Aortic Valve Stenosis: From Basic Mechanisms to Novel Therapeutic Targets

Major Intraprocedural Complications During Transcatheter Aortic Valve Implantation Requiring Emergent Cardiac Surgery: An Updated Systematic Review

Transcatheter aortic valve implantation (TAVI) is an established treatment for patients >75 years old with severe aortic stenosis. From the technique's beginnings in the early 2000s, over 20 years of experience in the TAVI procedure have allowed its wide diffusion with optimal procedural results. Intraprocedural complications during TAVI are yet a fearful scenario, sometimes requiring emergent open-heart surgery (EOHS) that is burdened by high intraoperative mortality (50% at 30 days). Furthermore, also when a surgical treatment is not needed, intraprocedural complications have a challenging management and a critical impact on patients' prognosis. The volume of procedures in the last 10 years has been observed to increase substantially, with an incidence of major intraprocedural complications of around 1%. However, the features and specific incidence for each complication have not been revised recently. This work aims to update the knowledge about major intraprocedural complications during TAVI, considering the increased operators' experience and recent device developments. An updated point of view on major intraprocedural complications could suggest a need for change in the TAVI paradigm, promoting TAVI programs even in centers without on-site cardiac surgery.

miR-210 overexpression increases pressure overload-induced cardiac fibrosis

Aortic stenosis, a common valvular heart disease, can lead to left ventricular pressure overload, triggering pro-fibrotic responses in the heart. miR-210 is a microRNA that responds to hypoxia and ischemia and plays a role in immune regulation and in cardiac remodeling upon myocardial infarction. This study investigated the effects of miR-210 on cardiac fibrosis caused by pressure overload. Using a mouse model with inducible miR-210 over-expression, we subjected mice to transverse aortic constriction (TAC) to induce pressure overload. Mice with miR-210 over-expression developed eccentric hypertrophy, heightened expression of hypertrophic markers (Nppa and Nppb) and increased cross sectional area of cardiomyocytes, impacting the free wall of the left ventricle. These findings suggest that miR-210 worsens cardiac dysfunction. Furthermore, miR-210 over-expression led to a more robust and sustained inflammatory response in the heart, increased interstitial and perivascular fibrosis, and activation of myofibroblasts. miR-210 also promoted angiogenesis. In vitro, cardiac fibroblasts over-expressing miR-210 showed increased adhesion, wound healing and migration capacity. Our results demonstrate that miR-210 contributes to adverse cardiac remodeling in response to pressure overload, including eccentric hypertrophy, inflammation, and fibrosis.

An oxidized chondroitin sulfate-crosslinked and CuCDs-loaded decellularized bovine pericardium with improved anti-coagulation, pro-endothelialization and anti-calcification properties for BHVs

With the growth of the elderly people and the development of transcatheter aortic valve replacement (TAVR) technology, bioprosthetic heart valves (BHVs) originating from the decellularized bovine pericardium (DBP) have become a favourable option for severe valvular heart disease (VHD). However, currently, available commercial bioprosthetic heart valves prepared from glutaraldehyde (GA)-crosslinked xenografts have limited durability because of various factors, including severe cytotoxicity, inflammatory response, poor pro-endothelialization ability and calcification. Therefore, the development of valve materials with better performance is urgent. In this work, we first synthesized Cu-doped carbon dots (CuCDs) with excellent biocompatibility and high stability using sodium citrate, ethylenediamine and copper chloride. Subsequently, oxidized chondroitin sulfate (OCS) was used to crosslink the decellularized bovine pericardium to obtain OCS-BP followed by loading CuCDs onto the surface of this OCS-fixed BP sample through amide bonds formed by an EDC/NHS-catalyzed reaction between the functional groups on CuCDs and OCS-BP to prepare the BHV (CuCDs-OCS-BP) with specific properties. Relevant experiments conducted both in vivo and in vitro indicate that CuCDs-OCS-BP with good stability showed improved mechanical properties, compliance and flexibility, encouraging HUVEC-cytocompatibility, excellent anti-blood cell adhesion, antithrombogenic properties, anti-inflammatory and anti-calcification properties, and a good endothelialisation ability due to the catalytic generation of endogenous nitric oxide. Overall, CuCDs-OCS-BP is a promising material for BHVs.

Sodium-Glucose Cotransporter 2 Inhibitors in Aortic Stenosis: Toward a Comprehensive Cardiometabolic Approach

Aortic stenosis (AS), the most prevalent valvular heart disease, is increasingly recognized as an active disease process driven by a convergence of hemodynamic stress, inflammation, oxidative injury, and metabolic remodeling. While transcatheter and surgical valve replacement remain the standard interventions for severe AS, they fail to reverse the chronic myocardial remodeling that underlies adverse outcomes in many patients. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have emerged as promising cardioprotective agents, with effects extending well beyond glycemic control. Recent mechanistic studies reveal that SGLT2 is expressed in the myocardium of patients with AS and is linked to pathways of fibrosis, inflammation, and energetic dysfunction. Experimental models and translational data demonstrate that SGLT2 inhibition attenuates maladaptive remodeling through modulation of TGF-β, NF-κB, NLRP3 inflammasome, and oxidative stress signaling while enhancing mitochondrial energetics and endothelial function. Importantly, clinical evidence from randomized and real-world studies suggests that SGLT2 inhibitors improve heart failure outcomes following valve replacement and may slow AS progression. This review integrates current pathophysiological insights with emerging molecular and clinical data to delineate the therapeutic rationale for SGLT2 inhibition in AS. By targeting both myocardial and valvular components of the disease, SGLT2 inhibitors may offer a novel disease-modifying strategy with potential implications across the AS continuum-from asymptomatic stages to the post-interventional setting. Ongoing and future trials are warranted to define optimal patient selection, timing, and biomarkers for response to SGLT2 inhibitor therapy in this increasingly high-risk population.

Lipoprotein(a) and aortic stenosis: Practical insights

AIMS

The role of Lp(a) in cardiovascular diseases is increasingly recognized, with high Lp(a) levels shown to be associated with worse outcomes. In this review, we aim to summarize the literature and the current research status regarding AS and Lp(a) with a comprehensive approach, in order to inform basic and clinical scientists with the most up-to-date data and insights.

DATA SYNTHESIS

Lp(a) is significantly involved in the pathogenesis of aortic stenosis (AS), with the interplay between AS and Lp(a) being documented in observational studies and a causal association being proposed based on genetic studies. Patients with AS have generally higher levels of Lp(a) and increased Lp(a) levels are associated with higher risk of AS development. The above observations offer opportunities for further research, mainly regarding potential therapeutic implications, particularly considering the Lp(a)-specific lowering therapies that are awaited to influence the prevention and treatment strategies for AS.

CONCLUSION

Increased Lp(a) levels can be predictive of the presence, development and progression of AS, as well as could offer novel insights in the pathophysiology of bioprosthetic valve function. Further research, focusing on Lp(a)-lowering agents, is key in order to identify any benefit in such patient phenotypes.

Circulating inflammatory cytokines and risk of aortic stenosis: A Mendelian randomization analysis

BACKGROUND

Observational studies have consistently reported positive associations between inflammatory biomarkers and the risk of developing aortic stenosis (AS). However, it is crucial to acknowledge that conventional observational studies are prone to various forms of bias, including reverse causation and residual confounding. To delve deeper into unraveling the potential causal relationship between inflammatory biomarkers and aortic stenosis, we conducted a comprehensive two-sample Mendelian randomization (MR) analysis.

METHODS

In order to explore the causal effect of exposure to various circulating cytokines on the risk of developing AS, we carefully selected AS datasets as the exposures from the summary statistics of the genome-wide association study (GWAS) conducted by FinnGen. The dataset consisted of a sample size of 3283 for AS cases and 210,463 for controls. To estimate the MR analysis, we primarily adopted the inverse variance weighted (IVW) method. Additionally, we employed complementary methods, including Weighted Median, MR Egger, Weighted Mode, and Simple Mode, to analyze the causal associations comprehensively. In order to assess the presence of heterogeneity, we utilized Cochran's Q statistic and MR-Egger regression. To ensure the robustness and consistency of our findings, we conducted a leave-one-out analysis.

RESULT

We observed a positive association between interleukin-18 (IL-18) levels and AS (odds ratio [OR] per standard deviation [SD] = 1.080; 95 % confidence interval [CI] 1.024 to 1.139), as well as between interferon-gamma levels (IFN-γ) and AS (OR per SD = 1.157; 95 % CI 1.028 to 1.302). Conversely, we found an inverse association between interleukin-13 (IL-13) levels and AS (OR per SD = 0.942; 95 % CI 0.890 to 0.997), as well as between interleukin-5 (IL-5) levels and AS (OR per SD = 0.892; 95 % CI 0.804 to 0.990).

CONCLUSION

Our research enhances the current understanding of the role of specific inflammatory biomarker pathways in aortic stenosis. Nevertheless, further validation is required to assess the viability of targeting these cytokines through pharmacological or lifestyle interventions as potential treatments for aortic stenosis.

