Impact of myocardial fibrosis on left ventricular remodelling, recovery, and outcome after transcatheter aortic valve implantation in different haemodynamic subtypes of severe aortic stenosis

The role of Matrix Metalloproteinase-2 and Galectin-3 as predictive biomarkers for all-cause mortality in patients undergoing transfemoral transcatheter aortic valve implantation

BACKGROUND

Currently available risk scores fail to accurately predict morbidity and mortality in patients with severe symptomatic aortic stenosis who undergo transcatheter aortic valve implantation (TAVI). In this context, biomarkers like matrix metalloproteinase-2 (MMP-2) and Galectin-3 (Gal-3) may provide additional prognostic information.

METHODS

Patients with severe aortic stenosis undergoing consecutive, elective, transfemoral TAVI were included. Baseline demographic data, functional status, echocardiographic findings, clinical outcomes and biomarker levels were collected and analysed.

RESULTS

The study cohort consisted of 89 patients (age 80.4 ± 5.1 years, EuroScore II 7.1 ± 5.8%). During a median follow-up period of 526 d, 28 patients (31.4%) died. Among those who died, median baseline MMP-2 (alive: 221.6 [170.4; 263] pg/mL vs. deceased: 272.1 [225; 308.8] pg/mL, p < 0.001) and Gal-3 levels (alive: 19.1 [13.5; 24.6] pg/mL vs. deceased: 25 [17.6; 29.5] pg/mL, p = 0.006) were higher than in survivors. In ROC analysis, MMP-2 reached an acceptable level of discrimination to predict mortality (AUC 0.733, 95% CI [0.62; 0.83], p < 0.001), but the predictive value of Gal-3 was poor (AUC 0.677, 95% CI [0.56; 0.79], p = 0.002). Kaplan-Meier and Cox regression analyses showed that patients with MMP-2 and Gal-3 concentrations above the median at baseline had significantly impaired long-term survival (p = 0.004 and p = 0.02, respectively).

CONCLUSIONS

In patients with severe aortic stenosis undergoing transfemoral TAVI, MMP-2 and to a lesser extent Gal-3, seem to have additive value in optimizing risk prediction and streamlining decision-making.

Predicting Left Ventricular Adverse Remodeling After Transcatheter Aortic Valve Replacement: A Radiomics Approach

RATIONALE AND OBJECTIVES

To develop a radiomics model based on cardiac computed tomography (CT) for predicting left ventricular adverse remodeling (LVAR) in patients with severe aortic stenosis (AS) who underwent transcatheter aortic valve replacement (TAVR).

MATERIALS AND METHODS

Patients with severe AS who underwent TAVR from January 2019 to December 2022 were recruited. The cohort was divided into adverse remodeling group and non-adverse remodeling group based on LVAR occurrence, and further randomly divided into a training set and a validation set at an 8:2 ratio. Left ventricular radiomics features were extracted from cardiac CT. The least absolute shrinkage and selection operator regression was utilized to select the most relevant radiomics features and clinical features. The radiomics features were used to construct the Radscore, which was then combined with the selected clinical features to build a nomogram. The predictive performance of the models was evaluated using the area under the curve (AUC), while the clinical value of the models was assessed using calibration curves and decision curve analysis.

RESULTS

A total of 273 patients were finally enrolled, including 71 with adverse remodeling and 202 with non-adverse remodeling. 12 radiomics features and five clinical features were extracted to construct the radiomics model, clinical model, and nomogram, respectively. The radiomics model outperformed the clinical model (training AUC: 0.799 vs. 0.760; validation AUC: 0.766 vs. 0.755). The nomogram showed highest accuracy (training AUC: 0.859, validation AUC: 0.837) and was deemed most clinically valuable by decision curve analysis.

CONCLUSION

The cardiac CT-based radiomics features could predict LVAR after TAVR in patients with severe AS.

Age-Dependent RGS5 Loss in Pericytes Induces Cardiac Dysfunction and Fibrosis

BACKGROUND

Pericytes are capillary-associated mural cells involved in the maintenance and stability of the vascular network. Although aging is one of the main risk factors for cardiovascular disease, the consequences of aging on cardiac pericytes are unknown.

METHODS

In this study, we have combined single-nucleus RNA sequencing and histological analysis to determine the effects of aging on cardiac pericytes. Furthermore, we have conducted in vivo and in vitro analysis of RGS5 (regulator of G-protein signaling 5) loss of function and finally have performed pericytes-fibroblasts coculture studies to understand the effect of RGS5 deletion in pericytes on the neighboring fibroblasts.

RESULTS

Aging reduced the pericyte area and capillary coverage in the murine heart. Single-nucleus RNA sequencing analysis further revealed that the expression of Rgs5 was reduced in cardiac pericytes from aged mice. In vivo and in vitro studies showed that the deletion of RGS5 impaired cardiac function, induced fibrosis, and morphological changes in pericytes characterized by a profibrotic gene expression signature and the expression of different ECM (extracellular matrix) components and growth factors, for example, TGFB2 and PDGFB. Indeed, culturing fibroblasts with the supernatant of RGS5-deficient pericytes induced their activation as evidenced by the increased expression of αSMA (alpha smooth muscle actin) in a TGFβ (transforming growth factor beta)2-dependent mechanism.

CONCLUSIONS

Our results have identified RGS5 as a crucial regulator of pericyte function during cardiac aging. The deletion of RGS5 causes cardiac dysfunction and induces myocardial fibrosis, one of the hallmarks of cardiac aging.

Quality of Life 5 Years Following Transfemoral TAVR or SAVR in Intermediate Risk Patients

BACKGROUND

Symptomatic patients with severe aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR) sustain comparable improvements in health status over 5 years after transcatheter aortic valve replacement (TAVR) or SAVR. Whether a similar long-term benefit is observed among intermediate-risk AS patients is unknown.

OBJECTIVES

The purpose of this study was to assess health status outcomes through 5 years in intermediate risk patients treated with a self-expanding TAVR prosthesis or SAVR using data from the SURTAVI (Surgical Replacement and Transcatheter Aortic Valve Implantation) trial.

METHODS

Intermediate-risk patients randomized to transfemoral TAVR or SAVR in the SURTAVI trial had disease-specific health status assessed at baseline, 30 days, and annually to 5 years using the Kansas City Cardiomyopathy Questionnaire (KCCQ). Health status was compared between groups using fixed effects repeated measures modelling.

RESULTS

Of the 1,584 patients (TAVR, n = 805; SAVR, n = 779) included in the analysis, health status improved more rapidly after TAVR compared with SAVR. However, by 1 year, both groups experienced large health status benefits (mean change in KCCQ-Overall Summary Score (KCCQ-OS) from baseline: TAVR: 20.5 ± 22.4; SAVR: 20.5 ± 22.2). This benefit was sustained, albeit modestly attenuated, at 5 years (mean change in KCCQ-OS from baseline: TAVR: 15.4 ± 25.1; SAVR: 14.3 ± 24.2). There were no significant differences in health status between the cohorts at 1 year or beyond. Similar findings were observed in the KCCQ subscales, although a substantial attenuation of benefit was noted in the physical limitation subscale over time in both groups.

CONCLUSIONS

In intermediate-risk AS patients, both transfemoral TAVR and SAVR resulted in comparable and durable health status benefits to 5 years. Further research is necessary to elucidate the mechanisms for the small decline in health status noted at 5 years compared with 1 year in both groups. (Safety and Efficacy Study of the Medtronic CoreValve® System in the Treatment of Severe, Symptomatic Aortic Stenosis in Intermediate Risk Subjects Who Need Aortic Valve Replacement [SURTAVI]; NCT01586910).

Codonopsis Radix Inhibits the Inflammatory Response and Oxidative Stress in Chronic Obstructive Pulmonary Disease Mice through Regulation of the Nrf2/NF-κB Signaling Pathway

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a nonspecific chronic inflammatory lung disease with no known cure. Codonopsis Radix (CR) has been shown to exhibit anti-inflammatory and antioxidant effects. Therefore, this study aimed to investigate the potential anti-inflammatory effects of different CR varieties on COPD mice.

METHODS

Sixty male-specified pathogen-free grade C57BL/6J mice were randomly divided into 6 groups, 10 mice in each group. The COPD mice model was induced by cigarette smoke extract combined with lipopolysaccharide, and the mice in each group were given corresponding drugs. Lung function was assessed in all mice. Lung tissues were stained with hematoxylin-eosin, Masson, and periodic acid-Schiff stains, and serum levels of interleukin (IL)-8 and tumor necrosis factor (TNF)-α were detected using an ELISA. Further, serum and lung tissue levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were detected by colorimetric assay. Network pharmacology and molecular docking were used to predict signaling pathways, which were validated by Western blot analysis.

RESULTS

Compared with the COPD group, the mice in each dosing group of CR exhibited significant reductions in serum IL-8 and TNF-α levels, serum and lung tissue MDA levels, and pathological lung tissue damage, alongside elevations in lung function and SOD levels (p < 0.01). Western blot analysis also indicated significant downregulation of p-p65/p65 and p-IκB-α/IκB-α protein expression, alongside significant upregulation of Nrf2 protein expression in the lung tissues of mice treated with CR (p < 0.01).

