospective cohort study explored whether progressive aortic stenosis predicted the rate of cardiac events and mortality in those patients.

Methods

A total of 283 consecutive hemodialysis patients (no aortic stenosis, 248; progressive aortic stenosis, 35) underwent echocardiography for assessment of aortic stenosis, with a median follow-up period of 4.1 years. Study endpoints were cardiac events, all-cause mortality, and cardiac death. Kaplan–Meier analysis and multivariate Cox proportional hazard analysis were performed to estimate cardiac events, all-cause mortality, and cardiac death.

Results

Cumulative cardiac event rate, all-cause mortality rate, and the rate of cardiac death at 3-year follow-up were 44.9%, 40.5%, and 26.4% in patients with progressive aortic stenosis and 22.1%, 19.0%, and 7.5% in those without aortic stenosis, respectively. Kaplan–Meier analysis demonstrated the cumulative rates of cardiac events and all-cause mortality. And cardiac death was significantly higher in patients with progressive aortic stenosis than in those without aortic stenosis. Multivariate Cox proportional hazard analysis revealed that progressive aortic stenosis was predictive of cardiac events (adjusted hazard ratio 2.47; 95% confidence interval 1.38–4.39) and cardiac death (adjusted hazard ratio 4.21; 95% confidence interval 2.10–8.46). Age, physical activity, C-reactive protein, and serum albumin levels—but not progressive aortic stenosis—predicted all-cause mortality.

Conclusions

The rates of cardiac events and cardiac death were higher in hemodialysis patients with progressive aortic stenosis than in those without aortic stenosis. Furthermore, progressive aortic stenosis predicted cardiac events and cardiac death. Compared with those without aortic stenosis, patients with progressive aortic stenosis had higher all-cause mortality, which was related to their comorbidities.

Trial registration This study was retrospectively registered with University Hospital Medical Information Network Clinical Trials Registry (registration number, UMIN 000024023) at September 12th, 2016.

Cohort study: "Outcomes of kidney transplantation in patients with prosthetic heart valves"

The number of kidney transplant candidates with prosthetic heart valves (PHVs) is increasing. Yet, outcomes of kidney transplantation in these patients are still unclear. This is the first report of post-transplant outcomes in patients with PHVs at time of kidney transplantation. We conducted a matched cohort study among recipients from the multicentric and prospective DIVAT cohort to compare the outcomes in patients with left-sided PHVs at time of transplantation and a group of recipients without PHV matched according to age, dialysis time, initial disease, pretransplant DSA, diabetes, and cardiovascular events. Of 23 018 patients, 92 patients with PHVs were included and compared to 276 patients without PHV. Delayed graft function and postoperative bleeding occurred more frequently in patients with PHVs. Kidney graft survival was similar between groups. 5-year overall survival was 68.5% in patients with PHV vs. 87.9% in patients without PHV [HR, 2.72 (1.57-4.70), P = 0.0004]. Deaths from infection, endocarditis, and bleeding were more frequent in patients with PHV. Mechanical valves, but not bioprosthetic valves, were independent risk factors for mortality [HR, 2.89 (1.68-4.97), P = 0.0001]. Patients with PHV have high mortality rates after kidney transplantation. These data suggest that mechanical valves, but not biological valves, increase risks of post-transplant mortality.

Statin initiation and all-cause mortality in incident statin-naïve dialysis patients

BACKGROUND AND AIMS

Cardiovascular disease is the main cause of death in end-stage kidney disease (ESKD) patients. We aimed to explore the association between statin initiation after starting dialysis and all-cause mortality in statin-naïve ESKD patients.

METHODS

We analyzed nationwide claims data of incident dialysis patients from 2010 to 2017 in South Korea. Patients who had previous cardiovascular events or were administered statins before dialysis were excluded. The study group included dialysis patients receiving statins within 1 year after dialysis initiation. The control group was organized after propensity-score matching with age, sex, time of dialysis initiation, and underlying diabetes mellitus and hypertension. The main outcomes were all-cause mortality and major cardiovascular events.

RESULTS

We included 1596 patients who started statin treatment and 1:1 matched statin-nonusers. During the 9438 person-year follow-up, 468 deaths and 264 major adverse cardiovascular events (MACEs) occurred. Statin initiation was associated with a reduced risk of all-cause mortality (adjusted hazard ratio (aHR) 0.72, 95% confidence interval (CI) 0.60-0.87, p = 0.001), but not with MACE incidence (aHR 1.06, 95% CI 0.83-1.36, p = 0.62). In particular, patients prescribed the recommended dosage of statins according to the Kidney Disease Improving Global Outcomes guidelines showed the lowest mortality risk (aHR 0.55, 95% CI 0.40-0.75, p < 0.001).