Trpv4-mediated mechanotransduction regulates the differentiation of valvular interstitial cells to myofibroblasts: implications for aortic valve stenosis

As aortic valve stenosis (AVS) progresses, the valve tissue also stiffens. This increase in tissue stiffness causes the valvular interstitial cells (VICs) to transform into myofibroblasts in response. VIC-to-myofibroblast differentiation is critically involved in the development of AVS. Herein, we investigated the role of mechanosensitive Ca2+-permeant transient receptor potential vanilloid 4 (Trpv4) channels in matrix stiffness- and transforming growth factor β1 (TGFβ1)-induced VIC-myofibroblast activation. We confirmed Trpv4 functionality in primary mouse wild-type VICs compared with Trpv4 null VICs using live Ca2+ influx detection during application of its selective agonist and antagonist. Using physiologically relevant hydrogels of varying stiffness that respectively mimic healthy or diseased aortic valve tissue stiffness, we found that genetic ablation of Trpv4 blocked matrix stiffness- and TGFβ1-induced VIC-myofibroblast activation as determined by changes in morphology, alterations of expression of α-smooth muscle actin, and modulations of F-actin generation. Our results showed that N-terminal residues 30-130 in Trpv4 were crucial for cellular force generation and VIC-myofibroblast activation, while deletion of residues 1-30 had no noticeable negative effect on these processes. Collectively, these data suggest a differential regulatory role for Trpv4 in stiffness/TGFβ1-induced VIC-myofibroblast activation. Our data further showed that Trpv4 regulates stiffness/TGFβ1-induced PI3K-AKT activity that is required for VIC-myofibroblast differentiation and cellular force generation, suggesting a mechanism by which Trpv4 activity regulates VIC-myofibroblast activation. Altogether, these data identify a novel role for Trpv4 mechanotransduction in regulating VIC-myofibroblast activation, implicating Trpv4 as a potential therapeutic target to slow and/or reverse AVS development.NEW & NOTEWORTHY Aortic valve stenosis (AVS) progression involves stiffened valve tissue, driving valvular interstitial cells (VICs) to transform into myofibroblasts. This study highlights the role of Trpv4 channels in VIC activation triggered by matrix stiffness and TGFß1. Using hydrogels mimicking healthy and diseased valves, researchers found that Trpv4 regulates cellular force generation and differentiation via PI3K-AKT activity. These findings identify Trpv4 as a potential therapeutic target to slow or reverse AVS progression.

Immediate transcatheter aortic valve replacement versus temporizing balloon aortic valvuloplasty in severe aortic stenosis: A systematic review and meta-analysis immediate TAVR vs. temporizing BAV

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a first-line therapy for severe aortic stenosis (AS). In patients with contraindications to immediate TAVR, temporizing balloon aortic valvuloplasty (BAV) may be performed to stabilize patients prior to TAVR. The relative efficacy and safety of TAVR with or without temporizing BAV remains inadequately described.

METHODS

We searched PubMed, Embase, and Cochrane databases for studies comparing TAVR with and without temporizing BAV in patients with severe AS. Random-effects models were used to calculate pooled odds, risk ratios (RRs) and mean differences with 95 % confidence intervals (CIs).

RESULTS

Nine studies (59,205 patients: 95.7 % immediate TAVR, 4.3 % BAV + TAVR) met inclusion criteria. Mean age was 82.9 ± 6.6 years old, and 45.9 % were males. Patients in the TAVR group were a mean difference of 1 year younger with no difference in gender distribution between groups. Direct TAVR was associated with a lower risk of 30-day all-cause mortality than BAV + TAVR (RR = 0.62; 95 % CI 0.41 to 0.93; p = 0.02). There were no significant differences in risks of post-procedural pacemaker implantation, myocardial infarction, cardiac tamponade, major vascular complications, ischemic stroke, major bleeding, 2+ or greater aortic regurgitation grade or acute kidney injury.

CONCLUSION

While immediate TAVR was associated with slightly lower short-term mortality compared to BAV + TAVR in patients with severe AS, other binary endpoints were equivalent. This potential mortality difference should be considered when offering BAV + TAVR in patients with contraindications to immediate TAVR. Randomized studies are required to confirm these results.

Diabetes and calcific aortic valve disease: implications of glucose-lowering medication as potential therapy

Calcific aortic valve disease (CAVD) is a progressive disease, of which the 2-year mortality is >50% for symptomatic disease. However, there are currently no pharmacotherapies to prevent the progression of CAVD unless transcatheter or surgical aortic valve replacement is performed. The prevalence of diabetes among CAVD has increased rapidly in recent decades, especially among those undergoing aortic valve replacement. Diabetes and its comorbidities, such as hypertension, hyperlipidemia, chronic kidney disease and ageing, participated jointly in the initiation and progression of CAVD, which increased the management complexity in patients with CAVD. Except from hyperglycemia, the molecular links between diabetes and CAVD included inflammation, oxidative stress and endothelial dysfunction. Traditional cardiovascular drugs like lipid-lowering agents and renin-angiotensin system blocking drugs have proven to be unsuccessful in retarding the progression of CAVD in clinical trials. In recent years, almost all kinds of glucose-lowering medications have been specifically assessed for decelerating the development of CAVD. Based on the efficacy for atherosclerotic cardiovascular disease and CAVD, this review summarized current knowledge about glucose-lowering medications as promising treatment options with the potential to retard CAVD.

PTEN Regulates Myofibroblast Activation in Valvular Interstitial Cells Based on Subcellular Localization

Aortic valve stenosis (AVS) is characterized by altered mechanics of the valve leaflets, which disrupts blood flow through the aorta and can cause left ventricle hypotrophy. These changes in the valve tissue result in the activation of resident valvular interstitial cells (VICs) into myofibroblasts, which have increased levels of αSMA in their stress fibers. The persistence of VIC myofibroblast activation is a hallmark of AVS. In recent years, the tumor suppressor gene phosphatase and tensin homolog (PTEN) has emerged as an important player in the regulation of fibrosis in various tissues (e.g., lung, skin), which motivated to investigate PTEN as a potential protective factor against matrix-induced myofibroblast activation in VICs. In aortic valve samples from humans, high levels of PTEN are found in healthy tissue and low levels of PTEN in diseased tissue. Then, using pharmacological inducers to treat VIC cultures, it is observed that PTEN overexpression prevented stiffness-induced myofibroblast activation, whereas genetic and pharmacological inhibition of PTEN further activated myofibroblasts. The increased nuclear PTEN localization is also observed in VICs cultured on stiff matrices, and nuclear PTEN also correlated with smaller nuclei, altered expression of histones, and a quiescent fibroblast phenotype. Together, these results suggest that PTEN not only suppresses VIC activation, but functions to promote quiescence, and can serve as a potential pharmacological target for the treatment of AVS.

Comprehensive Plasma Proteomic Profiling Reveals Differentially Regulated Signaling Pathways Underlying Left Ventricular Hypertrophy Between Hypertrophic Cardiomyopathy and Aortic Stenosis

Hypertrophic cardiomyopathy (HCM) is the most common genetic myocardial disease, characterized by asymmetric left ventricular hypertrophy (LVH) due to sarcomeric mutations. Aortic stenosis (AS) results in concentric LVH, due to pressure overload. The aim of this study was to identify signaling pathways differentially regulated in HCM compared to AS, using plasma proteomic profiling. 76 HCM cases and 36 AS controls were matched by age and sex. A machine-learning (ML) model to predict HCM was built in the training set (70% cohort) and examined in the test set (30% cohort). Pathway analysis of proteins differentially expressed between HCM and AS was performed. The ML model accurately distinguished HCM from AS, with area under the receiver operating characteristic curve of 0.90 (95% CI: 0.79-1.00). Pathway analysis revealed differential regulation of Ras-MAPK, inflammatory and metabolic pathways. In conclusion, this study identified distinctive proteomic profiles and signaling pathways underlying LVH in HCM compared to AS.

A novel approach to studying infective endocarditis: Ultrasound-guided wire injury and bacterial challenge in mice

BACKGROUND

Infective endocarditis (IE) is frequently caused by Staphylococcus aureus (S. aureus) and most commonly affects the aortic valve. Early diagnosis and treatment initiation are challenging because the involved immunological processes are poorly understood due to a lack of suitable in vivo models.

OBJECTIVES

To establish a novel reproducible murine IE model, based on ultrasound-guided wire injury (WI) induced endothelial damage.

METHODS

IE was established by inducing endothelial damage via ultrasound-guided wire injury followed by bacterial challenge with S. aureus using 104-6 colony-forming units (CFU) 24h to 72h after wire injury. Cross-sections of valvular leaflets were prepared for scanning electron microscopy (SEM) and immunofluorescence microscopy to visualize valvular invasion of macrophages, neutrophils, and S. aureus. Bacterial cultivation was carried out from blood and valve samples. Systemic immune response was assessed using flow cytometry.

RESULTS

Wire injury induced endothelial damage was observed in all mice after wire-injury in SEM imaging. We reliably induced IE using 105 (85%) and 106 (91%) CFU S. aureus after wire injury. Aortic regurgitation was more prevalent in wire injury mice after bacterial challenge. Mice undergoing bacterial challenge responded with significant neutrophilia and elevated pro-inflammatory cytokines in the blood. Immunofluorescence staining revealed significantly increased immune cell accumulations using our proposed model compared to controls.

CONCLUSION

Echocardiography and ex vivo histological staining demonstrated consistent infective endocarditis induction in our new model, combining a wire injury-induced endothelial damage and S. aureus administration. Further exploration of the initial immune cell response and biomarker expression could potentially identify indicators for early IE diagnosis and novel treatment targets.

Telomere Length and Clonal Hematopoiesis of Indeterminate Potential: A Loop Between Two Key Players in Aortic Valve Disease?