CONCLUSION

In summary, CR effectively enhances lung function, minimizes lung tissue damage, and inhibits inflammation and oxidative stress in mice with COPD. Additionally, these findings suggest that inhibition of the Nrf2/NF-κB axis may be a key mechanism of action of CR in the alleviation of COPD.

A Multimodal Video-Based AI Biomarker for Aortic Stenosis Development and Progression

Importance

Aortic stenosis (AS) is a major public health challenge with a growing therapeutic landscape, but current biomarkers do not inform personalized screening and follow-up. A video-based artificial intelligence (AI) biomarker (Digital AS Severity index [DASSi]) can detect severe AS using single-view long-axis echocardiography without Doppler characterization.

Objective

To deploy DASSi to patients with no AS or with mild or moderate AS at baseline to identify AS development and progression.

Design, Setting, and Participants

This is a cohort study that examined 2 cohorts of patients without severe AS undergoing echocardiography in the Yale New Haven Health System (YNHHS; 2015-2021) and Cedars-Sinai Medical Center (CSMC; 2018-2019). A novel computational pipeline for the cross-modal translation of DASSi into cardiac magnetic resonance (CMR) imaging was further developed in the UK Biobank. Analyses were performed between August 2023 and February 2024.

Exposure

DASSi (range, 0-1) derived from AI applied to echocardiography and CMR videos.

Main Outcomes and Measures

Annualized change in peak aortic valve velocity (AV-Vmax) and late (>6 months) aortic valve replacement (AVR).

Results

A total of 12 599 participants were included in the echocardiographic study (YNHHS: n = 8798; median [IQR] age, 71 [60-80] years; 4250 [48.3%] women; median [IQR] follow-up, 4.1 [2.4-5.4] years; and CSMC: n = 3801; median [IQR] age, 67 [54-78] years; 1685 [44.3%] women; median [IQR] follow-up, 3.4 [2.8-3.9] years). Higher baseline DASSi was associated with faster progression in AV-Vmax (per 0.1 DASSi increment: YNHHS, 0.033 m/s per year [95% CI, 0.028-0.038] among 5483 participants; CSMC, 0.082 m/s per year [95% CI, 0.053-0.111] among 1292 participants), with values of 0.2 or greater associated with a 4- to 5-fold higher AVR risk than values less than 0.2 (YNHHS: 715 events; adjusted hazard ratio [HR], 4.97 [95% CI, 2.71-5.82]; CSMC: 56 events; adjusted HR, 4.04 [95% CI, 0.92-17.70]), independent of age, sex, race, ethnicity, ejection fraction, and AV-Vmax. This was reproduced across 45 474 participants (median [IQR] age, 65 [59-71] years; 23 559 [51.8%] women; median [IQR] follow-up, 2.5 [1.6-3.9] years) undergoing CMR imaging in the UK Biobank (for participants with DASSi ≥0.2 vs those with DASSi <.02, adjusted HR, 11.38 [95% CI, 2.56-50.57]). Saliency maps and phenome-wide association studies supported associations with cardiac structure and function and traditional cardiovascular risk factors.

Conclusions and Relevance

In this cohort study of patients without severe AS undergoing echocardiography or CMR imaging, a new AI-based video biomarker was independently associated with AS development and progression, enabling opportunistic risk stratification across cardiovascular imaging modalities as well as potential application on handheld devices.

FAPI-PET in Cardiovascular Disease

PET probes targeting fibroblasts are frequently used for varying applications in oncology. In recent years, the clinical spectrum has been expanded towards cardiovascular medicine, e.g., after myocardial infarction, in aortic stenosis or as a non-invasive read-out of atherosclerosis. We herein provide a brief overview of the current status of this PET radiotracer in the context of cardiovascular disease, including translational and clinical evidence. In addition, we will also briefly discuss future applications, e.g., the use of fibroblast-targeting PET to investigate bilateral organ function along the cardiorenal axis.

[Precision medicine enhances personalized medicine in cardiology]

Personalized medicine and precision medicine, frequently used synonymously, shall be clearly differentiated. Accordingly, personalization in cardiac medicine is based on the clinical presentation of a patient, as well as his/her cardiovascular risk factors and comorbidities, electrocardiography, imaging, and biomarkers for myocardial load and ischemia. Personalization is based on large clinical trials with detailed subgroup analyses and is practiced on the basis of guidelines. Further in depth personalization is achieved by precision medicine, which is based on innovative imaging for myocardial structure, coronary morphology, and electrophysiology. From the clinical perspective, genome analyses are relevant for comparatively rare monogenetic cardiovascular diseases. While these as well as transcriptome and metabolome analyses play a significant role in cardiovascular research with great translation potential, they have not yet been broadly introduced in the diagnosis, prevention, and treatment of complex cardiovascular diseases. Furthermore, digital technologies have considerable potential in cardiovascular precision medicine. On the one hand, this is based on the frequency of the diseases with the availability of Big Data and, on the other hand, on the availability of bio-signals and sensors of those signals in cardiovascular diseases.

Epicardial adipose tissue as an independent predictor of long-term outcome in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

BACKGROUND

Accurate risk stratification is important to improve patient selection and outcome of patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). As epicardial adipose tissue (EAT) is discussed to be involved in cardiovascular disease, it could be useful as a marker of poor prognosis in patients with severe AS undergoing TAVR.

METHODS

A total of 416 patients diagnosed with severe AS by transthoracic echocardiography were assigned for TAVR and enrolled for systematic assessment. Patients underwent clinical surveys and 5-year long-term follow-up, with all-cause mortality as the primary endpoint. EAT volume was quantified on pre-TAVR planning CTs. Patients were retrospectively dichotomized at the median of 74 cm3 of EAT into groups with low EAT and high EAT volumes. Mortality rates were compared using Kaplan-Meyer plots and uni- and multivariable cox regression analyses.

RESULTS

A total number of 341 of 416 patients (median age 80.9 years, 45% female) were included in the final analysis. Patients with high EAT volumes had similar short-term outcome (p = 0.794) but significantly worse long-term prognosis (p = 0.023) compared to patients with low EAT volumes. Increased EAT volumes were associated with worse long-term outcome (HR1.59; p = 0.031) independently from concomitant cardiovascular risk factors, general type of AS, and functional echocardiography parameters of AS severity (HR1.69; p = 0.013).

CONCLUSION

Increased EAT volume is an independent predictor of all-cause mortality in patients with severe AS undergoing TAVR. It can be easily obtained from pre-TAVR planning CTs and may thus qualify as a novel marker to improve prognostication and management of patient with severe AS.

TRIAL REGISTRATION

DRKS, DRKS00024479.

Low-flow in aortic valve stenosis patients with reduced ejection fraction does not depend on left ventricular function

BACKGROUND

Patients with severe aortic stenosis (AS) and reduced left ventricular ejection fraction (LVEF) can be distinguished into high- (HG) and low-gradient (LG) subgroups. However, less is known about their characteristics and underlying (pathophysiological) hemodynamic mechanisms.

METHODS

98 AS patients with reduced LVEF were included. Subgroup characteristics were analyzed by a multimodal approach using clinical and histological data, next-generation sequencing (NGS) and applying echocardiography as well as cardiovascular magnetic resonance (CMR) imaging. Biopsy samples were analyzed with respect to fibrosis and mRNA expression profiles.

RESULTS

40 patients were classified as HG-AS and 58 patients as LG-AS. Severity of AS was comparable between the subgroups. Comparison of both subgroups revealed no differences in LVEF (p = 0.1), LV mass (p = 0.6) or end-diastolic LV diameter (p = 0.12). Neither histological (HG: 23.2% vs. LG: 25.6%, p = 0.73) and circulating biomarker-based assessment (HG: 2.6 ± 2.2% vs. LG: 3.2 ± 3.1%; p = 0.46) of myocardial fibrosis nor global gene expression patterns differed between subgroups. Mitral regurgitation (MR), atrial fibrillation (AF) and impaired right ventricular function (MR: HG: 8% vs. LG: 24%; p < 0.001; AF: HG: 30% vs. LG: 51.7%; p = 0.03; RVSVi: HG 36.7 vs. LG 31.1 ml/m2, p = 0.045; TAPSE: HG 20.2 vs. LG 17.3 mm, p = 0.002) were more frequent in LG-AS patients compared to HG-AS. These pathologies could explain the higher mortality of LG vs. HG-AS patients.

CONCLUSION

In patients with low-flow severe aortic stenosis, low transaortic gradient and cardiac output are not primarily due to LV dysfunction or global changes in gene expression, but may be attributed to other additional cardiac pathologies like mitral regurgitation, atrial fibrillation or right ventricular dysfunction. These factors should also be considered during planning of aortic valve replacement.

Association Between Left Ventricular Apical-to-Basal Strain Ratio and Conduction Disorders after Aortic Valve Replacement

BACKGROUND

The aim of the study was to evaluate whether left ventricular apical-to-basal longitudinal strain differences, representing advanced basal interstitial fibrosis, are associated with conduction disorders after aortic valve replacement (AVR) in patients with severe aortic stenosis.

