Midwall fibrosis is an independent predictor of mortality in patients with aortic stenosis

Limiting extracellular matrix expansion in diet-induced obese mice reduces cardiac insulin resistance and prevents myocardial remodelling

OBJECTIVE

Obesity increases deposition of extracellular matrix (ECM) components of cardiac tissue. Since obesity aggregates with insulin resistance and heart disease, it is imperative to determine whether the increased ECM deposition contributes to this disease cluster. The hypotheses tested in this study were that in cardiac tissue of obese mice i) increased deposition of ECM components (collagens and hyaluronan) contributes to cardiac insulin resistance and that a reduction in these components improves cardiac insulin action and ii) reducing excess collagens and hyaluronan mitigates obesity-associated cardiac dysfunction.

METHODS

Genetic and pharmacological approaches that manipulated collagen and hyaluronan contents were employed in obese C57BL/6 mice fed a high fat (HF) diet. Cardiac insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp and cardiac function was measured by pressure-volume loop analysis in vivo.

RESULTS

We demonstrated a tight association between increased ECM deposition with cardiac insulin resistance. Increased collagen deposition by genetic deletion of matrix metalloproteinase 9 (MMP9) exacerbated cardiac insulin resistance and pirfenidone, a clinically available anti-fibrotic medication which inhibits collagen expression, improved cardiac insulin resistance in obese mice. Furthermore, decreased hyaluronan deposition by treatment with PEGylated human recombinant hyaluronidase PH20 (PEGPH20) improved cardiac insulin resistance in obese mice. These relationships corresponded to functional changes in the heart. Both PEGPH20 and pirfenidone treatment in obese mice ameliorated HF diet-induced abnormal myocardial remodelling.

CONCLUSION

Our results provide important new insights into the role of ECM deposition in the pathogenesis of cardiac insulin resistance and associated dysfunction in obesity of distinct mouse models. These findings support the novel therapeutic potential of targeting early cardiac ECM abnormalities in the prevention and treatment of obesity-related cardiovascular complications.

Multimodality Imaging in Aortic Stenosis: Beyond the Valve - Focusing on the Myocardium

Current guidelines of aortic stenosis (AS) management focus on valve parameters, LV systolic dysfunction, and symptoms; however, emerging data suggest that there may be benefit of aortic valve replacement before it becomes severe by present criteria. Myocardial assessment using novel multimodality imaging techniques exhibits subclinical myocardial injury and remodeling at various stages before guideline-directed interventions, which predicts adverse outcomes. This raises the question of whether implementing serial myocardial assessment should become part of the standard appraisal, thereby identifying high-risk patients aiming to minimize adverse outcomes.

Ventricular arrhythmias in patients with bicuspid aortic valves

INTRODUCTION

Bicuspid aortic valves (BAV) are the most common congenital heart defects and the extent of ventricular arrhythmias (VA) in patients with BAV is unclear. The objective of this study is to describe VAs and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) in patients with BAV.

METHODS

A total of 19 patients with BAV (18 males, age: 58 ± 13 years) were referred for VA ablation procedures. Ten patients had BAVs at the time of ablation, nine patients had prior aortic valve replacement for a BAV. All but one patient had LGE-CMR and all patients underwent programmed ventricular stimulation at the time of the ablation.

RESULTS

Frequent PVCs were the targeted VAs in 17/19 patients and VT in 2/19 patients. Monomorphic ventricular tachycardia (VT) was inducible in 6 patients. A total of 15 VTs were inducible (2.5 ± 1.0 VTs per patient with a mean cycle length of 322 ± 83 msec). LGE was present in 13 patients. Patients with inducible VT had larger borderzone and core scar compared to non-inducible patients (7.8 ± 2.1 cm3 vs. 2.5 ± 3.1 cm3 and 5.1 ± 2.6 cm3 vs. 1.9 ± 3.0 cm3, p-value < .05 for both). PVCs and VTs were mapped to the periaortic valve area in 12 patients and 4 patients, respectively. The PVC burden was reduced from 27 ± 13 to 3 ± 6 (p < .001) and the ejection fraction improved from 49 ± 13% to 55 ± 9% (p = .005).

CONCLUSIONS

VAs in patients with BAV often originate from the perivalvular area and patients often have LGE and inducible VT. LGE may be due to ventricular remodeling secondary to the presence of BAV and harbors the arrhythmogenic substrate for VT.

Diagnostic Challenges in Aortic Stenosis

Aortic stenosis (AS) is the most prevalent degenerative valvular disease in western countries. Transthoracic echocardiography (TTE) is considered, nowadays, to be the main imaging technique for the work-up of AS due to high availability, safety, low cost, and excellent capacity to evaluate aortic valve (AV) morphology and function. Despite the diagnosis of AS being considered straightforward for a very long time, based on high gradients and reduced aortic valve area (AVA), many patients with AS represent a real dilemma for cardiologist. On the one hand, the acoustic window may be inadequate and the TTE limited in some cases. On the other hand, a growing body of evidence shows that patients with low gradients (due to systolic dysfunction, concentric hypertrophy or coexistence of another valve disease such as mitral stenosis or regurgitation) may develop severe AS (low-flow low-gradient severe AS) with a similar or even worse prognosis. The use of complementary imaging techniques such as transesophageal echocardiography (TEE), multidetector computed tomography (MDTC), or cardiac magnetic resonance (CMR) plays a key role in such scenarios. The aim of this review is to summarize the diagnostic challenges associated with patients with AS and the advantages of a comprehensive multimodality cardiac imaging (MCI) approach to reach a precise grading of the disease, a crucial factor to warrant an adequate management of patients.

Asymptomatic Aortic Stenosis: From Risk Stratification to Treatment

Our understanding of the natural history of aortic stenosis has significantly increased over the last decade. There have been considerable advances in the diagnosis and risk stratification of patients with aortic stenosis and in surgical and anesthetic techniques. In addition, transcatheter aortic valve replacement has established itself as a viable alternative to surgical management. Inevitably, these developments have raised questions regarding the merits of waiting for symptom onset in asymptomatic patients with severe aortic stenosis before offering treatment. Recent observational and randomized trial data suggest that early intervention in asymptomatic patients with severe aortic stenosis and normal left ventricular function may confer a prognostic advantage to a watchful waiting strategy. In this review, we highlight advances in the management and risk stratification of patients with asymptomatic severe aortic stenosis with particular consideration of recent findings supporting early valvular intervention.

Regional Distribution of Extracellular Volume Quantified by Cardiac CT in Aortic Stenosis: Insights Into Disease Mechanisms and Impact on Outcomes

BACKGROUND

Extracellular volume fraction (ECV) is a marker for myocardial fibrosis and infiltration, can be quantified using cardiac computed tomography (ECVCT), and has prognostic utility in several diseases. This study aims to map out regional differences in ECVCT to obtain greater insights into the pathophysiological mechanisms of ECV expansion and its clinical implications.

METHODS

Three prospective cohorts were included: patients with aortic stenosis (AS) and coexisting AS and transthyretin cardiac amyloidosis were referred for a transcatheter aortic valve replacement and had ECG-gated CT angiography and Technetium-99m-labelled 3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy to differentiate between the 2 cohorts. Controls had CT angiography and cardiac magnetic resonance demonstrating no significant coronary artery disease or infarction. Global and regional ECVCT was analyzed, and its association with mortality was assessed for patients with AS.

RESULTS

In 199 patients, controls (n=65; 66% male), AS (n=115), and coexisting AS and transthyretin cardiac amyloidosis (n=19) had a global ECVCT of 26.1 (25.0-27.8%) versus 29.1 (27.5-31.1%) versus 37.4 (32.5-46.6%), respectively; P<0.001. Across cohorts, ECVCT was higher at the base (versus apex), the inferoseptum (versus anterolateral wall), and the subendocardium (versus subepicardium); P<0.05 for all. Among patients with AS, epicardial ECVCT, rather than any other regional value or global ECVCT, was the strongest predictor of mortality at a median of 3.9 (max 6.3) years (adjusted hazard ratio, 1.21 [95% CI, 1.08-1.36]; P=0.002).

CONCLUSIONS

Regional differences in ECVCT suggest a predilection for fibrosis and amyloid infiltration at the base, subendocardium, inferior wall, and septum more than the anterior and lateral myocardium. ECVCT can predict long-term mortality with the subepicardium demonstrating the strongest discriminatory power.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03029026 and NCT03094143.