Aortic valve stenosis (AVS) is the most common valvular heart disease that was considered, for a long time, a passive degenerative disease due to physiological aging. More recently, it has been recognized as an active, modifiable disease in which many cellular processes are involved. Nevertheless, since aging remains the major risk factor for AVS, a field of research has focused on the role of early (biological) aging and its dependent pathways in the initiation and progression of AVS. Telomeres are regions at the ends of chromosomes that are critical for maintaining genome stability in eukaryotic cells. Telomeres are the hallmarks and molecular drivers of aging and age-related degenerative pathologies. Clonal hematopoiesis of indeterminate potential (CHIP), a condition caused by somatic mutations of leukemia-associated genes in individuals without hematologic abnormalities or clonal disorders, has been reported to be associated with aging. CHIP represents a new and independent risk factor in cardiovascular diseases, including AVS. Interestingly, evidence suggests a causal link between telomere biology and CHIP in several pathological disorders. In this review, we discussed the current knowledge of telomere biology and CHIP as possible mechanisms of aortic valve degeneration. We speculated on how a better understanding of the complex relationship between telomere and CHIP might provide great potential for an early diagnosis and for developing novel medical therapies to reduce the constant increasing health burden of AVS.

Advances in Pathophysiological Mechanisms of Degenerative Aortic Valve Disease

Degenerative aortic valve disease (DAVD) represents the most prevalent valvular ailment among the elderly population, which significantly impacts their physical well-being and potentially poses a lethal risk. Currently, the underlying mechanisms of DAVD remain incompletely understood. While the progression of this disease has traditionally been attributed to degenerative processes associated with aging, numerous recent studies have revealed that heart valve calcification may represent a response of valve tissue to a specific initiating factor, involving the interaction of various genes and signaling pathways. This calcification process is further influenced by a range of factors, including genetic predispositions, environmental exposures, metabolic factors, and hemodynamic considerations. Based on the identification of its biomarkers, potential innovative therapeutic targets are proposed for the treatment of this complex condition. The present article primarily delves into the underlying pathophysiological mechanisms and advancements in diagnostic and therapeutic modalities pertaining to this malady.

Navigating the Landscape of Translational Medicine of Calcific Aortic Valve Disease: Bridging Bench to Bedside

Calcific aortic valve disease (CAVD) is a prevalent condition characterized by pathological thickening and calcification of the aortic valve, leading to increased pressure overload and cardiac remodeling, particularly in individuals aged 65 and older. This review synthesizes recent advances in understanding the pathogenesis of CAVD, focusing on key mechanisms including hemodynamic alterations, endothelial dysfunction, lipid deposition, inflammation, and fibrotic calcification. We evaluate emerging therapeutic targets based on pivotal basic research and clinical trials, highlighting the potential for mechanism-oriented interventions. Furthermore, we explore the implications of lipid-lowering therapies, anti-inflammatory strategies, and antifibrocalcific agents, as well as novel bioprosthetic designs aimed at enhancing patient outcomes. Additionally, we discuss the inherent genetic and molecular backgrounds influencing individual susceptibility to CAVD, emphasizing the promise of personalized therapy. By bridging the gap between basic science and clinical application, this review aims to guide future research efforts toward more effective prevention and treatment strategies for CAVD.

Automated prediction of fibroblast phenotypes using mathematical descriptors of cellular features

Fibrosis is caused by pathological activation of resident fibroblasts to myofibroblasts that leads to aberrant tissue stiffening and diminished function of affected organs with limited pharmacological interventions. Despite the prevalence of myofibroblasts in fibrotic tissue, existing methods to grade fibroblast phenotypes are typically subjective and qualitative, yet important for screening of new therapeutics. Here, we develop mathematical descriptors of cell morphology and intracellular structures to identify quantitative and interpretable cell features that capture the fibroblast-to-myofibroblast phenotypic transition in immunostained images. We train and validate models on features extracted from over 3000 primary heart valve interstitial cells and test their predictive performance on cells treated with the small molecule drugs 5-azacytidine and bisperoxovanadium (HOpic), which inhibited and promoted myofibroblast activation, respectively. Collectively, this work introduces an analytical framework that unveils key features associated with distinct fibroblast phenotypes via quantitative image analysis and is broadly applicable for high-throughput screening assays of candidate treatments for fibrotic diseases.

The Relationship Between Aortic Stenosis and the Possibility of Subsequent Macular Diseases: A Nationwide Database Study

Objectives: This study aimed to investigate the possible relationship between aortic stenosis (AS) occupancy and the incidence of subsequent macular diseases. Methods: A retrospective cohort study was conducted using the TriNetX database, and participants with AS were enrolled and matched to non-AS participants. A total of 421,860 and 421,860 participants were evenly divided into the AS and non-AS groups, respectively. The major outcomes of the present study include the development of age-related macular degeneration (AMD), retinal vascular occlusion (RVO), epiretinal membrane (ERM), and central serous chorioretinopathy (CSC). Cox proportional hazard regression was utilized for statistical analysis. Results: There were 4426 and 3013 AMD events; 7315 and 4753 RVO events; 2780 and 1910 ERM events; and 113 and 64 CSC events in the AS and non-AS groups, respectively. According to the results of Cox proportional hazard regression analysis, the AS group demonstrated significantly higher incidences of all macular diseases, including AMD, RVO, ERM, and CSC, compared to the non-AS group (all p < 0.05). The cumulative probabilities of all macular diseases were significantly higher in the AS group than in the non-AS group (all p < 0.05). In the sensitivity analysis, the developmental risks of AMD were significantly higher in the AS group than in the non-AS group with all traits. Conclusions: This study determined that AS occupancy is related to a higher risk of developing macular diseases, which positively correlated to the disease time of AS.

Y chromosome-linked UTY modulates sex differences in valvular fibroblast methylation in response to nanoscale extracellular matrix cues

Aortic valve stenosis (AVS) is a progressive disease, wherein males more often develop valve calcification relative to females that develop valve fibrosis. Valvular interstitial cells (VICs) aberrantly activate to myofibroblasts during AVS, driving the fibrotic valve phenotype in females. Myofibroblasts further differentiate into osteoblast-like cells and produce calcium nanoparticles, driving valve calcification in males. We hypothesized that the lysine demethylase UTY (ubiquitously transcribed tetratricopeptide repeat containing Y-linked) decreases methylation uniquely in male VICs responding to nanoscale extracellular matrix cues to promote an osteoblast-like cell phenotype. Here, we describe a hydrogel biomaterial cell culture platform to interrogate how nanoscale cues modulate sex-specific methylation states in VICs activating to myofibroblasts and osteoblast-like cells. We found that UTY modulates the osteoblast-like cell phenotype in response to nanoscale cues uniquely in male VICs. Overall, we reveal a previously unidentified role of UTY in the regulation of calcification processes in males during AVS progression.

MicroRNA-143-3p and miR-452-5p: A Fingerprint for the Diagnosis of Aortic Stenosis in the Geriatric Population

Background/Objectives: Aortic stenosis (AS) is the most common valvular pathology in the geriatric population and is the primary cause of valve replacement. However, misdiagnoses and delays in treatment are common due to comorbidities, frailty, and sedentary lifestyles among elderly individuals. MicroRNAs (miRNAs) are highly conserved molecular regulators involved in various cellular processes and have gained recognition as reliable biomarkers in cardiovascular diseases. In the present study, we evaluated plasma miRNAs as potential biomarkers for the early diagnosis of AS in the geriatric population to identify early therapeutic strategies. Methods: This prospective, case-control study included 87 individuals over 75 years of age. The participants were divided into AS (n = 58) and control (n = 29) groups. Results: Fifty-four miRNAs were differentially expressed between patients with AS and controls. Among those genes, 29 were upregulated and 25 were downregulated in patients with AS relative to controls. We selected seven candidate genes (miR-185-5p, miR-143-3p, miR-370-3p, let-7d-3p, miR-452-5p, miR-6787-3p, and miR-21-3p) for experimental validation by qRT-PCR. Only miR-143-3p and miR-452-5p were significantly upregulated in the plasma of patients with AS compared with controls. We developed a multiparametric model by combining the two-miRNA signature with echocardiographic parameters (left ventricular ejection fraction, stroke volume, and global longitudinal strain) to increase diagnostic power; this model yielded sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) values of 78.2%, 70.7%, and 0.837, respectively. Conclusions: In clinical practice, the use of a multiparametric model involving this set of miRNAs combined with echocardiographic variables may improve the accuracy of AS diagnosis and risk stratification.

TREM2 modulates macrophage pyroptosis and inflammatory responses to ameliorate aortic valve calcification

BACKGROUND

Calcific aortic valve disease (CAVD) leads to valve thickening and calcification. Valvular interstitial cells (VICs) play a crucial role in valve homeostasis and their differentiation into osteoblast-like cells is influenced by macrophages. Triggering receptor expressed on myeloid cells 2 (TREM2) is involved in lipid metabolism and inflammation, but its role in CAVD remains unclear.

METHODS

We evaluated TREM2 expression in CAVD using public datasets and clinical aortic valve samples. To investigate the impact and underlying mechanisms of macrophage TREM2 on VIC osteogenic differentiation, we utilized a high-fat diet (HFD)-induced ApoE-/- mouse model and a THP-1-VIC transwell co-culture system.