METHODS

Patients with aortic stenosis undergoing AVR were included. The apical-to-basal strain ratio was calculated by dividing the average strain of the apical segments by the average strain of the basal segments. Values >1.9 were considered abnormal, as previously described. All patients were followed up for the occurrence of complete left or right bundle branch block or permanent pacemaker implantation within 2 years after AVR. Subgroup analysis was performed in patients undergoing transcatheter AVR.

RESULTS

Two hundred seventy-four patients were included (median age of 74 years [interquartile range, 65, 80], 46.4% male). During a median follow-up of 12.2 months (interquartile range, 0.2, 24.3), 74 patients (27%) developed complete bundle branch block or were implanted with a permanent pacemaker. These patients more often had an abnormal apical-to-basal strain ratio. Cumulative event-free survival analysis showed worse outcome in patients with an abnormal apical-to-basal strain ratio (log rank χ2 = 7.258, P = .007). In multivariable Cox regression analysis, an abnormal apical-to-basal strain ratio was the only independent factor associated with the occurrence of complete bundle branch block or permanent pacemaker implantation after adjusting for other factors previously shown to be associated with conduction disorders after AVR. Subgroup analysis confirmed the independent association of an abnormal apical-to-basal strain ratio with conduction disorders after transcatheter AVR.

CONCLUSION

The apical-to-basal strain ratio is independently associated with conduction disorders after AVR and could guide risk stratification in patients potentially at risk for pacemaker implantation.

Strain Assessment in Aortic Stenosis: Pathophysiology and Clinical Utility

Contemporary echocardiographic criteria for grading aortic stenosis severity have remained relatively unchanged, despite significant advances in noninvasive imaging techniques over the last 2 decades. More recently, attention has shifted to the ventricular response to aortic stenosis and how this might be quantified. Global longitudinal strain, semiautomatically calculated from standard two-dimensional echocardiographic images, has been the focus of extensive research. Global longitudinal strain is a sensitive marker of subtle hypertrophy-related impairment in left ventricular function and has shown promise as a relatively robust prognostic marker, both independently and when added to severity classification systems. Herein we review the pathophysiological basis underpinning the potential utility of global longitudinal strain in the assessment of aortic stenosis, as well as its potential role in quantifying myocardial recovery and prognostic discrimination following aortic valve replacement.

Myocardial Fibrosis: Emerging Target for Cardiac Molecular Imaging and Opportunity for Image-Guided Therapy

Myocardial fibrosis is a major contributor to the development and progression of heart failure. Significant progress in the understanding of its pathobiology has led to the introduction and preclinical testing of multiple highly specific antifibrotic therapies. Because the mechanisms of fibrosis are highly dynamic, and because the involved cell populations are heterogeneous and plastic, there is increasing emphasis that any therapy directed specifically against myocardial fibrosis will require personalization and guidance by equally specific diagnostic testing for successful clinical translation. Noninvasive imaging techniques have undergone significant progress and provide increasingly specific information about the quantity, quality, and activity of myocardial fibrosis. Cardiac MRI can precisely map the extracellular space of the myocardium, whereas nuclear imaging characterizes activated fibroblasts and immune cells as the cellular components contributing to fibrosis. Existing techniques may be used in complementarity to provide the imaging biomarkers needed for the success of novel targeted therapies. This review provides a road map on how progress in basic fibrosis research, antifibrotic drug development, and high-end noninvasive imaging may come together to facilitate the success of fibrosis-directed cardiovascular medicine.

Role of Cardiac Energetics in Aortic Stenosis Disease Progression: Identifying the High-risk Metabolic Phenotype

BACKGROUND

Severe aortic stenosis (AS) is associated with left ventricular (LV) hypertrophy and cardiac metabolic alterations with evidence of steatosis and impaired myocardial energetics. Despite this common phenotype, there is an unexplained and wide individual heterogeneity in the degree of hypertrophy and progression to myocardial fibrosis and heart failure. We sought to determine whether the cardiac metabolic state may underpin this variability.

METHODS

We recruited 74 asymptomatic participants with AS and 13 healthy volunteers. Cardiac energetics were measured using phosphorus spectroscopy to define the myocardial phosphocreatine to adenosine triphosphate ratio. Myocardial lipid content was determined using proton spectroscopy. Cardiac function was assessed by cardiovascular magnetic resonance cine imaging.

RESULTS

Phosphocreatine/adenosine triphosphate was reduced early and significantly across the LV wall thickness quartiles (Q2, 1.50 [1.21-1.71] versus Q1, 1.64 [1.53-1.94]) with a progressive decline with increasing disease severity (Q4, 1.48 [1.18-1.70]; P=0.02). Myocardial triglyceride content levels were overall higher in all the quartiles with a significant increase seen across the AV pressure gradient quartiles (Q2, 1.36 [0.86-1.98] versus Q1, 1.03 [0.81-1.56]; P=0.034). While all AS groups had evidence of subclinical LV dysfunction with impaired strain parameters, impaired systolic longitudinal strain was related to the degree of energetic impairment (r=0.219; P=0.03). Phosphocreatine/adenosine triphosphate was not only an independent predictor of LV wall thickness (r=-0.20; P=0.04) but also strongly associated with myocardial fibrosis (r=-0.24; P=0.03), suggesting that metabolic changes play a role in disease progression. The metabolic and functional parameters showed comparable results when graded by clinical severity of AS.

CONCLUSIONS

A gradient of myocardial energetic deficit and steatosis exists across the spectrum of hypertrophied AS hearts, and these metabolic changes precede irreversible LV remodeling and subclinical dysfunction. As such, cardiac metabolism may play an important and potentially causal role in disease progression.

Low levels of circulating methylated IRX3 are related to worse outcome after transcatheter aortic valve implantation in patients with severe aortic stenosis

BACKGROUND

Aortic stenosis (AS) is one of the most common cardiac diseases and major cause of morbidity and mortality in the elderly. Transcatheter aortic valve implantation (TAVI) is performed in such patients with symptomatic severe AS and reduces mortality for the majority of these patients. However, a significant percentage dies within the first two years after TAVI, such that there is an interest to identify parameters, which predict outcome and could guide pre-TAVI patient selection. High levels of cardiac fibrosis have been identified as such independent predictor of cardiovascular mortality after TAVI. Promoter hypermethylation commonly leads to gene downregulation, and the Iroquois homeobox 3 (IRX3) gene was identified in a genome-wide transcriptome and methylome to be hypermethylated and downregulated in AS patients. In a well-described cohort of 100 TAVI patients in which cardiac fibrosis levels were quantified histologically in cardiac biopsies, and which had a follow-up of up to two years, we investigated if circulating methylated DNA of IRX3 in the peripheral blood is associated with cardiac fibrosis and/or mortality in AS patients undergoing TAVI and thus could serve as a biomarker to add information on outcome after TAVI.

RESULTS

Patients with high levels of methylation in circulating IRX3 show a significantly increased survival as compared to patients with low levels of IRX3 methylation indicating that high peripheral IRX3 methylation is associated with an improved outcome. In the multivariable setting, peripheral IRX3 methylation acts as an independent predictor of all-cause mortality. While there is no significant correlation of levels of IRX3 methylation with cardiac death, there is a significant but very weak inverse correlation between circulating IRX3 promoter methylation level and the amount of cardiac fibrosis. Higher levels of peripheral IRX3 methylation further correlated with decreased cardiac IRX3 expression and vice versa.

CONCLUSIONS

High levels of IRX3 methylation in the blood of AS patients at the time of TAVI are associated with better overall survival after TAVI and at least partially reflect myocardial IRX3 expression. Circulating methylated IRX3 might aid as a potential biomarker to help guide both pre-TAVI patient selection and post-TAVI monitoring.

First-Phase Ejection Fraction and Long-Term Survival in Patients Who Underwent Transcatheter Aortic Valve Implantation

Early recognition of deteriorating left ventricular function plays a key prognostic role in patients with aortic stenosis (AS). First-phase ejection fraction (EF1), the ejection fraction (EF) up to time of maximal contraction, has been suggested for detection of early left ventricular dysfunction in patients with AS with preserved EF. This work aims to evaluate the predictive value of EF1 for assessment of long-term survival in patients with symptomatic severe AS and preserved EF who undergo transcatheter aortic valve implantation (TAVI). We included 102 consecutive patients (median age 84 years [interquartile range 80 to 86 years]) who underwent TAVI between 2009 and 2011. Patients were retrospectively stratified into tertiles by EF1. Device success and procedural complications were defined according to the Valve Academic Research Consortium-3 criteria. Mortality data were retrieved from a computerized interface of the Israeli Ministry of Health. Baseline characteristics, co-morbidities, clinical presentation, and echocardiographic findings were similar among groups. The groups did not differ significantly regarding device success and in-hospital complications. During a potential follow-up period of >10 years, 88 patients died. Kaplan-Meier analysis (log-rank p = 0.017) followed by multivariable Cox regression analysis showed that EF1 predicted long-term mortality independently, either as continuous variable (hazard ratio 1.04, 95% confidence interval 1.01 to 1.07, p = 0.012) or for each decrease in tertile group (hazard ratio 1.40, 95% confidence interval 1.05 to 1.86, p = 0.023). In conclusion, low EF1 is associated with a significant decrease in adjusted hazard for long-term survival in patients with preserved EF who undergo TAVI. Low EF1 might delineate a population at great risk who would benefit from prompt intervention.

