Chronic Kidney Disease and the Pathophysiology of Valvular Heart Disease

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.

Echocardiographic manifestations in end-stage renal disease

End-stage renal disease (ESRD) is a common but profound clinical condition, and it is associated with extremely increased morbidity and mortality. ESRD can represent four major echocardiographic findings-myocardial hypertrophy, heart failure, valvular calcification, and pericardial effusion. Multiple factors interplay leading to these abnormalities, including pressure/volume overload, oxidative stress, and neurohormonal imbalances. Uremic cardiomyopathy is characterized by left ventricular (LV) hypertrophy and marked diastolic dysfunction. In ESRD patients on hemodialysis, LV geometry is changeable bidirectionally between concentric and eccentric hypertrophy, depending upon changes in corporal fluid volume and arterial pressure, which eventually results in a characteristic of LV systolic dysfunction. Speckle tracking echocardiography enabling to detect subclinical disease might help prevent future advancement to heart failure. Heart valve calcification also is common in ESRD, keeping in mind which progresses faster than expected. In a modern era, pericardial effusion observed in ESRD patients tends to result from volume overload, rather than pericarditis. In this review, we introduce and discuss those four echocardiography-assessed findings of ESRD, with which known and conceivable pathophysiologies for each are incorporated.

Novel Perspectives in Chronic Kidney Disease-Specific Cardiovascular Disease

Chronic kidney disease (CKD) affects > 10% of the global adult population and significantly increases the risk of cardiovascular disease (CVD), which remains the leading cause of death in this population. The development and progression of CVD-compared to the general population-is premature and accelerated, manifesting as coronary artery disease, heart failure, arrhythmias, and sudden cardiac death. CKD and CV disease combine to cause multimorbid cardiorenal syndrome (CRS) due to contributions from shared risk factors, including systolic hypertension, diabetes mellitus, obesity, and dyslipidemia. Additional neurohormonal activation, innate immunity, and inflammation contribute to progressive cardiac and renal deterioration, reflecting the strong bidirectional interaction between these organ systems. A shared molecular pathophysiology-including inflammation, oxidative stress, senescence, and hemodynamic fluctuations characterise all types of CRS. This review highlights the evolving paradigm and recent advances in our understanding of the molecular biology of CRS, outlining the potential for disease-specific therapies and biomarker disease detection.

In-hospital outcomes of transcatheter aortic valve replacement in patients with chronic and end-stage renal disease: a nationwide database study

BACKGROUND

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) have been associated with worse outcomes after transcatheter aortic valve replacement (TAVR). With TAVR indications extending to a wider range of patient populations, it is important to understand the current implications of chronic renal insufficiency on clinical outcomes. We aim to determine the impact of CKD and ESRD on in-hospital outcomes after TAVR.

METHODS

We queried the National Inpatient Sample for TAVR performed between 2016 and 2020 using International Classification of Diseases-10th Revision codes. We compared in-hospital mortality and clinical outcomes between three groups: normal renal function, CKD and ESRD. The association between CKD/ESRD and outcomes was tested with multivariable logistic regression analyses, using normal renal function as baseline.

RESULTS

In the five-year study period, 279,195 patients underwent TAVR (mean age 78.9 ± 8.5 years, 44.4% female). Of all patients, 67.1% had normal renal function, 29.2% had CKD, and 3.7% had ESRD. There were significant differences in age, sex, and prevalence of comorbidities across groups. In-hospital mortality was 1.3%. Compared to patients with normal renal function, patients with renal insufficiency had higher in-hospital mortality, with the highest risk found in patients with ESRD (adjusted odds ratio: 1.4 [95% confidence interval: 1.2-1.7] for CKD; adjusted odds ratio: 2.4 [95% confidence interval: 1.8-3.3] for ESRD). Patients with CKD or ESRD had a higher risk of cardiogenic shock, need for mechanical circulatory support, and vascular access complications, compared to those with normal renal function. In addition, patients with ESRD had a higher risk of cardiac arrest and periprocedural acute myocardial infarction. The incidence of conversion to open heart surgery was 0.3% and did not differ between groups. Post-procedural infectious and respiratory complications were more common among patients with CKD or ESRD.