RESULTS

TREM2 expression was significantly elevated in macrophages within calcified aortic valve tissues from CAVD patients, as determined by bioinformatics, flow cytometry, qRT-PCR, western blot, and immunofluorescence. Inhibition of TREM2 in ApoE-/- mice on an HFD exacerbated aortic valve calcification. Mechanistically, TREM2 inhibition activated the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, promoting pyroptosis and the release of inflammatory cytokines. Additionally, TREM2 downregulation led to reduced phosphorylation of Syk/PI3K/AKT, decreased activity of respiratory chain complexes, impaired oxidative phosphorylation (OXPHOS), diminished ATP production, and increased reactive oxygen species (ROS) levels.

CONCLUSION

TREM2 regulates macrophage oxidative phosphorylation, NLRP3 inflammasome activation, pyroptosis, and inflammatory responses through the PI3K/AKT pathway. This underscores TREM2 as a potential therapeutic target for mitigating aortic valve calcification and slowing the progression of CAVD.

Calcium score association with paravalvular leakage in patients who underwent TAVR, the Mexican values

Objective

The objective is to determinate the association between the degree of aortic valve calcification and the presence of paravalvular leakage (PVL) in Mexican patients who underwent transcatheter aortic valve replacement (TAVR).

Methods

We conducted a retrospective, analytic, cohort. Pooled data were retrospectively analyzed from the patient's files from January 2014 to July 2022. With a median follow-up of 6 months.

Results

We included 83 patients. 31 (37.3%) developed residual PVL. Several factors as male gender (men 58.1% versus women 41.9% p = 0.01), higher gradients previous TAVR (mean 57 mmHg in the group with versus mean 53 mmHg in the group without PVL, p = 0.01), bigger annulus diameters and perimeters as well as reduce left ventricular ejection fraction and a degree of aortic regurgitation previous TAVR were present more frequently in the group of residual PVL. Aortic valve calcification was the only predictor after the bivariate and multivariate analysis that showed an association with the presence of PVL after TAVR. The calculated cut-off value of calcium score was 2970 Agatston units, with a sensitivity of 70% and a specificity of 60% as a predictor for PVL.

Conclusions

The results are consistent with the previous data and there are no greater differences in the Mexican population. The severity of the aortic valve calcification is an independent predictor of PVL in patients who underwent TAVR.

A collagen-based laboratory model to mimic sex-specific features of calcific aortic valve disease

Calcific aortic valve disease (CAVD) shows in the deposition of calcium phosphates in the collagen-rich layer of the valve leaflets. This stiffens the leaflets and eventually leads to heart failure. Recent research suggests that CAVD follows sex-specific pathways: at the same severity of the disease, women tend to have fewer and less crystalline calcifications, and the phases of their calcifications are decidedly different than those of men; namely, dicalcium phosphate dihydrate (DCPD) - one of the mineral phases in CAVD - occurs almost exclusively in females. Furthermore, the morphologies of heart valve calcifications might be sex-specific, but the sex dependence of the morphologies has not been systematically investigated. Herein, we first show that male CAVD patients have more compact and less fibrous calcifications than females, establishing sex-dependent morphological features of heart valve calcification. We then build a model that recapitulates the sex differences of the calcifications in CAVD, which is based on a collagen gel that we calcify in simulated body fluid with varying fetuin A concentrations. With increasing fetuin A concentration, the calcifications become less crystalline and more fibrous, and more DCPD deposits in the collagen matrix, resembling the physicochemical characteristics of the calcifications in female valves. Lower fetuin A concentrations give rise to a model that replicates male-specific mineral characteristics. The models could be used to develop sex-specific detection and treatment methods for CAVD. STATEMENT OF SIGNIFICANCE: Although calcific aortic valve disease (CAVD) affects ∼10 million people globally, researchers have only discovered recently that the disease follows sex-specific pathways, and many of its sex-specific features remain unknown. To further our understanding of sex differences in CAVD and to develop better detection and treatment methods, there is an urgent need to establish models for CAVD that account for its sex-specific manifestations. In this study, we first show that CAVD calcifications in men and women take on different morphologies. Second, we present a model that can replicate physicochemical calcification characteristics of male or female valves, including morphology, and that can help to develop sex-specific detection and treatment methods for CAVD.

Emerging Gene Therapy Based on Nanocarriers: A Promising Therapeutic Alternative for Cardiovascular Diseases and a Novel Strategy in Valvular Heart Disease

Cardiovascular disease remains a leading cause of global mortality, with many unresolved issues in current clinical treatment strategies despite years of extensive research. Due to the great progress in nanotechnology and gene therapy in recent years, the emerging gene therapy based on nanocarriers has provided a promising therapeutic alternative for cardiovascular diseases. This review outlines the status of nanocarriers as vectors in gene therapy for cardiovascular diseases, including coronary heart disease, pulmonary hypertension, hypertension, and valvular heart disease. It discusses challenges and future prospects, aiming to support emerging clinical treatments. This review is the first to summarize gene therapy using nanocarriers for valvular heart disease, highlighting their potential in targeting challenging tissues.

Distinct Genetic Risk Profile in Aortic Stenosis Compared With Coronary Artery Disease

Importance

Aortic stenosis (AS) and coronary artery disease (CAD) frequently coexist. However, it is unknown which genetic and cardiovascular risk factors might be AS-specific and which could be shared between AS and CAD.

Objective

To identify genetic risk loci and cardiovascular risk factors with AS-specific associations.

Design, Setting, and Participants

This was a genomewide association study (GWAS) of AS adjusted for CAD with participants from the European Consortium for the Genetics of Aortic Stenosis (EGAS) (recruited 2000-2020), UK Biobank (recruited 2006-2010), Estonian Biobank (recruited 1997-2019), and FinnGen (recruited 1964-2019). EGAS participants were collected from 7 sites across Europe. All participants were of European ancestry, and information on comorbid CAD was available for all participants. Follow-up analyses with GWAS data on cardiovascular traits and tissue transcriptome data were also performed. Data were analyzed from October 2022 to July 2023.

Exposures

Genetic variants.

Main Outcomes and Measures

Cardiovascular traits associated with AS adjusted for CAD. Replication was performed in 2 independent AS GWAS cohorts.

Results

A total of 18 792 participants with AS and 434 249 control participants were included in this GWAS adjusted for CAD. The analysis found 17 AS risk loci, including 5 loci with novel and independently replicated associations (RNF114A, AFAP1, PDGFRA, ADAMTS7, HAO1). Of all 17 associated loci, 11 were associated with risk specifically for AS and were not associated with CAD (ALPL, PALMD, PRRX1, RNF144A, MECOM, AFAP1, PDGFRA, IL6, TPCN2, NLRP6, HAO1). Concordantly, this study revealed only a moderate genetic correlation of 0.15 (SE, 0.05) between AS and CAD (P = 1.60 × 10-3). Mendelian randomization revealed that serum phosphate was an AS-specific risk factor that was absent in CAD (AS: odds ratio [OR], 1.20; 95% CI, 1.11-1.31; P = 1.27 × 10-5; CAD: OR, 0.97; 95% CI 0.94-1.00; P = .04). Mendelian randomization also found that blood pressure, body mass index, and cholesterol metabolism had substantially lesser associations with AS compared with CAD. Pathway and transcriptome enrichment analyses revealed biological processes and tissues relevant for AS development.

Conclusions and Relevance

This GWAS adjusted for CAD found a distinct genetic risk profile for AS at the single-marker and polygenic level. These findings provide new targets for future AS research.

Association between triglyceride-glucose-body mass index and risk of aortic stenosis progression in patients with non-severe aortic stenosis: a retrospective cohort study

BACKGROUND

Triglyceride-glucose-BMI (TyG-BMI) index is a surrogate marker of insulin resistance and an important predictor of cardiovascular disease. However, the predictive value of TyG-BMI index in the progression of non-severe aortic stenosis (AS) is still unclear.

METHODS

The present retrospective observational study was conducted using patient data from Aortic valve diseases RISk facTOr assessmenT andprognosis modeL construction (ARISTOTLE). A total of 190 patients were recruited from one-center. Patients were divided into two groups according to the cut-off value of TyG-BMI index (Ln[triglycerides (mg/dL)* glucose (mg/dL)/2]*BMI). Cox regression and restricted subgroup analysis were used to evaluate the association of TyG-BMI index and progression of non-severe AS.

RESULTS

A total of 190 patients (mean age 72.52 ± 11.97 years, 51.58% male) were included in the study. During a median follow-up period of 27.48 months, 44 participants experienced disease progression. The cut-off of the TyG-BMI index is 239. After fully adjusting for confounding factors, high TyG-BMI index group was associated with a 2.219-fold higher risk of aortic stenosis progression (HR 2.219, 95%CI 1.086-4.537, p = 0.029).

CONCLUSION

TyG-BMI index was significantly associated with a higher risk of progression to non-severe AS. TyG-BMI index, as an effective alternative indicator of IR, can identify people at high risk of AS progression at an early stage of the disease, thereby improving the prognosis and reducing the socio-economic burden.

Targeting Sphingosine-1-Phosphate Signaling to Prevent the Progression of Aortic Valve Disease

BACKGROUND

Aortic valve disease (AVD) is associated with high mortality and morbidity. To date, there is no pharmacological therapy available to prevent AVD progression. Because valve calcification is the hallmark of AVD and S1P (sphingosine-1-phosphate) plays an important role in osteogenic signaling, we examined the role of S1P signaling in aortic stenosis disease.