Impact of early changes in cardiac damage following transcatheter aortic valve implantation

BACKGROUND

The staging classification of aortic stenosis (AS) which characterises the extent of cardiac damage has been validated in patients undergoing transcatheter aortic valve implantation (TAVI). Short-term changes in cardiac damage after TAVI and their association with long-term prognosis remain unknown.

AIMS

This study aims to investigate the early evolution of cardiac damage after TAVI and the association of residual cardiac damage with clinical outcomes in TAVI recipients.

METHODS

AS patients undergoing TAVI were consecutively enrolled and classified into five stages of cardiac damage (0-4). Early change in cardiac damage was defined as any change of stage at 30 days (Δcardiac damage between baseline pre-TAVI and 30 days post-TAVI).

RESULTS

Within 30 days post-TAVI, the baseline cardiac damage stage had changed in 22.2% of 644 TAVI recipients, accompanied by improvements in the degree of dyspnoea and left ventricular ejection fraction (LVEF). Two-year mortality was associated with residual cardiac damage within 30 days post-TAVI (hazard ratio [HR] 2.97, 95% confidence interval [CI]: 2.07-4.25; p<0.001). Compared to unchanged cardiac damage post-TAVI, further cardiac damage within 30 days was associated with a higher crude risk of 2-year mortality (HR 22.04, 95% CI: 9.87-49.20; p<0.001). Cardiac deterioration within 30 days post-TAVI was an independent risk factor for 2-year mortality (HR 19.564, 95% CI: 8.047-47.565; p<0.001).

CONCLUSIONS

This investigation provided insight into the early evolution of cardiac damage in TAVI recipients and confirmed the predictive value of both residual and early changes in cardiac damage post-TAVI. Cardiac deterioration within 30 days is associated with poor clinical prognosis.

Molecular Imaging of Myocardial Fibroblast Activation in Patients with Advanced Aortic Stenosis Before Transcatheter Aortic Valve Replacement: A Pilot Study

Using multimodal imaging, we investigated the extent and functional correlates of myocardial fibroblast activation in patients with aortic stenosis (AS) scheduled for transcatheter aortic valve replacement (TAVR). AS may cause myocardial fibrosis, which is associated with disease progression and may limit response to TAVR. Novel radiopharmaceuticals identify upregulation of fibroblast activation protein (FAP) as a cellular substrate of cardiac profibrotic activity. Methods: Twenty-three AS patients underwent ⁶⁸Ga-FAP inhibitor 46 (⁶⁸Ga-FAPI) PET, cardiac MRI, and echocardiography within 1-3 d before TAVR. Imaging parameters were correlated and then were integrated with clinical and blood biomarkers. Control cohorts of subjects without a history of cardiac disease and with (n = 5) and without (n = 9) arterial hypertension were compared with matched AS subgroups. Results: Myocardial FAP volume varied significantly among AS subjects (range, 1.54-138 cm³, mean ± SD, 42.2 ± 35.6 cm³) and was significantly higher than in controls with (7.42 ± 8.56 cm³, P = 0.007) and without (2.90 ± 6.67 cm³; P < 0.001) hypertension. FAP volume correlated with N-terminal prohormone of brain natriuretic peptide (r = 0.58, P = 0.005), left ventricular ejection fraction (r = -0.58, P = 0.02), mass (r = 0.47, P = 0.03), and global longitudinal strain (r = 0.55, P = 0.01) but not with cardiac MRI T1 (spin-lattice relaxation time) and extracellular volume (P = not statistically significant). In-hospital improvement in left ventricular ejection fraction after TAVR correlated with pre-TAVR FAP volume (r = 0.440, P = 0.035), N-terminal prohormone of brain natriuretic peptide, and strain but not with other imaging parameters. Conclusion: FAP-targeted PET identifies varying degrees of left ventricular fibroblast activation in TAVR candidates with advanced AS. ⁶⁸Ga-FAPI signal does not match other imaging parameters, generating the hypothesis that it may become useful as a tool for personalized selection of optimal TAVR candidates.

The Role of ECG Strain Pattern in Prognosis after TAVI: A Sub-Analysis of the DIRECT Trial

BACKGROUND

The presence of an electrocardiographic (ECG) strain pattern-among other ECG features-has been shown to be predictive of adverse cardiovascular outcomes in asymptomatic patients with aortic stenosis. However, data evaluating its impact on symptomatic patients undergoing TAVI are scarce. Therefore, we tried to investigate the prognostic impact of baseline ECG strain pattern on clinical outcomes after TAVI.

METHODS

A sub-group of patients of the randomized DIRECT (Pre-dilatation in Transcatheter Aortic Valve Implantation Trial) trial with severe aortic stenosis who underwent TAVI with a self-expanding valve in one single center were consecutively enrolled. Patients were categorized into two groups according to the presence of ECG strain. Left ventricular strain was defined as the presence of ≥1 mm convex ST-segment depression with asymmetrical T-wave inversion in leads V5 to V6 on the baseline 12-lead ECG. Patients were excluded if they had paced rhythm or left bundle branch block at baseline. Multivariate Cox proportional hazard regression models were generated to assess the impact on outcomes. The primary clinical endpoint was all-cause mortality at 1 year after TAVI.

RESULTS

Of the 119 patients screened, 5 patients were excluded due to left bundle branch block. Among the 114 included patients (mean age: 80.8 ± 7), 37 patients (32.5%) had strain pattern on pre-TAVI ECG, while 77 patients (67.5%) did not exhibit an ECG strain pattern. No differences in baseline characteristics were found between the two groups. At 1 year, seven patients reached the primary clinical endpoint, with patients in the strain group demonstrating significantly higher mortality in Kaplan-Meier plots compared to patients without left ventricular strain (five vs. two, log-rank p = 0.022). There was no difference between the strain and no strain group regarding the performance of pre-dilatation (21 vs. 33, chi-square p = 0.164). In the multivariate analysis, left ventricular strain was found to be an independent predictor of all-cause mortality after TAVI [Exp(B): 12.2, 95% Confidence Intervals (CI): 1.4-101.9].

CONCLUSION

Left ventricular ECG strain is an independent predictor of all-cause mortality after TAVI. Thus, baseline ECG characteristics may aid in risk-stratifying patients scheduled for TAVI.

Association between trajectories in cardiac damage and clinical outcomes after transcatheter aortic valve replacement

BACKGROUND

There is little evidence of evolution in cardiac damage after transcatheter aortic valve replacement (TAVR) in aortic stenosis (AS) patients. Less is known about the prognostic value and potential utility of different cardiac damage trajectories following TAVR.

OBJECTIVES

This study aims to investigate the cardiac damage trajectories following TAVR and explore their association with subsequent clinical outcomes.

METHODS

AS patients undergoing TAVR were enrolled and classified into five cardiac damage stages (0-4) based on the echocardiographic staging classification retrospectively. They were further grouped into early stage (stage 0-2) and advanced stage (stage 3-4). The cardiac damage trajectories in TAVR recipients were evaluated according to their trend between baseline and 30 days after TAVR.

RESULTS

A total of 644 TAVR recipients were enrolled, with four distinct trajectories identified. Compared to patients with early-early trajectory, patients with early-advanced trajectory were at 30-fold risk of all-cause death (HR 30.99, 95% CI 13.80-69.56; p < 0.001). In multivariable analyses, early-advanced trajectory was associated with higher 2-year all-cause death (HR 24.08, 95% CI 9.07-63.90; p < 0.001), cardiac death (HR 19.34, 95% CI 3.06-122.34; p < 0.05), and cardiac rehospitalization (HR 4.19, 95% CI 1.49-11.76; p < 0.05) after TAVR.

CONCLUSIONS

This investigation provided insight into four cardiac damage trajectories in TAVR recipients and confirmed the prognostic value of distinct trajectories. Early-advanced trajectory was associated with poor clinical prognosis following TAVR.

Regression of cardiac hypertrophy in health and disease: mechanisms and therapeutic potential

Left ventricular hypertrophy is a leading risk factor for cardiovascular morbidity and mortality. Although reverse ventricular remodelling was long thought to be irreversible, evidence from the past three decades indicates that this process is possible with many existing heart disease therapies. The regression of pathological hypertrophy is associated with improved cardiac function, quality of life and long-term health outcomes. However, less than 50% of patients respond favourably to most therapies, and the reversibility of remodelling is influenced by many factors, including age, sex, BMI and disease aetiology. Cardiac hypertrophy also occurs in physiological settings, including pregnancy and exercise, although in these cases, hypertrophy is associated with normal or improved ventricular function and is completely reversible postpartum or with cessation of training. Studies over the past decade have identified the molecular features of hypertrophy regression in health and disease settings, which include modulation of protein synthesis, microRNAs, metabolism and protein degradation pathways. In this Review, we summarize the evidence for hypertrophy regression in patients with current first-line pharmacological and surgical interventions. We further discuss the molecular features of reverse remodelling identified in cell and animal models, highlighting remaining knowledge gaps and the essential questions for future investigation towards the goal of designing specific therapies to promote regression of pathological hypertrophy.

