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

Valvular calcification in chronic kidney disease: new insights from recent clinical and preclinical studies

Valvular calcification, developing either in the mitral or the aortic valve, is highly prevalent in patients suffering from chronic kidney disease (CKD), in whom their presence correlates with higher cardiovascular and all-cause mortality risk. To date, the exact mechanisms that promote heart valve calcification remain unclear, and none of the treatments tested so far have shown efficacy in preventing valvular fibrocalcific remodelling. It is therefore essential to improve our understanding of the mechanisms involved in the pathological process if we are to find new, effective therapies. The purpose of this review is to (i) summarize our current knowledge of the mechanisms by which CKD and related therapies affect valvular cell activity, (ii) present the latest therapeutic targets identified in preclinical studies, and (iii) discuss the most recent clinical trials evaluating the efficacy of therapies aimed at preventing valvular calcification in CKD.

Calcific aortic stenosis: omics-based target discovery and therapy development

Calcific aortic valve disease (CAVD) resulting in aortic stenosis (AS) is the most common form of valvular heart disease, affecting 2% of those over age 65. Those who develop symptomatic severe AS have an average further lifespan of <2 years without valve replacement, and three-quarters of these patients will develop heart failure, undergo valve replacement, or die within 5 years. There are no approved pharmaceutical therapies for AS, due primarily to a limited understanding of the molecular mechanisms that direct CAVD progression in the complex haemodynamic environment. Here, advances in efforts to understand the pathogenesis of CAVD and to identify putative drug targets derived from recent multi-omics studies [including (epi)genomics, transcriptomics, proteomics, and metabolomics] of blood and valvular tissues are reviewed. The recent explosion of single-cell omics-based studies in CAVD and the pathobiological and potential drug discovery insights gained from the application of omics to this disease area are a primary focus. Lastly, the translation of knowledge gained in valvular pathobiology into clinical therapies is addressed, with a particular emphasis on treatment regimens that consider sex-specific, renal, and lipid-mediated contributors to CAVD, and ongoing Phase I/II/III trials aimed at the prevention/treatment of AS are described.

Unexpected Clinically Relevant Findings Detected via Computed Tomography in Patients with Severe Aortic Stenosis Who Are Candidates for Transcatheter Aortic Valve Replacement

Background: The detection of unexpected findings (UF) during CT scans of patients undergoing TAVR is frequent; however, it is unclear whether such findings have a clinical impact on the TAVR pathway. Methods: We conducted a retrospective, single-center observational study enrolling patients who were candidates for TAVR. All enrolled patients underwent a CT scan before valve implantation. The primary outcome of this study was all-cause mortality, while the secondary outcome was to determine whether the diagnosis of clinically relevant UF on CT scans results in a significant delay in the TAVR procedure. Results: A total of 284 patients were enrolled. Clinically relevant UF were identified in 15% of the patients, with the most common types being pulmonary masses or nodules. During the follow-up period, 83 patients (29.2%) died. The prognosis was worsened by chronic kidney disease (HR 1.76, p = 0.03) and left ventricular dilatation (HR 1.74, p = 0.04), while the diagnosis of clinically relevant UF did not impact all-cause mortality (p = 0.38). No statistically significant differences were found in the delay from the diagnosis of severe aortic stenosis to TAVR between patients with and without clinically relevant UF (p = 0.07), although patients with clinically relevant UF experienced a median delay of approximately 37 days in the TAVR procedure. Conclusions: The presence of clinically relevant UF on preoperative CT scans does not affect all-cause mortality but shows a trend toward increasing the time from diagnosis to the procedure in patients with severe aortic stenosis undergoing TAVR. Further studies are required to confirm these findings in larger patient cohorts.

Transcatheter Aortic Valve Replacement in Aortic Stenosis Patients With New York Heart Association Functional Class III or IV

BACKGROUND

Patients with symptomatic aortic stenosis are a vulnerable population with associated cardiac damage and a significant comorbidity burden. In this study we aimed to determine the rate, factors associated with, and prognostic value of poor functional status (New York Heart Association [NYHA] class III-IV) in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR).

METHODS

This multicenter study included 6363 transarterial TAVR patients, classified according to baseline functional status (NYHA class I or II vs III or IV).

RESULTS

A total of 3800 (60%) patients presented with NYHA class III or IV before the TAVR procedure. Atrial fibrillation (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.11-1.58; P = 0.002), chronic kidney disease (CKD; OR, 1.73; 95% CI, 1.45-2.05; P < 0.001), chronic obstructive pulmonary disease (COPD; OR, 1.65; 95% CI, 1.32-2.05; P < 0.001), reduced left ventricular ejection fraction (OR, 2.28; 95% CI, 1.70-3.05; P < 0.001), and moderate and severe pulmonary hypertension were associated with a poor functional status. At 1-year follow-up, patients with NYHA class III or IV had higher rates of mortality (8.81 per 100 person-years [95% CI, 7.57-10.15] vs 13.12 per 100 person-years [95% CI, 11.80-14.58]; log rank, P < 0.001) and heart failure hospitalization (8.25 per 100 person-years [95% CI, 7.05-9.65] vs 12.5 per 100 person-years [95% CI, 11.24-14.00]; log rank, P = 0.005). Comorbidity factors (COPD, CKD) and signs of cardiac damage (atrial fibrillation, pulmonary hypertension) determined an increased risk of poorer clinical outcomes (P < 0.01 for all).