CONCLUSIONS

Statin initiation was associated with lower risk of all-cause mortality in statin-naïve ESKD patients. As indication bias may be present in observational study setting, further prospective studies are warranted to validate the association of statin initiation with mortality in incident dialysis cases.

Evaluation of structural valve deterioration and bioprosthetic valve failure utilizing the new European consensus definition in patients undergoing TAVI with first-generation devices: Outcomes beyond 5 years from a single center in Turkey

OBJECTIVE

The long-term durability of transcatheter aortic bioprosthetic valves continues to be a major concern. Standardized criteria of the structural valve deterioration (SVD) and bioprosthetic valve failure (BVF) have recently been defined. Limited studies have evaluated the long-term durability of transcatheter aortic valve implantation (TAVI) according to these new definitions. We aim to analyze the durability of TAVI beyond 5 years and to report the frequency of SVD and BVF.

METHODS

A total of 89 patients who had undergone TAVI and had theoretically completed at least 5 years after the procedure were included. Either a Medtronic CoreValve or an Edwards SAPIEN XT valve were implanted in the patients. New standardized definitions were used to evaluate SVD and BVF.

RESULTS

The mean age of the patients was 78.70±6.95 years. SVD occured in 4 (4.5%) patients during 6 years of follow-up. Severe SVD was observed in 2 patients (2.2%), and these patients had the New York Heart Association class II symptoms. Both patients with severe SVD also met the criteria of BVF. Moderate SVD was observed in 2 patients (2.2%), and these patients had no valve-related symptoms. Of the 4 SVD cases, 2 were associated with increased mean transaortic gradients, whereas the remaining 2 cases were associated with intraprosthetic aortic regurgitation. All patients with SVD are still alive, and none of them have required aortic valve reintervention.

CONCLUSION

Although first-generation TAVI devices were used, we determined the low rate of SVD and BVF at the 6-year follow-up. It may be suggested that there is no major concern associated with TAVI even with first-generation devices regarding long-term durability.

The Emerging Role of Nutraceuticals in Cardiovascular Calcification: Evidence from Preclinical and Clinical Studies

Cardiovascular calcification is the ectopic deposition of calcium-phosphate crystals within the arterial wall and the aortic valve leaflets. This pathological process leads to increased vascular stiffness, reduced arterial elasticity, and aortic valve stenosis, increasing the risk of cardiovascular diseases. Although cardiovascular calcification is an increasing health care burden, to date no medical therapies have been approved for treating or preventing it. Considering the current lack of therapeutic strategies and the increasing prevalence of cardiovascular calcification, the investigation of some nutraceuticals to prevent this pathological condition has become prevalent in recent years. Recent preclinical and clinical studies evaluated the potential anti-calcific role of nutraceuticals (including magnesium, zinc, iron, vitamin K, and phytate) in the progression of vascular calcification, providing evidence for their dietary supplementation, especially in high-risk populations. The present review summarizes the current knowledge and latest advances for nutraceuticals with the most relevant preclinical and clinical data, including magnesium, zinc, iron, vitamin K, and phytate. Their supplementation might be recommended as a cost-effective strategy to avoid nutritional deficiency and to prevent or treat cardiovascular calcification. However, the optimal dose of nutraceuticals has not been identified and large interventional trials are warranted to support their protective effects on cardiovascular disease.

All-cause and cardiovascular mortality in patients undergoing hemodialysis with aortic sclerosis and mild-to-moderate aortic stenosis: A cohort study

BACKGROUND AND AIMS

Mild-to-moderate aortic stenosis (AS) and aortic sclerosis, a precursor of AS, are associated with mortality in the general population; however, their association in patients undergoing hemodialysis with higher morbidity of AS is unknown. Thus, we investigated the mortality of aortic sclerosis and mild-to-moderate AS in patients undergoing hemodialysis.

METHODS

This was a retrospective multicenter cohort study of consecutive patients undergoing hemodialysis at nine dialysis facilities who underwent screening echocardiography between January 2008 and December 2019. We investigated the mortality of patients with aortic sclerosis or mild-to-moderate AS using multivariable Cox proportional hazards regression.