Echocardiographic Evaluation after Transcatheter Aortic Valve Implantation: A Comprehensive Review

Transcatheter aortic valve implantation (TAVI) is an increasingly popular treatment option for patients with severe aortic stenosis. Recent advancements in technology and imaging tools have significantly contributed to the success of TAVI procedures. Echocardiography plays a pivotal role in the evaluation of TAVI patients, both before and after the procedure. This review aims to provide an overview of the most recent technical advancements in echocardiography and their use in the follow-up of TAVI patients. In particular, the focus will be on the examination of the influence of TAVI on left and right ventricular function, which is frequently accompanied by other structural and functional alterations. Echocardiography has proven to be key also in detecting valve deterioration during extended follow-up. This review will provide valuable insights into the technical advancements in echocardiography and their role in the follow-up of TAVI patients.

Aggravated pneumonia and diabetes in SARS-CoV-2 infected diabetic mice

Multiple clinical and epidemiological studies have shown an interconnection between coronavirus disease 2019 (COVID-19) and diabetes, but experimental evidence is still lacking. Understanding the interplay between them is important because of the global health burden of COVID-19 and diabetes. We found that C57BL/6J mice were susceptible to the alpha strain of SARS-CoV-2. Moreover, diabetic C57BL/6J mice with leptin receptor gene deficiency (db/db mice) showed a higher viral load in the throat and lung and slower virus clearance in the throat after infection than C57BL/6J mice. Histological and multifactor analysis revealed more advanced pulmonary injury and serum inflammation in SARS-CoV-2 infected diabetic mice. Moreover, SARS-CoV-2 infected diabetic mice exhibited more severe insulin resistance and islet cell loss than uninfected diabetic mice. By RNA sequencing analysis, we found that diabetes may reduce the collagen level, suppress the immune response and aggravate inflammation in the lung after infection, which may account for the greater susceptibility of diabetic mice and their more severe lung damage after infection. In summary, we successfully established a SARS-CoV-2 infected diabetic mice model and demonstrated that diabetes and COVID-19 were risk factors for one another.

Aortic valve calcification and myocardial fibrosis determine outcome following transcatheter aortic valve replacement

AIMS

There is evidence to suggest that the subtype of aortic stenosis (AS), the degree of myocardial fibrosis (MF), and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Because little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as their association with adverse cardiac events following transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

One hundred consecutive patients with severe AS and indication for TAVR were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multidetector computed tomography, and left ventricular endomyocardial biopsies at the time of TAVR. The final study cohort consisted of 92 patients with a completed study protocol, 39 (42.4%) of whom showed a normal ejection fraction (EF) high-gradient (NEFHG) AS, 13 (14.1%) a low EF high-gradient (LEFHG) AS, 25 (27.2%) a low EF low-gradient (LEFLG) AS, and 15 (16.3%) a paradoxical low-flow, low-gradient (PLFLG) AS. The high-gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807 ± 421 and 813 ± 281 mm³ , respectively) as compared with the low-gradient phenotypes (LEFLG and PLFLG; 503 ± 326 and 555 ± 594 mm³ , respectively, P < 0.05). Conversely, MF was most prevalent in low-output phenotypes (LEFLG > LEFHG > PLFLG > NEFHG, P < 0.05). This was paralleled by a greater cardiovascular (CV) mortality within 600 days after TAVR (LEFLG 28% > PLFLG 26.7% > LEFHG 15.4% > NEFHG 2.5%; P = 0.023). In patients with a high MF burden, a higher AVC was associated with a lower mortality following TAVR (P = 0.045, hazard ratio 0.261, 95% confidence interval 0.07-0.97).

CONCLUSIONS

MF is associated with adverse CV outcome following TAVR, which is most prevalent in low EF situations. In the presence of large MF burden, patients with large AVC have better outcome following TAVR. Conversely, worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy. The better survival rates in large AVC patients following TAVR indicate TAVR induced relief of severe AS-associated pressure overload with subsequently improved outcome.

Disease- and sex-specific differences in patients with heart valve disease: a proteome study

Pressure overload in patients with aortic valve stenosis and volume overload in mitral valve regurgitation trigger specific forms of cardiac remodeling; however, little is known about similarities and differences in myocardial proteome regulation. We performed proteome profiling of 75 human left ventricular myocardial biopsies (aortic stenosis = 41, mitral regurgitation = 17, and controls = 17) using high-resolution tandem mass spectrometry next to clinical and hemodynamic parameter acquisition. In patients of both disease groups, proteins related to ECM and cytoskeleton were more abundant, whereas those related to energy metabolism and proteostasis were less abundant compared with controls. In addition, disease group-specific and sex-specific differences have been observed. Male patients with aortic stenosis showed more proteins related to fibrosis and less to energy metabolism, whereas female patients showed strong reduction in proteostasis-related proteins. Clinical imaging was in line with proteomic findings, showing elevation of fibrosis in both patient groups and sex differences. Disease- and sex-specific proteomic profiles provide insight into cardiac remodeling in patients with heart valve disease and might help improve the understanding of molecular mechanisms and the development of individualized treatment strategies.

Peak systolic myocardial velocity in patients undergoing surgical aortic valve replacement for severe aortic stenosis: prognostic value and natural course

Myocardial systolic longitudinal function has been known to decrease in patients with severe aortic stenosis (AS). Preoperative peak systolic myocardial velocity at the septal mitral valve annulus (S'), measured using Doppler tissue imaging, was used as an indicator for myocardial systolic longitudinal function. The prognostic value and natural course of S' after surgical aortic valve replacement for severe AS have not been elucidated. This retrospective observational study included patients from January 2006 to December 2018. The patients were divided to 2 groups (pre-S'_HIGH vs. pre-S'_LOW) with a cut-off 5.4 cm/s of preoperative S' (pre-S') that was identified by restricted cubic spline curve. The primary outcome was postoperative long-term all-cause mortality. Nine hundred and five patients were analyzed. All-cause mortality rate at the median follow-up period of 5.2 years was 12% in pre-S'_LOW and 8% in pre-S'_HIGH. Multivariate analysis showed that pre-S'_LOW was associated with an increased all-cause mortality (hazard ratio, 1.60; 95% confidence interval, 1.04-2.48; P = 0.032). Significantly different trajectories of postoperative S' (post-S') were found between two groups (P < 0.001 for difference): In pre-S'_LOW, post-S' increased within 6 months after surgery, and gradually decreased over time, whereas it slowly decreased up to 5 years after surgery and then reached a plateau in pre-S'_HIGH. The difference in pre-S' level maintained over time, and remained consistent in the adjusted analysis. Pre-S' < 5.4 cm/s was found to be associated with an increased long-term all-cause mortality. In addition, the trajectories for post-S' were different according to pre-S', which remained after adjustment.

Metabolomic Profiling in Patients with Different Hemodynamic Subtypes of Severe Aortic Valve Stenosis

Severe aortic stenosis (AS) is a common pathological condition in an ageing population imposing significant morbidity and mortality. Based on distinct hemodynamic features, i.e., ejection fraction (EF), transvalvular gradient and stroke volume, four different AS subtypes can be distinguished: (i) normal EF and high gradient, (ii) reduced EF and high gradient, (iii) reduced EF and low gradient, and (iv) normal EF and low gradient. These subtypes differ with respect to pathophysiological mechanisms, cardiac remodeling, and prognosis. However, little is known about metabolic changes in these different hemodynamic conditions of AS. Thus, we carried out metabolomic analyses in serum samples of 40 AS patients (n = 10 per subtype) and 10 healthy blood donors (controls) using ultrahigh-performance liquid chromatography-tandem mass spectroscopy. A total of 1293 biochemicals could be identified. Principal component analysis revealed different metabolic profiles in all of the subgroups of AS (All-AS) vs. controls. Out of the determined biochemicals, 48% (n = 620) were altered in All-AS vs. controls (p < 0.05). In this regard, levels of various acylcarnitines (e.g., myristoylcarnitine, fold-change 1.85, p < 0.05), ketone bodies (e.g., 3-hydroxybutyrate, fold-change 11.14, p < 0.05) as well as sugar metabolites (e.g., glucose, fold-change 1.22, p < 0.05) were predominantly increased, whereas amino acids (e.g., leucine, fold-change 0.8, p < 0.05) were mainly reduced in All-AS. Interestingly, these changes appeared to be consistent amongst all AS subtypes. Distinct differences between AS subtypes were found for metabolites belonging to hemoglobin metabolism, diacylglycerols, and dihydrosphingomyelins. These findings indicate that relevant changes in substrate utilization appear to be consistent for different hemodynamic subtypes of AS and may therefore reflect common mechanisms during AS-induced heart failure. Additionally, distinct metabolites could be identified to significantly differ between certain AS subtypes. Future studies need to define their pathophysiological implications.