Myocardial analysis from routine 4D cardiac-CT to predict reverse remodeling and clinical outcomes after transcatheter aortic valve implantation

PURPOSE

Our study aimed to determine whether 4D cardiac computed tomography (4DCCT) based quantitative myocardial analysis may improve risk stratification and can predict reverse remodeling (RRM) and mortality after transcatheter aortic valve implantation (TAVI).

METHODS

Consecutive patients undergoing clinically indicated 4DCCT prior to TAVI were prospectively enrolled. 4DCCT-derived left- (LV) and right ventricular (RV), and left atrial (LA) dimensions, mass, ejection fraction (EF) and myocardial strain were evaluated to predict RRM and survival. RRM was defined by either relative increase in LVEF by 5% or relative decline in LV end diastolic diameter (LVEDD) by 5% assessed by transthoracic echocardiography prior TAVI, at discharge, and at 12-month follow-up compared to baseline prior to TAVI.

RESULTS

Among 608 patients included in this study (55 % males, age 81 ± 6.6 years), RRM was observed in 279 (54 %) of 519 patients at discharge and in 218 (48 %) of 453 patients at 12-month echocardiography. While no CCT based measurements predicted RRM at discharge, CCT based LV mass index and LVEF independently predicted RRM at 12-month (ORadj = 1.012; 95 %CI:1.001-1.024; p = 0.046 and ORadj = 0.969; 95 %CI:0.943-0.996; p = 0.024, respectively). The most pronounced changes in LVEF and LVEDD were observed in patients with impaired LV function at baseline. In multivariable analysis age (HRadj = 1.037; 95 %CI:1.005-1.070; p = 0.022) and CCT-based LVEF (HRadj = 0.972; 95 %CI:0.945-0.999; p = 0.048) and LAEF (HRadj = 0.982; 95 %CI:0.968-0.996; p = 0.011) independently predicted survival.

CONCLUSION

Comprehensive myocardial functional information derived from routine 4DCCT in patients with severe aortic stenosis undergoing TAVI could predict reverse remodeling and clinical outcomes at 12-month following TAVI.

[Update on the treatment of aortic valve stenosis in symptomatic and asymptomatic patients]

Aortic valve stenosis is one of the most frequent valvular heart diseases requiring treatment in industrialized countries. The symptom onset is associated with a significantly increased mortality, so that there is a clear indication for treatment in patients with severe, symptomatic aortic valve stenosis; however, data on the optimal treatment of patients with asymptomatic aortic valve stenosis are scarce. Smaller studies in the field of cardiac surgery suggest that early surgical valve replacement is superior to a conservative approach. For this reason, the results of additional adequately powered randomized trials are awaited with great interest. In this year numerous long-term results from randomized comparisons of the two available treatment options (surgical versus transcatheter aortic valve replacement) were published, which will further guide the heart team to find the best treatment approach for each individual.

Prognostic value of high-sensitive troponin T in patients with severe aortic stenosis undergoing valve replacement surgery

Background

Aortic stenosis (AS) is a well-known cause of mortality. We aimed to assess the prognostic value of high-sensitive troponin T (hs-TnT) in symptomatic patients with severe AS and preserved left ventricular ejection fraction (LVEF) after surgical aortic valve replacement (AVR).

Patients and methods

The study recruited patients with severe symptomatic AS fulfilling the inclusion criteria in the period between April 2020 and February 2022. Comprehensive echocardiography was done. The following parameters were assessed: AS severity, LV mass index (LVMI), left atrium volume index (LAVI), and LVEF. E/e' and LVEF were calculated using the biplane method of Simpsons. Global longitudinal strain (GLS) was assessed by speckle tracking echocardiography. Peripheral blood samples were collected for hs-TnT measurement. All patients underwent surgical AVR. The patients were followed for the following 6 months for major adverse cardiovascular events (MACE). MACE was defined as cardiac death, re-admission for congestive heart failure (CHF) and fatal arrhythmia.

Results

One hundred and eight patients (mean age = 58.7 ± 7.68 years) with severe AS were recruited. Seventeen patients presented with MACE including 8 cardiac deaths. We divided the patients into two groups based on the normal hs-TnT values. The Kaplan-Meier curve revealed a statistically significant difference in MACE rate among troponin groups (log-rank test = 5.06, p = 0.025). There was significant difference between both groups regarding GLS with smaller GLS in negative hs-TnT group. In multivariate analysis, GLS and hs-TnT were significantly associated with MACE (p = 0.022 and < 0.01 respectively). The cutoff value of hs-TnT of 238.25 had a sensitivity of 70% and a specificity of 81% for predicting future MACE. There was a significant correlation between GLS and troponin (p < 0.001).

Conclusions

hs-TnT is associated with bad short-term prognosis after AVR. hs-TnT and GLS could be significant predictors for future MACE in patients with severe symptomatic AS and preserved LVEF who underwent AVR. Elevated hs-TnT and impaired GLS could set an indication of early intervention in asymptomatic severe AS.

Multimodality imaging for the global evaluation of aortic stenosis: The valve, the ventricle, the afterload

Aortic stenosis (AS) is the most common valvular heart disease growing in parallel to the increment of life expectancy. Besides the valve, the degenerative process affects the aorta, impairing its elastic properties and leading to increased systemic resistance. The composite of valvular and systemic afterload mediates ventricular damage. The first step of a thorough evaluation of AS should include a detailed assessment of valvular anatomy and hemodynamics. Subsequently, the ventricle, and the global afterload should be assessed to define disease stage and prognosis. Multimodality imaging is of paramount importance for the comprehensive evaluation of these three elements. Echocardiography is the cornerstone modality whereas Multi-Detector Computed Tomography and Cardiac Magnetic Resonance provide useful complementary information. This review comprehensively examines the merits of these imaging modalities in AS for the evaluation of the valve, the ventricle, and the afterload and ultimately endeavors to integrate them in a holistic assessment of AS.

The prognostic impact of diastolic dysfunction after transcatheter aortic valve replacement: A systematic review and meta-analysis

BACKGROUND

Diastolic dysfunction (DD) is a long-established marker of disease progression in patients with aortic valve stenosis (AS), indicating valvular myocardial damage. Recently, substantial observational data have emerged demonstrating that worse pre-operative DD assessed using echocardiography is associated with adverse long-term clinical outcomes after transcatheter aortic valve replacement (TAVR).

AIM

To systematically appraise and quantitatively synthesize current evidence on the prognostic impact of echocardiographic severe DD derived by echocardiography before TAVR.

METHODS

A systemic literature review was undertaken in electronic databases to identify studies reporting the predictive value of severe DD in AS subjects undergoing TAVR. A random-effects meta-analysis was conducted to quantify the adjusted and unadjusted hazard ratios (HRs) for all-cause mortality and major adverse cardiovascular events (MACEs) for the presence of severe DD.

RESULTS

Ten studies were deemed eligible for inclusion. Of those, 9 provided appropriate quantitative data for the meta-analysis, encompassing a total of 4,619 patients. The presence of severe DD was associated with increased risk for all-cause mortality (pooled unadjusted HR=2.56 [1.46-4.48]; p<0.01; I2=76 %) and MACEs (pooled unadjusted HR=1.82 [1.29-2.58]; p<0.01; I2=86 %). When adjusted for clinically-relevant parameters, the presence of severe DD retained independent association with all-cause mortality (pooled adjusted HR=2.35 [1.26-4.37]; p<0.01; I2=79 %) and MACEs (pooled adjusted HR= 2.52 [1.72-3.65]; p<0.01; I2=0 %). In subgroup analysis there was no difference on post-TAVR risk between the use of different diastolic function grading scores.

CONCLUSION

Presence of severe DD assessed by echocardiography pre-TAVR is a major determinant of long-term adverse outcomes after the procedure.