CONCLUSIONS

More than half of the patients undergoing TAVR in the contemporary era have presented with advanced functional class before the procedure, and this was associated with a greater comorbidity and cardiac damage burden. Patients with poorer baseline functional status exhibited worse clinical outcomes at 1-year follow-up. These findings highlight the need for further study on earlier interventions for patients with aortic stenosis.

Causal associations between kidney function and aortic valve stenosis: a bidirectional Mendelian randomization analysis

BACKGROUND

Aortic valve stenosis (AVS) is currently the most common heart valve disease. The results of observational studies on the incidence of AVS in the renal dysfunction population are contradictory due to the short follow-up period and different diagnostic criteria, etc. This study aimed to explore the causal relationship between kidney function and AVS using Mendelian randomization (MR) analysis.

METHODS

We acquired summary statistics of estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) from the CKDGen Consortium and a study on AVS from the FinnGen biobank. Univariate and multivariable MR analyses were conducted to evaluate the causal associations. The MR-Egger intercept and MR-PRESSO Global test were applied to assess the pleiotropic effects. The heterogeneity of MR results was tested by Cochran's Q statistic. Moreover, the Bonferroni and FDR corrections were performed for multiple tests.

RESULTS

Genetically predicted decreased eGFR may be associated with a raised risk of AVS (OR = 0.045, p = 1.317e-04 by IVW; OR = 0.002, p = 0.004 by MR-Egger, OR = 0.091, p = 0.057 by WM). The causal association still established after multiple comparisons. Quality control analyses indicated the absence of heterogeneity and pleiotropy in our MR research. In addition, the causality of eGFR and AVS remained significant in multivariable MR analysis after adjusting BMI, hypertension, T2DM, LDL-C, and smoking.

CONCLUSION

Our MR study discovered that reduced eGFR may be a causative risk factor for AVS. In addition, the evidence did not support a significant causal association of AVS on kidney function.

Relationship between peak aortic jet velocity and progression of aortic stenosis in patients undergoing hemodialysis

BACKGROUND

The natural history of aortic stenosis (AS) progression, especially before severe AS development, is not well documented. We aimed to investigate the time course of peak aortic jet velocity (Vmax) and AS progression risk according to baseline Vmax, particularly whether there is a Vmax threshold.

METHODS

In a retrospective multicenter cohort study of patients on hemodialysis with aortic valve calcification, we investigated the time series of Vmax and the relationship between the baseline Vmax and progression to severe AS by analyzing longitudinal echocardiographic data.

RESULTS

Among 758 included patients (mean age, 71 years; 65% male), patients with Vmax <1.5, 1.5-1.9, 2.0-2.4, 2.5-2.9, and 3.0-3.9 m/s were 395 (52%), 216 (29%), 85 (11%), 39 (5.1%), and 23 (3.0%), respectively. The Vmax slope was gradual (mean 0.05-0.07 m/s/year) at Vmax <2 m/s, but steeper (mean 0.13-0.21 m/s/year) at Vmax ≥2 m/s. During a median 3.2-year follow-up, 52 (6.9%) patients developed severe AS. While patients with Vmax <2 m/s rarely developed severe AS, the risk of those with Vmax ≥2 m/s increased remarkably with an increasing baseline Vmax; the adjusted incidence rates in patients with Vmax <1.5, 1.5-1.9, 2.0-2.4, 2.5-2.9, and 3.0-3.9 m/s were 0.59, 0.57, 4.25, 13.8, and 56.1 per 100 person-years, respectively; the adjusted hazard ratio per 0.2 m/s increase in the baseline Vmax was 1.49 (95% confidence interval: 1.32-1.68) when Vmax ≥2 m/s.

CONCLUSIONS

The risk of progression to severe AS increased with the baseline Vmax primarily at ≥2 m/s; a Vmax threshold of 2 m/s was observed.

Pre-TAVI imaging: an Italian survey by the CT PRotocol optimization (CT-PRO) group

PURPOSE

The purpose of this survey was to evaluate the current state-of-art of pre-TAVI imaging in a large radiological professional community.

METHODS

Between December 2022 and January 2023 all members of the Italian Society of Medical and Interventional Radiology (SIRM) were invited by the CT PRotocol Optimization group (CT-PRO group) to complete an online 24-item questionnaire about pre-TAVI imaging.

RESULTS

557 SIRM members participated in the survey. The greatest part of respondents were consultant radiologists employed in public hospitals and 84% claimed to routinely perform pre-TAVI imaging at their institutions. The most widespread acquisition protocol consisted of an ECG-gated CT angiography (CTA) scan of the aortic root and heart followed by a non-ECG-synchronized CTA of the thorax, abdomen, and pelvis. Contrast agent administration was generally tailored on the patient's body weight with a preference for using high concentration contrast media. The reports were commonly written by radiologists with expertise in cardiovascular imaging, and included all the measurements suggested by current guidelines for adequate pre-procedural planning. About 60% of the subjects affirmed that the Heart Team is present at their institutions, however only 7% of the respondents regularly attended the multidisciplinary meetings.