RESULTS

Among 1,878 patients undergoing hemodialysis, those with normal aortic valves, aortic sclerosis, mild AS, moderate AS, severe AS, and prosthetic aortic valves were 844 (45%), 793 (42%), 161 (8.6%), 38 (2.0%), 11 (0.6%), and 31 (1.7%), respectively. After excluding patients with severe AS and prosthetic aortic valves, we performed comparative analysis on 1,836 patients (mean age, 67 years; 66% male). In a median follow-up of 3.6 years, crude death rates (per 100 person-years) were 5.2, 10.6, and 13.0 in patients with normal aortic valves, aortic sclerosis, and mild-to-moderate AS, respectively. Compared with normal aortic valves, both aortic sclerosis and mild-to-moderate AS were associated with all-cause and cardiovascular death: adjusted hazard ratios (95% confidence intervals) were 1.36 (1.13-1.65) and 1.36 (1.02-1.80) for all-cause death; and 1.52 (1.06-2.17) and 1.74 (1.04-2.92) for cardiovascular death, respectively.

CONCLUSIONS

Aortic sclerosis and mild-to-moderate AS were independent risk factors for all-cause and cardiovascular death in patients undergoing hemodialysis.

Evaluation and Management of Aortic Stenosis in Chronic Kidney Disease: A Scientific Statement From the American Heart Association

Aortic stenosis with concomitant chronic kidney disease (CKD) represents a clinical challenge. Aortic stenosis is more prevalent and progresses more rapidly and unpredictably in CKD, and the presence of CKD is associated with worse short-term and long-term outcomes after aortic valve replacement. Because patients with advanced CKD and end-stage kidney disease have been excluded from randomized trials, clinicians need to make complex management decisions in this population that are based on retrospective and observational evidence. This statement summarizes the epidemiological and pathophysiological characteristics of aortic stenosis in the context of CKD, evaluates the nuances and prognostic information provided by noninvasive cardiovascular imaging with echocardiography and advanced imaging techniques, and outlines the special risks in this population. Furthermore, this statement provides a critical review of the existing literature pertaining to clinical outcomes of surgical versus transcatheter aortic valve replacement in this high-risk population to help guide clinical decision making in the choice of aortic valve replacement and specific prosthesis. Finally, this statement provides an approach to the perioperative management of these patients, with special attention to a multidisciplinary heart-kidney collaborative team-based approach.

Genetic and Developmental Contributors to Aortic Stenosis

Aortic stenosis (AS) remains one of the most common forms of valve disease, with significant impact on patient survival. The disease is characterized by left ventricular outflow obstruction and encompasses a series of stenotic lesions starting from the left ventricular outflow tract to the descending aorta. Obstructions may be subvalvar, valvar, or supravalvar and can be present at birth (congenital) or acquired later in life. Bicuspid aortic valve, whereby the aortic valve forms with two instead of three cusps, is the most common cause of AS in younger patients due to primary anatomic narrowing of the valve. In addition, the secondary onset of premature calcification, likely induced by altered hemodynamics, further obstructs left ventricular outflow in bicuspid aortic valve patients. In adults, degenerative AS involves progressive calcification of an anatomically normal, tricuspid aortic valve and is attributed to lifelong exposure to multifactoral risk factors and physiological wear-and-tear that negatively impacts valve structure-function relationships. AS continues to be the most frequent valvular disease that requires intervention, and aortic valve replacement is the standard treatment for patients with severe or symptomatic AS. While the positive impacts of surgical interventions are well documented, the financial burden, the potential need for repeated procedures, and operative risks are substantial. In addition, the clinical management of asymptomatic patients remains controversial. Therefore, there is a critical need to develop alternative approaches to prevent the progression of left ventricular outflow obstruction, especially in valvar lesions. This review summarizes our current understandings of AS cause; beginning with developmental origins of congenital valve disease, and leading into the multifactorial nature of AS in the adult population.

Short-Term Outcomes of Transcatheter Aortic Valve Implantation Versus Surgical Aortic Valve Replacement in Kidney Transplant Recipients (from the US Nationwide Representative Study)

Kidney transplant recipients (KTRs) are considered high-risk patients for surgical interventions. Transcatheter aortic valve implantation (TAVI) has been introduced as an alternative to surgical aortic valve replacement (SAVR) in patients with aortic stenosis (AS) at high operative risk. However, the outcomes of TAVI compared with SAVR KTRs have not been well-studied in nationally representative data. Patients with prior history of functioning kidney transplant who were hospitalized for TAVI and SAVR between January 2012 and December 2017 were identified retrospectively in the Nationwide Readmissions Database. Our study included 762 TAVI and 1,278 SAVR KTRs. Compared with SAVR, TAVI patients generally had higher rates of co-morbidities with lower risk of in-hospital mortality (3.1% vs 6.3, p = 0.002), blood transfusion (11.5% vs 38.6%, p <0.001), acute myocardial infarction (3.9% vs 6.5%, p = 0.16), acute kidney injury (24.5% vs 42.1%, p <0.001), sepsis (3.9% vs 9.5%, p <0.001) and discharge with disability (42.6% vs 68.4%, p <0.001). However, the rate of permanent pacemaker implantation was significantly higher in TAVI group (11.4% vs 3.9%, p <0.001). Of note, in-hospital stroke and 30-day readmission were comparable between both groups. These findings were confirmed after adjusting for other co-morbidities. TAVI is growing as a valid and safe alternative for KTRs with severe AS.