CONCLUSION

Patients with CKD and ESRD are at higher risk of in-hospital mortality, cardiovascular, and non-cardiovascular complications after TAVR. The risk of complications is highest in patients with ESRD and does not result in more frequent conversion to open heart surgery. These results emphasize the importance of individualized patient selection for TAVR and procedural planning among patients with chronic renal insufficiency.

Renal Outcomes Following Transcatheter Mitral Valve Repair - Analysis of COAPT Trial Data

The prevalence of valvular heart disease in the United States has been estimated at 4.2-to-5.6 million, with mitral regurgitation (MR) being the most common lesion. Significant MR is associated with heart failure (HF) and death if left untreated. When HF is present, renal dysfunction (RD) is common and is associated with worse outcomes (ie, it is a marker of HF disease progression). Additionally, a complex interplay exists in patients with HF who also have MR, as this combination further impairs renal function, and the presence of RD further worsens prognosis and often limits guideline-directed management and therapy (GDMT). This has important implications in secondary MR because GDMT is the standard of care. However, with the development of minimally invasive transcatheter mitral valve repair, mitral transcatheter edge-to-edge repair (TEER) has become a new treatment option for secondary MR that is now incorporated into current guidelines published in 2020 that listed mitral TEER as a class 2a recommendation (moderate recommendation with benefit >> risk) as an addition to GDMT in a subset of patients with left ventricular ejection fraction <50%. The Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial, which demonstrated favorable outcomes in secondary MR by adding mitral TEER to GDMT versus GDMT alone, was the evidence base for these guidelines. Considering these guidelines and the understanding that concomitant RD often limits GDMT in secondary MR, there is emerging research studying the renal outcomes from the COAPT trial. This review analyzes this evidence, which could further influence current decision-making and future guidelines.

Prediction of Heart Disease Based on Machine Learning Using Jellyfish Optimization Algorithm

Heart disease is one of the most known and deadly diseases in the world, and many people lose their lives from this disease every year. Early detection of this disease is vital to save people's lives. Machine Learning (ML), an artificial intelligence technology, is one of the most convenient, fastest, and low-cost ways to detect disease. In this study, we aim to obtain an ML model that can predict heart disease with the highest possible performance using the Cleveland heart disease dataset. The features in the dataset used to train the model and the selection of the ML algorithm have a significant impact on the performance of the model. To avoid overfitting (due to the curse of dimensionality) due to the large number of features in the Cleveland dataset, the dataset was reduced to a lower dimensional subspace using the Jellyfish optimization algorithm. The Jellyfish algorithm has a high convergence speed and is flexible to find the best features. The models obtained by training the feature-selected dataset with different ML algorithms were tested, and their performances were compared. The highest performance was obtained for the SVM classifier model trained on the dataset with the Jellyfish algorithm, with Sensitivity, Specificity, Accuracy, and Area Under Curve of 98.56%, 98.37%, 98.47%, and 94.48%, respectively. The results show that the combination of the Jellyfish optimization algorithm and SVM classifier has the highest performance for use in heart disease prediction.

Effect of Myocardial Tissue Characterization Using Native T1 to Predict the Occurrence of Adverse Events in Patients With Chronic Kidney Disease and Severe Aortic Stenosis

Among patients with chronic kidney disease (CKD), aortic stenosis (AS) is associated with a significantly higher rate of mortality. We aimed to evaluate whether diffuse myocardial fibrosis, determined using native T1 mapping, has prognostic utility in predicting major adverse cardiovascular events (MACEs), including all-cause mortality or heart failure hospitalization, in patients with CKD and severe AS who are evaluated for transcatheter aortic valve implantation. Cardiac magnetic resonance with T1 mapping using the modified Look-Locker inversion recovery technique was performed in 117 consecutive patients with severe AS and CKD (stage ≥3). Patients were followed up to determine the occurrence of MACE. The mean age of the 117 patients in the cohort was 82 ± 8 years. Native T1 was 1,055 ms (25th- to 75th percentiles 1,031 to 1,078 ms), which is higher than previously reported in healthy controls. Patients with higher T1 times were more likely to have higher N-terminal pro-B-type natriuretic peptide levels (4,122 [IQR 1,578 to 7,980] pg/ml vs 1,678 [IQR 493 to 2,851] pg/ml, p = 0.005) and a history of heart failure (33% vs 9%, p = 0.034). After median follow-up of 3.4 years, MACE occurred in 71 patients (61%). The Society of Thoracic Surgeons predicted risk of mortality score (hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.02 to 1.12, p = 0.006), native T1 >1,024 ms (HR 2.10, 95% CI 1.09 to 4.06, p = 0.028), and New York Heart Association class (HR 1.56, 95% 1.09 to 2.34, p = 0.016) were independent predictors of MACE. Longer native T1 was associated with MACE occurrence in patients with CKD and severe AS.