CONCLUSIONS

This survey defines the current pre-TAVI imaging practice in a large radiological professional community. Interestingly, despite the majority of radiologists follow the current guidelines regarding acquisition and reporting of pre-TAVI imaging studies, there is still a noteworthy absence from multidisciplinary meetings and from the Heart Team.

Impact of resistance exercise on patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) has become an increasingly important public health disease with a high incidence rate and mortality. Although several studies have explored the effectiveness of resistance exercise in improving the prognosis of CKD patients, the number of studies is still limited and the results are still controversial.

OBJECTIVES

We conducted this meta-analysis of randomized controlled trials (RCT) studies to evaluate the effectiveness of resistance exercise on CKD patients.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched from the inception date to October 2023. The meta-analysis was conducted to evaluate 12 main indicators, including glomerular filtration rate (GFR)(ml/(min•1.73m2)), C-reactive protein (CRP) (mg/L), serum creatinine (mg/dL), hemoglobin (g/dL), Glycosylated Hemoglobin, Type A1C (HBA1c) (%), high Density Lipoprotein (HDL) (mg/dL), low Density Lipoprotein (LDL) (mg/dL), 6-min walk(m), body mass index (BMI) (kg/m2), fat-free mass (kg), fat mass (kg), grip strength (kgf).

RESULTS

Sixteen RCT studies were included in this meta-analysis from 875 records. GFR exhibited no significant change in CKD patients treated with resistance exercise (WMD 1.82; 95%CI -0.59 to 4.23; P = 0.139). However, 6-min walk (WMD 89.93; 95%CI 50.12 to 129.74; P = 0.000), fat-free mass (WMD 6.53; 95%CI 1.14 to 11.93; P = 0.018) and grip strength (WMD 3.97; 95%CI 1.89 to 6.05; P = 0.000) were significantly improved with resistance exercise. The level of CRP (WMD - 2.46; 95%CI -4.21 to -0.72; P = 0.006) and HBA1c (WMD - 0.46; 95%CI -0.63 to -0.29; P = 0.000) dropped significantly after resistance exercise treatment.

CONCLUSIONS

Resistance exercise can improve physical function, metabolic condition, inflammatory response and cardiopulmonary function in CKD patients, specifically reflected in the increase of indicators fat-free mass, grip strength, 6-min walk, as well as the decrease of indicators HBA1c and CRP.

Cardiac Devices and Kidney Disease

A growing variety of cardiac devices are available to monitor or support cardiovascular function. The entwined nature of cardiovascular disease and kidney disease makes the relationship of these devices with kidney disease a multifaceted question relating to the use of these devices in individuals with kidney disease and to the effects of the devices and device placement on kidney health. Cardiac devices can be categorized broadly into cardiac implantable electronic devices, structural devices, and circulatory assist devices. Cardiac implantable electronic devices include devices for monitoring and managing cardiac electrical activity and devices for monitoring hemodynamics. Structural devices modify cardiac structure and include valve prostheses, valve repair clips, devices for treating atrial septal abnormalities, left atrial appendage closure devices, and interatrial shunt devices. Circulatory assist devices support the failing heart or support cardiac function during high-risk cardiac procedures. Evidence for the use of these devices in individuals with kidney disease, effects of the devices on kidney health and function, specific considerations with devices in kidney disease, and important knowledge gaps are surveyed in this article. With the growing prevalence of combined cardiorenal disease and the increasing variety of cardiac devices, kidney disease considerations are an important aspect of device therapy.

Minimally invasive, surgical, and transcatheter aortic valve replacement: A network meta-analysis

BACKGROUND

Transcatheter aortic valve replacement (TAVR) has evolved as an alternative to surgical aortic valve replacement (SAVR). In addition to full-sternotomy (FS), recent reports have shown successful minimally-invasive SAVR approaches, including mini-sternotomy (MS) and mini-thoracotomy (MT). This network-meta-analysis (NMA) seeks to provide an outcomes comparison based on these different modalities (MS, MT, TAVR) compared with FS as a reference arm for the management of aortic valve disease.

METHODS

A comprehensive literature search was performed to identify studies that compared minimally-invasive SAVR (MS/MT) to conventional FS-SAVR, and/or TAVR. Bayesian NMA was performed using the random effects model. Outcomes were pooled as risk ratios (RR) with their 95 % confidence intervals (CIs). Our primary outcomes included 30-day mortality, stroke, acute kidney injury (AKI), major bleeding, new permanent pacemaker (PPM), and paravalvular leak (PVL). We also assessed long-term mortality at the latest follow-up.