Hyperphosphatemia and Cardiovascular Disease

Hyperphosphatemia or even serum phosphate levels within the “normal laboratory range” are highly associated with increased cardiovascular disease risk and mortality in the general population and patients suffering from chronic kidney disease (CKD). As the kidney function declines, serum phosphate levels rise and subsequently induce the development of hypertension, vascular calcification, cardiac valvular calcification, atherosclerosis, left ventricular hypertrophy and myocardial fibrosis by distinct mechanisms. Therefore, phosphate is considered as a promising therapeutic target to improve the cardiovascular outcome in CKD patients. The current therapeutic strategies are based on dietary and pharmacological reduction of serum phosphate levels to prevent hyperphosphatemia in CKD patients. Large randomized clinical trials with hard endpoints are urgently needed to establish a causal relationship between phosphate excess and cardiovascular disease (CVD) and to determine if lowering serum phosphate constitutes an effective intervention for the prevention and treatment of CVD.

Vascular pathologies in chronic kidney disease: pathophysiological mechanisms and novel therapeutic approaches

Cardiovascular disease (CVD) is a major cause of death in patients with chronic kidney disease (CKD). Both conditions are rising in incidence as well as prevalence, creating poor outcomes for patients and high healthcare costs. Recent data suggests CKD to be an independent risk factor for CVD. Accumulation of uremic toxins, chronic inflammation, and oxidative stress have been identified to act as CKD-specific alterations that increase cardiovascular risk. The association between CKD and cardiovascular mortality is markedly influenced through vascular alterations, in particular atherosclerosis and vascular calcification (VC). While numerous risk factors promote atherosclerosis by inducing endothelial dysfunction and its progress to vascular structural damage, CKD affects the medial layer of blood vessels primarily through VC. Ongoing research has identified VC to be a multifactorial, cell-mediated process in which numerous abnormalities like mineral dysregulation and especially hyperphosphatemia induce a phenotype switch of vascular smooth muscle cells to osteoblast-like cells. A combination of pro-calcifying stimuli and an impairment of inhibiting mechanisms like fetuin A and vitamin K-dependent proteins like matrix Gla protein and Gla-rich protein leads to mineralization of the extracellular matrix. In view of recent studies, intercellular communication pathways via extracellular vesicles and microRNAs represent key mechanisms in VC and thereby a promising field to a deeper understanding of the involved pathomechanisms. In this review, we provide an overview about pathophysiological mechanisms connecting CKD and CVD. Special emphasis is laid on vascular alterations and more recently discovered molecular pathways which present possible new therapeutic targets.

Is there a role for bisphosphonates in vascular calcification in chronic kidney disease?

Theoretically bisphosphonates could accelerate or retard vascular calcification. In subjects with low GFR, the position is further confounded by a combination of uncertain pharmacokinetics (GI absorption is poor and inconsistent at all levels of renal function and the effect of low GFR generally is to increase bioavailability) and a highly variable skeletal substrate with extremes of turnover that increase unpredictably further. Although bisphosphonates reduce bone formation by 70-90% in subjects with normal GFR and reduce the ability of bone to buffer exogenous calcium fluxes, in bisphosphonate treated postmenopausal women accelerated vascular calcification has not been documented. The kidneys assist with this buffering, but the capacity to modulate calcium excretion declines as GFR falls, increasing the risk of hypercalcaemia in the event of high calcium influx. In the ESRD patient, decreased buffering capacity substantially increases the risk of transient hypercalcaemia, especially in the setting of dialysis, and as such may promote vascular calcification which is highly prevalent in the CKD population. Low bone turnover may thus be less of a vascular problem in patients with preserved renal function and a bigger problem when the GFR is low. In patients with stage 4 and 5 CKD, adynamic bone disease associates with the severity and progression of arterial calcification, including coronary artery calcification, and further suppression of bone turnover by a bisphosphonate might exacerbate an already high predisposition to vascular calcification. No convincing signal of harm has emerged from clinical studies thus far. For example 51 individuals with CKD stage 3-4 treated with either alendronate 70 mg per week or placebo for 18 months showed no difference in the rate of vascular calcifications. Conversely an observational study of women with stage 3-4 CKD with pre-existing cardiovascular disease found an increased risk of mortality with a hazard ratio of 1.22 (1.04-1.42) in those given bisphosphonates. Direct suppression of vascular calcification by bisphosphonates is probably confined to etidronate - treatment of soft tissue calcification was a recognized indication for this drug and etidronate markedly reduced progression of vascular calcification in CKD patients. Bisphosphonates are analogues of pyrophosphate, a potent calcification inhibitor in bone and soft tissue. Thus the efficacy of etidronate as treatment for soft tissue calcification brought with it a problematic tendency to cause osteomalacia. In contrast, conventional doses of nitrogen-containing bisphosphonates fail to yield circulating concentrations sufficient to exert direct anti-calcifying effects, at least in patients with good renal function and studies using alendronate and ibandronate have yielded inconsistent vascular outcomes.