METHODS

AVD progression and its consequences for cardiac function were examined in a murine wire injury-induced AVD model with and without pharmacological and genetic modulation of S1P production, degradation, and receptor signaling. S1P was measured by liquid chromatography-mass spectrometry. Calcification of human valvular interstitial cells and their response to biomechanical stress were analyzed in the context of S1P signaling. Human explanted aortic valves from patients undergoing aortic valve replacement and cardiovascular magnetic resonance imaging were analyzed for S1P by liquid chromatography-mass spectrometry.

RESULTS

Raising S1P concentrations in mice with injury-induced AVD by pharmacological inhibition of its sole degrading enzyme S1P lyase vastly enhanced AVD progression and impaired cardiac function resembling human disease. In contrast, low S1P levels caused by SphK1 (sphingosine kinase 1) deficiency potently attenuated AVD progression. We found S1P/S1PR2 (S1P receptor 2) signaling to be responsible for the adverse S1P effect because S1PR2-deficient mice were protected against AVD progression and its deterioration by high S1P. It is important to note that pharmacological S1PR2 inhibition administered after wire injury successfully prevented AVD development. Mechanistically, biomechanical stretch stimulated S1P production by SphK1 in human valvular interstitial cells as measured by C17-S1P generation, whereas S1P/S1PR2 signaling induced their osteoblastic differentiation and calcification through osteogenic RUNX2/OPG signaling and the GSK3β-Wnt-β-catenin pathway. In patients with AVD, stenotic valves exposed to high wall shear stress had higher S1P content and increased SphK1 expression.

CONCLUSIONS

Increased systemic or local S1P levels lead to increased valvular calcification. S1PR2 antagonists and SphK1 inhibitors may offer feasible pharmacological approaches to human AVD in prophylactic, disease-modifying or relapse-preventing manners.

Progress on long non-coding RNAs in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is a common cardiovascular condition in the elderly population. The aortic valve, influenced by factors such as endothelial dysfunction, inflammation, oxidative stress, lipid metabolism disorders, calcium deposition, and extracellular matrix remodeling, undergoes fibrosis and calcification, ultimately leading to stenosis. In recent years, long non-coding RNAs (lncRNAs) have emerged as significant regulators of gene expression, playing crucial roles in the occurrence and progression of various diseases. Research has shown that lncRNAs participate in the pathological process underlying CAVD by regulating osteogenic differentiation and inflammatory response of valve interstitial cells. Specifically, lncRNAs, such as H19, MALAT1, and TUG1, are closely associated with CAVD. Some lncRNAs can act as miRNA sponges, form complex regulatory networks, and modulate the expression of calcification-related genes. In brief, this review discusses the mechanisms and potential therapeutic targets of lncRNAs in CAVD.

Frailty in Older Adults with Severe Aortic Stenosis: The Role of Systemic Inflammation and Calcium Homeostasis

Background: Frailty and severe aortic stenosis (AoS) are critical conditions in older adults, both of which share pathophysiological mechanisms including chronic inflammation and calcium metabolism dysregulation, potentially influencing the development and progression of these conditions. This study aimed to analyze systemic inflammation and calcium homeostasis biomarkers and their associations with frailty in older adults with severe AoS. Methods: This prospective study included 191 patients aged ≥75 years with severe AoS who were candidates for aortic valve replacement and were evaluated at a Geriatrics Frailty Assessment and Intervention Clinic. Frailty was defined as a score ≤6 on the Short Physical Performance Battery (SPPB). Biomarkers analyzed included aortic valve calcium score, parathyroid hormone (PTH), calcidiol (vitamin D), calcium, phosphate, creatinine, interleukin-6 (IL-6), and the Systemic Immune-Inflammation Index. Multivariate logistic regression was performed to identify independent predictors of frailty. Results: Of the 191 patients studied, 53.9% were women, with a mean age of 84.1 ± 4.1 years. Frailty was identified in 28.3% of patients (mean SPPB score 7.6 ± 2.5). Statistically significant differences between frail and non-frail patients were observed for PTH (87.7 ± 61.1 pg/mL vs. 70 ± 44.4 pg/mL, p = 0.028) and IL-6 (10.4 ± 11.2 pg/mL vs. 7 ± 8.2 pg/mL, p = 0.049). Notably, in the multivariate model, IL-6 emerged as a significant independent predictor of frailty (OR 1.037; CI 1.001-1.074, p = 0.043). Conclusions: IL-6 was identified as a biomarker significantly associated with frailty in older adults with severe AoS. Evaluating IL-6 could enhance the precision of frailty assessments, complement functional measures, and support clinical decision-making in this population.

Transient Receptor Potential Vanilloid 4 Calcium-Permeable Channel Contributes to Valve Stiffening in Aortic Stenosis

BACKGROUND

Aortic valve stenosis (AVS) is a progressive disease characterized by fibrosis, inflammation, calcification, and stiffening of the aortic valve leaflets, leading to disrupted blood flow. If untreated, AVS can progress to heart failure and death within 2 to 5 years. Uncovering the molecular mechanisms behind AVS is key for developing effective noninvasive therapies. Emerging evidence highlights that matrix stiffness affect gene expression, inflammation, and cell differentiation. Activation of valvular interstitial cells into myofibroblasts, along with excessive extracellular matrix accumulation and remodeling, are major contributors to AVS progression. Inflammation further exacerbates the disease, as macrophages infiltrate valve leaflets, enhancing inflammation, activating valvular interstitial cells, and driving extracellular matrix remodeling. Our lab and others have shown that the activities of macrophages and fibroblasts are sensitive to matrix stiffness. Previously, we identified mechanosensitive transient receptor potential vanilloid 4 (TRPV4) channels as key regulators of fibrosis and macrophage activation, implicating TRPV4 in AVS as a potential stiffness sensor.

METHODS AND RESULTS

Herein, we found elevated levels of TRPV4, α-smooth muscle actin, and cluster of differentiation 68 proteins in human AVS tissues compared with controls. Furthermore, the stiffening of human aortic valve tissue is associated with the levels of myofibroblasts, macrophages, and TRPV4 protein expression. In a mouse model, TRPV4 promoted valve stiffening during hypercholesterolemia-induced AVS. Additionally, TRPV4 mediated intracellular stiffness in valvular interstitial cells in response to transforming growth factor β1, which was blocked by the TRPV4 antagonist GSK2193874.

CONCLUSIONS

These findings reveal a novel mechanism linking TRPV4 to valve stiffening, providing insights into how extracellular matrix mechanical properties drive inflammation and fibrosis in AVS.

Pre-interventional renal artery calcification and survival after transcatheter aortic valve implantation

The prognostic significance of renal artery calcification (RAC) is unknown in patients with severe aortic stenosis (AS) eligible for transcatheter aortic valve implantation (TAVI). RAC can be assessed by computed tomography (CT) performed during pre-interventional planning for TAVI. This study aimed at investigating the utility of RAC for predicting survival after TAVI. In this longitudinal cohort study, RAC volume was measured by CT in 268 consecutive patients with severe AS undergoing TAVI. Association of RAC with mortality was assessed using Cox regression analysis. RAC was evaluated as a binary parameter and in a supplementary analysis as a logarithmically transformed continuous variable. Over a median follow-up time of 9.6 years, 237 (88.4%) patients died, with 174 (73.4%) deaths attributable to a cardiovascular cause. RAC was highly prevalent (N = 150 (86.2%)) among patients suffering cardiovascular death. Competing risk cumulative incidence curves revealed a higher occurrence of cardiovascular death in patients with RAC (P-value = 0.008), while this was not the case for non-cardiovascular death (P-value = 0.71). RAC was independently associated with cardiovascular death (HR 1.61 [95% CI: 1.01-2.57]; P = 0.047) after adjustment for age, sex, cardiovascular risk factors, impaired renal function, and aortic valve calcification. The presence or absence of RAC rather than its volume was important in all the analyses. RAC is a strong and independent predictor of cardiovascular death in patients with severe AS undergoing TAVI. Given its favourable properties for event prediction, RAC may be considered valuable for prognostic assessment of TAVI patients.

Prognostic Value of Transvalvular Flow Rate in Aortic Stenosis: Implications for Risk Stratification

BACKGROUND

Timing of treatment of aortic stenosis (AS) is of key importance. AS severity is currently determined by transthoracic echocardiography (TTE) with a main focus on mean trans-aortic gradients. However, echocardiography has its limitations. The transvalvular flow rate (Q), is defined as the ratio of stroke volume (SV) to ejection time (ET): Q = SV/ET.

PURPOSE

To examine the prognostic value of aortic transvalvular flow rate (Q), in patients with moderate or severe AS.

METHODS

Clinical data from 824 patients diagnosed with AS between 2017 and 2020, and followed up until 2022 for four clinical outcomes: mortality, congestive heart failure (CHF), transcatheter aortic valve implantation (TAVI), and surgical aortic valve replacement (SAVR) was used for this retrospective study. Univariate and multivariate regression analyses were performed for the whole cohort and for the moderate AS subgroup, to identify prognostic markers. Kaplan-Meier survival analysis was conducted for different transvalvular flow rates and AS severities.

RESULTS

Findings demonstrate that lower Q is a significant risk factor for all-cause mortality even when adjusted for other echocardiographic and clinical variables. Survival analysis for the composite outcome occurrence (TAVI, SAVR, CHF, or mortality) and mortality showed significant differences between groups stratified by AS severity and Q (p value <0.0001). Specifically, Q was more substantial in the moderate AS group.