RESULTS

A total of 27,117 patients (56 studies) were included; 10,397 patients had FS SAVR, 9523 had MS, 5487 had MT, and 1710 had TAVR. Compared to FS, MS was associated with statistically-significantly lower rates of 30-day mortality (RR, 0.76, 95%CI 0.59-0.98), stroke (RR, 0.84, 95%CI 0.72-0.97), AKI (RR, 0.76, 95%CI 0.61-0.94), and long-term mortality (RR 0.84, 95%CI 0.72-0.97) at a weighted mean follow-up duration of 10.4 years, while MT showed statistically-significantly higher rates of 30-day PVL (RR, 3.76, 95%CI 1.31-10.85) and major bleeding (RR 1.45; 95%CI 1.08-1.94). TAVR had statistically significant lower rates of 30-day AKI (RR 0.49, 95%CI 0.31-0.77), but showed statistically-significantly higher PPM (RR 2.50; 95%CI 1.60-3.91) and 30-day PVL (RR 12.85, 95%CI 5.05-32.68) compared to FS.

CONCLUSIONS

MS was protective against 30-day mortality, stroke, AKI, and long-term mortality compared to FS; TAVR showed higher rates of 30-day PVL and PPM but was protective against AKI. Conversely, MT showed higher rates of 30-day PVL and major bleeding. With the emergence of TAVR, the appropriate benchmarks for SAVR comparison in future trials should be the minimally-invasive SAVR approaches to provide clinical equipoise.

Cardiovascular Consequences of Uremic Metabolites: an Overview of the Involved Signaling Pathways

The crosstalk of the heart with distant organs such as the lung, liver, gut, and kidney has been intensively approached lately. The kidney is involved in (1) the production of systemic relevant products, such as renin, as part of the most essential vasoregulatory system of the human body, and (2) in the clearance of metabolites with systemic and organ effects. Metabolic residue accumulation during kidney dysfunction is known to determine cardiovascular pathologies such as endothelial activation/dysfunction, atherosclerosis, cardiomyocyte apoptosis, cardiac fibrosis, and vascular and valvular calcification, leading to hypertension, arrhythmias, myocardial infarction, and cardiomyopathies. However, this review offers an overview of the uremic metabolites and details their signaling pathways involved in cardiorenal syndrome and the development of heart failure. A holistic view of the metabolites, but more importantly, an exhaustive crosstalk of their known signaling pathways, is important for depicting new therapeutic strategies in the cardiovascular field.

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.

Aortic valve calcification is promoted by interleukin-8 and restricted through antagonizing CXC motif chemokine receptor 2

AIMS

Inflammatory cytokines play a critical role in the progression of calcific aortic valve disease (CAVD), for which there is currently no pharmacological treatment. The aim of this study was to test the hypothesis that interleukin-8 (IL-8), known to be involved in arterial calcification, also promotes aortic valve calcification (AVC) and to evaluate whether pharmacologically blocking the IL-8 receptor, CXC motif chemokine receptor 2 (CXCR2), could be effective in preventing AVC progression.

METHODS AND RESULTS

A cohort of 195 patients (median age 73, 74% men) diagnosed with aortic valve stenosis (severe in 16.9% of cases) were prospectively followed by CT for a median time of 2.6 years. A Cox proportional hazards regression analysis indicated that baseline IL-8 serum concentrations were associated with rapid progression of AVC, defined as an annualized change in the calcification score by CT ≥ 110 AU/year, after adjustment for age, gender, bicuspid anatomy, and baseline disease severity. In vitro, exposure of primary human aortic valvular interstitial cells (hVICs) to 15 pg/mL IL-8 induced a two-fold increase in inorganic phosphate (Pi)-induced calcification. IL-8 promoted NFκB pathway activation, MMP-12 expression, and elastin degradation in hVICs exposed to Pi. These effects were prevented by SCH527123, an antagonist of CXCR2. The expression of CXCR2 was confirmed in hVICs and samples of aortic valves isolated from patients with CAVD, in which the receptor was mainly found in calcified areas, along with MMP-12 and a degraded form of elastin. Finally, in a rat model of chronic kidney disease-associated CAVD, SCH527123 treatment (1 mg/kg/day given orally for 11 weeks) limited the decrease in aortic cusp separation, the increase in maximal velocity of the transaortic jet, and the increase in aortic mean pressure gradient measured by echocardiography, effects that were associated with a reduction in hydroxyapatite deposition and MMP-12 expression in the aortic valves.

CONCLUSION

Overall, these results highlight, for the first time, a significant role for IL-8 in the progression of CAVD by promoting calcification via a CXCR2- and MMP-12-dependent mechanism that leads to elastin degradation, and identify CXCR2 as a promising therapeutic target for the treatment of CAVD.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in dialysis-dependent patients: a meta-analysis

OBJECTIVES

This meta-analysis aims to compare the clinical outcomes of transcatheter aortic valve implantation (TAVI) versus aortic valve replacement (AVR) for aortic stenosis in dialysis-dependent patients.

METHODS

Literature searches employed PubMed, Web of Science, Google Scholar and Embase to identify relevant studies. Bias-treated data were prioritized, isolated and pooled for analysis; raw data were utilized where bias-treated data were unavailable. Outcomes were analysed to assess for study data crossover.

