Timing of intervention in aortic stenosis: a review of current and future strategies

Soft robotic platform for progressive and reversible aortic constriction in a small-animal model

Our understanding of cardiac remodeling processes due to left ventricular pressure overload derives largely from animal models of aortic banding. However, these studies fail to enable control over both disease progression and reversal, hindering their clinical relevance. Here, we describe a method for progressive and reversible aortic banding based on an implantable expandable actuator that can be finely tuned to modulate aortic banding and debanding in a rat model. Through catheterization, imaging, and histologic studies, we demonstrate that our platform can recapitulate the hemodynamic and structural changes associated with pressure overload in a controllable manner. We leveraged soft robotics to enable noninvasive aortic debanding, demonstrating that these changes can be partly reversed because of cessation of the biomechanical stimulus. By recapitulating longitudinal disease progression and reversibility, this animal model could elucidate fundamental mechanisms of cardiac remodeling and optimize timing of intervention for pressure overload.

Pilot study to evaluate the use of remote patient monitoring to guide the timing of valve intervention in patients with severe asymptomatic aortic stenosis (APRAISE-AS): study protocol for a randomised controlled trial delivered in two tertiary cardiac centres in the UK

INTRODUCTION

Aortic stenosis (AS) is common affecting >13% of adults over the age of 75 years. In people who develop symptoms, without valve replacement, prognosis is dismal with mortality as high as 50% at 1 year. In asymptomatic patients, the timing of valve intervention is less well defined and a strategy of watchful waiting is recommended. Many, however, may develop symptoms and attribute this to age related decline, rather than worsening AS. Timely intervention in asymptomatic severe AS is critical, since delayed intervention often results in poor outcomes. Proactive surveillance of symptoms, quality of life and functional capacity should enable timely identification of people who will benefit from aortic valve replacement. There are no data however, to support the clinical and cost effectiveness of such an approach in a healthcare setting in the UK. The aim of this pilot trial is to test the feasibility of a full-scale randomised controlled trial (RCT) to determine the utility of proactive surveillance in people with asymptomatic severe AS to guide the timing of intervention.

METHODS AND ANALYSIS

APRAISE-AS is a multi-centre, non-blinded, two-arm, parallel group randomised controlled trial of up to 66 participants aged >18 years with asymptomatic severe AS. Participants will be randomised to either standard care or standard care supplemented with the APRAISE-AS intervention. Primary outcomes will capture; adherence to and participant acceptability of the intervention, recruitment and retention rates, and completeness of data collection. The findings will be used to inform the sample size and most appropriate outcome measure(s) for a full-scale RCT and health economic evaluation.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Black Country REC, reference: 22/WM/0214. Results will be submitted for publication in peer-reviewed journals and disseminated at local, regional and national meetings where appropriate.

TRIAL REGISTRATION NUMBER

ISRCTN19413194 registered on 14.07.2023.

Myocardial Blood Flow Reserve, Microvascular Coronary Health, and Myocardial Remodeling in Patients With Aortic Stenosis

BACKGROUND

Coronary microvascular function and hemodynamics may play a role in coronary circulation and myocardial remodeling in patients with aortic stenosis (AS). We aimed to evaluate the relationship between myocardial blood flow and myocardial function in patients with AS, no AS, and aortic valve sclerosis.

METHODS AND RESULTS

We included consecutive patients who had resting transthoracic echocardiography and clinically indicated positron emission tomography myocardial perfusion imaging to capture their left ventricular ejection fraction, global longitudinal strain (GLS), and myocardial flow reserve (MFR). The primary outcome was major adverse cardiovascular event (all-cause mortality, myocardial infarction, or late revascularization). There were 2778 patients (208 with aortic sclerosis, 39 with prosthetic aortic valve, 2406 with no AS, and 54, 49, and 22 with mild, moderate, and severe AS, respectively). Increasing AS severity was associated with impaired MFR (P<0.001) and GLS (P<0.001), even when perfusion was normal. Statistically significant associations were noted between MFR and GLS, MFR and left ventricular ejection fraction, and MFR and left ventricular ejection fraction reserve. After a median follow-up of 349 (interquartile range, 116-662) days, 4 (7.4%), 5 (10.2%), and 6 (27.3%) patients experienced a major adverse cardiovascular event in the mild, moderate, and severe AS groups, respectively. In a matched-control analysis, patients with mild-to-moderate AS had higher rates of impaired MFR (52.9% versus 39.9%; P=0.048) and major adverse cardiovascular event (11.8% versus 3.0%; P=0.002).

CONCLUSIONS

Despite lack of ischemia, as severity of AS increased, MFR decreased and GLS worsened, reflecting worse coronary microvascular health and myocardial remodeling. Positron emission tomography-derived MFR showed a significant independent correlation with left ventricular ejection fraction and GLS. Patients with prosthetic aortic valve showed a high prevalence of impaired MFR.

Moderate aortic stenosis: Navigating the uncharted

Aortic stenosis (AS) stands as the most common valvular heart disease in developed countries and is characterized by progressive narrowing of the aortic valve orifice resulting in elevated transvalvular flow resistance, left ventricular hypertrophy, and progressive increased risk of heart failure and sudden death. This narrative review explores clinical challenges and evolving perspectives in moderate AS, where discrepancies between aortic valve area and pressure gradient measurements may pose diagnostic and therapeutic quandaries. Transthoracic echocardiography is the first-line imaging modality for AS evaluation, yet cases of discordance may require the application of ancillary noninvasive diagnostic modalities. This review underscores the importance of accurate grading of AS severity, especially in low-gradient phenotypes, emphasizing the need for vigilant follow-up. Current clinical guidelines primarily recommend aortic valve replacement for severe AS, potentially overlooking latent risks in moderate disease stages. The noninvasive multimodality imaging approach-including echocardiography, cardiac magnetic resonance, computed tomography, and nuclear techniques-provides unique insights into adaptive and maladaptive cardiac remodeling in AS and offers a promising avenue to deliver precise indications and exact timing for intervention in moderate AS phenotypes and asymptomatic patients, potentially improving long-term outcomes. Nevertheless, what we may have gleaned from a large amount of observational data is still insufficient to build a robust framework for clinical decision-making in moderate AS. Future research will prioritize randomized clinical trials designed to weigh the benefits and risks of preemptive aortic valve replacement in the management of moderate AS, as directed by specific imaging and nonimaging biomarkers.

Diagnostic Value of Aortic Valve Calcification Levels in the Assessment of Low-Gradient Aortic Stenosis

BACKGROUND

In patients with low-gradient aortic stenosis (AS) and low transvalvular flow, dobutamine stress echocardiography (DSE) is recommended to determine AS severity, whereas the degree of aortic valve calcification (AVC) supposedly correlates with AS severity according to current European and American guidelines.