Performance of the heart team approach in daily clinical practice in high-risk patients with aortic stenosis

OBJECTIVE

The heart team (HT) approach plays a key role in selecting the optimal treatment strategy for patients with aortic stenosis (AS). However, little is known about the HT decision process and its impact on outcomes. The aim of this study was to identify the factors associated with the HT decision and evaluate clinical outcomes according to the treatment choice.

METHODS

The study included a total of 286 consecutive patients with AS referred for discussion in the weekly HT meeting in a cardiovascular institute over 2 years. Patients were stratified according to the selected therapeutic approach: medical treatment (MT), surgical (SAVR), or transcatheter (TAVR) aortic valve replacement. Baseline characteristics involved in making a therapeutic choice were identified and a decision-making tree was built using classification and regression tree methodology.

RESULTS

Based on HT discussion, 53 patients were assigned to SAVR, 210 to TAVR, and 23 to MT. Older patients (≥88 years old) were mainly assigned to TAVR or MT according to the logistic EuroSCORE (<or≥28, respectively). While among younger patients (<88 years), significant mitral regurgitation (≥grade III), frailty, Society of Thoracic Surgeons score, and estimated glomerular filtration rate were the most relevant factors influencing treatment allocation. One-year all-cause mortality was 16.6% in the invasive groups (TAVR = 17.2%, SAVR = 14.0%) and 68.7% in the MT arm.

CONCLUSION

The HT decision was determined by well-recognized risk factors that were used to define a treatment decision algorithm. Future studies with younger and lower-risk patients may identify new contributory factors that may alter the selection process and treatment choice.

Advancements in therapeutic drugs targeting of senescence

Aging leads to a high burden on society, both medically and economically. Cellular senescence plays an essential role in the initiation of aging and age-related diseases. Recent studies have highlighted the therapeutic value of senescent cell deletion in natural aging and many age-related disorders. However, the therapeutic strategies for manipulating cellular senescence are still at an early stage of development. Among these strategies, therapeutic drugs that target cellular senescence are arguably the most highly anticipated. Many recent studies have demonstrated that a variety of drugs exhibit healthy aging effects. In this review, we summarize different types of drugs promoting healthy aging – such as senolytics, senescence-associated secretory phenotype (SASP) inhibitors, and nutrient signaling regulators – and provide an update on their potential therapeutic merits. Taken together, our review synthesizes recent advancements in the therapeutic potentialities of drugs promoting healthy aging with regard to their clinical implications.

Malnutrition as a risk factor for cardiac valve calcification in patients under maintenance dialysis: a cross-sectional study

PURPOSE

Cardiac valve calcification (CVC) is a significant risk factor for cardiovascular morbidity and mortality in patients with chronic kidney disease on maintenance hemodialysis. The aim of this study was to investigate the association of several risk factors and particularly of malnutrition on CVC.

METHODS

In this cross-sectional cohort study, we included stable adult patients on maintenance hemodialysis. Calcification of cardiac valves was evaluated using two-dimensional echocardiography. Nutritional assessment and body composition measurements were performed using the MQSGA clinical tool and bioelectrical impedance analysis, respectively. Biochemical parameters such as serum calcium, phosphorus, iPTH, 1.25 hydroxy-vitamin-D, triglycerides, total cholesterol, HDL-C, LDL-C, total proteins, albumin, creatinine and CRP were assessed as potentially risk factors. The receiver operating characteristic (ROC) curve analysis was used to evaluate the prognostic ability of the aforementioned variables on severe degree CVC. Binary logistic regression analysis was also performed to identify independent variables of severe CVC.