CONCLUSION

Transvalvular flow rate (Q) is independently prognostic for all-cause mortality. Furthermore, patients with moderate AS and lower Q should be closely monitored. Flow rate assessment should be integrated into the diagnosis, classification, and prognosis framework for AS.

The association between triglyceride to high-density-lipoprotein cholesterol ratio and calcific aortic valve disease: a retrospective study

BACKGROUND

The ratio of triglycerides to high-density-lipoprotein cholesterol (TG/HDL-C) is increasingly recognized as a practical marker for insulin resistance and cardiovascular risk assessment. This retrospective study investigates the potential of the TG/HDL-C ratio to predict the development of calcific aortic valve disease (CAVD), thereby extending its applicability in cardiovascular diagnostics.

METHODS

Data from 400 individuals, comprising 200 patients with diagnosed CAVD and 200 matched healthy controls, were analyzed. Clinical parameters were compared between groups, and logistic regression was utilized to explore the association of the TG/HDL-C ratio with CAVD. The diagnostic performance of the TG/HDL-C ratio was assessed using receiver operating characteristic (ROC) curves.

RESULTS

The TG/HDL-C ratio was notably higher in the CAVD group than in the controls (Z = -7.98, P < 0.001). Multivariable logistic regression analysis indicated that the TG/HDL-C ratio is an independent predictor of CAVD after adjusting for confounders including gender. The ROC curve analysis revealed that the TG/HDL-C ratio achieved a sensitivity of 80.5%, a specificity of 59.5%, and an area under the curve (AUC) of 0.731 (P < 0.001), confirming its efficacy in predicting CAVD.

CONCLUSIONS

High TG/HDL-C ratio was significantly associated with the occurrence of CAVD, and the TG/HDL-C ratio could be used as a potential diagnostic tool and risk assessment indicator for CAVD.

CLINICAL TRIAL NUMBER

Not applicable.

Calcific Aortic Stenosis: A Review

Importance

Calcific aortic stenosis (AS) restricts the aortic valve opening during systole due to calcification and fibrosis of either a congenital bicuspid or a normal trileaflet aortic valve. In the US, AS affects 1% to 2% of adults older than 65 years and approximately 12% of adults older than 75 years. Worldwide, AS leads to more than 100 000 deaths annually.

Observations

Calcific AS is characterized by aortic valve leaflet lipid infiltration and inflammation with subsequent fibrosis and calcification. Symptoms due to severe AS, such as exercise intolerance, exertional dyspnea, and syncope, are associated with a 1-year mortality rate of up to 50% without aortic valve replacement. Echocardiography can detect AS and measure the severity of aortic valve dysfunction. Although progression rates vary, once aortic velocity is higher than 2 m/s, progression to severe AS occurs typically within 10 years. Severe AS is defined by an aortic velocity 4 m/s or higher, a mean gradient 40 mm Hg or higher, or a valve area less than or equal to 1.0 cm2. Management of mild to moderate AS and asymptomatic severe AS consists of patient education about the typical progression of disease; clinical and echocardiographic surveillance at intervals of 3 to 5 years for mild AS, 1 to 2 years for moderate AS, and 6 to 12 months for severe AS; and treatment of hypertension, hyperlipidemia, and cigarette smoking as indicated. When a patient with severe AS develops symptoms, surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) is recommended, which restores an average life expectancy; in patients aged older than 70 years with a low surgical risk, 10-year all-cause mortality was 62.7% with TAVI and 64.0% with SAVR. TAVI is associated with decreased length of hospitalization, more rapid return to normal activities, and less pain compared with SAVR. However, evidence supporting TAVI for patients aged younger than 65 years and long-term outcomes of TAVI are less well defined than for SAVR. For patients with symptomatic severe AS, the 2020 American College of Cardiology/American Heart Association guideline recommends SAVR for individuals aged 65 years and younger, SAVR or TAVI for those aged 66 to 79 years, and TAVI for individuals aged 80 years and older or those with an estimated surgical mortality of 8% or higher.

Conclusions

Calcific AS is a common chronic progressive condition among older adults and is diagnosed via echocardiography. Symptomatic patients with severe AS have a mortality rate of up to 50% after 1 year, but treatment with SAVR or TAVI reduces mortality to that of age-matched control patients. The type and timing of valve replacement should be built on evidence-based guidelines, shared decision-making, and involvement of a multidisciplinary heart valve team.

Macrophages in Calcific Aortic Valve Disease: Paracrine and Juxtacrine Disease Drivers

A significant role in the pathogenesis of CAVD is played by innate immunity cells, such as macrophages. In stenotic valves, macrophages have enhanced inflammatory activity, and the population's balance is shifted toward pro-inflammatory ones. Pro-inflammatory macrophages release cytokines, chemokines, and microRNA, which can directly affect the resident valvular cells and cause valve calcification. In CAVD patients, macrophages may have more pronounced pro-inflammatory properties, enhanced not only by paracrine signals but also by juxtacrine Notch signaling and epigenetic factors, which influence the maturation of macrophages' progenitors. In this review, we observe the accumulated data on the involvement of macrophages in CAVD development via paracrine and juxtacrine interactions.

Immunotherapy in the Context of Aortic Valve Diseases

PURPOSE

Aortic valve disease (AVD) affects millions of people around the world, with no pharmacological intervention available. Widely considered a multi-faceted disease comprising both regurgitative pathogenesis, in which retrograde blood flows back through to the left ventricle, and aortic valve stenosis, which is characterized by the thickening, fibrosis, and subsequent mineralization of the aortic valve leaflets, limiting the anterograde flow through the valve, surgical intervention is still the main treatment, which incurs considerable risk to the patient.

RESULTS

Though originally thought of as a passive degeneration of the valve or a congenital malformation that has occurred before birth, the paradigm of AVD is shifting, and research into the inflammatory drivers of valve disease as a potential mechanism to modulate the pathobiology of this life-limiting pathology is taking center stage. Following limited success in mainstay therapeutics such as statins and mineralisation inhibitors, immunomodulatory strategies are being developed. Immune cell therapy has begun to be adopted in the cancer field, in which T cells (chimeric antigen receptor (CAR) T cells) are isolated from the patient, programmed to attack the cancer, and then re-administered to the patient. Within cardiac research, a novel T cell-based therapeutic approach has been developed to target lipid nanoparticles responsible for increasing cardiac fibrosis in a failing heart. With clonally expanded T-cell populations recently identified within the diseased valve, their unique epitope presentation may serve to identify novel targets for the treatment of valve disease.

CONCLUSION

Taken together, targeted T-cell therapy may hold promise as a therapeutic platform to target a multitude of diseases with an autoimmune aspect, and this review aims to frame this in the context of cardiovascular disease, delineating what is currently known in the field, both clinically and translationally.

The Use of the Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio in Predicting Transcatheter Aortic Valve Implantation Mortality

AIM

Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are simple biomarkers that reflect systemic inflammation and are associated with adverse cardiovascular disease outcomes. The utility of NLR and PLR for risk prediction following transcatheter aortic valve implantation (TAVI) is not clear.

METHOD

We retrospectively analysed a prospectively maintained database of patients who underwent TAVI at a tertiary hospital from 2009 to 2022. Baseline demographics, NLR, PLR and Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) scores were obtained. The 30-day and 1-year survival rates were analysed using a logistic regression model while overall survival was analysed using the Kaplan-Meier method. Predictors of survival were calculated using a Cox-hazards regression model and presented as odds ratio (OR) with 95% confidence interval (CI).

RESULTS

Overall, 367 patients were included in this study (mean age 84 years, 51% male). Median follow-up was 19 months (interquartile range 8.8-40 months) with a median survival of 7.2 years (interquartile range 3.5-10.3 years). NLR was associated with 30-day mortality (OR 1.75; 95% CI 1.25-2.68; p<0.01). PLRs marginally predicted 1-year mortality (OR 1.01; 95% CI 1.00-1.02). However, only the STS-PROM score significantly predicted overall survival (hazard ratio 1.07; 95% CI 1.02-1.12; p=0.03) after adjustment for NLR and PLR.

CONCLUSIONS

NLR is associated with 30-day mortality following TAVI. PLR was not a clinically significant predictor of mortality after TAVI. Only the STS-PROM score remained a significant predictor of overall survival.

PTEN Regulates Myofibroblast Activation in Valvular Interstitial Cells based on Subcellular Localization

Aortic valve stenosis (AVS) is characterized by altered mechanics of the valve leaflets, which disrupts blood flow through the aorta and can cause left ventricle hypotrophy. These changes in the valve tissue result in activation of resident valvular interstitial cells (VICs) into myofibroblasts, which have increased levels of αSMA in their stress fibers. The persistence of VIC myofibroblast activation is a hallmark of AVS. In recent years, the tumor suppressor gene phosphatase and tensin homolog (PTEN) has emerged as an important player in the regulation of fibrosis in various tissues (e.g., lung, skin), which motivated us to investigate PTEN as a potential protective factor against matrix-induced myofibroblast activation in VICs. In aortic valve samples from humans, we found high levels of PTEN in healthy tissue and low levels of PTEN in diseased tissue. Then, using pharmacological inducers to treat VIC cultures, we observed PTEN overexpression prevented stiffness-induced myofibroblast activation, whereas genetic and pharmacological inhibition of PTEN further activated myofibroblasts. We also observed increased nuclear PTEN localization in VICs cultured on stiff matrices, and nuclear PTEN also correlated with smaller nuclei, altered expression of histones and a quiescent fibroblast phenotype. Together, these results suggest that PTEN not only suppresses VIC activation, but functions to promote quiescence, and could serve as a potential pharmacological target for the treatment of AVS.