OBJECTIVES

The purpose of this study was to assess the relationship between AVC and AS severity as determined using echocardiography and DSE in patients with aortic valve area <1 cm2 and peak aortic valve velocity <4.0 m/s.

METHODS

All patients underwent DSE to determine AS severity and multislice computed tomography to quantify AVC. Receiver-operating characteristics curve analysis was used to assess the diagnostic value of AVC for AS severity grading as determined using echocardiography and DSE in men and women.

RESULTS

A total of 214 patients were included. Median age was 78 years (25th-75th percentile: 71-84 years) and 25% were women. Left ventricular ejection fraction was reduced (<50%) in 197 (92.1%) patients. Severe AS was diagnosed in 106 patients (49.5%). Moderate AS was diagnosed in 108 patients (50.5%; in 77 based on resting transthoracic echocardiography, in 31 confirmed using DSE). AVC score was high (≥2,000 for men or ≥1,200 for women) in 47 (44.3%) patients with severe AS and in 47 (43.5%) patients with moderate AS. AVC sensitivity was 44.3%, specificity was 56.5%, and positive and negative predictive values for severe AS were 50.0% and 50.8%, respectively. Area under the receiver-operating characteristics curve was 0.508 for men and 0.524 for women.

CONCLUSIONS

Multi-slice computed tomography-derived AVC scores showed poor discrimination between grades of AS severity using DSE and cannot replace DSE in the diagnostic work-up of low-gradient severe AS.

Medical treatment of heart failure with renin-angiotensin-aldosterone system inhibitors and beta-blockers in aortic stenosis: association with long-term outcome after aortic valve replacement

Aims

There is a lack of robust data on the optimal medical treatment of heart failure in patients with severe aortic stenosis, with no randomized controlled trials guiding treatment. The study aimed to study the association between exposure to renin-angiotensin-aldosterone system (RAS) inhibitors or beta-blockers and outcome after aortic valve replacement in patients with aortic stenosis and heart failure.

Methods and results

The study included all patients with heart failure undergoing aortic valve replacement for aortic stenosis in Sweden between 2008 and 2016 (n = 4668 patients). Exposure to treatment was assessed by a continuous tracking of drug dispensations, and outcome events were all-cause mortality and hospitalization for heart failure collected from national patient registries. After adjustment for age, sex, atrial fibrillation, hypertension, diabetes mellitus, and prior myocardial infarction, Cox regression analysis showed that RAS inhibition was associated with a lower risk of all-cause mortality in patients with reduced left ventricular ejection fraction (LV-EF) [hazard ratio (HR) 0.58, 95% confidence interval (CI) 0.51-0.65] and preserved LV-EF (HR 0.69, 95% CI 0.56-0.85). Beta-blockade was associated with a lower risk of all-cause mortality in patients with reduced LV-EF (HR 0.81, 95% CI 0.71-0.92), but not in preserved LV-EF (HR 0.87, 95% CI 0.69-1.10). There was no association between RAS inhibition or beta-blockade and the risk of hospitalization for heart failure.

Conclusion

The RAS inhibition was associated with a lower all-cause mortality after valve replacement in patients with both reduced and preserved LV-EF. Beta-blockade was associated with lower all-cause mortality only in patients with reduced LV-EF.

Signal intensity coefficient as a detector of aortic stenosis-induced myocardial fibrosis and its correlation to the long term outcome

OBJECTIVE

Despite advanced aortic valve replacement techniques, aortic stenosis (AS)-induced irreversible myocardial fibrosis contributes to poorer outcomes. Therefore, in addition to early diagnosis of AS, detecting myocardial fibrosis is crucial for physicians to determine the timing of surgery. The Signal Intensity Coefficient (SIC) was used to detect subtle myocardial deformation. Hence, we aimed to investigate whether SIC correlated with myocardial dysfunction and fibrosis from both clinical and preclinical perspectives.

METHODS

We collected medical records and echocardiography images, including the SIC of patients who underwent surgical aortic valve replacement (AVR) for AS from 2010 to 2015. The endpoint of the study was mortality. Median follow-up period was 80 months.

RESULTS

Among 109 patients, 15 died due to cardiovascular causes. Although SIC decreased in all patients post-AVR, patients with an SIC ≥0.34 before surgeries presented with a higher probability of cardiovascular death. In contrast, changes in the left ventricular (LV) ejection fraction, LV mass index, and LV volume failed to predict outcomes. Similarly, SIC was obtained in mice undergoing aortic banding and debanding surgery for comparison with the degree of myocardial fibrosis. SIC was continuously elevated after aortic banding and declined gradually after debanding surgery in mice. Debanding surgery indicated the regression of aortic banding-induced myocardial fibrosis.

CONCLUSION

Pre-AVR SIC was associated with the risk of cardiovascular death and reflected the degree of myocardial fibrosis. Further investigations are required to study the clinical application of SIC in patients with AS.

High resolution monitoring of valvular interstitial cell driven pathomechanisms in procalcific environment using label-free impedance spectroscopy

Introduction

Fibro-calcific aortic valve disease has high prevalence and is associated with significant mortality. Fibrotic extracellular matrix (ECM) remodeling and calcific mineral deposition change the valvular microarchitecture and deteriorate valvular function. Valvular interstitial cells (VICs) in profibrotic or procalcifying environment are frequently used in vitro models. However, remodeling processes take several days to weeks to develop, even in vitro. Continuous monitoring by real-time impedance spectroscopy (EIS) may reveal new insights into this process.

Methods

VIC-driven ECM remodeling stimulated by procalcifying (PM) or profibrotic medium (FM) was monitored by label-free EIS. Collagen secretion, matrix mineralization, viability, mitochondrial damage, myofibroblastic gene expression and cytoskeletal alterations were analyzed.

Results and Discussion

EIS profiles of VICs in control medium (CM) and FM were comparable. PM reproducibly induced a specific, biphasic EIS profile. Phase 1 showed an initial impedance drop, which moderately correlated with decreasing collagen secretion (r = 0.67, p = 0.22), accompanied by mitochondrial membrane hyperpolarization and cell death. Phase 2 EIS signal increase was positively correlated with augmented ECM mineralization (r = 0.97, p = 0.008). VICs in PM decreased myofibroblastic gene expression (p < 0.001) and stress fiber assembly compared to CM. EIS revealed sex-specific differences. Male VICs showed higher proliferation and in PM EIS decrease in phase 1 was significantly pronounced compared to female VICs (male minimum: 7.4 ± 4.2%, female minimum: 26.5 ± 4.4%, p < 0.01). VICs in PM reproduced disease characteristics in vitro remarkably fast with significant impact of donor sex. PM suppressed myofibroblastogenesis and favored ECM mineralization. In summary, EIS represents an efficient, easy-to-use, high-content screening tool enabling patient-specific, subgroup- and temporal resolution.