Functionally unicuspid aortic valve in an adult: Case report and literature review

Aortic stenosis is one of the most prevalent cardiac valvular diseases throughout the world and has a significant impact on quality of life. While there are several etiologies, we will be discussing the case of a male in his mid-thirties of southeast Asian descent with a bicuspid aortic valve which was found to be functionally unicuspid and complicated by aortic dilation. Following a comprehensive review of literature, it appears this subset of aortic stenosis is not commonly encountered. In addition to presenting this fascinating case, we will review the epidemiology, classification and management of aortic stenosis. Furthermore, we will examine the latest evidence-based literature on bicuspid aortic valve and unicuspid aortic valve and discuss interventions and diagnostic tools that may improve clinical prognosis.

Prognostic Value of Cardiac Magnetic Resonance Feature Tracking Strain in Aortic Stenosis

BACKGROUND

Recent data have suggested that global longitudinal strain (GLS) could be useful for risk stratification of patients with severe aortic stenosis (AS). In this study, we aimed to investigate the prognostic role of GLS in patients with AS and also its incremental value in relation to left ventricular ejection fraction (LVEF) and late gadolinium enhancement (LGE).

METHODS

We analysed all consecutive patients with AS and LGE-CMR in our institution. Survival data were obtained from office of national statistics, a national body where all deaths in England are registered by law. Death certificates were obtained from the general register office.

RESULTS

Some 194 consecutive patients with aortic stenosis were investigated with CMR at baseline and followed up for 7.3 ± 4 years. On multivariate Cox regression analysis, only increasing age remained significant for both all-cause and cardiac mortality, while LGE (any pattern) retained significance for all-cause mortality and had a trend to significance for cardiac mortality. Kaplan-Meier survival analysis demonstrated that patients in the best and middle GLS tertiles had significantly better mortality compared to patients in the worst GLS tertiles. Importantly though, sequential Cox proportional-hazard analysis demonstrated that GLS did not have significant incremental prognostic value for all-cause mortality or cardiac mortality in addition to LVEF and LGE.

CONCLUSIONS

Our study has demonstrated that age and LGE but not GLS are significant poor prognostic indicators in patients with moderate and severe AS.

Decellularized heart extracellular matrix alleviates activation of hiPSC-derived cardiac fibroblasts

Human induced pluripotent stem cell derived cardiac fibroblasts (hiPSC-CFs) play a critical role in modeling human cardiovascular diseases in vitro. However, current culture substrates used for hiPSC-CF differentiation and expansion, such as Matrigel and tissue culture plastic (TCPs), are tissue mismatched and may provide pathogenic cues. Here, we report that hiPSC-CFs differentiated on Matrigel and expanded on tissue culture plastic (M-TCP-iCFs) exhibit transcriptomic hallmarks of activated fibroblasts limiting their translational potential. To alleviate pathogenic activation of hiPSC-CFs, we utilized decellularized extracellular matrix derived from porcine heart extracellular matrix (HEM) to provide a biomimetic substrate for improving hiPSC-CF phenotypes. We show that hiPSC-CFs differentiated and expanded on HEM (HEM-iCFs) exhibited reduced expression of hallmark activated fibroblast markers versus M-TCP-iCFs while retaining their cardiac fibroblast phenotype. HEM-iCFs also maintained a reduction in expression of hallmark genes associated with pathogenic fibroblasts when seeded onto TCPs. Further, HEM-iCFs more homogenously integrated into an hiPSC-derived cardiac organoid model, resulting in improved cardiomyocyte sarcomere development. In conclusion, HEM provides an improved substrate for the differentiation and propagation of hiPSC-CFs for disease modeling.

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.

Multimodality Imaging in Aortic Stenosis: Beyond the Valve - Focusing on the Myocardium

Current guidelines of aortic stenosis (AS) management focus on valve parameters, LV systolic dysfunction, and symptoms; however, emerging data suggest that there may be benefit of aortic valve replacement before it becomes severe by present criteria. Myocardial assessment using novel multimodality imaging techniques exhibits subclinical myocardial injury and remodeling at various stages before guideline-directed interventions, which predicts adverse outcomes. This raises the question of whether implementing serial myocardial assessment should become part of the standard appraisal, thereby identifying high-risk patients aiming to minimize adverse outcomes.

Blockade of Inflammatory Markers Attenuates Cardiac Remodeling and Fibrosis in Rats with Supravalvular Aortic Stenosis

Since cardiac inflammation has been considered an important mechanism involved in heart failure, an anti-inflammatory treatment could control cardiac inflammation and mitigate the worsening of cardiac remodeling. This study evaluated the effects of dexamethasone (DEX) and ramipril treatment on inflammation and cardiac fibrosis in an experimental model of heart failure induced by supravalvular aortic stenosis. Wistar rats (21d) were submitted to an aortic stenosis (AS) protocol. After 21 weeks, an echocardiogram and a maximal exercise test were performed, and after 24 weeks, rats were treated with DEX, ramipril or saline for 14d. The left ventricle (LV) was removed for histological and inflammatory marker analyses. The AS group showed exercise intolerance (-32% vs. Sham), higher relative wall thickness (+63%), collagen deposition and capillary rarefaction, followed by cardiac disfunction. Both treatments were effective in reducing cardiac inflammation, but only DEX attenuated the increased relative wall thickness (-17%) and only ramipril reduced LV fibrosis. In conclusion, both DEX and ramipril decreased cardiac inflammatory markers, which probably contributed to the reduced cardiac fibrosis and relative wall thickness; however, treated AS rats did not show any improvement in cardiac function. Despite the complex pharmacological treatment of heart failure, treatment with an anti-inflammatory could delay the patient's poor prognosis.

Epicardioid single-cell genomics uncovers principles of human epicardium biology in heart development and disease

The epicardium, the mesothelial envelope of the vertebrate heart, is the source of multiple cardiac cell lineages during embryonic development and provides signals that are essential to myocardial growth and repair. Here we generate self-organizing human pluripotent stem cell-derived epicardioids that display retinoic acid-dependent morphological, molecular and functional patterning of the epicardium and myocardium typical of the left ventricular wall. By combining lineage tracing, single-cell transcriptomics and chromatin accessibility profiling, we describe the specification and differentiation process of different cell lineages in epicardioids and draw comparisons to human fetal development at the transcriptional and morphological levels. We then use epicardioids to investigate the functional cross-talk between cardiac cell types, gaining new insights into the role of IGF2/IGF1R and NRP2 signaling in human cardiogenesis. Finally, we show that epicardioids mimic the multicellular pathogenesis of congenital or stress-induced hypertrophy and fibrotic remodeling. As such, epicardioids offer a unique testing ground of epicardial activity in heart development, disease and regeneration.

Extracellular Matrix Abnormalities Contribute to Cardiac Insulin Resistance and Associated Dysfunction in Diet-induced Obese Mice

Increased deposition of extracellular matrix (ECM) components such as collagens and hyaluronan contributes to the pathogenesis of obesity-associated insulin resistance in muscle, liver, and adipose tissue. Despite the significance of the heart in cardiovascular and metabolic diseases, maladaptive ECM remodelling in obesity-associated cardiac insulin resistance and cardiac dysfunction has not been studied. Using genetic and pharmacological approaches in mice fed a high fat (HF) diet, we demonstrated a tight association between increased ECM deposition with cardiac insulin resistance. Increased collagen deposition by genetic deletion of matrix metalloproteinase 9 (MMP9) exacerbated cardiac insulin resistance and decreased hyaluronan deposition by treatment with PEGylated human recombinant hyaluronidase PH20 (PEGPH20) improved cardiac insulin resistance in obese mice. These relationships corresponded to functional changes in the heart. PEGPH20 treatment in obese mice ameliorated HF diet-induced abnormal myocardial remodelling. In addition to hyaluronan, increased collagen deposition is a characteristic of the obese mouse heart. We further demonstrated that pirfenidone, a clinically available anti-fibrotic medication which inhibits collagen expression, improved cardiac insulin resistance and cardiac function in obese mice. Our results provide important new insights into the role of ECM remodelling in the pathogenesis of cardiac insulin resistance and associated dysfunction in obesity of distinct mouse models. These findings support the novel therapeutic potential of targeting early cardiac ECM abnormalities in the prevention and treatment of obesity-related cardiovascular complications.