Determinants of Aortic Stenosis Progression in Bicuspid and Tricuspid Aortic Valves

Background

Bicuspid aortic valve (BAV) is associated with a faster progression of aortic stenosis (AS). Whether the determinants of AS progression are the same or different in patients with BAV vs tricuspid aortic valve (TAV) is unknown. The aim of this study was to identify the factors associated with the progression of AS in patients with BAV vs patients with TAV.

Methods

Patients with AS were prospectively recruited in the Metabolic Determinants of the Progression of Aortic Stenosis (PROGRESSA) study (ClinicalTrials.gov Identifier: NCT01679431). The haemodynamic progression rate of AS was assessed by the annualized progression rate of peak aortic jet velocity (Vpeak). Univariable and multivariable linear regression analyses were used to identify the factors associated with a faster progression of AS in patients with BAV vs patients with TAV.

Results

There were 79 patients with BAV and 208 patients with TAV. The baseline severity of AS was similar between the 2 groups of patients as well as the annualized progression rate of AS. In patients with BAV, obesity (β = 0.25, P = 0.04), diabetes (β = 0.26, P = 0.02), and BAV with right-noncoronary cusp fusion (β = 0.29, P = 0.01) were found to be independently associated with a faster progression of AS, whereas in patients with TAV, AS baseline severity (baseline Vpeak, β = 0.14, P = 0.04) and chronic kidney disease (β = 0.16, P = 0.02) were significantly associated with AS progression.

Conclusion

Factors associated with progression rate of AS are different in BAV and TAV. The main factors associated with a faster progression of AS appear to be obesity, diabetes, right-noncoronary cusp fusion in patients with BAV vs chronic kidney disease in patients with TAV.

An Approach for Cardiac Coronary Detection of Heart Signal Based on Harris Hawks Optimization and Multichannel Deep Convolutional Learning

Automatic diagnosis of arrhythmia by electrocardiogram has a significant role to play in preventing and detecting cardiovascular disease at an early stage. In this study, a deep neural network model based on Harris hawks optimization is presented to arrive at a temporal and spatial fusion of information from ECG signals. Compared with the initial model of the multichannel deep neural network mechanism, the proposed model of this research has a flexible input length; the number of parameters is halved and it has a more than 50% reduction in computations in real-time processing. The results of the simulation demonstrate that the approach proposed in this research had a rate of 96.04%, 93.94%, and 95.00% for sensitivity, specificity, and accuracy. Furthermore, the proposed approach has a practical advantage over other similar previous methods.

Temporal trends of aortic stenosis and comorbid chronic kidney disease in the province of Quebec, Canada

OBJECTIVE

To investigate temporal trends of chronic kidney disease (CKD) among patients with incident aortic stenosis (AS) and to compare these trends with that of a matched control population.

METHODS

Using the Quebec Integrated Chronic Disease Surveillance System, we performed a population-based nested case-control study including 108 780 patients newly hospitalised with AS and 543 900 age-matched, sex-matched and fiscal year-matched patients without AS from 2000 to 2016 in Quebec (Canada). Three subgroups were considered. Dialysis subgroup had at least two outpatient billing codes of dialysis. The predialysis subgroup had at least one hospital or two billing diagnostic codes of CKD. The remaining individuals were included in the non-CKD subgroup. We estimated overall and sex-specific standardised annual proportions of CKD subgroups through direct standardisation using the 2016-2017 age structure of the incident AS cohort. The trends overtime were estimated through fitting robust Poisson regression models. Age-specific distribution of AS and control population were assessed for each subgroup.