Shear-Sensing by C-Reactive Protein: Linking Aortic Stenosis and Inflammation

BACKGROUND

CRP (C-reactive protein) is a prototypical acute phase reactant. Upon dissociation of the pentameric isoform (pCRP [pentameric CRP]) into its monomeric subunits (mCRP [monomeric CRP]), it exhibits prothrombotic and proinflammatory activity. Pathophysiological shear rates as observed in aortic valve stenosis (AS) can influence protein conformation and function as observed with vWF (von Willebrand factor). Given the proinflammatory function of dissociated CRP and the important role of inflammation in the pathogenesis of AS, we investigated whether shear stress can modify CRP conformation and induce inflammatory effects relevant to AS.

METHODS

To determine the effects of pathological shear rates on the function of human CRP, pCRP was subjected to pathophysiologically relevant shear rates and analyzed using biophysical and biochemical methods. To investigate the effect of shear on CRP conformation in vivo, we used a mouse model of arterial stenosis. Levels of mCRP and pCRP were measured in patients with severe AS pre- and post-transcatheter aortic valve implantation, and the presence of CRP was investigated on excised valves from patients undergoing aortic valve replacement surgery for severe AS. Microfluidic models of AS were then used to recapitulate the shear rates of patients with AS and to investigate this shear-dependent dissociation of pCRP and its inflammatory function.

RESULTS

Exposed to high shear rates, pCRP dissociates into its proinflammatory monomers (mCRP) and aggregates into large particles. Our in vitro findings were further confirmed in a mouse carotid artery stenosis model, where the administration of human pCRP led to the deposition of mCRP poststenosis. Patients undergoing transcatheter aortic valve implantation demonstrated significantly higher mCRP bound to circulating microvesicles pre-transcatheter aortic valve implantation compared with post-transcatheter aortic valve implantation. Excised human stenotic aortic valves display mCRP deposition. pCRP dissociated in a microfluidic model of AS and induces endothelial cell activation as measured by increased ICAM-1 (intercellular adhesion molecule 1) and P-selectin expression. mCRP also induces platelet activation and TGF-β (transforming growth factor beta) expression on platelets.

CONCLUSIONS

We identify a novel mechanism of shear-induced pCRP dissociation, which results in the activation of cells central to the development of AS. This novel mechanosensing mechanism of pCRP dissociation to mCRP is likely also relevant to other pathologies involving increased shear rates, such as in atherosclerotic and injured arteries.

TRPV4-mediated Mechanotransduction Regulates the Differentiation of Valvular Interstitial Cells to Myofibroblasts: Implications for Aortic Stenosis

As aortic valve stenosis (AVS) progresses, the valve tissue also stiffens. This increase in tissue stiffness causes the valvular interstitial cells (VICs) to transform into myofibroblasts in response. VIC-to-myofibroblast differentiation is critically involved in the development of AVS. Herein, we investigated the role of mechanosensitive Ca2+-permeant transient receptor potential vanilloid 4 (Trpv4) channels in matrix stiffness- and transforming growth factor β1 (TGFβ1)-induced VIC-myofibroblast activation. We confirmed Trpv4 functionality in primary mouse wild-type VICs compared to Trpv4 null VICs using live Ca2+ influx detection during application of its selective agonist and antagonist. Using physiologically relevant hydrogels of varying stiffness that respectively mimic healthy or diseased aortic valve tissue stiffness, we found that genetic ablation of Trpv4 blocked matrix stiffness- and TGFβ1-induced VIC-myofibroblast activation as determined by changes in morphology, alterations of expression of α-smooth muscle actin, and modulations of F-actin generation. Our results showed that N-terminal residues 30-130 in Trpv4 were crucial for cellular force generation and VIC-myofibroblast activation, while deletion of residues 1-30 had no noticeable negative effect on these processes. Collectively, these data suggest a differential regulatory role for Trpv4 in stiffness/TGFβ1-induced VIC-myofibroblast activation. Our data further showed that Trpv4 regulates stiffness/TGFβ1-induced PI3K-AKT activity that is required for VIC-myofibroblast differentiation and cellular force generation, suggesting a mechanism by which Trpv4 activity regulates VIC-myofibroblast activation. Altogether, these data identify a novel role for Trpv4 mechanotransduction in regulating VIC-myofibroblast activation, implicating Trpv4 as a potential therapeutic target to slow and/or reverse AVS development.

Beyond the Heartbeat: Single-Cell Omics Redefining Cardiovascular Research

PURPOSE OF REVIEW

This review aims to explore recent advances in single-cell omics techniques as applied to various regions of the human heart, illuminating cellular diversity, regulatory networks, and disease mechanisms. We examine the contributions of single-cell transcriptomics, genomics, proteomics, epigenomics, and spatial transcriptomics in unraveling the complexity of cardiac tissues.

RECENT FINDINGS

Recent strides in single-cell omics technologies have revolutionized our understanding of the heart's cellular composition, cell type heterogeneity, and molecular dynamics. These advancements have elucidated pathological conditions as well as the cellular landscape in heart development. We highlight emerging applications of integrated single-cell omics, particularly for cardiac regeneration, disease modeling, and precision medicine, and emphasize the transformative potential of these technologies to advance cardiovascular research and clinical practice.

Calcific aortic valve disease and cardiometabolic triggers: an explanation behind progression of aortic valvular disease and failure of medical therapy interventions

Calcific aortic valve disease (CAVD), a nonrheumatic stenosis of the trileaflet aortic valve, is a complex, multifaceted cardiovascular condition involving a widespread inflammatory process and an analogous atheromatous process affecting the arteries. It is currently the most encountered valvular abnormality in cardiology. Although distinctive abnormal mechanical forces are at the core propelling a responsive mechanosensitive feedback cascade, implicated in both initiation and perpetuation of CAVD; we propose a conundrum of metabolic abnormalities including hypertension, elevated fasting blood sugar, decreased high-density lipoprotein, hypertriglyceridemia, and abdominal obesity as perpetuators of this process. Furthermore, we suggest CAVD as a cardio metabolic disorder. New perspectives as well as which pathways we believe are critically involved and ideas for early intervention are discussed.

Effect of Glucagon-like Peptide-1 Receptor Agonism on Aortic Valve Stenosis Risk: A Mendelian Randomization Analysis

Background: Aortic valve repair is currently the only effective treatment for calcific aortic valve stenosis (CAVS), as no pharmacological therapies exist to prevent or slow its progression. Recent promising results showed that glucagon-like peptide-1 (GLP-1) attenuates the calcification of aortic valve interstitial cells. Therefore, we conducted a two-sample Mendelian randomization analysis to investigate the effect of GLP-1 receptor agonism (GLP-1Ra) on the risk of CAVS. Methods: The inverse variance weighted (IVW) method was used to obtain the primary causal inference, and several sensitivity analyses, including MR-Egger, were performed to assess the robustness of the results. Results: Based on the IVW estimates, the GLP-1Ra showed a neutral effect on the risk of CAVS (odds ratio [OR] per 1 mmol/mol decrease in glycated hemoglobin = 0.87, 95% CI = [0.69, 1.11], p = 0.259; I2 = 4.5%, Cohran's Q = 2.09, heterogeneity p = 0.35; F statistic = 16.8). A non-significant effect was also derived by the sensitivity analyses. No evidence of horizontal pleiotropy was identified. Conclusions: GLP-1Ra was not significantly associated with the risk of CAVS. Furthermore, pragmatically designed studies are required to evaluate the effect of GLP-1Ra on the clinical course of CAVS in different patient subgroups.

Aortic valve calcification volume and prognosis in patients undergoing transcatheter aortic valve implantation

INTRODUCTION AND OBJECTIVES

It is unknown whether aortic valve calcium volume, as measured by contrast-enhanced computed tomography angiography (angio-CT), is associated with mortality in patients undergoing transcatheter aortic valve implantation (TAVI). We aimed to confirm that contrast-enhanced aortic valve calcium correlates with noncontrast-enhanced calcium score and provides useful prognostic information in patients undergoing TAVI.

METHODS

This retrospective observational study included patients from 2 high-volume TAVI centers in Germany, all of whom underwent high-quality angio-CT prior to TAVI. Calcium volume in contrast-enhanced angio-CT was calculated using 3Mensio software (Pie Medical, The Netherlands), while the calcium score from noncontrast-enhanced angio-CT was obtained using the Syngo.via (Siemens Healthineers, Germany) workstation to validate contrast-enhanced angio-CT values. Calcium volume was dichotomized using the median based on to sex-specific values from contrast-enhanced angio-CT, and the risk associated with increased calcium volume was determined using Cox proportional hazard regression analysis.

RESULTS

We included 3318 TAVI patients. A good correlation was observed between noncontrast-enhanced and contrast-enhanced angio-CT (r2=0.680; P<.001). The median values for sex-specific contrast-enhanced angio-CT calcium volume were 514 mm3 for women and 1025 mm3 for men. Patients with higher calcium volumes showed lower mortality at 1 year (8.8% vs 12.1%; adjusted HR, 0.86; 95%CI, 0.75-0.98; P=.02) compared with those with lower calcium volumes.