Early Transcatheter or Surgical Aortic Valve Replacement Versus Conservative Management in Asymptomatic Patients With Severe Aortic Stenosis: A Systematic Review and Meta-analysis

The merits of conservative management vs early intervention in patients with asymptomatic severe aortic stenosis remains unknown. Digital databases (MEDLINE, Google Scholar, and Embase) were searched for all relevant studies from inception through September 2022. Studies comparing conservative management with early intervention were compared using a random-effects model to calculate risk ratios (RRs) with 95% confidence interval (CI). A total of 12 studies comprising 3624 asymptomatic aortic stenosis patients (1747 receiving surgery, and 1877 receiving conservative treatment) were included in the analysis. The average follow-up time was 4.45 (IQR 3.5-5) years. Early intervention was associated with a significantly reduced risk of cardiac (RR 0.42, 95% CI 0.25-0.72; P = 0.001; I² = 54%), non-cardiac (RR 0.46, 95% CI 0.32-0.68; P < 0.0001; I² = 0%), all-cause mortality (RR 0.40, 95% CI 0.32-0.51; P < 0.00001; I² = 58%), heart failure hospitalization (RR 0.21, 95% CI 0.13-0.36; P < 0.00001; I² = 0%), sudden cardiac death (RR 0.29, 95% CI 0.12-0.66; P = 0.004, I² = 24%), and MACE (RR 0.46, 95% CI; 0.28-0.75; P = 0.002; I² = 68%), compared with conservative management. There was no significant difference in the 30-day mortality (RR 0.63, 95% CI 0.19-2.04; P = 0.44; I² = 28%), myocardial infarction (RR 0.44, 95% CI 0.19-1.06; P = 0.07, I²=0%), and 90-day mortality (RR 0.68, 95% CI 0.20-2.37; P = 0.55; I² = 61%) between the 2 groups. This meta-analysis shows statistically significant reductions in the risk for all-cause mortality, cardiac specific mortality, non-cardiac mortality, heart failure hospitalization, MACE, and sudden cardiac death among asymptomatic aortic stenosis patients who underwent early intervention as opposed to conservative management.

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.

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.

Tissue and Serum Biomarkers in Degenerative Aortic Stenosis-Insights into Pathogenesis, Prevention and Therapy

Background and Aim. Degenerative Aortic Stenosis (DAS) is a common disease that causes substantial morbidity and mortality worldwide, especially in the older population. Our aim was to further investigate novel serum and tissue biomarkers to elucidate biological processes involved in this entity. Material and Methods. We evaluated the expression of six biomarkers significantly involved in cardiovascular pathology, i.e., irisin, periostin, osteoglycin, interleukin 18, high mobility group box 1 and proprotein convertase subtilisin/kexin type 9 in the serum at the protein level, and in the tissue at both the protein and mRNA levels of patients with AS (N = 60). Five normal valves obtained after transplantation from hearts of patients with idiopathic dilated cardiomyopathy were also studied. Serum measurements were also performed in 22 individuals without valvular disease who served as controls (C). Results. Higher levels of all factors were found in DAS patients’ serum than in normal C. IHC and PCR mRNA tissue analysis showed the presence of all biomarkers in the aortic valve cusps with DAS, but no trace of PCR mRNA was found in the five transplantation valves. Moreover, periostin serum levels correlated significantly with IHC and mRNA tissue levels in AS patients. Conclusion. We showed that six widely prevalent biomarkers affecting the atherosclerotic process were also involved in DAS, suggesting a strong osteogenic and pro-inflammatory profile, indicating that aortic valve calcification is a multifactorial biological process.

Aortic valve replacement reduces mortality in moderate aortic stenosis: a systematic review and meta-analysis

BACKGROUND

With the introduction of transcatheter aortic valve replacement and an evolving understanding of the natural progression and history of aortic stenosis, the potential for earlier intervention in appropriate patients is promising; however, the benefit of aortic valve replacement in moderate aortic stenosis remains unclear.

METHODS

Pubmed, Embase, and the Cochrane Library databases were searched up until 30^th of December 2021 using keywords including moderate aortic stenosis and aortic valve replacement. Studies reporting all-cause mortality and outcomes in early aortic valve replacement (AVR) compared to conservative management in patients with moderate aortic stenosis were included. Hazard ratios were generated using random-effects meta-analysis to determine effect estimates.

RESULTS

3470 publications were screened with title and abstract review, which left 169 articles for full-text review. Of these studies, 7 met inclusion criteria and were included, totalling 4,827 patients. All studies treated AVR as a time-dependent co-variable in cox-regression multivariate analysis of all-cause mortality. Intervention with surgical or transcatheter AVR was associated with a 45% decreased risk of all-cause mortality (HR = 0.55 [0.42-0.68], I ² = 51.5%, P < 0.001). All studies were representative of the overall cohort with appropriate sample sizes, with no evidence of publication, detection, or information biases in any of the studies.

CONCLUSION

In this systematic review and meta-analysis, we report a 45% reduction in all-cause mortality in patients with moderate aortic stenosis who were treated with early aortic valve replacement compared to a strategy of conservative management. Randomised control trials are awaited to determine the utility of AVR in moderate aortic stenosis.

Non-invasive and contemporaneous cardiac imaging in heart failure

This article reviews the current non-invasive cardiac imaging modalities used in the diagnosis and management of heart failure patients. Heart failure is a complex syndrome secondary to functional and structural changes of the heart, with a wide range of possible causes for its onset. Different imaging investigations can inform diagnosis and guide care plans, so nurses across clinical practice will benefit from having knowledge on when these modalities are used. Echocardiography remains the most common investigation due to its low cost and reproducible nature when compared with other methods. It allows quantification of left ventricular function, which is an important prognostic marker in heart failure. Through cardiac magnetic resonance imaging, identification of potential reversible causes is possible, and further identification of underlying causes, when other modalities fail to do so. Finally, computed tomography coronary angiography is the currently recommended test in all patients presenting with typical or atypical anginal symptoms, diagnostically comparable to invasive coronary angiography.

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.