RESULTS

From 2000 to 2016, age-standardised proportions of patients with AS with dialysis and predialysis increased by 41% (99% CI 12.0% to 78.1%) and by 45% (99% CI 39.1% to 51.6%), respectively. Inversely, age-standardised proportions of dialysis and pre-dialysis among non-AS patients decreased by 63% (99% CI 55.8% to 68.7%) and by 32% (99% CI 29.9% to 34.6%), respectively, during the same study period. In patients with and without AS, age-standardised annual proportions of males in predialysis were significantly higher than females in most of the study period. Patients with AS on dialysis and predialysis were younger than their respective controls (dialysis: 29.6% vs 45.1% had ≥80 years, predialysis: 60.8% vs 72.7% had ≥80 years).

CONCLUSIONS

Over time, the proportion of patients with CKD increased significantly and remained consistently higher in incident AS individuals compared with controls. Our results highlight the need to investigate whether interventions targeting CKD risk factors may influence AS incidence in the future.

Ubiquitin-specific protease 47 is associated with vascular calcification in chronic kidney disease by regulating osteogenic transdifferentiation of vascular smooth muscle cells

Chronic kidney disease (CKD) has recently become a serious health and social concern. Vascular calcification, a common complication of CKD, is a risk factor that increases the incidence and mortality of cardiovascular events in patients with CKD. However, there are currently no effective therapeutic targets that can facilitate treatment with fewer side effects for vascular calcification in CKD. To identify potential therapeutic targets, we performed label-free quantification (LFQ) analyses of protein samples from rat aortic vascular smooth muscle cells (RASMCs) after high-phosphorus treatment by nano-UPLC-MS/MS. We determined that ubiquitin-specific protease 47 (USP47) may be associated with CKD vascular calcification by regulating the osteogenic transdifferentiation of the vascular smooth muscle cell (VSMC) phenotype, thus suggesting a novel and potentially effective therapeutic target for CKD vascular calcification. USP47 knockdown significantly reduced the expression of β-transducin repeat-containing protein (BTRC), serine/threonine-protein kinase akt-1 (AKT1), Klotho, fibroblast growth factor (FGF23), and matrix Gla protein (MGP) in RASMCs after high-phosphorus treatment. Consistent with the results of protein-protein interaction (PPI) analyses, USP47 may be involved in regulating osteogenic transdifferentiation markers, such as runt-related transcription factor 2 (RUNX2), Klotho, FGF23, and MGP through the BTRC/AKT1 pathway upon CKD vascular calcification. These data indicate that USP47 may be associated with vascular calcification in CKD by regulating osteogenic differentiation of VSMCs. USP47 may regulate osteogenic transdifferentiation in VSMCs upon CKD vascular calcification through a process involving the BTRC/AKT1 pathway. This study identified a novel potential therapeutic target for the treatment of vascular calcification in CKD.

Valvular Heart Disease in Patients with Chronic Kidney Disease

Valvular heart disease (VHD) is highly prevalent in patients with chronic kidney disease (CKD) from the early stages to end-stage renal disease (ESRD). Aortic and mitral valves are the most frequently affected, leading to aortic valve and/or mitral annular calcification, which, in turn, causes either valve stenosis or regurgitation at an accelerated rate compared with the general population. Tricuspid regurgitation is also prevalent in CKD and ESRD, and haemodialysis patients are at an increasingly high risk of infective endocarditis. As for pathophysiology, several mechanisms causing VHD in CKD have been proposed, highlighting the complexity of the process. Echocardiography constitutes the gold standard for the assessment of VHD in CKD/ESRD patients, despite the progress of other imaging modalities. With regard to treatment, the existing 2017 European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on the management of VHD addressing patients with normal kidney function are also applied to patients with CKD/ESRD.

Myeloid leukocytes' diverse effects on cardiovascular and systemic inflammation in chronic kidney disease

Chronic kidney disease's prevalence rises globally. Whereas dialysis treatment replaces the kidney's filtering function and prolongs life, dreaded consequences in remote organs develop inevitably over time. Even milder reductions in kidney function not requiring replacement therapy associate with bacterial infections, cardiovascular and heart valve disease, which markedly limit prognosis in these patients. The array of complications is diverse and engages a wide gamut of cellular and molecular mechanisms. The innate immune system is profoundly and systemically altered in chronic kidney disease and, as a unifying element, partakes in many of the disease's complications. As such, a derailed immune system fuels cardiovascular disease progression but also elevates the propensity for serious bacterial infections. Recent data further point towards a role in developing calcific aortic valve stenosis. Here, we delineate the current state of knowledge on how chronic kidney disease affects innate immunity in cardiovascular organs and on a systemic level. We review the role of circulating myeloid cells, monocytes and neutrophils, resident macrophages, dendritic cells, ligands, and cellular pathways that are activated or suppressed when renal function is chronically impaired. Finally, we discuss myeloid cells' varying responses to uremia from a systems immunology perspective.