Pleomorphic Ventricular Tachycardia in Dilated Cardiomyopathy Predicts Ventricular Tachycardia Recurrence After Ablation Independent From Cardiac Function: Comparison With Patients With Ischemic Heart Disease

BACKGROUND

In dilated cardiomyopathy (DCM), outcome after catheter ablation of ventricular tachycardia (VT) is modest, compared with ischemic heart disease (IHD). Pleomorphic VT (PL-VT) has been associated with fibrotic remodeling and end-stage heart failure in IHD. The prognostic role of PL-VT in DCM is unknown.

METHODS

Consecutive IHD (2009-2016) or DCM (2008-2018) patients undergoing ablation for monomorphic VT were included. PL-VT was defined as ≥1 spontaneous change of the 12-lead VT-morphology during the same induced VT episode. Patients were followed for VT recurrence and mortality.

RESULTS

A total of 247 patients (86% men; 63±13 years; IHD n=152; DCM n=95) underwent ablation for monomorphic VT. PL-VT was observed in 22 and 29 patients with IHD and DCM, respectively (14% versus 31%, P=0.003). In IHD, PL-VT was associated with lower LVEF (28±9% versus 34±12%, P=0.02) and only observed in those with LVEF<40%. In contrast, in DCM, PL-VT was not related to LVEF and induced in 27% of patients with LVEF>40%. During a median follow-up of 30 months, 79 (32%) patients died (IHD 48; DCM 31; P=0.88) and 120 (49%) had VT recurrence (IHD 59; DCM 61; P<0.001). PL-VT was associated with mortality in IHD but not in DCM. In IHD, VT recurrence was independently associated with LVEF, number of induced VTs, and procedural noncomplete success. Of note, in DCM, PL-VT (HR, 2.62 [95% CI, 1.47-4.69]), pathogenic mutation (HR, 2.13 [95% CI, 1.16-3.91]), and anteroseptal VT substrate (HR, 1.75 [95% CI, 1.00-3.07]) independently predicted VT recurrence.

CONCLUSIONS

In IHD, PL-VT was associated with low LVEF and mortality. In DCM, PL-VT was not associated with mortality but a predictor of VT recurrence independent from LVEF. PL-VT in DCM may indicate a specific arrhythmic substrate difficult to control by current ablation techniques.

Radiomic analysis of enhanced CMR cine images predicts left ventricular remodeling after TAVR in patients with symptomatic severe aortic stenosis

Objective

This study aimed to develop enhanced cine image-based radiomic models for non-invasive prediction of left ventricular adverse remodeling following transcatheter aortic valve replacement (TAVR) in symptomatic severe aortic stenosis.

Methods

A total of 69 patients (male:female = 37:32, median age: 66 years, range: 47-83 years) were retrospectively recruited, and severe aortic stenosis was confirmed via transthoracic echocardiography detection. The enhanced cine images and clinical variables were collected, and three types of regions of interest (ROIs) containing the left ventricular (LV) myocardium from the short-axis view at the basal, middle, and apical LV levels were manually labeled, respectively. The radiomic features were extracted and further selected by using the least absolute shrinkage and selection operator (LASSO) regression analysis. Clinical variables were also selected through univariate regression analysis. The predictive models using logistic regression classifier were developed and validated through leave-one-out cross-validation. The model performance was evaluated with respect to discrimination, calibration, and clinical usefulness.

Results

Five basal levels, seven middle levels, eight apical level radiomic features, and three clinical factors were finally selected for model development. The radiomic models using features from basal level (Rad I), middle level (Rad II), and apical level (Rad III) had achieved areas under the curve (AUCs) of 0.761, 0.909, and 0.913 in the training dataset and 0.718, 0.836, and 0.845 in the validation dataset, respectively. The performance of these radiomic models was improved after integrating clinical factors, with AUCs of the Combined I, Combined II, and Combined III models increasing to 0.906, 0.956, and 0.959 in the training dataset and 0.784, 0.873, and 0.891 in the validation dataset, respectively. All models showed good calibration, and the decision curve analysis indicated that the Combined III model had a higher net benefit than other models across the majority of threshold probabilities.

Conclusion

Radiomic models and combined models at the mid and apical slices showed outstanding and comparable predictive effectiveness of adverse remodeling for patients with symptomatic severe aortic stenosis after TAVR, and both models were significantly better than the models of basal slice. The cardiac magnetic resonance radiomic analysis might serve as an effective tool for accurately predicting left ventricular adverse remodeling following TAVR in patients with symptomatic severe aortic stenosis.

Scleraxis and fibrosis in the pressure-overloaded heart

AIMS

In response to pro-fibrotic signals, scleraxis regulates cardiac fibroblast activation in vitro via transcriptional control of key fibrosis genes such as collagen and fibronectin; however, its role in vivo is unknown. The present study assessed the impact of scleraxis loss on fibroblast activation, cardiac fibrosis, and dysfunction in pressure overload-induced heart failure.

METHODS AND RESULTS

Scleraxis expression was upregulated in the hearts of non-ischemic dilated cardiomyopathy patients, and in mice subjected to pressure overload by transverse aortic constriction (TAC). Tamoxifen-inducible fibroblast-specific scleraxis knockout (Scx-fKO) completely attenuated cardiac fibrosis, and significantly improved cardiac systolic function and ventricular remodelling, following TAC compared to Scx+/+ TAC mice, concomitant with attenuation of fibroblast activation. Scleraxis deletion, after the establishment of cardiac fibrosis, attenuated the further functional decline observed in Scx+/+ mice, with a reduction in cardiac myofibroblasts. Notably, scleraxis knockout reduced pressure overload-induced mortality from 33% to zero, without affecting the degree of cardiac hypertrophy. Scleraxis directly regulated transcription of the myofibroblast marker periostin, and cardiac fibroblasts lacking scleraxis failed to upregulate periostin synthesis and secretion in response to pro-fibrotic transforming growth factor β.

CONCLUSION

Scleraxis governs fibroblast activation in pressure overload-induced heart failure, and scleraxis knockout attenuated fibrosis and improved cardiac function and survival. These findings identify scleraxis as a viable target for the development of novel anti-fibrotic treatments.

Direct proteomic and high-resolution microscopy biopsy analysis identifies distinct ventricular fates in severe aortic stenosis

The incidence of aortic valve stenosis (AS), the most common reason for aortic valve replacement (AVR), increases with population ageing. While untreated AS is associated with high mortality, different hemodynamic subtypes range from normal left-ventricular function to severe heart failure. However, the molecular nature underlying four different AS subclasses, suggesting vastly different myocardial fates, is unknown. Here, we used direct proteomic analysis of small left-ventricular biopsies to identify unique protein expression profiles and subtype-specific AS mechanisms. Left-ventricular endomyocardial biopsies were harvested from patients during transcatheter AVR, and inclusion criteria were based on echocardiographic diagnosis of severe AS and guideline-defined AS-subtype classification: 1) normal ejection fraction (EF)/high-gradient; 2) low EF/high-gradient; 3) low EF/low-gradient; and 4) paradoxical low-flow/low-gradient AS. Samples from non-failing donor hearts served as control. We analyzed 25 individual left-ventricular biopsies by data-independent acquisition mass spectrometry (DIA-MS), and 26 biopsies by histomorphology and cardiomyocytes by STimulated Emission Depletion (STED) superresolution microscopy. Notably, DIA-MS reliably detected 2273 proteins throughout each individual left-ventricular biopsy, of which 160 proteins showed significant abundance changes between AS-subtype and non-failing samples including the cardiac ryanodine receptor (RyR2). Hierarchical clustering segregated unique proteotypes that identified three hemodynamic AS-subtypes. Additionally, distinct proteotypes were linked with AS-subtype specific differences in cardiomyocyte hypertrophy. Furthermore, superresolution microscopy of immunolabeled biopsy sections showed subcellular RyR2-cluster fragmentation and disruption of the functionally important association with transverse tubules, which occurred specifically in patients with systolic dysfunction and may hence contribute to depressed left-ventricular function in AS.

Current and novel echocardiographic assessment of left ventricular systolic function in aortic stenosis-A comprehensive review

Aortic stenosis (AS) is a complex and progressive condition that can significantly reduce the quality of life and increase the incidence of premature mortality. Transthoracic echocardiography (TTE) is the gold standard imaging modality for the assessment of AS severity. While left ventricular ejection fraction (LVEF) derived from TTE is a very well-understood parameter, limitations such as high inter and intra-observer variability, insensitivity to sub-clinical dysfunction, and influence of loading conditions make LVEF a complicated and unreliable parameter. Myocardial deformation imaging has been identified as a promising parameter for identifying subclinical left ventricular dysfunction, however, this parameter is still afterload dependent. Myocardial Work is a promising novel assessment technique that accounts for afterload by combining the use of myocardial deformation imaging and non-invasive blood pressure to provide a more comprehensive assessment of mechanics beyond LVEF. This review evaluates the evidence for various echocardiographic assessment parameters used to quantify left ventricular function including myocardial work in patients with AS.