RESULTS

Literature search identified 10 retrospective studies; following data source analysis, five studies were included. Upon pooling of bias-treated data, TAVI was significantly favoured in early mortality [odds ratio (OR), 0.42; 95% confidence interval (95% CI), 0.19-0.92; I2  = 92%; P  = 0.03], 1-year mortality (OR, 0.88; 95% CI 0.80-0.97; I2  = 0%; P  = 0.01), rates of stroke/cerebrovascular events (OR, 0.71; 95% CI 0.55-0.93; I2  = 0%; P  = 0.01) and blood transfusions (OR, 0.36; 95% CI 0.21-0.62; I2  = 86%; P  = 0.0002). Pooling demonstrated fewer new pacemaker implantations in the AVR group (OR, 3.33; 95% CI 1.94-5.73; I2  = 74%; P  ≤ 0.0001) and no difference in the rate of vascular complications (OR, 2.27; 95% CI 0.60-8.59; I2  = 83%; P  = 0.23). Analysis including raw data revealed the length of hospital stay to favour TAVI with a mean difference of -9.20 days (95% CI -15.58 to -2.82; I2  = 97%; P  = 0.005).

CONCLUSION

Bias-treated meta-analysis comparing surgical AVR and TAVI favoured TAVI in early mortality, 1-year mortality, rates of stroke/cerebrovascular events and blood transfusions. There was no difference in the rates of vascular complications; however, TAVI required more pacemaker implantations. Data pooling including raw data revealed that the length of hospital admission favours TAVI.

Focusing on the Native Matrix Proteins in Calcific Aortic Valve Stenosis

Calcific aortic valve stenosis (CAVS) is a widespread valvular heart disease affecting people in aging societies, primarily characterized by fibrosis, inflammation, and progressive calcification, leading to valve orifice stenosis. Understanding the factors associated with CAVS onset and progression is crucial to develop effective future pharmaceutical therapies. In CAVS, native extracellular matrix proteins modifications, play a significant role in calcification in vitro and in vivo. This work aimed to review the evidence on the alterations of structural native extracellular matrix proteins involved in calcification development during CAVS and highlight its link to deregulated biomechanical function.

Beyond Aortic Stenosis: Addressing the Challenges of Multivalvular Disease Assessment

Aortic stenosis (AS) can often coexist with other valvular diseases or be combined with aortic regurgitation (AR), leading to unique pathophysiological conditions. The combination of affected valves can vary widely, resulting in a lack of standardized diagnostic or therapeutic approaches. Echocardiography is crucial in assessing patients with valvular heart disease (VHD), but careful consideration of the hemodynamic interactions between combined valvular defects is necessary. This is important as it may affect the reliability of commonly used echocardiographic parameters, making the diagnosis challenging. Therefore, a multimodality imaging approach, including computed tomography or cardiac magnetic resonance, is often not just beneficial but crucial. It represents the future of diagnostics in this intricate field due to its unprecedented capacity to quantify and comprehend valvular pathology. The absence of definitive data and guidelines for the therapeutic management of AS in the context of multiple valve lesions makes this condition particularly challenging. As a result, an individualized, case-by-case approach is necessary, guided primarily by the recommendations for the predominant valve lesion. This review aims to summarize the pathophysiology of AS in the context of multiple and mixed valve disease, with a focus on the hemodynamic implications, diagnostic challenges, and therapeutic options.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

Perioperative management of aortic stenosis in patients undergoing non-cardiac surgery

Aortic stenosis is one of the most common cardiac valve pathologies in the world and its prevalence increases with age. Although previously associated with increased perioperative mortality, more recent studies suggest that mortality rates may be decreasing. Recent guidelines suggest that major non-cardiac surgery can be performed safely in asymptomatic severe aortic stenosis patients with close hemodynamic monitoring. Among symptomatic patients, the guidelines recommend aortic valve intervention prior to major non-cardiac surgery because of a reduction in the incidence of postoperative heart failure and improved rates of long-term overall survival. This review provides a comprehensive and contemporary review of the perioperative management of patients with severe aortic valve stenosis.

Indoxyl-sulfate activation of the AhR- NF-κB pathway promotes interleukin-6 secretion and the subsequent osteogenic differentiation of human valvular interstitial cells from the aortic valve

BACKGROUND

Calcific aortic stenosis (CAS) is more prevalent, occurs earlier, progresses faster and has worse outcomes in patients with chronic kidney disease (CKD). The uremic toxin indoxyl sulfate (IS) is powerful predictor of cardiovascular mortality in these patients and a strong promoter of ectopic calcification whose role in CAS remains poorly studied. The objective of this study was to evaluate whether IS influences the mineralization of primary human valvular interstitial cells (hVICs) from the aortic valve.

METHODS

Primary hVICs were exposed to increasing concentrations of IS in osteogenic medium (OM). The hVICs' osteogenic transition was monitored by qRT-PCRs for BMP2 and RUNX2 mRNA. Cell mineralization was assayed using the o-cresolphthalein complexone method. Inflammation was assessed by monitoring NF-κB activation using Western blots as well as IL-1β, IL-6 and TNF-α secretion by ELISAs. Small interfering RNA (siRNA) approaches enabled us to determine which signaling pathways were involved.