RESULTS

Overall, 42 patients were included in the study with half of them exhibiting mitral calcification, 38% aortic valve calcification, and 16.7% calcification in both valves. ROC analysis indicated that aging (p = 0.011), increased CRP (p = 0.038) and decreased value of serum albumin to total proteins ratio (p = 0.012) were positive prognostic factors for moderate to severe degree cardiac valve calcification. Low phase angle was also associated with CVC, although with moderate specificity.

CONCLUSION

Aging, inflammation, low serum albumin to total proteins ratio and low phase angle values as indicators of malnutrition are predictors of severe CVC in end-stage renal disease patients on hemodialysis.

Transcatheter and surgical aortic valve replacement impact on outcomes and cancer treatment schedule

BACKGROUND

Recent data suggest that transcatheter aortic valve replacement (TAVR) for the treatment of severe aortic stenosis (AS) is viable in cancer patients. TAVR may be preferred in cancer patients due to its minimally invasive nature and smaller impact on oncologic therapies compared to SAVR. Objectives We sought to determine if TAVR is an acceptable alternative to SAVR in cancer patients and whether TAVR allows for earlier initiation or resumption of anti-cancer therapies.

METHODS

Cancer patients in a tertiary cancer center diagnosed with severe AS were retrospectively included. Patients accepted by the heart team underwent either TAVR or SAVR, while remaining patients received medical therapy alone. Time intervals to initiation of cancer treatment and the impact of cancer treatment on the replaced valves were recorded. Logistic regression was performed to determine the impact of treatment strategy on overall survival (OS) in all 3 subgroups.

RESULTS

One hundred and eighty-seven cancer patients diagnosed with severe AS were identified. AVR was associated with better OS compared to medical therapy alone (p < 0.0001). TAVR was associated with better OS at 72 months (HR = 0.468, p < 0.001) compared to medical therapy alone, with no difference in OS observed between SAVR and TAVR. Time intervals to initiation of cancer treatments were shorter in the TAVR group, with no valve deterioration or infection observed in all groups.

CONCLUSION

Cancer patients with severe AS benefit from AVR. TAVR is a viable alternative to SAVR in high-risk cancer patients to prolong survival and allow for earlier administration or resumption of anti-neoplastic therapies.

Implications of Renal Disease in Patients Undergoing Structural Interventions

Chronic kidney disease patients have a high prevalence of severe valvular heart disease, which reduces life expectancy. Transcatheter valve interventions has revamped the way we manage severe valvular heart disease and are an attractive alternative to invasive surgery in patients with chronic kidney disease and severe valvular heart disease. This review summarizes the impact of transcatheter valve interventions in patients with severe valvular heart disease and chronic kidney disease.

PCSK9 and HS-CRP Predict Progression of Aortic Stenosis in Patients with Stable Coronary Artery Disease

It is essential to study the factors associated with the evolution of aortic stenosis progression (ASP) to develop therapies that could reduce it. We studied 283 patients 6 months after acute coronary syndrome (ACS). ASP was defined as an increase in the maximum aortic velocity of at least 0.5 m/s between the echocardiogram performed during ACS hospitalization and the last one recorded in the electronic medical registry. The median follow-up was 72.4 months. Twenty patients (7%) had ASP. A multivariate binary logistic regression analysis was performed showing that PCSK9 plasma levels (OR, 0.668 CI (0.457-0.977); p = 0.038), HS-CRP (OR, 1.034 CI (1.005-1.063); p = 0.022), the presence of dyslipidemia (OR, 4.622 CI (1.285-16.618); p = 0.019), the history of PAD (OR, 9.453 CI (1.703-52.452); p = 0.010), and GFR (OR, 0.962 CI (0.939-0.986); p = 0.002) were independent predicting factors of ASP. In patients with ischemic heart disease, low plasma levels of PCSK9 and elevated levels of HS-CRP are independent predictors of ASP.

Association of aortic valve calcification with carotid artery lesions and peripheral artery disease in patients with chronic kidney disease: a cross-sectional study

Background

Patients with chronic kidney disease (CKD) reportedly have a high prevalence of aortic valve calcification (AVC). In population-based studies, AVC is considered a manifestation of systemic atherosclerosis. The association of AVC with atherosclerotic lesions has not been fully investigated in predialysis patients. The present study was performed to determine whether carotid artery lesions and peripheral artery disease (PAD) are associated with AVC in patients with CKD not on dialysis.

Methods

In total, 749 patients were included in this cross-sectional study. AVC was evaluated using echocardiography. Carotid artery lesions including carotid artery plaque (CAP) and PAD were simultaneously examined in each patient. A logistic regression analysis was applied to determine the factors associated with AVC.