Incidence and clinical impact of tachyarrhythmic events following transcatheter aortic valve replacement: A review

Transcatheter aortic valve replacement (TAVR) is well established for treating severe symptomatic aortic stenosis. Whereas broad information on the epidemiology, clinical implications, and management of bradyarrhythmias after TAVR is available, data about tachyarrhythmic events remain scarce. Despite the progressively lower risk profile of TAVR patients and the improvement in device characteristics and operator skills, approximately 10% of patients develop new-onset atrial fibrillation (NOAF) after TAVR. The proportion of patients in whom NOAF actually corresponds to previously undiagnosed silent atrial fibrillation (AF) has not been properly determined. The transapical approach, the need for pre- or post- balloon dilation, and the presence of periprocedural complications have been associated with a higher risk of NOAF. Older age, left atrial volume, or worse functional class are patient-derived risk factors shared with preprocedural AF. NOAF after TAVR has been associated with poorer survival and a higher incidence of cerebrovascular events. However, patient management differs markedly among different centers, especially with regard to anticoagulation in patients with short-duration AF episodes detected in the periprocedural setting and in cases of silent NOAF detected during continuous electrocardiographic (ECG) monitoring. Evidence about ventricular arrhythmias is even more scarce than for AF. Some case reports of sudden cardiac death after TAVR in patients with a pacemaker have identified ventricular tachycardia or ventricular fibrillation in device interrogation. TAVR has been shown to reduce the arrhythmic burden, but a significant proportion of patients (16%) present with complex premature ventricular complex arrhythmias within the year after TAVR. Whether these events are related to poorer outcomes is unknown. Continuous ECG monitoring after TAVR may help describe the frequency, risk factors, and prognostic implications of tachyarrhythmias in this population.

Left Ventricular Global Longitudinal Strain in Patients with Moderate Aortic Stenosis

Moderate aortic stenosis (AS) is associated with an increased risk for adverse events. Although reduced left ventricular (LV) global longitudinal strain (GLS) is associated with worse outcomes in patients with severe AS, its prognostic value in patients with moderate AS is unknown. The aim of this study was to investigate the prognostic implications of LV GLS in patients with moderate AS.

METHODS

LV GLS was evaluated using speckle-tracking echocardiography in patients with moderate AS (aortic valve area 1.0-1.5 cm²) and reported as absolute (i.e., positive) values. Patients were divided into three groups: LV ejection fraction (LVEF) < 50% (group 1), LVEF ≥ 50% but LV GLS < 16% (group 2), and LVEF ≥ 50% and LV GLS ≥ 16% (group 3). The LV GLS value of 16% was based on spline curve analysis. The primary end point was all-cause mortality.

RESULTS

A total of 760 patients (mean age, 71 ± 12 years; 61% men) were analyzed. During a median follow-up period of 50 months (interquartile range, 26-94 months), 257 patients (34%) died. Patients with LVEF < 50% and LVEF ≥ 50% but LV GLS < 16% showed significantly higher mortality rates at 1-, 3-, and 5-year follow-up (82%, 71%, and 58%; and 92%, 77%, and 58%, respectively) compared with those with LVEF ≥ 50% and LV GLS ≥ 16% (96%, 91%, and 85%, respectively; P < .001). Long-term outcomes were not different between patients with LVEF < 50% and those with LVEF ≥ 50% but LV GLS < 16% (P = .592). LV GLS discriminated higher risk patients even among those with LVEF ≥ 60% (P < .001) or those who were asymptomatic (P < .001). On multivariable analysis, LVEF < 50% (hazard ratio, 2.384; 95% CI, 1.614-3.522; P < .001) and LVEF ≥ 50% but LV GLS < 16% (hazard ratio, 2.467; 95% CI, 1.802-3.378; P < .001) were independently associated with all-cause mortality.

CONCLUSIONS

In patients with moderate AS, reduced LV GLS is associated with an increased risk for all-cause mortality, even if LVEF is still preserved.

Functional and structural reverse myocardial remodeling following transcatheter aortic valve replacement: a prospective cardiovascular magnetic resonance study

BACKGROUND

Since cardiovascular magnetic resonance (CMR) imaging allows comprehensive quantification of both myocardial function and structure we aimed to assess myocardial remodeling processes in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR).

METHODS

CMR imaging was performed in 40 patients with severe AS before and 1 year after TAVR. Image analyses comprised assessments of myocardial volumes, CMR-feature-tracking based atrial and ventricular strain, myocardial T1 mapping, extracellular volume fraction-based calculation of left ventricular (LV) cellular and matrix volumes, as well as ischemic and non-ischemic late gadolinium enhancement analyses. Moreover, biomarkers including NT-proBNP as well as functional and clinical status were documented.

RESULTS

Myocardial function improved 1 year after TAVR: LV ejection fraction (57.9 ± 16.9% to 65.4 ± 14.5%, p = 0.002); LV global longitudinal (- 21.4 ± 8.0% to -25.0 ± 6.4%, p < 0.001) and circumferential strain (- 36.9 ± 14.3% to - 42.6 ± 11.8%, p = 0.001); left atrial reservoir (13.3 ± 6.3% to 17.8 ± 6.7%, p = 0.001), conduit (5.5 ± 3.2% to 8.4 ± 4.6%, p = 0.001) and boosterpump strain (8.2 ± 4.6% to 9.9 ± 4.2%, p = 0.027). This was paralleled by regression of total myocardial volume (90.3 ± 21.0 ml/m2 to 73.5 ± 17.0 ml/m2, p < 0.001) including cellular (55.2 ± 13.2 ml/m2 to 45.3 ± 11.1 ml/m2, p < 0.001) and matrix volumes (20.7 ± 6.1 ml/m2 to 18.8 ± 5.3 ml/m2, p = 0.036). These changes were paralleled by recovery from heart failure (decrease of NYHA class: p < 0.001; declining NT-proBNP levels: 2456 ± 3002 ng/L to 988 ± 1222 ng/L, p = 0.001).

CONCLUSION

CMR imaging enables comprehensive detection of myocardial remodeling in patients undergoing TAVR. Regression of LV matrix volume as a surrogate for reversible diffuse myocardial fibrosis is accompanied by increase of myocardial function and recovery from heart failure. Further data are required to define the value of these parameters as therapeutic targets for optimized management of TAVR patients. Trial registration DRKS, DRKS00024479. Registered 10 December 2021-Retrospectively registered, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00024479.

Risk Stratification of New Persistent Left Bundle Branch Block After Transcatheter Aortic Valve Implantation

Previous studies reported that new-onset persistent left bundle branch block (NOP-LBBB) was related to worse outcomes after transcatheter aortic valve implantation (TAVI). However, these results can be confounded by the presence of permanent pacemaker (PPM) implantation before and after TAVI. Long-term outcomes and the risk stratification of NOP-LBBB not having PPM implantation before and after TAVI have not been fully investigated. This is an international, multicenter, retrospective study of patients who underwent TAVI from July 31, 2007, to May 8, 2020. A total of 2,240 patients were included, and 17.5% of patients developed NOP-LBBB. NOP-LBBB was associated with cardiac mortality (adjusted hazard ratio [aHR] 1.419, 95% confidence interval [CI] 1.014 to 1.985, p = 0.041) and the composite outcomes of cardiac mortality and/or heart failure readmission (aHR 1.313, 95% CI 1.027 to 1.678, p = 0.030). Patients who developed NOP-LBBB with pre-TAVI left ventricular ejection fraction (LVEF) <40% were significantly associated with cardiac mortality (aHR 2.049, 95% CI 1.039 to 4.041, p = 0.038), heart failure (aHR 3.990, 95% CI 2.362 to 6.741, p <0.001), and the composite outcome (aHR 2.729, 95% CI 1.703 to 4.374, p <0.001). Although NOP-LBBB with pre-TAVI LVEF >40% had a significant decrease in LVEF 6 to 12 months after TAVI (-1.8 ± 9.7% vs +0.6 ± 8.1%, p = 0.003), NOP-LBBB with pre-TAVI LVEF <40% had a significant increase in LVEF 6 to 12 months after TAVI (+9.7 ± 13.6% vs +13.0 ± 11.7%, p = 0.157). In conclusion, patients with NOP-LBBB without pre-TAVI and post-TAVI PPM developed significantly worse long-term outcomes, especially in patients with pre-TAVI LVEF <40%. Further prospective investigation should be undertaken.