Left Ventricular Mass, Myocardial Structure, and Function in Severe Aortic Stenosis: an Echocardiographic and Cardiac Magnetic Resonance Imaging Study

In severe aortic stenosis (AS), there are conflicting data on the prognostic implications of left ventricular (LV) hypertrophy (LVH). We aimed to characterize the LV geometry, myocardial matrix structural changes, and prognostic stratification using cardiac magnetic resonance imaging (CMR) and echocardiography in subjects with severe AS with and without LVH. Consecutive patients who had severe isolated AS and sufficient quality echocardiography and CMR within 6 months of each other were evaluated for LVH, cardiac structure, morphology, and late gadolinium-enhancement imaging. Kaplan-Meier curves, linear models, and proportional hazards models were used for prognostic stratification. There were 93 patients enrolled (mean age 74 ± 11 years, 48% female), of whom 38 (41%) had a normal LV mass index (LVMI), 41 (44%) had LVH defined at CMR by LVMI >2 SD higher than normal, and 14 (15% of the total) with >4 SD higher than the reference LVMI (severely elevated). The Society of Thoracic Surgeons scores were similar among the LVMI groups. Compared with those with normal LVMI, patients with LVH had higher LV end-diastolic and end-systolic volumes, increased late gadolinium-enhancement burden, and lower LV ejection fraction. Most notably, CMR feature-tracking global radial strain, 2-dimensional speckle-tracking echocardiography global longitudinal strain, and left atrial reservoir function were significantly worse. On the survival analyses, LVMI was not associated with a composite of all-cause mortality and/or heart failure hospitalization. In conclusion, compared with normal LVMI, elevated LVMI was not associated with a higher risk of adverse outcomes.

Prognostic Value of Electrocardiographic Left Ventricular Hypertrophy After Transcatheter Aortic Valve Implantation: Insights from the OCEAN-TAVI Registry

Electrocardiogram (ECG) left ventricular hypertrophy (LVH) is associated with the prognosis of patients with aortic stenosis. However, the impact of the presence or absence of ECG-LVH on the clinical outcomes after transcatheter aortic valve implantation (TAVI) is limited. This study aimed to assess the prognostic value of ECG-LVH among patients with aortic stenosis treated by TAVI. A total of 1,667 patients who underwent TAVI were prospectively enrolled into the OCEAN-TAVI (Optimized CathEter vAlvular iNtervention-Transcatheter Aortic Valve Implantation) registry. A total of 1,446 patients (mean age 84 years; 29.9% men) were analyzed. The Sokolow-Lyon index was used to determine the presence of ECG-LVH. LVH was also assessed using transthoracic echocardiography (TTE). We investigated the association between ECG-LVH and all-cause and cardiovascular mortality. This study identified ECG-LVH and TTE-LVH in 743 (51.5%) and 1,242 patients (86.0%), respectively. The Kaplan-Meier analysis revealed that all-cause mortality was significantly higher among patients without ECG-LVH than among those with ECG-LVH (log-rank p <0.001). In the multivariable analysis, the absence of ECG-LVH was independently associated with all-cause mortality (hazard ratio 1.98, 95% confidence interval 1.39 to 2.82, p <0.001), regardless of the presence or absence of TTE-LVH. Furthermore, the presence of TTE-LVH with the absence of ECG-LVH was observed in 575 patients (40%), which was associated with cardiovascular mortality (hazard ratio 2.84, 95% confidence interval 1.56 to 5.17, p <0.001). In conclusion, the absence of ECG-LVH was independently associated with an increased risk of all-cause mortality after TAVI. Risk stratification using both ECG-LVH and TTE-LVH is a useful predictor of adverse clinical outcomes after TAVI.

Multimodality Imaging in Aortic Stenosis: Beyond the Valve - Focusing on the Myocardium

Current guidelines of aortic stenosis (AS) management focus on valve parameters, LV systolic dysfunction, and symptoms; however, emerging data suggest that there may be benefit of aortic valve replacement before it becomes severe by present criteria. Myocardial assessment using novel multimodality imaging techniques exhibits subclinical myocardial injury and remodeling at various stages before guideline-directed interventions, which predicts adverse outcomes. This raises the question of whether implementing serial myocardial assessment should become part of the standard appraisal, thereby identifying high-risk patients aiming to minimize adverse outcomes.

Urinary peptides provide information about the risk of mortality across a spectrum of diseases and scenarios

BACKGROUND

There is evidence of pre-established vulnerability in individuals that increases the risk of their progression to severe disease or death, although the mechanisms causing this are still not fully understood. Previous research has demonstrated that a urinary peptide classifier (COV50) predicts disease progression and death from SARS-CoV-2 at an early stage, indicating that the outcome prediction may be partly due to vulnerabilities that are already present. The aim of this study is to examine the ability of COV50 to predict future non-COVID-19-related mortality, and evaluate whether the pre-established vulnerability can be generic and explained on a molecular level by urinary peptides.

METHODS

Urinary proteomic data from 9193 patients (1719 patients sampled at intensive care unit (ICU) admission and 7474 patients with other diseases (non-ICU)) were extracted from the Human Urinary Proteome Database. The previously developed COV50 classifier, a urinary proteomics biomarker panel consisting of 50 peptides, was applied to all datasets. The association of COV50 scoring with mortality was evaluated.

RESULTS

In the ICU group, an increase in the COV50 score of one unit resulted in a 20% higher relative risk of death [adjusted HR 1.2 (95% CI 1.17-1.24)]. The same increase in COV50 in non-ICU patients resulted in a higher relative risk of 61% [adjusted HR 1.61 (95% CI 1.47-1.76)], consistent with adjusted meta-analytic HR estimate of 1.55 [95% CI 1.39-1.73]. The most notable and significant changes associated with future fatal events were reductions of specific collagen fragments, most of collagen alpha I (I).

CONCLUSION

The COV50 classifier is predictive of death in the absence of SARS-CoV-2 infection, suggesting that it detects pre-existing vulnerability. This prediction is mainly based on collagen fragments, possibly reflecting disturbances in the integrity of the extracellular matrix. These data may serve as a basis for proteomics-guided intervention aiming towards manipulating/ improving collagen turnover, thereby reducing the risk of death.

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.

Unmet Needs in the Assessment of Right Ventricular Function for Severe Tricuspid Regurgitation

Tricuspid regurgitation (TR) is a highly prevalent valvular heart disease that has been long overlooked, but lately its independent association with adverse cardiovascular outcomes was recognized. The time point to intervene and repair the tricuspid valve is defined by the right ventricular (RV) dilation and dysfunction that comes up at a later stage. While guidelines favor tricuspid valve repair before severe RV dysfunction ensues, the definition of RV dysfunction in a universal manner remains vague. As a result, the candidates for transcatheter or surgical TR procedures are often referred late, when advanced RV dysfunction is established, and any derived procedural survival benefit is attenuated. Thus, it is of paramount importance to establish a universal means of RV function assessment in patients with TR. Conventional echocardiographic indices of RV function routinely applied have fundamental flaws that limit the precise characterization of RV performance. More recently, novel echocardiographic indices such as strain via speckle-tracking have emerged, demonstrating promising results in the identification of early RV damage. Additionally, evidence of the role of alternative imaging modalities such as cardiac computed tomography and cardiac magnetic resonance, for RV functional assessment in TR, has recently arisen. This review provides a systematic appraisal of traditional and novel multimodality indices of RV function in severe TR and aims to refine RV function assessment, designate future directions, and ultimately, to improve the outcome of patients suffering from severe TR.

Soluble ST2 levels are related to replacement myocardial fibrosis in severe aortic stenosis

INTRODUCTION AND OBJECTIVES

Patients with aortic stenosis (AS) exhibit left ventricular (LV) remodeling and replacement myocardial fibrosis (RMF). Whether sST2 is associated with RMF measured by cardiac magnetic resonance and with sex remains unknown.

METHODS

We recruited 79 consecutive patients (73.0 [68.0-78.0] years; 61% men) with severe isolated AS underdoing valve replacement. RMF was identified and quantified by late gadolinium enhancement (LGE). Serum sST2 levels were determined.

RESULTS

RMF was associated with higher circulating sST2 levels, LV hypertrophy and dilation, and lower LV ejection fraction. All patients with LV dysfunction had RMF. Circulating levels of sST2 ≥ 28.8 ng/mL were associated with RMF and greater LV hypertrophy. LGE mass was correlated with LV remodeling and sST2. Of note, sST2 levels were also associated with the RMF pattern, being higher in midwall than in subendocardial fibrosis. Multivariate analyses showed that only LV ejection fraction and sST2 levels were associated with RMF. Moreover, men had higher levels of sST2 and RMF. RMF was associated with higher LV dilation and hypertrophy only in men and was correlated with LGE mass.