Direct relationship between transvalvular velocity and cardiac dysfunction, morbidity, and mortality in patients with aortic stenosis

OBJECTIVE

Current guidelines recommend intervention in subjects with severe symptomatic aortic stenosis (AS), even though any degree of AS is associated with a higher risk of mortality. We investigated the association between the degree of AS, delineated by transvalvular flow velocity, and patient morbidity and mortality.

METHODS

Medically managed patients aged 40-95 years with maximum flow velocity (V_max ) by echocardiography between 2013 and 2018 were stratified into five groups (A-E) based on the 75th, 90th, 97.5th, and the 99th percentiles of V_max distribution. Patient characteristics, cardiac structural changes, and end-organ disease were compared using Kruskal-Wallis and Cochran-Armitage tests. Mortality over a median of 2.8 (1.52-4.8) years was compared using Kaplan-Meier curves and risk estimates were derived from the Cox model.

RESULTS

The V_max was reported in 37,131 patients. There was a steady increase (from Group A towards E) in age, Caucasian race, structural cardiac changes, end-organ morbidities, and all-cause mortality. In reference to Group A, there as an increased risk of mortality in Groups B (hazard ratio [HR] = 1.3; confidence interval [CI]: 1.2-1.35; p < .0001), C (HR = 1.5; CI: 1.4-1.6; p < .0001), and D (HR = 1.8; CI: 1.6-2; p < .0001), with an exponential increase in Group E (HR = 2.5; CI: 2.2-2.8; p < .0001).

CONCLUSIONS

A direct, strong correlation exists between the degree of AS and cardiac structural changes and mortality. Patients with V_max  ≥ 97.5th percentile (≥3.2 m/s) might benefit from early intervention.

Procedural and long-term outcome among patients undergoing expedited trans-catheter aortic valve replacement

OBJECTIVE

Patients with rapidly deteriorating clinical status due to severe aortic stenosis are often referred for expedited transcatheter aortic valve replacement (TAVR). Data regarding the outcome of such interventions is limited. We aimed to evaluate the outcome of patients undergoing expedited TAVR.

DESIGN AND SETTING

Data were derived from the Israeli Multicenter Registry.

SUBJECTS

Subjects were divided into two groups based on procedure urgency: patients who were electively hospitalized for the procedure (N = 3140) and those who had an expedited TAVR (N = 142). Procedural and periprocedural complication rates were significantly higher among patients with an expedited indication for TAVR compared to those having an elective procedure: valve malposition 4.6% versus 0.6% (p &lt; 0.001), procedural cardiopulmonary resuscitation 4.3% versus 1.0% (p = 0.007), postprocedure myocardial infarction 2.0% versus 0.4% (p = 0.002), and stage 3 acute kidney injury 3.0% versus 1.1%, (p &lt; 0.001). Patients with expedited indication for TAVR had significantly higher in hospital mortality (5.6% vs. 1.4%, p = 0.003). Kaplan-Meier's survival analysis showed that patients undergoing expedited TAVR had higher 3-year mortality rates compared to patients undergoing an elective TAVR procedure (p &lt; 0.001). Multivariate analysis found that patients with expedited indication had fourfolds increased risk of in-hospital mortality (odds ratio: 4.07, p = 0.001), and nearly twofolds increased risk of mortality at 3-year (hazard ratio: 1.69, p = 0.001) compared to those having an elective procedure.

CONCLUSION

Patients with expedited indications for TAVR suffer from poor short- and long-term outcomes. It is important to characterize and identify these patients before the deterioration to perform TAVR in a fast-track pathway to minimize their procedural risk.

Patients With Bicuspid Aortic Stenosis Demonstrate Adverse Left Ventricular Remodeling and Impaired Cardiac Function Before Surgery With Increased Risk of Postoperative Heart Failure

BACKGROUND

Differences in adverse cardiac remodeling between patients who have bicuspid (BAV) and tricuspid aortic valve (TAV) with severe isolated aortic stenosis (AS) and its prognostic impact after surgical aortic valve replacement remains unclear. We sought to investigate differences in preoperative diastolic and systolic function in patients with BAV and TAV who have severe isolated AS and the incidence of postoperative heart failure hospitalization and mortality.

METHODS

Two hundred seventy-one patients with BAV (n=152) or TAV (n=119) and severe isolated AS without coronary artery disease or other valvular heart disease, scheduled for surgical aortic valve replacement, were prospectively included. Comprehensive preoperative echocardiographic assessment of left ventricular (LV) diastolic and systolic function was performed. The heart failure events were registered during a mean prospective follow-up of 1260 days versus 1441 days for patients with BAV or TAV, respectively.

RESULTS

Patients with BAV had a more pronounced LV hypertrophy with significantly higher indexed LV mass ([LVMi] 134 g/m² versus 104 g/m², P<0.001), higher prevalence of LV diastolic dysfunction (72% versus 44%, P<0.001), reduced LV ejection fraction (55% versus 60%, P<0.001), significantly impaired global longitudinal strain (P<0.001), significantly higher NT-proBNP (N-terminal pro-brain natriuretic peptide) levels (P=0.007), and a higher prevalence of preoperative levosimendan treatment (P<0.001) than patients with TAV. LVMi was associated with diastolic dysfunction in both patients with BAV and TAV. There was a significant interaction between aortic valve morphology and LVMi on LV ejection fraction, which indicated a pronounced association between LVMi and LV ejection fraction for patients with BAV and lack of association between LVMi and LV ejection fraction for patients with TAV. Postoperatively, the patients with BAV required significantly more inotropic support (P<0.001). The patients with BAV had a higher cumulative incidence of postoperative heart failure admissions compared with patients with TAV (28.2% versus 10.6% at 6 years after aortic valve replacement, log-rank P=0.004). Survival was not different between patients with BAV and TAV (log-rank P=0.165).

CONCLUSIONS

Although they were significantly younger, patients with BAV who had isolated severe AS had worse preoperative LV function and an increased risk of postoperative heart failure hospitalization compared with patients who had TAV. Our findings suggest that patients who have BAV with AS might benefit from closer surveillance and possibly earlier intervention.