Association between serum cystatin C level and hemodynamically significant aortic stenosis: a prospective cohort study

BACKGROUND

Cystatin C (CysC) is a cysteine protease inhibitor involved in proteins catabolism and plays an essential role in human vascular pathophysiology. CysC may also increase the risk of aortic stenosis (AS), but limited studies have reported on this association. This study aimed to investigate if elevated serum CysC levels are associated with hemodynamically significant AS.

METHODS

Serum CysC levels were estimated in 4,791 participants, samples were collected in 1990-1992. The study population was divided into quintile groups. Follow-up continued in 2011-2013 when participants returned for echocardiography examination. Incidence of aortic valve disease (AVD) was ascertained by Doppler echocardiography through the end of 2013. AVD defined in hemodynamic progression was assessed and classified as aortic sclerosis, mild stenosis, and moderate-to-severe stenosis.

RESULTS

Overall, a total of 4,791 participants (mean age: 54.8 ± 5.0 years, females: 57.6%, blacks: 8.2%) were included in this study. During a follow-up of 21 years, we identified 736 cases (15.4%) of aortic sclerosis, 194 cases (4.0%) of mild stenosis, and 42 cases (0.7%) of moderate-to-severe stenosis. Compared with serum CysC levels within individual quintile groups, the odds ratio (OR) was per standard deviation associated with an increased incidence of AVD (OR = 1.15, 95% CI: 1.05-1.26,P = 0.002).

CONCLUSIONS

In this large population-based study, an increased serum CysC levels is independently associated with the incidence of hemodynamically significant AS. However, this association appears not to extend to patients with extremely high serum CysC levels and necessitate further investigation.

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.

5-Year Outcomes Comparing Surgical Versus Transcatheter Aortic Valve Replacement in Patients With Chronic Kidney Disease

OBJECTIVES

The aim of this study was to compare 5-year cardiovascular, renal, and bioprosthetic valve durability outcomes in patients with severe aortic stenosis (AS) and chronic kidney disease (CKD) undergoing transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR).

BACKGROUND

Patients with severe AS and CKD undergoing TAVR or SAVR are a challenging, understudied clinical subset.

METHODS

Intermediate-risk patients with moderate to severe CKD (estimated glomerular filtration rate <60 mL/min/m²) from the PARTNER (Placement of Aortic Transcatheter Valve) 2A trial (patients randomly assigned to SAPIEN XT TAVR or SAVR) and SAPIEN 3 Intermediate Risk Registry were pooled. The composite primary outcome of death, stroke, rehospitalization, and new hemodialysis was evaluated using Cox regression analysis. Patients with and without perioperative acute kidney injury (AKI) were followed through 5 years. A core laboratory-adjudicated analysis of structural valve deterioration and bioprosthetic valve failure was also performed.

RESULTS

The study population included 1,045 TAVR patients (512 SAPIEN XT, 533 SAPIEN 3) and 479 SAVR patients. At 5 years, SAVR was better than SAPIEN XT TAVR (52.8% vs 68.0%; P = 0.04) but similar to SAPIEN 3 TAVR (52.8% vs 58.7%; P = 0.89). Perioperative AKI was more common after SAVR than TAVR (26.3% vs 10.3%; P < 0.001) and was independently associated with long-term outcomes. Compared with SAVR, bioprosthetic valve failure and stage 2 or 3 structural valve deterioration were significantly greater for SAPIEN XT TAVR (P < 0.05) but not for SAPIEN 3 TAVR.

CONCLUSIONS

In intermediate-risk patients with AS and CKD, SAPIEN 3 TAVR and SAVR were associated with a similar risk for the primary endpoint at 5 years. AKI was more common after SAVR than TAVR, and SAPIEN 3 valve durability was comparable with that of surgical bioprostheses.