CONCLUSIONS

Calcium volume in contrast-enhanced angio-CT correlated well with noncontrast-enhanced angio-CT calcium score. Patients with higher calcium volume showed lower mortality at 1 year after TAVI.

Proposing new lipoprotein (a) cut off value for Kazakhstan: pilot study

Introduction

There is no consensus on the optimal concentration of lipoprotein(a) (Lp(a)) for the risk of atherosclerotic cardiovascular diseases (ASCVD) and aortic valve stenosis. In various clinical guidelines and agreed documents, the threshold level of Lp (a) is 30 mg/dl or 50 mg/dl. We estimated the cut-off value of Lp (a) associated with the risk of developing various localizations of atherosclerosis for the Central Asia, including Kazakhstani population.

Methods

This study was conducted at National Research Cardiac Surgery Center, Kazakhstan. 487 patients were included, of which 61.3% were men. The mean age of all participants was 57.3 ± 12.6 years. Bivariate and multivariable logistic regression analysis was used to study the relationship between risk factors and plasma lipoprotein (a) levels. The threshold value of lipoprotein (a) was predicted using the Youden index.

Results

For Kazakhstani population the lipoprotein (a) cut offs for the risk of developing atherosclerotic CVD and aortic valve calcification was 21.1 mg/dl (p < 0.05). There was no relationship with the level of lipoprotein (a) and low-density lipoprotein cholesterol (LDL-C), which suggests that lipoprotein (a) is an independent risk factor for the development of ASCVD.

Discussion

This study offers new insights into the threshold value of lipoprotein (a) in Kazakhstan, highlighting its role as a risk factor for atherosclerotic cardiovascular diseases and aortic valve calcification. The findings suggest that the internationally recommended Lp(a) cutoffs may not be suitable for Central Asian populations, as the threshold in our study is significantly lower at 21.2 mg/dL. These results emphasize the need for further research with larger sample sizes to establish more region-specific cutoffs.

Apical Sparing of Longitudinal Strain as a Specific Pattern of Myocardial Fibrosis in Patients with Severe Left Ventricular Hypertrophy: A Comparison between Deformation Imaging and Histological Findings

Objectives: This study aimed to investigate the correlation between apical sparing of longitudinal strain (LS), as measured by speckle-tracking echocardiography (STE), and the histological presence of myocardial fibrosis (MF), in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods: Twenty-seven HOCM patients who underwent elective Morrow procedures +/- aortic valve replacement (AVR) were included. All patients had standard echocardiography, with STE pre- and post-operatively. Intraoperative probes of the interventricular septum were sent for histological analysis. Correlation of different regional LS patterns with the histological findings of MF and with clinical outcome were analyzed. In addition, a logistic regression and ROC analysis were performed. Results: All patients underwent the Morrow procedure for HOCM, with 33.3% also undergoing AVR. A total of 74.1% showed evidence of MF in the histological analysis. Patients with MF had significantly lower GLS than patients without MF (-12.7 ± 2.7% vs. -23.0 ± 5.7%, p < 0.001). The LS in patients with MF was significantly lower at the basal regions of the LV segments and increased significantly towards the apex as compared to the patients without MF (mean basal-strain %: -10.6 ± 2.6 vs. -17.3 ± 4.6, p < 0.001; mean apical strain %: -21.8 ± 4.8 vs. -16.7 ± 5.6, p = 0.032). In the logistic regression, only the GLS remained as an independent predictor of MF with an Odds ratio of 1.07 (95%-CI: 1.05-1.09, p < 0.001). Conclusions: Our study highlights the significant correlation between GLS and MF in HOCM patients. These findings contribute to the growing understanding of MF in HOCM and may inform future approaches to patient management and risk stratification.

Multiomics identification of ALDH9A1 as a crucial immunoregulatory molecule involved in calcific aortic valve disease

Mitochondrial dysfunction and immune cell infiltration play crucial yet incompletely understood roles in the pathogenesis of calcific aortic valve disease (CAVD). This study aimed to identify immune-related mitochondrial genes critical to the pathological process of CAVD using multiomics approaches. The CIBERSORT algorithm was employed to evaluate immune cell infiltration characteristics in CAVD patients. An integrative analysis combining weighted gene coexpression network analysis (WGCNA), machine learning, and summary data-based Mendelian randomization (SMR) was performed to identify key mitochondrial genes implicated in CAVD. Spearman's rank correlation analysis was also performed to assess the relationships between key mitochondrial genes and infiltrating immune cells. Compared with those in normal aortic valve tissue, an increased proportion of M0 macrophages and resting memory CD4 T cells, along with a decreased proportion of plasma cells and activated dendritic cells, were observed in CAVD patients. Additionally, eight key mitochondrial genes associated with CAVD, including PDK4, LDHB, SLC25A36, ALDH9A1, ECHDC2, AUH, ALDH2, and BNIP3, were identified through the integration of WGCNA and machine learning methods. Subsequent SMR analysis, incorporating multiomics data, such as expression quantitative trait loci (eQTLs) and methylation quantitative trait loci (mQTLs), revealed a significant causal relationship between ALDH9A1 expression and a reduced risk of CAVD. Moreover, ALDH9A1 expression was inversely correlated with M0 macrophages and positively correlated with M2 macrophages. These findings suggest that increased ALDH9A1 expression is significantly associated with a reduced risk of CAVD and that it may exert its protective effects by modulating mitochondrial function and immune cell infiltration. Specifically, ALDH9A1 may contribute to the shift from M0 macrophages to anti-inflammatory M2 macrophages, potentially mitigating the pathological progression of CAVD. In conclusion, ALDH9A1 represents a promising molecular target for the diagnosis and treatment of CAVD. However, further validation through in vivo and n vitro studies is necessary to confirm its role in CAVD pathogenesis and therapeutic potential.

Lumican promotes calcific aortic valve disease through H3 histone lactylation

BACKGROUND AND AIMS

Valve interstitial cells (VICs) undergo a transition to intermediate state cells before ultimately transforming into the osteogenic cell population, which is a pivotal cellular process in calcific aortic valve disease (CAVD). Herein, this study successfully delineated the stages of VIC osteogenic transformation and elucidated a novel key regulatory role of lumican (LUM) in this process.

METHODS

Single-cell RNA-sequencing (scRNA-seq) from nine human aortic valves was used to characterize the pathological switch process and identify key regulatory factors. The in vitro, ex vivo, in vivo, and double knockout mice were constructed to further unravel the calcification-promoting effect of LUM. Moreover, the multi-omic approaches were employed to analyse the molecular mechanism of LUM in CAVD.

RESULTS

ScRNA-seq successfully delineated the process of VIC pathological transformation and highlighted the significance of LUM as a novel molecule in this process. The pro-calcification role of LUM is confirmed on the in vitro, ex vivo, in vivo level, and ApoE-/-//LUM-/- double knockout mice. The LUM induces osteogenesis in VICs via activation of inflammatory pathways and augmentation of cellular glycolysis, resulting in the accumulation of lactate. Subsequent investigation has unveiled a novel LUM driving histone modification, lactylation, which plays a role in facilitating valve calcification. More importantly, this study has identified two specific sites of histone lactylation, namely, H3K14la and H3K9la, which have been found to facilitate the process of calcification. The confirmation of these modification sites' association with the expression of calcific genes Runx2 and BMP2 has been achieved through ChIP-PCR analysis.

CONCLUSIONS

The study presents novel findings, being the first to establish the involvement of lumican in mediating H3 histone lactylation, thus facilitating the development of aortic valve calcification. Consequently, lumican would be a promising therapeutic target for intervention in the treatment of CAVD.

Hydrogen sulfide inhibits gene expression associated with aortic valve degeneration by inducing NRF2-related pro-autophagy effect in human aortic valve interstitial cells

Aortic valve stenosis (AS) is the most common valvular heart disease but there are currently no effective medical treatments that can delay disease progression due to a lack of knowledge of the precise pathophysiology. The expression of sulfide: quinone oxidoreductase (SQOR) and nuclear factor erythroid 2-related factor 2 (NRF2) was decreased in the aortic valve of AS patients. However, the role of SQOR and NRF2 in the pathophysiology of AS has not been found. We investigated the effects of hydrogen sulfide (H2S)-releasing compounds on diseased aortic valve interstitial cells (AVICs) to explain the cellular mechanism of SQOR and elucidate the medical value of H2S for AS treatment. Sodium hydrosulfide (NaHS) treatment increased the expression of SQOR and NRF2 gene and consequently induced the NRF2 target genes, such as NAD(P)H quinone dehydrogenase 1 and cystathionine γ-lyase. In addition, NaHS dose-dependently decreased the expression level of fibrosis and inflammation-related genes (MMP9, TNF-α, IL6) and calcification-related genes (ALP, osteocalcin, RUNX2, COL1A1) in human AVICs. Furthermore, NaHS activated the AMPK-mTOR pathway and inhibited the PI3K-AKT pathway, resulting in a pro-autophagy effect in human AVICs. An NRF2 inhibitor, brusatol, attenuated NaHS-induced AMPK activation and decreased the autophagy markers Beclin-1 and LC3AB, suggesting that the mechanism of action of H2S is related to NRF2. In conclusion, H2S decreased gene expression levels related to aortic valve degeneration and activated AMPK-mTOR-mediated pro-autophagy function associated with NRF2 in human AVICs. Therefore, H2S could be a potential therapeutic target for the development of AS treatment.