RESULTS

Indoxyl-sulfate increased OM-induced hVICs osteogenic transition and calcification in a concentration-dependent manner. This effect was blocked by silencing the receptor for IS (the aryl hydrocarbon receptor, AhR). Exposure to IS promoted p65 phosphorylation, the blockade of which inhibited IS-induced mineralization. Exposure to IS promoted IL-6 secretion by hVICs, a phenomenon blocked by silencing AhR or p65. Incubation with an anti-IL-6 antibody neutralized IS's pro-calcific effects.

CONCLUSION

IS promotes hVIC mineralization through AhR-dependent activation of the NF-κB pathway and the subsequent release of IL-6. Further research should seek to determine whether targeting inflammatory pathways can reduce the onset and progression of CKD-related CAS.

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.

Transcatheter Aortic Valve Replacement-Associated Acute Kidney Injury: An Update

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a relatively novel minimally invasive procedure for the treatment of symptomatic patients with severe aortic stenosis. Although it has been proven effective in improving mortality and quality of life, TAVR is associated with serious complications, such as acute kidney injury (AKI).

SUMMARY

TAVR-associated AKI is likely due to several factors such as sustained hypotension, transapical approach, volume of contrast use, and baseline low GFR. This narrative review aims to present an overview of the latest literature and evidence regarding the definition of TAVR-associated AKI, its risk factors, and its impact on morbidity and mortality. The review used a systematic search strategy with multiple health-focused databases (Medline, EMBASE) and identified 8 clinical trials and 27 observational studies concerning TAVR-associated AKI. Results showed that TAVR-associated AKI is linked to several modifiable and nonmodifiable risk factors and is associated with higher mortality. A variety of diagnostic imaging modalities have the potential to identify patients at high risk for development of TAVR-AKI; however, there are no existing consensus recommendations regarding their use as of this time. The implications of these findings highlight the importance of identifying high-risk patients for which preventive measures may play a crucial role, and should be maximized.

KEY MESSAGE

This study reviews the current understanding of TAVR-associated AKI including its pathophysiology, risk factors, diagnostic modalities, and preventative management for patients.

Subtotal Nephrectomy Associated with a High-Phosphate Diet in Rats Mimics the Development of Calcified Aortic Valve Disease Associated with Chronic Renal Failure

Introduction. This study addressed the hypothesis that subtotal nephrectomy associated with a high-phosphorus diet (5/6Nx + P) in rats represents a suitable animal model to mimic the cardiovascular consequences of chronic kidney disease (CKD) including calcified aortic valve disease (CAVD). Indeed, the latter contributes to the high morbidity and mortality of CKD patients and sorely lacks preclinical models for pathophysiological and pharmacological studies. Methods. Renal and cardiovascular function and structure were compared between sham-operated and 5/6 Nx rats + P 10 to 12 weeks after surgery. Results. As expected, 11 weeks after surgery, 5/6Nx + P rats developed CKD as demonstrated by their increase in plasma creatinine and urea nitrogen and decrease in glomerular filtration rate, estimated by using fluorescein-isothiocyanate-labelled sinistrin, anemia, polyuria, and polydipsia compared to sham-operated animals on a normal-phosphorus diet. At the vascular level, 5/6Nx + P rats had an increase in the calcium content of the aorta; a decrease in mesenteric artery dilatation in response to a stepwise increase in flow, illustrating the vascular dysfunction; and an increase in blood pressure. Moreover, immunohistology showed a marked deposition of hydroxyapatite crystals in the aortic valve of 5/6Nx + P rats. Echocardiography demonstrated that this was associated with a decrease in aortic valve cusp separation and an increase in aortic valve mean pressure gradient and in peak aortic valve velocity. Left-ventricular diastolic and systolic dysfunction as well as fibrosis were also present in 5/6Nx + P rats. Conclusion. This study demonstrates that 5/6Nx + P recapitulates the cardiovascular consequences observed in humans with CKD. In particular, the initiation of CAVD was shown, highlighting the interest of this animal model to study the mechanisms involved in the development of aortic stenosis and test new therapeutic strategies at an early stage of the disease.

Microcirculatory tissue oxygenation correlates with kidney function after transcatheter aortic valve implantation-Results from a prospective observational study

Introduction

Kidney dysfunction is common in patients with aortic stenosis (AS) and correction of the aortic valve by transcatheter aortic valve implantation (TAVI) often affects kidney function. This may be due to microcirculatory changes.

Methods

We evaluated skin microcirculation with a hyperspectral imaging (HSI) system, and compared tissue oxygenation (StO₂), near-infrared perfusion index (NIR), tissue hemoglobin index (THI) and tissue water index (TWI) in 40 patients undergoing TAVI versus 20 control patients. HSI parameters were measured before TAVI (t1), directly after TAVI (t2), and on postinterventional day 3 (t3). The primary outcome was the correlation of tissue oxygenation (StO₂) to the creatinine level after TAVI.