Results

AVC, CAP, and PAD were found in 201, 583, and 123 patients, respectively. In the multivariable analyses adjusted for covariates including the estimated glomerular filtration rate and makers of mineral metabolism (serum calcium, serum phosphorus, parathyroid hormone, 1,25-dihydroxyvitamin D, and fibroblast growth factor 23), AVC was significantly associated with the presence of CAP [odds ratio (OR), 3.37; 95% confidence interval (CI), 1.43–7.95], the presence of PAD (OR, 1.76; 95% CI, 1.10–2.81), the CAP score (per 1.0-point increase) (OR, 1.06; 95% CI, 1.02–1.11), and the ankle-brachial blood pressure index (per 0.1-point increase) (OR, 0.83; 95% CI, 0.72–0.95).

Conclusions

AVC was associated with atherosclerotic lesions independent of kidney function and mineral metabolism. We consider that this association between AVC and atherosclerosis might reflect the burden of shared atherosclerotic risk factors.

The Role of Sclerostin in Bone and Ectopic Calcification

Sclerostin, a 22-kDa glycoprotein that is mainly secreted by the osteocytes, is a soluble inhibitor of canonical Wnt signaling. Therefore, when present at increased concentrations, it leads to an increased bone resorption and decreased bone formation. Serum sclerostin levels are known to be increased in the elderly and in patients with chronic kidney disease. In these patient populations, there is a high incidence of ectopic cardiovascular calcification. These calcifications are strongly associated with cardiovascular morbidity and mortality. Although data are still controversial, it is likely that there is a link between ectopic calcification and serum sclerostin levels. The main question, however, remains whether sclerostin exerts either a protective or deleterious role in the ectopic calcification process.

Zinc ameliorates human aortic valve calcification through GPR39 mediated ERK1/2 signalling pathway

AIMS

Calcific aortic valve disease (CAVD) is the most common heart valve disease in the Western world. It has been reported that zinc is accumulated in calcified human aortic valves. However, whether zinc directly regulates CAVD is yet to be elucidated. The present study sought to determine the potential role of zinc in the pathogenesis of CAVD.

METHODS AND RESULTS

Using a combination of a human valve interstitial cell (hVIC) calcification model, human aortic valve tissues, and blood samples, we report that 20 μM zinc supplementation attenuates hVIC in vitro calcification, and that this is mediated through inhibition of apoptosis and osteogenic differentiation via the zinc-sensing receptor GPR39-dependent ERK1/2 signalling pathway. Furthermore, we report that GPR39 protein expression is dramatically reduced in calcified human aortic valves, and there is a significant reduction in zinc serum levels in patients with CAVD. Moreover, we reveal that 20 μM zinc treatment prevents the reduction of GPR39 observed in calcified hVICs. We also show that the zinc transporter ZIP13 and ZIP14 are significantly increased in hVICs in response to zinc treatment. Knockdown of ZIP13 or ZIP14 significantly inhibited hVIC in vitro calcification and osteogenic differentiation.

CONCLUSIONS

Together, these findings suggest that zinc is a novel inhibitor of CAVD, and report that zinc transporter ZIP13 and ZIP14 are important regulators of hVIC in vitro calcification and osteogenic differentiation. Zinc supplementation may offer a potential therapeutic strategy for CAVD.

Urea level is an independent predictor of mortality in patients with severe aortic valve stenosis

Introduction

Severe aortic stenosis (AS) is the most common valvular heart disease in the western world. Various factors are related to severe AS prognosis, including chronic kidney disease. The aim of this study was to evaluate the prognostic value of urea level in patients with severe AS.

Methods

We prospectively enrolled 142 patients (79.1±9.4 years, 88 women) with severe AS (mean valve area 0.67± 0.17 cm²). Clinical assessment, blood tests and echocardiography were performed at enrollment and follow up. The patient population was divided into low and high urea level groups, according to the median urea level at enrollment (72 patients, mean urea 35.5±6.2 mg/dL and 70 patients, mean urea 61.1±17.8 mg/dL, respectively). Hundred and twelve patients (79%) underwent aortic valve intervention. The primary endpoint was all-cause and cardiovascular mortality.