CONCLUSIONS

SST2 was an independent factor for RMF in patients with severe isolated AS. The presence of RMF was predicted by sST2 ≥ 28.2 ng/mL, and was associated with greater LV hypertrophy. sST2 expression and clinical associations may be sex-specific.

Electrocardiographic Markers of Adverse Left Ventricular Remodeling and Myocardial Fibrosis in Severe Aortic Stenosis

The optimal timing for aortic valve replacement (AVR) in aortic stenosis (AS) is still controversial and may be guided by markers of adverse left ventricular (LV) remodeling. We aim to assess electrocardiographic (ECG) strain in relation to LV remodeling and myocardial fibrosis. 83 severe AS patients underwent surgical AVR, with preoperative 12-lead ECG, cardiovascular magnetic resonance with T1 mapping and echocardiography with global longitudinal strain analysis. Collagen volume fraction (CVF) was measured in myocardial biopsies sampled during AVR. Patients with ECG strain had more severe AS, more advanced LV remodeling and evidence of heart failure. Patients with ECG strain had more diffuse fibrosis, as evident by higher mean native T1 values (974.8 ± 34 ms vs. 946.5 ± 28 ms, p < 0.001). ECG strain was the only predictor of increased LV mass index on multivariate regression analysis (OR = 7.10, 95% CI 1.46-34.48, p = 0.02). Patients with persistent ECG strain at 1 year following AVR had more advanced LV remodeling and more histological fibrosis (CVF 12.5% vs. 7.3%, p = 0.009) at baseline assessment. Therefore, ECG strain is a marker of adverse LV remodeling and interstitial myocardial fibrosis. Lack of improvement in ECG strain following AVR indicates more advanced baseline LV injury and higher levels of myocardial fibrosis.

Renin-angiotensin system inhibitors reduce cardiovascular mortality in hypertensive patients with severe aortic stenosis undergoing transcatheter aortic valve implantation: insights from the EffecTAVI registry

Objectives

Arterial hypertension is associated with the triggering of the renin-angiotensin system, leading to left ventricle fibrosis and worse cardiovascular outcomes. In this study, patients with comorbid arterial hypertension and severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) were selected from the EffecTAVI registry to evaluate the impact of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) on cardiovascular mortality.

Methods

We enrolled 327 patients undergoing TAVI from the EffecTAVI registry. Using Kaplan-Meier event rates and study-stratified multivariable Cox proportional hazards regression models, we evaluated 2-year clinical outcomes according to the ACEI/ARB therapy status at enrollment.

Results

Among the included patients, 222 (67.9%) were on ACEIs/ARBs at baseline, whereas 105 (32.1%) were not. Treatment with ACEIs/ARBs was significantly associated with a 2-year decrease in the rate of cardiovascular mortality (HR = 0.44, 95% CI: 0.23-0.81, p = 0.009). This association remained stable after both multivariable adjustment and propensity score matching.

Conclusion

In a cohort of hypertensive patients with severe AS who were selected from the EffecTAVI registry, ACEI/ARB treatment at baseline was found to be independently associated with a lower risk of 2-year cardiovascular mortality, suggesting a potential benefit of this treatment. More trials are needed to validate this finding and to understand the full benefit of this treatment.

Negative Prognostic Impact of Mineralocorticoid Receptor Antagonist in Elderly Patients Receiving TAVR

Background: Morbidity and mortality following trans-catheter aortic valve replacement (TAVR) remain high. Renin-angiotensin system inhibitors improve clinical outcomes in the cohort studied in this work. However, post-TAVR prognostic impact of mineralocorticoid receptor antagonist (MRA), another neuro-hormonal blocker, remains uncertain. Here, we hypothesized that MRA was associated with improved clinical outcomes in elderly patients with severe aortic stenosis receiving TAVR.

METHODS

Consecutive patients who received TAVR at our institute between 2015 and 2022 were considered for inclusion. Propensity score matching analysis was performed to match pre-procedural baseline characteristics between those with and without MRA. The prognostic impact of MRA use on the composite primary endpoint consisting of all-cause death and heart failure during the 2-year observational period following index discharge was evaluated.

RESULTS

Among 352 patients who received TAVR, 112 patients (median 86 years, 31 men) were included, consisting of baseline-matched 56 patients with MRA and 56 patients without MRA. Following TAVR, patients with MRA had more impaired renal function compared with no MRA group. Following index discharge, serum potassium tended to increase, and renal function tended to decline in patients with MRA. Patients with MRA had a higher cumulative incidence of the primary endpoints during a two-year observational period (30% versus 8%, p = 0.022).

CONCLUSIONS

Routine prescription of MRA might not be recommended in elderly patients with severe aortic stenosis receiving TAVR, given its negative prognostic impact. Optimal patient selection for MRA administration in this cohort needs further study.

Shifting from Left Ventricular Ejection Fraction to Strain Imaging in Aortic Stenosis

Adverse ventricular remodeling is an inflexion point of disease progression in aortic stenosis (AS) and a major determinant of prognosis. Intervention before irreversible myocardial damage is of paramount importance to sustain favorable post-operative outcomes. Current guidelines recommend a left ventricular ejection fraction (LVEF)-based strategy to determine the threshold for intervention in AS. However, LVEF has several pitfalls: it denotes the left ventricular cavity volumetric changes and it is not suited to detecting subtle signs of myocardial damage. Strain has emerged as a contemporary imaging biomarker that describes intramyocardial contractile force, providing information on subclinical myocardial dysfunction due to fibrosis. A large body of evidence advocates its use to determine the switch from adaptive to maladaptive myocardial changes in AS, and to refine thresholds for intervention. Although mainly studied in echocardiography, studies exploring the role of strain in multi-detector row computed tomography and cardiac magnetic resonance are emerging. This review, therefore, summarizes contemporary evidence on the role of LVEF and strain imaging in AS prognosis, aiming to move from an LVEF-based to a strain-based approach for risk stratification and therapeutic decision-making in AS.

Advanced Cardiac Imaging in the Assessment of Aortic Stenosis

Aortic stenosis is the most common form of valve disease in the Western world and a major healthcare burden. Although echocardiography remains the central modality for the diagnosis and assessment of aortic stenosis, recently, advanced cardiac imaging with cardiovascular magnetic resonance, computed tomography, and positron emission tomography have provided invaluable pathological insights that may guide the personalized management of the disease. In this review, we discuss applications of these novel non-invasive imaging modalities for establishing the diagnosis, monitoring disease progression, and eventually planning the invasive treatment of aortic stenosis.

Impact of aortic valve replacement in symptomatic low-risk patients with less than severe aortic stenosis

OBJECTIVE

To evaluate whether transcatheter or surgical aortic valve replacement (TAVR or SAVR) affects clinical and haemodynamic outcomes in symptomatic patients with moderately-severe aortic stenosis (AS).

METHODS

Echocardiographic evidence of severe AS for enrolment in the Evolut Low Risk trial was based on site-reported measurements. For this post hoc analysis, core laboratory measurements identified patients with symptomatic moderately-severe AS (1.0

RESULTS

Moderately-severe AS was identified in 113 out of 1414 patients (8%). Baseline AVA was 1.1±0.1 cm2, peak velocity 3.7±0.2 m/s, MG 32.7±4.8 mm Hg and aortic valve calcium volume 588 (364, 815) mm3. Valve haemodynamics improved following TAVR (AVA 2.5±0.7 cm2, peak velocity 1.9±0.5 m/s and MG 8.4±4.8 mm Hg; p<0.001 for all) and SAVR (AVA 2.0±0.6 cm2, peak velocity 2.1±0.4 m/s and MG 10.0±3.4 mm Hg; p<0.001 for all). At 24 months, the rates of death or disabling stroke were similar (TAVR 7.7% vs SAVR 6.5%; p=0.82). Kansas City Cardiomyopathy Questionnaire overall summary score assessing quality of life improved from baseline to 30 days after TAVR (67.0±20.6 to 89.3±13.4; p<0.001) and SAVR (67.5±19.6 to 78.3±22.3; p=0.001).