Results

We performed 116 HSI image recordings in patients undergoing TAVI for the treatment of severe aortic stenosis and 20 HSI image recordings in control patients. Patients with AS had a lower THI at the palm (p = 0.034) and a higher TWI at the fingertips (p = 0.003) in comparison to control patients. TAVI led to an increase of TWI, but had no uniform enduring effect on StO₂ and THI. Tissue oxygenation StO₂ at both measurement sites correlated negatively with creatinine levels after TAVI at t2 (palm: ρ = -0.415; p = 0.009; fingertip: ρ = -0.519; p < 0.001) and t3 (palm: ρ = -0.427; p = 0.008; fingertip: ρ = -0.398; p = 0.013). Patients with higher THI at t3 reported higher physical capacity and general health scores 120 days after TAVI.

Conclusion

HSI is a promising technique for periinterventional monitoring of tissue oxygenation and microcirculatory perfusion quality, which are related to kidney function, physical capacity, and clinical outcomes after TAVI.

Clinical trial registration

https://drks.de/search/de/trial, identifier DRKS00024765.

Management of cardiac diseases in liver transplant recipients: Comprehensive review and multidisciplinary practice-based recommendations

Cardiac diseases are one of the most common causes of morbidity and mortality following liver transplantation (LT). Prior studies have shown that cardiac diseases affect close to one-third of liver transplant recipients (LTRs) long term and that their incidence has been on the rise. This rise is expected to continue as more patients with advanced age and/or non-alcoholic steatohepatitis undergo LT. In view of the increasing disease burden, a multidisciplinary initiative was developed to critically review the existing literature (between January 1, 1990 and March 17, 2021) surrounding epidemiology, risk assessment, and risk mitigation of coronary heart disease, arrhythmia, heart failure, and valvular heart disease and formulate practice-based recommendations accordingly. In this review, the expert panel emphasizes the importance of optimizing management of metabolic syndrome and its components in LTRs and highlights the cardioprotective potential for the newer diabetes medications (e.g., sodium glucose transporter-2 inhibitors) in this high-risk population. Tailoring the multidisciplinary management of cardiac diseases in LTRs to the cardiometabolic risk profile of the individual patient is critical. The review also outlines numerous knowledge gaps to pave the road for future research in this sphere with the ultimate goal of improving clinical outcomes.

Management of Patients With Kidney Disease in Need of Cardiovascular Catheterization: A Scientific Workshop Cosponsored by the National Kidney Foundation and the Society for Cardiovascular Angiography and Interventions

Patients with chronic kidney disease (CKD) are at an increased risk of developing cardiovascular disease (CVD), whereas those with established CVD are at risk of incident or progressive CKD. Compared with individuals with normal or near normal kidney function, there are fewer data to guide the management of patients with CVD and CKD. As a joint effort between the National Kidney Foundation and the Society for Cardiovascular Angiography and Interventions, a workshop and subsequent review of the published literature was held. The present document summarizes the best practice recommendations of the working group and highlights areas for further investigation.

Rapidly Progressive and Catastrophic Calciphylaxis After Mechanical Valve Replacement: An Anticoagulation Dilemma

Warfarin is the only approved anticoagulant after mechanical valve replacement, but it is a well described risk factor for calciphylaxis among patients with end-stage kidney disease. Our patient with end-stage kidney disease rapidly developed calciphylaxis after dual mechanical valve replacement in association with warfarin initiation, posing significant challenges in clinical management and a fatal outcome. (Level of Difficulty: Intermediate.).

S2 Heart Sound Detects Aortic Valve Calcification Independent of Hemodynamic Changes in Mice

Background

Calcific aortic valve disease (CAVD) is often undiagnosed in asymptomatic patients, especially in underserved populations. Although artificial intelligence has improved murmur detection in auscultation exams, murmur manifestation depends on hemodynamic factors that can be independent of aortic valve (AoV) calcium load and function. The aim of this study was to determine if the presence of AoV calcification directly influences the S2 heart sound.

Methods

Adult C57BL/6J mice were assigned to the following 12-week-long diets: (1) Control group (n = 11) fed a normal chow, (2) Adenine group (n = 4) fed an adenine-supplemented diet to induce chronic kidney disease (CKD), and (3) Adenine + HP (n = 9) group fed the CKD diet for 6 weeks, then supplemented with high phosphate (HP) for another 6 weeks to induce AoV calcification. Phonocardiograms, echocardiogram-based valvular function, and AoV calcification were assessed at endpoint.

Results

Mice on the Adenine + HP diet had detectable AoV calcification (9.28 ± 0.74% by volume). After segmentation and dimensionality reduction, S2 sounds were labeled based on the presence of disease: Healthy, CKD, or CKD + CAVD. The dataset (2,516 S2 sounds) was split subject-wise, and an ensemble learning-based algorithm was developed to classify S2 sound features. For external validation, the areas under the receiver operating characteristic curve of the algorithm to classify mice were 0.9940 for Healthy, 0.9717 for CKD, and 0.9593 for CKD + CAVD. The algorithm had a low misclassification performance of testing set S2 sounds (1.27% false positive, 1.99% false negative).

Conclusion

Our ensemble learning-based algorithm demonstrated the feasibility of using the S2 sound to detect the presence of AoV calcification. The S2 sound can be used as a marker to identify AoV calcification independent of hemodynamic changes observed in echocardiography.