The Evolution of Pulmonary Hypertension and Its Prognostic Implications Post-TAVI-Single Center Experience

Background and Objectives: Since the first transcatheter aortic valve implantation (TAVI) procedure was performed in 2002, advances in technology and refinement of the method have led to its widespread use in patients with severe aortic stenosis (AS) and high surgical risk. We aim to identify the impact of TAVI on the clinical and functional status of patients with severe AS at the one-month follow-up and to identify potential predictors associated with the evolution of pulmonary hypertension (PH) in this category of patients. Materials and Methods: We conducted a prospective study which included 86 patients diagnosed with severe AS undergoing TAVI treatment. We analyzed demographics, clinical and echocardiographic parameters associated with AS and PH both at enrolment and at the 30-day follow-up. Results: In our study, the decrease of EUROSCORE II score (p < 0.001), improvement of angina (p < 0.001) and fatigue (p < 0.001) as clinical benefits as well as a reduction in NYHA functional class in patients with heart failure (p < 0.001) are prognostic predictors with statistical value. Regression of left ventricular hypertrophy (p = 0.001), increase in the left ventricle ejection fraction (p = 0.007) and improvement of diastolic dysfunction (p < 0.001) are echocardiographic parameters with a prognostic role in patients with severe AS undergoing TAVI. The pulmonary artery acceleration time (PAAT) (p < 0.001), tricuspid annular plane systolic excursion (TAPSE) (p = 0.020), pulmonary arterial systolic pressure (PASP) (p < 0.001) and the TAPSE/PASP ratio (p < 0.001) are statistically significant echocardiographic parameters in our study that assess both PH and its associated prognosis in patients undergoing TAVI. Conclusions: PAAT, TAPSE, PASP and the TAPSE/PASP ratio are independent predictors that allow the assessment of PH and its prognostic implications post-TAVI.

Impact of Managing Provider Type on Severe Aortic Stenosis Management and Mortality

Background Many patients with symptomatic severe aortic stenosis do not undergo aortic valve replacement (AVR) despite clinical guidelines. This study analyzed the association of managing provider type with cardiac specialist follow-up, AVR, and mortality for patients with newly diagnosed severe aortic stenosis (sAS). Methods and Results We identified adults with newly diagnosed sAS per echocardiography performed between January 2017 and March 2019 using Optum electronic health record data. We then selected from those meeting all eligibility criteria patients managed by a primary care provider (n=1707 [25%]) or cardiac specialist (n=5039 [75%]). We evaluated the association of managing provider type with cardiac specialist follow-up, AVR, and mortality, as well as the independent association of cardiac specialist follow-up and AVR with mortality, within 1 year of echocardiography detecting sAS. A subgroup analysis was limited to patients with symptomatic sAS. Patient characteristics and comorbidities at baseline were used for covariate-adjusted cause-specific and multivariable Cox proportional hazard models assessing group differences in outcomes by managing provider type. An adjusted Cox proportional hazard model with additional time-dependent covariates for follow-up and AVR was used to assess these practices' association with mortality. Within 1 year of echocardiography detecting sAS, data revealed that primary care provider management was associated with lower rates of cardiac specialist follow-up (hazard ratio [HR], 0.47 [95% CI, 0.43-0.50], P<0.0001) and AVR (HR, 0.58 [95% CI, 0.53-0.64], P<0.0001) and with higher 1-year mortality (HR, 1.45 [95% CI, 1.26-1.66], P<0.0001). Cardiac specialist follow-up and AVR were independently associated with lower mortality (follow-up: HR, 0.55 [95% CI, 0.48-0.63], P<0.0001; AVR: HR, 0.70 [95% CI, 0.60-0.83], P<0.0001). Results were similar for patients with symptomatic sAS. All analyses were adjusted for baseline patient characteristics and comorbidities. Conclusions For patients newly diagnosed with sAS, we observed differences in rates of cardiac specialist follow-up and AVR and risk of mortality between primary care provider- versus cardiologist-managed patients with sAS. In addition, a lower likelihood of receiving follow-up and AVR was independently associated with higher mortality.

Implementation of a CT-derived correction factor to refine the measurement of aortic valve area and stroke volume using Doppler echocardiography improves grading of severity and prediction of prognosis in patients with severe aortic stenosis

AIMS

To assess rates of reclassification of severity and associated 5-year survival in patients with severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF) after application of a CT-derived correction factor (CF) to refine the measurement of aortic valve area (AVA) and stroke volume index (SVi) using Doppler echocardiography.

METHODS AND RESULTS

We enrolled 1450 patients with severe AS and preserved LVEF from a French registry. Multiplication of echocardiographic LV outflow tract diameter by a CT-derived CF of 1.13 to calculate the AVA and SVi using the continuity equation resulted in reclassification of 39% of patients from severe to moderate AS (AVA > 1 cm²) and 77% from low flow (LF, SVi < 35 ml/m²) to normal flow (NF, SVi ≥ 35 ml/m²). After application of the CF, 5-year survival with conservative management was 50 ± 4% for severe AS compared to 62 ± 4% for moderate AS (p < 0.001). A strategy of medical management followed by intervention for severe AS was associated with higher risk of mortality over 5-year follow-up after adjustment for covariates and application of the CF (HR 1.35 [1.10-1.55], p = 0.015). Five-year survival was also poorer in patients remaining in the LF group after application of the CF, even after valve intervention (72%, 66% and 47% for NF to NF, LF to NF and LF to LF, respectively). After adjustment for covariates (including intervention), risk of mortality was higher in LF to LF patients compared to NF to NF (HR 1.78 [1.25-2.56]), but similar for NF to NF and LF to NF (HR 1.20 [0.90-1.60]).

CONCLUSION

Refined accuracy of echocardiographic LV outflow tract diameter measurement using a CF of 1.13 before derivation of AVA and SVi in patients with severe AS and preserved LVEF allows improved grading of severity, and prediction of prognosis. We recommend implementation of the CF during routine echocardiography when using the continuity equation for Doppler haemodynamic measurements.

Predicting outcomes in patients with aortic stenosis using machine learning: the Aortic Stenosis Risk (ASteRisk) score

Objective

To use echocardiographic and clinical features to develop an explainable clinical risk prediction model in patients with aortic stenosis (AS), including those with low-gradient AS (LGAS), using machine learning (ML).

Methods

In 1130 patients with moderate or severe AS, we used bootstrap lasso regression (BLR), an ML method, to identify echocardiographic and clinical features important for predicting the combined outcome of all-cause mortality or aortic valve replacement (AVR) within 5 years after the initial echocardiogram. A separate hold out set, from a different centre (n=540), was used to test the generality of the model. We also evaluated model performance with respect to each outcome separately and in different subgroups, including patients with LGAS.

Results

Out of 69 available variables, 26 features were identified as predictive by BLR and expert knowledge was used to further reduce this set to 9 easily available and input features without loss of efficacy. A ridge logistic regression model constructed using these features had an area under the receiver operating characteristic curve (AUC) of 0.74 for the combined outcome of mortality/AVR. The model reliably identified patients at high risk of death in years 2–5 (HRs ≥2.0, upper vs other quartiles, for years 2–5, p<0.05, p=not significant in year 1) and was also predictive in the cohort with LGAS (n=383, HRs≥3.3, p<0.05). The model performed similarly well in the independent hold out set (AUC 0.78, HR ≥2.5 in years 1–5, p<0.05).