CONCLUSIONS

In symptomatic patients with moderately-severe AS, AVR appears to be beneficial. Determination of the clinical and haemodynamic profile of patients who can benefit from earlier isolated AVR needs further investigation in randomised clinical trials.

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Key Words

• Aortic Valve Stenosis
• Heart Valve Diseases
• Transcatheter Aortic Valve Replacement

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MESH Headings

• Humans
• Aortic Valve/diagnostic imaging
• Aortic Valve/surgery
• Heart Valve Prosthesis Implantation/adverse effects
• Quality of Life
• Aortic Valve Stenosis/diagnostic imaging
• Aortic Valve Stenosis/surgery
• Aortic Valve Stenosis/etiology
• Treatment Outcome

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Grants

• UL1 TR001863 NCATS NIH HHS
• Medtronic

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Affiliation(s)

Saki Ito Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA
Roger Laham Department of Cardiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
Vuyisile T Nkomo Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA
John K Forrest Department of Internal Medicine (Cardiology), Yale-New Haven Hospital, New Haven, Connecticut, USA
Michael J Reardon Departments of Cardiology and Cardiothoracic Surgery, Houston Methodist Debakey Heart and Vascular Center, Houston, Texas, USA
Stephen H Little Departments of Cardiology and Cardiothoracic Surgery, Houston Methodist Debakey Heart and Vascular Center, Houston, Texas, USA
Mubashir Mumtaz Departments of Cardiothoracic Surgery and Interventional Cardiology, University of Pittsburgh Medical Center Pinnacle Health, Wormsleyburg, Pennsylvania, USA
Hemal Gada Departments of Cardiothoracic Surgery and Interventional Cardiology, University of Pittsburgh Medical Center Pinnacle Health, Wormsleyburg, Pennsylvania, USA
Tanvir Bajwa Aurora Cardiovascular and Thoracic Services, Aurora Saint Luke's Medical Center, Milwaukee, Wisconsin, USA
David Langholz Department of Cardiothoracic Surgery, Spectrum Health, Grand Rapids, Michigan, USA
John Heiser Department of Cardiothoracic Surgery, Spectrum Health, Grand Rapids, Michigan, USA
Atul Chawla Department of Cardiology, Mercy Medical Center, IA, Mercy Medical Center, Des Moines, Iowa, USA
Bart Jenson Department of Cardiology, Mercy Medical Center, IA, Mercy Medical Center, Des Moines, Iowa, USA
Guilherme Attizanni Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
Alan H Markowitz Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
Jian Huang Structural Heart and Aortic, Medtronic Inc, Mounds View, Minnesota, USA
Jae K Oh Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA

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Coronary Obstruction during Valve-in-Valve Transcatheter Aortic Valve Replacement: Pre-Procedural Risk Evaluation, Intra-Procedural Monitoring, and Follow-Up

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) is emerging as an effective treatment for patients with symptomatically failing bioprosthetic valves and a high prohibitive surgical risk; a longer life expectancy has led to a higher demand for these valve reinterventions due to the increased possibilities of outliving the bioprosthetic valve's durability. Coronary obstruction is the most feared complication of valve-in-valve (ViV) TAVR; it is a rare but life-threatening complication and occurs most frequently at the left coronary artery ostium. Accurate pre-procedural planning, mainly based on cardiac computed tomography, is crucial to determining the feasibility of a ViV TAVR and to assessing the anticipated risk of a coronary obstruction and the eventual need for coronary protection measures. Intraprocedurally, the aortic root and a selective coronary angiography are useful for evaluating the anatomic relationship between the aortic valve and coronary ostia; transesophageal echocardiographic real-time monitoring of the coronary flow with a color Doppler and pulsed-wave Doppler is a valuable tool that allows for a determination of real-time coronary patency and the detection of asymptomatic coronary obstructions. Because of the risk of developing a delayed coronary obstruction, the close postprocedural monitoring of patients at a high risk of developing coronary obstructions is advisable. CT simulations of ViV TAVR, 3D printing models, and fusion imaging represent the future directions that may help provide a personalized lifetime strategy and tailored approach for each patient, potentially minimizing complications and improving outcomes.

Pathophysiology, emerging techniques for the assessment and novel treatment of aortic stenosis

Our perspectives on aortic stenosis (AS) are changing. Evolving from the traditional thought of a passive degenerative disease, developing a greater understanding of the condition's mechanistic underpinning has shifted the paradigm to an active disease process. This advancement from the 'wear and tear' model is a result of the growing economic and health burden of AS, particularly within industrialised countries, prompting further research. The pathophysiology of calcific AS (CAS) is complex, yet can be characterised similarly to that of atherosclerosis. Progressive remodelling involves lipid-protein complexes, with lipoprotein(a) being of particular interest for diagnostics and potential future treatment options.There is an unmet clinical need for asymptomatic patient management; no pharmacotherapies are proven to slow progression and intervention timing varies. Novel approaches are developing to address this through: (1) screening with circulating biomarkers; (2) development of drugs to slow disease progression and (3) early valve intervention guided by medical imaging. Existing biomarkers (troponin and brain natriuretic peptide) are non-specific, but cost-effective predictors of ventricular dysfunction. In addition, their integration with cardiovascular MRI can provide accurate risk stratification, aiding aortic valve replacement decision making. Currently, invasive intervention is the only treatment for AS. In comparison, the development of lipoprotein(a) lowering therapies could provide an alternative; slowing progression of CAS, preventing left ventricular dysfunction and reducing reliance on surgical intervention.The landscape of AS management is rapidly evolving. This review outlines current understanding of the pathophysiology of AS, its management and future perspectives for the condition's assessment and treatment.

Prognostic value of echocardiographic evaluation of cardiac mechanics in patients with aortic stenosis and preserved left ventricular ejection fraction

Left ventricular ejection function (LVEF) is not reliable in identifying subtle systolic dysfunction. Speckle Tracking (ST) plays a promising role and hemodynamic forces (HDFs) are emerging as marker of LV function. The role of LV myocardial deformation and HDFs was investigated in a cohort of patients with aortic stenosis (AS) and normal LVEF. Two hundred fifty three patients (median age 79 years, IQR 73 - 83 years) with mild (n = 87), moderate (n =77) and severe AS (n =89) were retrospectively enrolled. 2D echocardiographic global longitudinal strain (GLS), circumferential strain (GCS) and HDFs were determined. The worsening of AS was associated with raising inappropriate LV mass (p < 0.001) and declined LVEF, despite being in the normal range (p < 0.001). ST and HDFs parameters declined as the AS became severe (p<0.0001, for all). When patients were grouped based on the median of LV endocardial GLS value (> -19,9%) and LV systolic longitudinal force (LVsysLF) value (< 12,49), patients with impaired ST and lower HDFs components had increased incidence of aortic valve replacement (AVR) and worse survival (p <0.024 and p <0.037, respectively). Among ST and HDFs parameters, only LVsysLF was independently associated with AVR and all causes mortality on multivariable Cox regression analysis (HR 0.94; 95% CI 0.89-0.99; p= 0.012). Reduced values of LVsysLF were associated with AVR and reduced survival in AS patients. LVsysLF could provide useful information in the stratification of patients with AS and possibly in the choice of timing for AVR.

Heart failure and excess mortality after aortic valve replacement in aortic stenosis

INTRODUCTION

In aortic stenosis (AS), the heart transitions from adaptive compensation to an AS cardiomyopathy and eventually leads to decompensation with heart failure. Better understanding of the underpinning pathophysiological mechanisms is required in order to inform strategies to prevent decompensation.

AREAS COVERED

In this review, we therefore aim to appraise the current pathophysiological understanding of adaptive and maladaptive processes in AS, appraise potential avenues of adjunctive therapy before or after AVR and highlight areas of further research in the management of heart failure post AVR.

EXPERT OPINION

Tailored strategies for the timing of intervention accounting for individual patient's response to the afterload insult are underway, and promise to guide better management in the future. Further clinical trials of adjunctive pharmacological and device therapy to either cardioprotect prior to intervention or promote reverse remodeling and recovery after intervention are needed to mitigate the risk of heart failure and excess mortality.