Progressive valvular calcifications with critical aortic stenosis in a 25-year-old woman with end-stage renal disease on haemodialysis: a case report

Background 

The increased risk of cardiovascular morbidity and mortality in chronic kidney disease (CKD) and end-stage renal disease (ESRD) seems particularly pronounced in patients with concomitant aortic and mitral valvular calcifications. Valvular calcification (VC) is accelerated in patients with CKD and even more so with ESRD and haemodialysis (HD) due to premature endothelial cell dysfunction. Mineral and bone disorder (CKD-MBD) is a common complication of CKD/ESRD and may play a pivotal role in VC.

Case summary 

A 25-year-old woman with congenital hypoplastic kidneys and ESRD on HD from the age of 19 was admitted to the emergency department suffering from chest pain and dyspnoea. Transthoracic echocardiogram (TTE) revealed critical aortic stenosis (AS) with indexed aortic valve area 0.4 cm²/m², a mean gradient 58 mmHg and a moderate mitral stenosis with a mean gradient 6–8 mmHg developed over the course of 2 years, as a normal TTE was performed at that time. During HD, the patient had longstanding alterations in calcium and phosphate metabolism including secondary hyperparathyroidism that eventually progressed into tertiary hyperparathyroidism. Efforts were made to treat CKD-MBD but patient compliance was low. Subtotal parathyroidectomy was performed 6 months prior to admission. The patient had dual mechanical valve replacement.

Discussion 

Valvular calcification is common in patients with CKD/ESRD and in particular in patients on HD. Rapid progression of valve disease in this case may be related to the combination of low patient adherence and sustained disturbed calcium and phosphate metabolism with tertiary hyperparathyroidism. Transthoracic echocardiogram should be performed in patients on HD even with minor suspicion of VC and in patients with low adherence and disturbance of calcium and phosphate metabolism.

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.

PTH-induced EndMT via miR-29a-5p/GSAP/Notch1 pathway contributed to valvular calcification in rats with CKD

Background

Endothelial‐to‐mesenchymal transition (EndMT) is a common pathophysiology in valvular calcification (VC) among non‐chronic kidney disease (CKD) patients. However, few studies were investigated in CKD‐induced VC. Parathyroid hormone (PTH) was considered to be an important component of EndMT in CKD‐induced cardiovascular diseases. Therefore, determining whether PTH could induce valvular EndMT and elucidating corresponding mechanism involved further study.

Methods

Performing a 5/6 nephrectomy with a high phosphorus diet was done to construct VC models in rats with CKD. miRNA sequencing was used to ascertain changes in microRNA in human umbilical vein endothelial cells (HUVECs) intervened by PTH. VC was observed by Von Kossa staining and scanning electron microscope.

Results

PTH induced valvular EndMT in VC. Global microRNA expression profiling of HUVECs was examined in PTH versus the control in vitro, in which miR‐29a‐5p was most notably decreased and was resumed by PTHrP(7‐34) (PTH‐receptor1 inhibitor). Overexpression of miR‐29a‐5p could inhibit PTH‐induced EndMT in vitro and valvular EndMT in vivo. The dual‐luciferase assay verified that γ‐secretase‐activating protein (GASP) served as the target of miR‐29a‐5p. miR‐29a‐5p‐mimics, si‐GSAP and DAPT (γ‐secretase inhibitor) inhibited PTH‐induced γ‐secretase activation, thus blocking Notch1 pathway activation to inhibit EndMT in vitro. Moreover, Notch1 pathway activation was observed in VC. Blocking Notch1 pathway activation via AAV‐miR‐29a and DAPT inhibited valvular EndMT. In addition, blocking Notch1 pathway activation was also shown to alleviate VC.

Conclusion

PTH activates valvular EndMT via miR‐29a‐5p/GSAP/Notch1 pathway, which can contribute to VC in CKD rats.

Clinical Relevance of Plasma Endogenous Tissue-Plasminogen Activator and Aortic Valve Sclerosis: Performance as a Diagnostic Biomarker

Background: Aortic valve sclerosis (AVSc), a common precursor to calcific aortic valve disease, may progress into advanced aortic stenosis with hemodynamic instability. However, plasma biomarkers of such a subclinical condition remain lacking. Since impaired fibrinolysis featuring dysregulated tissue plasminogen activator (t-PA) is involved in several cardiovascular diseases, we investigated whether endogenous t-PA was also associated with AVSc.