Conclusion

In two separate longitudinal databases, ML identified prognostic features and produced an algorithm that predicts outcome for up to 5 years of follow-up in patients with AS, including patients with LGAS. Our algorithm, the Aortic Stenosis Risk (ASteRisk) score, is available online for public use.

Prioritization of Candidate Biomarkers for Degenerative Aortic Stenosis through a Systems Biology-Based In-Silico Approach

Degenerative aortic stenosis is the most common valve disease in the elderly and is usually confirmed at an advanced stage when the only treatment is surgery. This work is focused on the study of previously defined biomarkers through systems biology and artificial neuronal networks to understand their potential role within aortic stenosis. The goal was generating a molecular panel of biomarkers to ensure an accurate diagnosis, risk stratification, and follow-up of aortic stenosis patients. We used in silico studies to combine and re-analyze the results of our previous studies and, with information from multiple databases, established a mathematical model. After this, we prioritized two proteins related to endoplasmic reticulum stress, thrombospondin-1 and endoplasmin, which have not been previously validated as markers for aortic stenosis, and analyzed them in a cell model and in plasma from human subjects. Large-scale bioinformatics tools allow us to extract the most significant results after using high throughput analytical techniques. Our results could help to prevent the development of aortic stenosis and open the possibility of a future strategy based on more specific therapies.

Novel predictive role for mid-regional proadrenomedullin in moderate to severe aortic stenosis

OBJECTIVE

We investigated the prognostic significance of selected known and novel circulating biomarkers in aortic stenosis (AS).

METHODS

N-terminal pro-BNP (NT-proBNP), high-sensitivity troponin-T (hsTnT), growth differentiation factor-15 (GDF-15), suppression of tumorigenicity-2 (ST2), mid-regional proadrenomedullin (MR-proADM) and mid-regional proatrial natriuretic peptide (MR-proANP) were measured in patients with moderate to severe AS, New York Heart Association (NYHA) class I-II and left ventricular ejection fraction ≥50%, recruited consecutively across five centres from 2011 to 2018. Their ability to predict both primary (all-cause mortality, heart failure hospitalisation or progression to NYHA class III-IV) and secondary (additionally incorporating syncope and acute coronary syndrome) outcomes was determined by competing risk analyses.

RESULTS

Among 173 patients with AS (age 69±11 years, 55% male, peak transaortic velocity (Vmax) 4.0±0.8 m/s), the primary and secondary outcomes occurred in 59 (34%) and 66 (38%), respectively. With aortic valve replacement as a competing risk, the primary outcome was determined consistently by the comorbidity index and each selected biomarker except ST2 (p<0.05), independent of NYHA class, Vmax, LV-global longitudinal strain and serum creatinine. MR-proADM had the highest discriminative value for both primary (subdistribution HR (SHR) 11.3, 95% CI 3.9 to 32.7) and secondary outcomes (SHR 12.6, 95% CI 4.7 to 33.5). Prognostic assessment of dual-biomarker combinations identified MR-proADM plus either hsTnT or NT-proBNP as the best predictive model for both clinical outcomes. Paired biomarker models were not superior to those including MR-proADM as the sole circulating biomarker.

CONCLUSION

MR-proADM most powerfully portended worse prognosis and should be further assessed as possibly the biomarker of choice for risk stratification in AS.

Long Term Prognostic Value of Contractile Reserve Assessed by Global Longitudinal Strain in Patients with Asymptomatic Severe Aortic Stenosis

Background. Left ventricle (LV) global longitudinal strain (GLS) at rest has shown prognostic value in patients (pts) with severe aortic stenosis (SAS). Contractile reserve (CR) during exercise stress echo (ESE) estimated via GLS (CR-GLS) could better stratify the asymptomatic patients who could benefit from early intervention. Aims. To determine the long-term prognostic value of CR-GLS in patients with asymptomatic SAS with an ESE without inducible ischemia. Additionally, to compare the prognostic value of CR assessed via ejection fraction (CR-EF) and CR-GLS. Methods. In a prospective, single-center, observational study between 2013 and 2019, 101 pts with asymptomatic SAS and preserved left ventricular ejection fraction (LVEF) > 55% were enrolled. CR was considered present with an exercise-rest increase in LVEF (Simpson’s rule) ≥ 5 points and > 2 absolute points in GLS. Patients were assigned to 2 groups (G): G1: 56 patients with CR-GLS present; and G2: 45 patients CR-GLS absent. All patients were followed up. Results. G2 Patients were older, with lower exercise capability, less aortic valve area (AVA), a higher peak aortic gradient, and less LVEF (71.5% ± 5.9 vs. 66.8% ± 7.9; p = 0.002) and GLS (%) at exercise (G1: −22.2 ± 2.8 vs. G2: −18.45 ± 2.4; p = 0.001). During mean follow-up of 46.6 ± 3.4 months, events occurred in 45 pts., with higher incidence in G2 (G2 = 57.8% vs. G1 = 42.2%, p < 0.01). At Cox regression analysis, CR-GLS was an independent predictor of major cardiovascular events (HR: 1.98, 95% CI 1.09–3.58, p = 0.025). Event-free survival was lower for patients with CR-GLS absent (log rank test p = 0.022). CR-EF was not outcome predictive (log rank test p 0.095). Conclusions: In patients with asymptomatic SAS, the absence of CR-GLS during ESE is associated with worse prognosis. Additionally, CR-GLS was a better predictor of events than CR-EF.

Relation of Preprocedure Platelet-to-Lymphocyte Ratio and Major Adverse Cardiovascular Events Following Transcatheter Aortic Valve Implantation for Aortic Stenosis

The platelet-to-lymphocyte ratio (PLR) is a novel inflammatory biomarker that has prognostic value in patients presenting with acute coronary syndrome. Transcatheter aortic valve implantation (TAVI) treats the inflammatory disease of aortic stenosis. However, the utility of preprocedure PLR in predicting major adverse cardiovascular events (MACE) after TAVI is not clear. Our study population included 470 patients who underwent TAVI at The Alfred Hospital in Melbourne, Australia from August 2008, to January 2019. Patients were divided into 4 groups based on PLR quartiles. The incidence of 30-day MACE (a composite of stroke, myocardial infarction, and death) was then compared. Outcomes were reported according to the Valve Academic Research Consortium-2 criteria. Of 470 patients, median age 84 years, 54% men, and median Society of Thoracic Surgeons score of 3.5%, 14 (3%) suffered a MACE within 30 days. Rates of MACE were low in all 4 groups (1.7%, 2.5%, 2.6%, 5.1%, respectively) with no statistically significant difference in the different PLR groups (p = 0.46). This nonsignificant association was supported by univariate logistic regression analysis of PLR as a continuous variable (odds ratio 1.01, p = 0.55). Using multivariable logistic regression analysis accounting for age, gender, self-expanding valve, and procedural risk, a higher PLR did not correlate with MACE (odds ratio 1.01, p = 0.60). In this study of a large cohort of TAVI patients, elevated preprocedure PLR was not independently associated with MACE after TAVI. This is a novel finding in comparison with previous studies.