Myocardial Evaluation in Patients with Aortic Stenosis by Cardiac Computed Tomography

BACKGROUND

 Aortic valve stenosis (AVS) is one of the most prevalent pathologies affecting the heart that can curtail expected survival and quality of life if not managed appropriately.

CURRENT STATUS

 Cardiac computed tomography (CT) has long played a central role in this subset, mostly for severity assessment and for procedural planning. Although not as widely accepted as other imaging modalities for functional myocardial assessment [i. e., transthoracic echocardiogram (TTE), cardiac magnetic resonance (CMR)], this technique has recently increased its clinical application in this regard.

FUTURE OUTLOOK

 The ability to provide morphological, functional, tissue, and preprocedural information highlights the potential of the "all-in-one" concept of cardiac CT as a potential reality for the near future for AVS assessment. In this review article, we sought to analyze the current applications of cardiac CT that allow a full comprehensive evaluation of aortic valve disease.

KEY POINTS

  · Noninvasive myocardial tissue characterization stopped being an exclusive feature of cardiac magnetic resonance.. · Emerging acquisition methods make cardiac CT an accurate and widely accessible imaging modality.. · Cardiac CT has the potential to become a "one-stop" exam for comprehensive aortic stenosis assessment..

CITATION FORMAT

· Gama FF, Patel K, Bennett J et al. Myocardial Evaluation in Patients with Aortic Stenosis by Cardiac Computed Tomography. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1999-7271.

Left ventricular hypertrophy as a predictor of cardiovascular outcomes after transcatheter aortic valve replacement

AIMS

This study aimed to clarify the relationship between cardiovascular prognosis and left ventricular hypertrophy (LVH) in patients with severe aortic stenosis who underwent transcatheter aortic valve replacement (TAVR) and to investigate the relationship between cardiac sympathetic nerve (CSN) function and these factors using ¹²³ I-metaiodobenzylguanidine scintigraphy.

METHODS AND RESULTS

In this single-centre, retrospective observational study, 349 patients who underwent TAVR at our institution between July 2017 and May 2020 were divided into two groups: those with severe LVH pre-operatively [severe LVH (+) group] and those without LVH pre-operatively [severe LVH (-) group]. The rates of freedom from cardiovascular events (cardiovascular death and heart failure hospitalization) were compared. The relationship between changes in left ventricular mass index (LVMi) and changes in delay heart-mediastinum ratio (H/M) from before TAVR to 6 months after TAVR was also investigated. The event-free rate was significantly lower in the severe LVH (+) group (87.1% vs. 96.0%, log-rank P = 0.021). The severe LVH (+) group exhibited a significantly lower delay H/M value, scored by ¹²³ I-metaiodobenzylguanidine scintigraphy, than the severe LVH (-) group (2.33 [1.92-2.67] vs. 2.67 [2.17-3.68], respectively, P < 0.001). Moreover, the event-free rate of post-operative cardiovascular events was lower among patients with a delay H/M value < 2.50 than that among other patients (87.7% vs. 97.2%, log-rank P = 0.012). LVMi was significantly higher (115 [99-130] vs. 90 [78-111] g/m² , P < 0.001) and delay H/M value was significantly lower (2.53 [1.98-2.83] vs. 2.71 [2.25-3.19], P = 0.025) in the severe LVH (+) group than in the severe LVH (-) group at 6 months after TAVR. Patients with improved LVH at 6 months after TAVR also had increased delay H/M (from 2.51 [2.01-2.81] to 2.67 [2.26-3.02], P < 0.001), whereas those without improved LVH had no significant change in delay H/M (from 2.64 [2.23-3.06] to 2.53 [1.97-3.00], P = 0.829).

CONCLUSIONS

Severe LVH before TAVR is a prognostic factor for poor post-operative cardiovascular outcomes. LVH associated with aortic stenosis and CSN function are correlated, suggesting their involvement in LVH prognosis.

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.

Association of renin-angiotensin system inhibitors use with short- and long-term mortality in patients with aortic stenosis: A systematic review and meta-analysis

Purpose

The present study aimed to investigate the association of renin-angiotensin system inhibitors (RASi) with short- and long-term mortality in patients with aortic stenosis (AS).

Methods

A systematic search was performed in PubMed, Embase, and Cochrane library databases for relevant studies published before March 2022. Studies meeting the inclusion criteria were included to assess the effect of RASi on short-term (≤30 days) and long-term (≥1 year) mortality in patients with AS.

Results

A total of 11 studies were included in the meta-analysis. Our results demonstrated that RASi reduced short-term mortality (OR = 0.76, 95% CI 0.63-0.93, p = 0.008) after aortic valve replacement (AVR). Subgroup analysis revealed that RASi was still associated with lower short-term mortality after transcatheter aortic valve replacement (TAVR); however, the association was relatively weak in patients who underwent surgical aortic valve replacement (SAVR). For long-term mortality, the pooled OR was 1.04 (95% CI 0.88-1.24, p = 0.63) after sensitivity analysis in patients who did not undergo AVR. In addition, our study confirmed that RASi significantly reduced long-term mortality (OR = 0.57, 95% CI 0.44-0.74, p < 0.0001) in patients who underwent AVR. Subgroup analysis showed that both TAVR and SAVR groups treated with RASi had lower long-term mortality.

Conclusion

Renin-angiotensin system inhibitors did not change long-term mortality in AS patients who did not undergo AVR. However, RASi reduced short- and long-term mortality in patients who underwent AVR.

Managing Patients With Moderate Aortic Stenosis

Current guidelines recommend that clinical surveillance for patients with moderate aortic stenosis (AS) and aortic valve replacement (AVR) may be considered if there is an indication for coronary revascularization. Recent observational studies, however, have shown that moderate AS is associated with an increased risk of cardiovascular events and mortality. Whether the increased risk of adverse events is caused by associated comorbidities, or to the underlying moderate AS itself, is incompletely understood. Similarly, which patients with moderate AS need close follow-up or could potentially benefit from early AVR is also unknown. In this review, the authors provide a comprehensive overview of the current literature on moderate AS. They first provide an algorithm that helps to diagnose moderate AS correctly, especially when discordant grading is observed. Although the traditional focus of AS assessment has been on the valve, it is increasingly acknowledged that AS is not only a disease of the aortic valve but also of the ventricle. The authors therefore discuss how multimodality imaging can help to evaluate the left ventricular remodeling response and improve risk stratification in patients with moderate AS. Finally, they summarize current evidence on the management of moderate AS and highlight ongoing trials on AVR in moderate AS.

Multimodality imaging methods and systemic biomarkers in classical low-flow low-gradient aortic stenosis: Key findings for risk stratification

Objectives

The aim of the present study is to assess multimodality imaging findings according to systemic biomarkers, high-sensitivity troponin I (hsTnI) and B-type natriuretic peptide (BNP) levels, in low-flow, low-gradient aortic stenosis (LFLG-AS).

Background

Elevated levels of BNP and hsTnI have been related with poor prognosis in patients with LFLG-AS.

Methods

Prospective study with LFLG-AS patients that underwent hsTnI, BNP, coronary angiography, cardiac magnetic resonance (CMR) with T1 mapping, echocardiogram and dobutamine stress echocardiogram. Patients were divided into 3 groups according to BNP and hsTnI levels: Group 1 (n = 17) when BNP and hsTnI levels were below median [BNP < 1.98 fold upper reference limit (URL) and hsTnI < 1.8 fold URL]; Group 2 (n = 14) when BNP or hsTnI were higher than median; and Group 3 (n = 18) when both hsTnI and BNP were higher than median.

Results

49 patients included in 3 groups. Clinical characteristics (including risk scores) were similar among groups. Group 3 patients had lower valvuloarterial impedance (P = 0.03) and lower left ventricular ejection fraction (P = 0.02) by echocardiogram. CMR identified a progressive increase of right and left ventricular chamber from Group 1 to Group 3, and worsening of left ventricular ejection fraction (EF) (40 [31-47] vs. 32 [29-41] vs. 26 [19-33]%; p < 0.01) and right ventricular EF (62 [53-69] vs. 51 [35-63] vs. 30 [24-46]%; p < 0.01). Besides, there was a marked increase in myocardial fibrosis assessed by extracellular volume fraction (ECV) (28.4 [24.8-30.7] vs. 28.2 [26.9-34.5] vs. 31.8 [28.9-35.5]%; p = 0.03) and indexed ECV (iECV) (28.7 [21.2-39.1] vs. 28.8 [25.4-39.9] vs. 44.2 [36.4-51.2] ml/m², respectively; p < 0.01) from Group 1 to Group 3.