Outcomes

During follow-up of 37±19.5 months, 56 (37.1%) patients died, 39 due to cardiovascular causes. In univariate analysis, age, urea level, creatinine, New York Heart Association (NYHA) class and aortic valve intervention were associated with all-cause mortality. However, in multivariate analysis only aortic valve intervention and blood urea were independent predictors of all-cause mortality (HR 0.494; 95% CI 0.226–0.918, P = 0.026 and HR 1.015; 95% CI 1.003–1.029, P = 0.046 respectively). Urea level, NYHA class and age were also significant predictors of cardiovascular mortality. Whereas, in multivariate analysis, only urea level predicted cardiovascular mortality in these patients (HR 1.017; CI 1.003–1.031 P = 0.019).

Conclusions

Blood urea, a generally readily available and routinely determined marker of renal function, is an independent prognostic factor in patients with severe AS.

Renal Transplantation after Transcatheter Aortic Valve Replacement: Case Report

Patients with chronic kidney disease (CKD) have an increased likelihood of developing calcific aortic stenosis (AS). These patients also often suffer from multiple comorbidities, potentially making them high-risk surgical candidates and limiting their treatment options. Transcatheter aortic valve replacement (TAVR) is the recommended therapeutic approach for severe AS in patients who are not suitable candidates for surgical aortic valve replacement (SAVR). TAVR is being increasingly considered as a viable alternative to SAVR. As such, its applications in patients with CKD and other chronic diseases, as well as methods to optimize peri- and postoperative results are of great interest and significance. We present the case of a successful renal transplant procedure, performed within a year following a TAVR, in a 52-year-old man who suffered from multiple comorbidities.

Pseudoxanthoma Elasticum: An Interesting Model to Evaluate Chronic Kidney Disease-Like Vascular Damage without Renal Disease

Background

Pseudoxanthoma elasticum (PXE; OMIM 264800) is an inherited multisystem disorder associated with accumulation of mineralized and fragmented elastic fibers in the skin, vascular walls, and brush membrane in the eye. Carriers exhibit characteristic lesions in the cardiovascular system, and peripheral and coronary arterial disease as well as mitral valvulopathy often present as a cardiovascular feature of this disease. PXE and chronic kidney disease (CKD) share some common patterns in the vascular damage and in therapeutic approaches as well.

Summary

To date, treating PXE has focused more on careful follow-up examinations with retinal specialists and cardiologist, avoiding long-term anticoagulation. Like CKD, maintaining a low-calcium diet, increasing dietary magnesium, and administering phosphate binders such as aluminum hydroxide or sevelamer may yield a modest benefit. Recently, 4-phenylbutyrate acid (4-PBA) has demonstrated a maturation of ABCC6 mutant effects into the plasma membrane. Moreover, in a humanized mouse model of PXE, 4-PBA administration restored the physiological function of ABCC6 mutants, resulting in enhanced calcification inhibition and thus a promising strategy for allele-specific therapy of ABCC6-associated calcification disorders.

Key Message

Vascular compromise in PXE patients share some components similar to CKD.

[The renin-angiotensin-aldosterone system as a potential target for therapy in patients with calcific aortic stenosis: a literature review]

Calcific aortic valve stenosis (CAVS) is a serious socio-economic problem in developed countries because this disease is the most common indication for aortic valve replacement. Currently, there are no methods for non-invasive treatment of CAVS. Nevertheless, it is assumed that effective drug therapy for CAVS can be developed on the basis of modulators of the renin-angiotensin-aldosterone system (RAAS), which is involved in the pathogenesis of this disease. The purpose of this paper is to compile and analyze current information on the role of RAAS in the CAVS pathophysiology. Recent data on the effectiveness of RAAS inhibition are reviewed.

Modifying Phosphate Toxicity in Chronic Kidney Disease

Phosphate toxicity is a well-established phenomenon, especially in chronic kidney disease (CKD), where hyperphosphatemia is a frequent occurrence when CKD is advanced. Many therapeutic efforts are targeted at phosphate, and comprise dietary intervention, modifying dialysis schemes, treating uncontrolled hyperparathyroidism and importantly, phosphate binder therapy. Despite all these interventions, hyperphosphatemia persists in many, and its pathological influence is ongoing. In nephrological care, a somewhat neglected aspect of treatment-when attempts fail to lower exposure to a toxin like phosphate-is to explore the possibility of "anti-dotes". Indeed, quite a long list of factors modify, or are mediators of phosphate toxicity. Addressing these, especially when phosphate itself cannot be sufficiently controlled, may provide additional protection. In this narrative overview, several factors are discussed that may qualify as either such a modifier or mediator, that can be influenced by other means than simply lowering phosphate exposure. A wider scope when targeting phosphate-induced comorbidity in CKD, in particular cardiovascular disease, may alleviate the burden of disease that is the consequence of this potentially toxic mineral in CKD.