Proteomic mapping of atrial and ventricular heart tissue in patients with aortic valve stenosis

Aortic valve stenosis (AVS) is one of the most common valve diseases in the world. However, detailed biological understanding of the myocardial changes in AVS hearts on the proteome level is still lacking. Proteomic studies using high-resolution mass spectrometry of formalin-fixed and paraffin-embedded (FFPE) human myocardial tissue of AVS-patients are very rare due to methodical issues. To overcome these issues this study used high resolution mass spectrometry in combination with a stem cell-derived cardiac specific protein quantification-standard to profile the proteomes of 17 atrial and 29 left ventricular myocardial FFPE human myocardial tissue samples from AVS-patients. In our proteomic analysis we quantified a median of 1980 (range 1495–2281) proteins in every single sample and identified significant upregulation of 239 proteins in atrial and 54 proteins in ventricular myocardium. We compared the proteins with published data. Well studied proteins reflect disease-related changes in AVS, such as cardiac hypertrophy, development of fibrosis, impairment of mitochondria and downregulated blood supply. In summary, we provide both a workflow for quantitative proteomics of human FFPE heart tissue and a comprehensive proteomic resource for AVS induced changes in the human myocardium.

Spontaneous Degenerative Aortic Valve Disease in New Zealand Obese Mice

Background Degenerative aortic valve (AoV) disease and resulting aortic stenosis are major clinical health problems. Murine models of valve disease are rare, resulting in a translational knowledge gap on underlying mechanisms, functional consequences, and potential therapies. Naïve New Zealand obese (NZO) mice were recently found to have a dramatic decline of left ventricular (LV) function at early age. Therefore, we aimed to identify the underlying cause of reduced LV function in NZO mice. Methods and Results Cardiac function and pulmonary hemodynamics of NZO and age-matched C57BL/6J mice were monitored by serial echocardiographic examinations. AoVs in NZO mice demonstrated extensive thickening, asymmetric aortic leaflet formation, and cartilaginous transformation of the valvular stroma. Doppler echocardiography of the aorta revealed increased peak velocity profiles, holodiastolic flow reversal, and dilatation of the ascending aorta, consistent with aortic stenosis and regurgitation. Compensated LV hypertrophy deteriorated to decompensated LV failure and remodeling, as indicated by increased LV mass, interstitial fibrosis, and inflammatory cell infiltration. Elevated LV pressures in NZO mice were associated with lung congestion and cor pulmonale, evident as right ventricular dilatation, decreased right ventricular function, and increased mean right ventricular systolic pressure, indicative for the development of pulmonary hypertension and ultimately right ventricular failure. Conclusions NZO mice demonstrate as a novel murine model to spontaneously develop degenerative AoV disease, aortic stenosis, and the associated end organ damages of both ventricles and the lung. Closely mimicking the clinical scenario of degenerative AoV disease, the model may facilitate a better mechanistic understanding and testing of novel treatment strategies in degenerative AoV disease.

Comparison of Echocardiographic Variables in Patients With Severe Aortic Stenosis and Preserved Ejection Fraction Grouped by Flow and Gradient

The pathophysiology of severe aortic stenosis (AS) is complex with vascular, valvular, and myocardial components. To better define this process, we compared echocardiographic and clinical variables in patients with severe AS and preserved EF according to flow and gradient. We retrospectively studied the clinical and echocardiographic data of 287 patients (mean age 76 ± 11 years, 57% men) from 2012 to 2017 with severe AS (indexed aortic valve area <0.6 cm²/m²) and preserved ejection fraction (>50%). Patients were divided into 4 groups based on flow (stroke volume index < or ≥35 ml/m²) and mean aortic pressure gradient (< or ≥40 mm Hg): normal flow, high gradient (NFHG), normal flow, low gradient (NFLG), low flow, high gradient (LFHG) and low flow, low gradient (LFLG). Among patients with severe AS, 23% had NFHG, 44% had NFLG, 10% had LFHG, and 23% had LFLG. Only diabetes was marginally significantly different among the clinical variables. Aortic valve area index was largest in NFLG and smallest in LFHG (p < 0.001 for pairwise comparisons). Valvuloarterial impedance was highest in LFHG (p < 0.01 for pairwise comparisons). Systemic arterial compliance was lower and systemic vascular resistance was higher in low flow compared with normal flow groups. In conclusion, LFHG had the smallest valve area index along with markers of increased vascular resistance combined with high gradients, which suggests a unique pathophysiology in this group of severe AS patients with preserved EF.

Immunohistochemical Detection of Bacteria in the Resected Valves was Associated with Stromal Immune Checkpoint Protein Expression that may Contribute to Calcific Aortic Stenosis

Aortic stenosis (AS) is a disease characterized by narrowing of the aortic valve (AV) orifice. The purpose of this study was to clarify the significance of bacterial detection and clinicopathological factors, including valve-infiltrating immune cells and disease severity, in relation to AS. After obtaining the written informed consent form from 50 patients with AS, we performed immunohistochemical analysis of lipopolysaccharide (LPS) for gram-negative bacteria and lipoteichoic acid (LTA) for gram-positive bacteria on surgically resected-AVs. Moreover, we evaluated the relationships among the presence of bacteria, immune checkpoint protein PD-L1 expression, and immune cell infiltrations such as CD8-positive T lymphocytes, CD163-positive macrophages, and FOXP3-positive regulatory T cell (Treg) in resected-aortic valves. LPS detection in the resected-aortic valve tissues was significantly associated with stromal PD-L1 expression, valve calcification, and LTA existence in resected samples. We showed that the presence of LPS was significantly related to high PD-L1 expression only in calcified-AVs, not in non-calcified-AVs. Moreover, the high expression of PD-L1 in AS samples without LPS was significantly associated with positive infiltration of CD163-positive macrophages and FOXP3-positive Tregs. Immunohistochemical bacterial detection in resected-aortic valves was associated with PD-L1 accumulation and valve calcification. PD-L1 significantly accumulated only in calcified valves with LPS existence.