The Stockholm CREAtinine Measurements (SCREAM) project: Fostering improvements in chronic kidney disease care

SCREAM (Stockholm CREAtinine Measurements project) was initiated in 2010 in collaboration with the healthcare provider of Stockholm County healthcare to quantify potential medication errors, estimate the burden of chronic kidney disease (CKD) and to illustrate the value of incorporating measures of kidney function into the medical decision process. Because most patients are unaware of their CKD and diagnoses are seldom issued, SCREAM took advantage of the commonness of serum/plasma creatinine testing, which can be used to estimate the glomerular filtration rate (eGFR) and classify the stage of CKD severity. SCREAM is periodically updated, and at present contains healthcare information of all residents in Stockholm region during 2006-2019 (about 3 million people), enriched with a broad range of laboratory measurements for those in whom creatinine or albuminuria has been measured (about 1.8 million people). This health information was linked with national administrative and quality registries via the unique personal identification number of each Swedish citizen, conforming the richest characterization in Sweden of the population's journey through health and disease. This review discusses the context of its creation, strengths and weakness, key findings and plans for the future. We summarize our findings related to the burden of CKD in Sweden, its adverse health risks (such as risk of infections, cancer or dementia) and how underlying kidney function alters the risk-benefit ratio of common medications. Results have had clinical impact and demonstrate the importance of population-based research in the spectrum of clinical research to improve health.

Trans-Apical Transcatheter Aortic Valve Replacement in a Dialysis Patient with Systolic Heart Failure

Mortality and morbidity remain high following transcatheter aortic valve replacement (TAVR) in dialysis patients or those with low left ventricular ejection fraction. Therapeutic strategy for those with these comorbidities remains unestablished. We had a dialysis patient with peripheral artery disease and low left ventricular ejection fraction, who received successfully scheduled trans-apical TAVR following sufficient reverse remodeling by 3-month optimal medical therapy. Our strategy should be validated in a larger robust cohort.

Epidemiology of Aortic Stenosis/Aortic Valve Replacement (from the Nationwide Swedish Renal Registry)

Contemporary data on the prevalence and incidence of aortic stenosis (AS) and aortic valve replacement (AVR) in patients initiating dialysis are scarce. This observational cohort study aimed to estimate (1) the point prevalence of AS and AVR at dialysis start and (2) the AS incidence and associated factors prospective to dialysis initiation. The study included 14,550 patients initiating dialysis registered in the Swedish Renal Registry between 2005 and 2018. AS was defined by the International Statistical Classification of Diseases, Tenth Revision codes, and AVR by the surgical procedure codes. Associations between covariates and outcomes were assessed in Cox regression models. The median age was 68 (57 to 77), 66% were males, and the point prevalence of AS and AVR was 3.4% and 1.1%, respectively. In those without known AS/AVR at dialysis initiation (n = 14,050), AS was diagnosed in 595 patients (incidence 16.3/1000 person-years, 95% confidence interval [CI] 15.1 to 17.7/1,000 person-years) during a median follow-up of 2.7 years (interquartile range 1.1 to 5.7). In adjusted Cox regression models, higher age (hazard ratio [HR] 1.03, 95% CI 1.02 to 1.04), male gender (HR 1.51, 95% CI 1.25 to 1.83), atrial fibrillation (HR 1.32, 95% CI 1.06 to 1.64), and hypertension (HR 1.65, 95% CI 1.03 to 2.65) were associated with incident AS. Peritoneal dialysis patients had a nonsignificant trend toward higher AS risk compared with hemodialysis (HR 1.18, 95% CI 0.99 to 1.40). About 20% of patients (n = 113) diagnosed with incident AS underwent AVR (incidence 3.1/1000 person-years, 95% CI 2.6 to 3.7/1,000). Only the male gender was associated with AVR (HR 2.07, 95% CI 1.30 to 3.30). In conclusion, the prevalence and incidence of AS and AVR in patients initiating dialysis are high. A fifth of newly diagnosed AS underwent AVR after dialysis onset.

Aortic stenosis in chronic kidney disease: challenges in diagnosis and treatment

Chronic kidney disease (CKD) is becoming increasingly common and is associated with development and rapid progression of aortic stenosis (AS). Patients with AS and CKD have higher mortality rates than those with AS of similar severity and normal kidney function. The diagnosis of severe AS in patients with CKD is often challenging due to alterations in haemodynamics and heart structure, and integration of data from multiple imaging modalities may be required. When indicated, the definitive treatment for severe AS is aortic valve replacement. Patients with CKD are candidates for bioprosthetic valve replacement (surgical or transcatheter aortic valve implantation) or mechanical valve replacement. However, for patients with CKD, lifetime management is complex, as patients with CKD have a higher competing risk of bioprosthetic structural valve deterioration, bleeding in the setting of systemic anticoagulation and mortality related to CKD itself. The involvement of a heart-kidney multidisciplinary team in the care of patients with CKD and severe AS is ideal to navigate the complexities of diagnosis and management decisions.

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.