Conclusions

Higher levels of BNP and hsTnI in LFLG-AS patients are associated with worse multi-modality evidence of cardiac remodeling and fibrosis.

Role of cardiovascular magnetic resonance in the clinical evaluation of left ventricular hypertrophy: a 360° panorama

Left ventricular hypertrophy (LVH) is a frequent imaging finding in the general population. In order to identify the precise etiology, a comprehensive diagnostic approach should be adopted, including the prevalence of each entity that may cause LVH, family history, clinical, electrocardiographic and imaging findings. By providing a detailed evaluation of the myocardium, cardiovascular magnetic resonance (CMR) has assumed a central role in the differential diagnosis of left ventricular hypertrophy, with the technique of parametric imaging allowing more refined tissue characterization. This article aims to establish a parallel between pathophysiological features and imaging findings through the broad spectrum of LVH entities, emphasizing the role of CMR in the differential diagnosis.

The Primary Alteration of Ventricular Myocardium Conduction: The Significant Determinant of Left Bundle Branch Block Pattern

Intraventricular conduction disturbances (IVCD) are currently generally accepted as ECG diagnostic categories. They are characterized by defined QRS complex patterns that reflect the abnormalities in the intraventricular sequence of activation that can be caused by pathology in the His-Purkinje conduction system (HP) or ventricular myocardium. However, the current understanding of the IVCD's underlying mechanism is mostly attributed to HP structural or functional alterations. The involvement of the working ventricular myocardium is only marginally mentioned or not considered. This opinion paper is focused on the alterations of the ventricular working myocardium leading to the most frequent IVCD pattern-the left bundle branch block pattern (LBBB). Recognizing the underlying mechanisms of the LBBB patterns and the involvement of the ventricular working myocardium is of utmost clinical importance, considering a patient's prognosis and indication for cardiac resynchronization therapy.

Multimodality Imaging to Explore Sex Differences in Aortic Stenosis

The aim of this article is to review sex differences in aortic stenosis (AS) assessed with multimodality imaging. Echocardiography remains the mainstay imaging technique to diagnose AS and provides important insights into the differences between men and women in relation to valve haemodynamic and left-ventricular response. However, echocardiography does not have adequate resolution to provide important insights into sex differences in the degenerative, calcific pathophysiological process of the aortic valve. CT shows that women with AS have more fibrotic changes of the aortic valve whereas men show more calcific deposits. Cardiac magnetic resonance shows that women have left ventricles that are less hypertrophic and smaller compared with those of men, while men have more replacement myocardial fibrosis. These differences may lead to different responses to aortic valve replacement because myocardial diffuse fibrosis but not replacement myocardial fibrosis may regress after the procedure. Sex differences in the pathophysiological process of AS can be assessed using multimodality imaging, assisting in decisionmaking in these patients.

The cardiac computed tomography-derived extracellular volume fraction predicts patient outcomes and left ventricular mass reductions after transcatheter aortic valve implantation for aortic stenosis

BACKGROUND

Transcatheter aortic valve implantation (TAVI) improved outcome of patients with severe aortic valve stenosis (AS). Myocardial fibrosis is associated with AS-related pathological left ventricular (LV) remodeling and predicts cardiovascular mortality after TAVI. The present study aimed to investigate the impact of preoperative extracellular volume (ECV) assessed by computed tomography (CT) on left ventricular mass (LVM) regression and clinical outcomes in severe AS patients after TAVI.

METHODS

We examined 71 consecutive severe AS patients who underwent CT with ECV determination before TAVI. ECV was calculated as the ratio of the change in Hounsfield units in the myocardium and LV blood before and after contrast administration, multiplied by (1-hematocrit). Delayed scan was performed at 5 min after contrast injection. Echocardiography was performed before and 6 months after TAVI. The primary endpoint was heart failure (HF) hospitalization after TAVI. Patients were divided into two subgroups according to the median value of global ECV with 32 % (Low-ECV group: n = 35, and High-ECV group: n = 36).

RESULTS

No significant differences were observed in background characteristics between the 2 groups. However, the preoperative LV ejection fraction and LVM index were similar between the 2 groups, the Low-ECV group had greater LVM index reduction than the High-CV group after 6 months (p < 0.001). Kaplan-Meier curves demonstrated that the High-ECV group had significantly higher rate of HF hospitalization than the Low-ECV group (p = 0.016). In addition, multivariate analyses identified high global ECV as an independent predictor of HF hospitalization (HR 10.8, 95 % confidence interval 1.36 to 84.8, p = 0.024).

CONCLUSION

The low preoperative ECV assessed by CT is associated with the greater LVM regression, and predict better outcome in AS patients after TAVI.

Long-term prognostic impact of paravalvular leakage on coronary artery disease requires patient-specific quantification of hemodynamics

Transcatheter aortic valve replacement (TAVR) is a frequently used minimally invasive intervention for patient with aortic stenosis across a broad risk spectrum. While coronary artery disease (CAD) is present in approximately half of TAVR candidates, correlation of post-TAVR complications such as paravalvular leakage (PVL) or misalignment with CAD are not fully understood. For this purpose, we developed a multiscale computational framework based on a patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-structure interaction model to quantify metrics of global circulatory function, metrics of global cardiac function and local cardiac fluid dynamics in 6 patients. Based on our findings, PVL limits the benefits of TAVR and restricts coronary perfusion due to the lack of sufficient coronary blood flow during diastole phase (e.g., maximum coronary flow rate reduced by 21.73%, 21.43% and 21.43% in the left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)). Moreover, PVL may increase the LV load (e.g., LV load increased by 17.57% (N = 6)) and decrease the coronary wall shear stress (e.g., maximum wall shear stress reduced by 20.62%, 21.92%, 22.28% and 25.66% in the left main coronary artery (LMCA), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)), which could promote atherosclerosis development through loss of the physiological flow-oriented alignment of endothelial cells. This study demonstrated that a rigorously developed personalized image-based computational framework can provide vital insights into underlying mechanics of TAVR and CAD interactions and assist in treatment planning and patient risk stratification in patients.

Integrating hemodynamics with ventricular and valvular remodeling in aortic stenosis. A paradigm shift in therapeutic decision making

Aortic valve stenosis (AS) has traditionally been approached in hemodynamic terms. Although hemodynamics and symptoms have formed the basis of recommending interventional treatment in AS, other factors reflecting left ventricular and valvular and/or vascular remodeling are equally important for the prognosis and outcome of patients with AS. Left ventricular and valvular/vascular remodeling in AS do not consistently correlate with hemodynamic severity of AS. Those remodeling changes are reflected and can be detected by a variety of novel laboratory and imaging techniques, including biomarkers, echocardiography, cardiac magnetic resonance and gated Computer Tomography (CT) imaging. Taking all those elements into Heart Team therapeutic decision making in patients with AS, can significantly improve appropriate patient selection for interventional treatment and patient outcomes. We review this novel approach and propose a simple algorithm for decision making by the Heart Team, in patients with moderate or severe AS.

Treatment in patients with severe asymptomatic aortic stenosis: is it best not to wait?

New insights into the natural history and pathophysiology of patients with aortic stenosis (AS), coupled with the dramatic evolution of transcatheter aortic valve implantation (TAVI), are fuelling intense interest in the management of asymptomatic patients with severe AS. This patient presenting for elective intervention poses a unique challenge. These patients are not traditionally offered surgical aortic valve replacement or TAVI given their lack of symptoms; however, they are at increased risk given the severity of their AS. Furthermore, clinical experience has shown that symptoms can be challenging to ascertain in many sedentary, deconditioned, and/or elderly patients. In addition, evolving data based on imaging and biomarker evidence of adverse ventricular remodelling, hypertrophy, inflammation, or fibrosis may radically transform existing clinical decision paradigms. However, management of asymptomatic severe AS is otherwise controversial and the decision to intervene requires careful assessment of the benefits and risks in an individual patient. Further randomized trials [EARLY TAVI (NCT03042104), AVATAR (NCT02436655), EVOLVED (NCT03094143)] will help determine future recommendations.