Exploring myocardial fibrosis in severe aortic stenosis: echo, CMR and histology data from FIB-AS study

Myocardial fibrosis in aortic stenosis is associated with worse survival following aortic valve replacement. We assessed myocardial fibrosis in severe AS patients, integrating echocardiographic, cardiovascular magnetic resonance (CMR) and histological data. A total of 83 severe AS patients (age 66.4 ± 8.3, 42% male) who were scheduled for surgical AVR underwent CMR with late gadolinium enhancement and T1 mapping and global longitudinal strain analysis. Collagen volume fraction was measured in myocardial biopsies (71) that were sampled at the time of AVR. Results. CVF correlated with imaging and serum biomarkers of LV systolic dysfunction and left side chamber enlargement and was higher in the sub-endocardium compared with midmyocardium (p<0.001). CVF median values were higher in LGE-positive versus LGE-negative patients [28.7% (19-33) vs 20.7% (15-30), respectively, p=0.040]. GLS was associated with invasively (CVF; r=-0.303, p=0.013) and non-invasively (native T1; r=-0.321, p<0.05) measured myocardial fibrosis. GLS and native T1 correlated with parameters of adverse LV remodelling, systolic and diastolic dysfunction and serum biomarkers of heart failure and myocardial injury. Conclusion. Our data highlight the role of myocardial fibrosis in adverse cardiac remodelling in AS. GLS has potential as a surrogate marker of myocardial fibrosis, and high native T1 and low GLS values differentiated patients with more advanced cardiac remodelling.

Prognostic implications of left ventricular diastolic dysfunction in moderate aortic stenosis

OBJECTIVE

To investigate the prognostic impact of left ventricular (LV) diastolic dysfunction in patients with moderate aortic stenosis (AS) and preserved LV systolic function.

METHODS

Patients with a first diagnosis of moderate AS (aortic valve area >1.0 and ≤1.5 cm²) and preserved LV systolic function (LV ejection fraction ≥50%) were identified. LV diastolic function was evaluated using echocardiographic criteria according to the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. Clinical outcomes were defined as all-cause mortality and a composite of all-cause mortality and aortic valve replacement (AVR).

RESULTS

Of 1247 patients (age 74±10 years, 47% men), 535 (43%) had LV diastolic dysfunction at baseline. Patients with LV diastolic dysfunction showed significantly higher mortality rates at 1-year, 3-year and 5-year follow-up (13%, 30% and 41%, respectively) when compared with patients with normal LV diastolic function (6%, 17% and 29%, respectively) (p<0.001). On multivariable analysis, LV diastolic dysfunction was independently associated with all-cause mortality (HR 1.368; 95% CI 1.085 to 1.725; p=0.008) and the composite endpoint of all-cause mortality and AVR (HR 1.241; 95% CI 1.035 to 1.488; p=0.020).

CONCLUSIONS

LV diastolic dysfunction is independently associated with all-cause mortality and the composite endpoint of all-cause mortality and AVR in patients with moderate AS and preserved LV systolic function. Assessment of LV diastolic function therefore contributes significantly to the risk stratification of patients with moderate AS. Future clinical trials are needed to investigate whether patients with moderate AS and LV diastolic dysfunction may benefit from earlier valve intervention.

Feasibility of Coronary CT Angiography-derived Left Ventricular Long-Axis Shortening as an Early Marker of Ventricular Dysfunction in Transcatheter Aortic Valve Replacement

Purpose

To evaluate the value of using left ventricular (LV) long-axis shortening (LAS) derived from coronary CT angiography (CCTA) to predict mortality in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR).

Materials and Methods

Patients with severe AS who underwent CCTA for preprocedural TAVR planning between September 2014 and December 2019 were included in this retrospective study. CCTA covered the whole cardiac cycle in 10% increments. Image series reconstructed at end systole and end diastole were used to measure LV-LAS. All-cause mortality within 24 months of follow-up after TAVR was recorded. Cox regression analysis was performed, and hazard ratios (HRs) are presented with 95% CIs. The C index was used to evaluate model performance, and the likelihood ratio χ² test was performed to compare nested models.

Results

The study included 175 patients (median age, 79 years [IQR, 73-85 years]; 92 men). The mortality rate was 22% (38 of 175). When adjusting for predictive clinical confounders, it was found that LV-LAS could be used independently to predict mortality (adjusted HR, 2.83 [95% CI: 1.13, 7.07]; P = .03). In another model using the Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM), LV-LAS remained significant (adjusted HR, 3.38 [95 CI: 1.48, 7.72]; P = .004), and its use improved the predictive value of the STS-PROM, increasing the STS-PROM C index from 0.64 to 0.71 (χ² = 29.9 vs 19.7, P = .001). In a subanalysis of patients with a normal LV ejection fraction (LVEF), the significance of LV-LAS persisted (adjusted HR, 3.98 [95 CI: 1.56, 10.17]; P = .004).

Conclusion

LV-LAS can be used independently to predict mortality in patients undergoing TAVR, including those with a normal LVEF.Keywords: CT Angiography, Transcatheter Aortic Valve Implantation/Replacement (TAVI/TAVR), Cardiac, Outcomes Analysis, Cardiomyopathies, Left Ventricle, Aortic Valve Supplemental material is available for this article. © RSNA, 2022See also the commentary by Everett and Leipsic in this issue.

Cardiac remodelling - Part 2: Clinical, imaging and laboratory findings. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes. The remodelling process ultimately involves all cardiac chambers, but has been traditionally evaluated in terms of left ventricular volumes and ejection fraction. This is the second part of a review paper by the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology dedicated to ventricular remodelling. This document examines the proposed criteria to diagnose RR and AR, their prevalence and prognostic value, and the variables predicting remodelling in patients managed according to current guidelines. Much attention will be devoted to RR in patients with heart failure with reduced ejection fraction because most studies on cardiac remodelling focused on this setting.

BMP7-based peptide agonists of BMPR1A protect the left ventricle against pathological remodeling induced by pressure overload

Aortic stenosis (AS) exposes the left ventricle (LV) to pressure overload leading to detrimental LV remodeling and heart failure. In animal models of cardiac injury or hemodynamic stress, bone morphogenetic protein-7 (BMP7) protects LV against remodeling by counteracting TGF-β effects. BMP receptor 1A (BMPR1A) might mediate BMP7 antifibrotic effects. Herein we evaluated BMP7-based peptides, THR123 and THR184, agonists of BMPR1A, as cardioprotective drugs in a pressure overload model. We studied patients with AS, mice subjected to four-week transverse aortic constriction (TAC) and TAC release (de-TAC). The LV of AS patients and TAC mice featured Bmpr1a downregulation. Also, pSMAD1/5/(8)9 was reduced in TAC mice. Pre-emptive treatment of mice with THR123 and THR184, during the four-week TAC period, normalized pSMAD1/5/(8)9 levels in the LV, attenuated overexpression of remodeling-related genes (Col 1α1, β-MHC, BNP), palliated structural damage (hypertrophy and fibrosis) and alleviated LV dysfunction (systolic and diastolic). THR184 administration, starting fifteen days after TAC, halted the ongoing remodeling and partially reversed LV dysfunction. The reverse remodeling after pressure overload release was facilitated by THR184. Both peptides diminished the TGF-β1-induced hypertrophic gene program in cardiomyocytes, collagen transcriptional activation in fibroblasts, and differentiation of cardiac fibroblasts to myofibroblasts. Molecular docking suggests that both peptides bind with similar binding energies to the BMP7 binding domain at the BMPR1A. The present study results provide a preclinical proof-of-concept of potential therapeutic benefits of BMP7-based small peptides, which function as agonists of BMPR1A, against the pathological LV remodeling in the context of aortic stenosis.

Left Ventricular Mechanics Differ in Subtypes of Aortic Stenosis Following Transcatheter Aortic Valve Replacement

Background

Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). We hypothesized that there would be differences in myocardial mechanics, measured by global longitudinal strain (GLS) recovery in patients with four subtypes of severe AS after transcatheter aortic valve replacement (TAVR), stratified based upon flow and gradient.

Methods

We retrospectively evaluated 204 patients with severe AS who underwent TAVR and were followed post-TAVR at our institution for clinical outcomes. Speckle-tracking transthoracic echocardiography was performed pre- and post-TAVR. Patients were classified as: (1) normal-flow and high-gradient, (2) normal-flow and high-gradient with reduced LV ejection fraction (LVEF), (3) classical low-flow and low-gradient, or (4) paradoxical low-flow and low-gradient.

Results

Both GLS (−13.9 ± 4.3 to −14.8 ± 4.3, P < 0.0001) and LVEF (55 ± 15 to 57 ± 14%, P = 0.0001) improved immediately post-TAVR. Patients with low-flow AS had similar improvements in LVEF (+2.6 ± 9%) and aortic valve mean gradient (−23.95 ± 8.34 mmHg) as patients with normal-flow AS. GLS was significantly improved in patients with normal-flow (−0.93 ± 3.10, P = 0.0004) compared to low-flow AS. Across all types of AS, improvement in GLS was associated with a survival benefit, with GLS recovery in alive patients (mean GLS improvement of −1.07 ± 3.10, P < 0.0001).

Conclusions

LV mechanics are abnormal in all patients with subtypes of severe AS and improve immediately post-TAVR. Recovery of GLS was associated with a survival benefit. Patients with both types of low-flow AS showed significantly improved, but still impaired, GLS post-TAVR, suggesting underlying myopathy that does not correct post-TAVR.