Methods: Plasma t-PA levels were measured in 295 consecutive patients undergoing standard echocardiography and Doppler flow imaging. Multiple logistic regression analyses were used to assess the association between t-PA and AVSc. Receiver operating characteristic curve analysis was performed for determining the diagnostic value of t-PA for AVSc. The performance of adding t-PA to clinical signatures of AVSc was evaluated. Concentration of t-PA was assessed in human sclerotic and non-sclerotic aortic valves by histology and immunohistochemistry analysis.

Results: Plasma t-PA was higher in patients with AVSc than in non-AVSc counterparts (median, 2063.10 vs. 1403.17 pg/mL, p < 0.01). C-statistics of plasma t-PA for discriminating AVSc was 0.698 (95%CI: 0.639–0.758). The performance of t-PA for identifying AVSc was better among male and non-hypertensive patients [C-statistics (95%CI): 0.712 (0.634–0.790) and 0.805 (0.693–0.916), respectively]. Combination of t-PA and clinical factors improved classification of the patients (category-free NRI: 0.452, p < 0.001; IDI: 0.020, p = 0.012). The concentration of t-PA was three times higher in sclerotic compared to non-sclerotic aortic valves.

Conclusion: Elevated circulating t-PA level confers an increased risk for AVSc. Further prospective studies with larger sample size are needed to examine if t-PA could serve as a diagnostic clinical marker for AVSc.

A Rat Model with Multivalve Calcification Induced by Subtotal Nephrectomy and High-Phosphorus Diet

Background

Chronic kidney disease (CKD) with known valve calcification (VC) places individuals at high risk of cardiovascular disease. The study of VC in CKD is challenging due to the lack of a suitable research model. Here, we established a rat model of multivalve calcification induced by subtotal nephrectomy and a high-phosphate (HP) diet and analyzed the valve characteristics.

Methods

We established a CKD model in Sprague-Dawley rats by performing 5/6 nephrectomy (5/6Nx) followed by feeding with chow containing different phosphate concentrations for 8, 12, or 16 weeks. The rats were divided into 4 groups: sham+normal phosphate (NP, 0.9% P), sham+high phosphate (HP, 2.0% P), 5/6Nx+NP, and 5/6Nx+HP. Serum creatinine (Scr), blood urea nitrogen (BUN), parathyroid hormone (PTH), calcium, phosphorus, and 24-h urine protein levels were investigated. Pathological examinations included histological characterization, safranin staining, Alcian blue staining, and von Kossa staining at different time points. Using nanoanalytical electron microscopy, we examined valves from rats in the 5/6Nx+HP and sham+HP groups and detected spherical particles using energy-dispersive spectroscopy (EDS) to observe microscopic changes in the valves. In addition, the calcified tissues were analyzed for phase and crystallization properties using an X-ray powder diffractometer.

Results

The rats in the 5/6Nx+HP and 5/6Nx+NP groups presented with increased levels of Scr, BUN, and 24-h urine protein compared with those of the rats in the sham+HP and sham+NP groups. High levels of PTH were observed, and hematoxylin and eosin staining and immunohistochemistry for proliferating cell nuclear antigen showed parathyroid hyperplasia in rats in the 5/6Nx+HP group but not in the 5/6Nx+NP group. In rats in the 5/6Nx+HP group, extracellular matrix glycosylation was observed in the aortic valve in the 12th week and the mitral valve in the 16th week. In the 16th week, chondrocytes appeared in the aortic valve, as confirmed by immunofluorescence and Western blotting. Calcified particles mainly composed of phosphorus and calcium were observed in both the aortic and mitral valves by transmission electron microscopy and scanning electron microscopy (SEM). The main mineral component of the calcified aortic valve particles was hydroxyapatite [Ca₅(PO₄)₃(OH)], as shown by X-ray diffraction. However, there were no obvious differences in heart function between rats in the 5/6Nx+HP and sham+HP groups.

Conclusions

Our findings demonstrate that multivalve calcification is involved in CKD following 16-week HP and that hydroxyapatite [Ca₅(PO₄)₃(OH)] is the main component of the calcified aortic valve particles of rats in the 5/6Nx+HP group.