Calcific Aortic Stenosis-A Review on Acquired Mechanisms of the Disease and Treatments

Calcific aortic stenosis is a progressive disease that has become more prevalent in recent decades. Despite advances in research to uncover underlying biomechanisms, and development of new generations of prosthetic valves and replacement techniques, management of calcific aortic stenosis still comes with unresolved complications. In this review, we highlight underlying molecular mechanisms of acquired aortic stenosis calcification in relation to hemodynamics, complications related to the disease, diagnostic methods, and evolving treatment practices for calcific aortic stenosis.

Multiscale simulations of left ventricular growth and remodeling

Cardiomyocytes can adapt their size, shape, and orientation in response to altered biomechanical or biochemical stimuli. The process by which the heart undergoes structural changes-affecting both geometry and material properties-in response to altered ventricular loading, altered hormonal levels, or mutant sarcomeric proteins is broadly known as cardiac growth and remodeling (G&R). Although it is likely that cardiac G&R initially occurs as an adaptive response of the heart to the underlying stimuli, prolonged pathological changes can lead to increased risk of atrial fibrillation, heart failure, and sudden death. During the past few decades, computational models have been extensively used to investigate the mechanisms of cardiac G&R, as a complement to experimental measurements. These models have provided an opportunity to quantitatively study the relationships between the underlying stimuli (primarily mechanical) and the adverse outcomes of cardiac G&R, i.e., alterations in ventricular size and function. State-of-the-art computational models have shown promise in predicting the progression of cardiac G&R. However, there are still limitations that need to be addressed in future works to advance the field. In this review, we first outline the current state of computational models of cardiac growth and myofiber remodeling. Then, we discuss the potential limitations of current models of cardiac G&R that need to be addressed before they can be utilized in clinical care. Finally, we briefly discuss the next feasible steps and future directions that could advance the field of cardiac G&R.

Severe aortic stenosis and transcatheter aortic valve replacement in elderly patients: utility vs futility

INTRODUCTION

Recently, transcatheter aortic valve replacement (TAVR) has emerged as established standard treatment for symptomatic severe aortic stenosis, providing an effective, less-invasive alternative to open cardiac surgery for inoperable or high-risk older patients.

EVIDENCE ACQUISITION

In order to assess the anticipated benefit of aortic replacement, considerable interest now lies in better identifying factors likely to predict outcome. In the elderly population frailty and medical comorbidities have been shown to significantly predict mortality, functional recovery and quality of life after transcatheter aortic valve replacement. Scientific literature focused on the three items will be discussed.

EVIDENCE SYNTHESIS

High likelihood of futility is described in patients with severe chronic lung, kidney, liver disease and/or frailty. The addition of frailty components to conventional risk prediction has been shown to result in improved discrimination for death and disability following the procedure and identifies those individuals least likely to derive benefit. Several dedicated risk score have been proposed to provide new insights into predicted "futile" outcome. However, assessment of frailty according to a limited number of variables is not sufficient, while a multi-dimensional geriatric assessment significantly improves risk prediction.

CONCLUSIONS

A multidisciplinary heart team that includes geriatricians can allow the customization of therapeutic interventions in elderly patients to optimise care and avoid futility.

Timing of Intervention in Asymptomatic Aortic Stenosis

The decision to perform an intervention for asymptomatic severe aortic stenosis (AS) requires careful weighing of the risks of early intervention against those of watchful observation, and the optimal timing of intervention remains controversial. With improvements in surgical and postoperative care, long-term survival after surgical aortic valve (AV) replacement (AVR) is excellent in low-risk patients, and the emergence of transcatheter AVR may change the thresholds for early preemptive intervention, although a durability issue has to be resolved. A watchful observation strategy also has a risk of sudden death, irreversible myocardial damage, and increase in operative risk while waiting for symptoms to develop. We have been waiting for a prospective randomized trial to solve the intense debate between early AVR and watchful observation, and the RECOVERY (Randomized Comparison of Early Surgery versus Conventional Treatment in Very Severe Aortic Stenosis) trial provides the evidence to support early AVR for asymptomatic severe AS. Risk assessment with severity of AS and staging classification may help to facilitate the identification of patients who may benefit from early intervention. Based on the results of the RECOVERY trial, early surgical AVR is reasonable for asymptomatic patients with very severe AS (aortic jet velocity ≥4.5 m/s) and low surgical risk. Further evidence is required to extend the indications of surgical AVR and to consider transcatheter AVR in asymptomatic patients with severe AS.

Reproducible In Vitro Tissue Culture Model to Study Basic Mechanisms of Calcific Aortic Valve Disease: Comparative Analysis to Valvular Interstitials Cells

The hallmarks of calcific aortic valve disease (CAVD), an active and regulated process involving the creation of calcium nodules, lipoprotein accumulation, and chronic inflammation, are the significant changes that occur in the composition, organization, and mechanical properties of the extracellular matrix (ECM) of the aortic valve (AV). Most research regarding CAVD is based on experiments using two-dimensional (2D) cell culture or artificially created three-dimensional (3D) environments of valvular interstitial cells (VICs). Because the valvular ECM has a powerful influence in regulating pathological events, we developed an in vitro AV tissue culture model, which is more closely able to mimic natural conditions to study cellular responses underlying CAVD. AV leaflets, isolated from the hearts of 6-8-month-old sheep, were fixed with needles on silicon rubber rings to achieve passive tension and treated in vitro under pro-degenerative and pro-calcifying conditions. The degeneration of AV leaflets progressed over time, commencing with the first visible calcified domains after 14 d and winding up with the distinct formation of calcium nodules, heightened stiffness, and clear disruption of the ECM after 56 d. Both the expression of pro-degenerative genes and the myofibroblastic differentiation of VICs were altered in AV leaflets compared to that in VIC cultures. In this study, we have established an easily applicable, reproducible, and cost-effective in vitro AV tissue culture model to study pathological mechanisms underlying CAVD. The valvular ECM and realistic VIC-VEC interactions mimic natural conditions more closely than VIC cultures or 3D environments. The application of various culture conditions enables the examination of different pathological mechanisms underlying CAVD and could lead to a better understanding of the molecular mechanisms that lead to VIC degeneration and AS. Our model provides a valuable tool to study the complex pathobiology of CAVD and can be used to identify potential therapeutic targets for slowing disease progression.

Transcatheter Aortic Valve Implantation During the COVID-19 Pandemic

Transcatheter aortic valve implantation (TAVI) outcomes during the coronavirus disease 2019 (COVID-19) pandemic have not been fully evaluated and some structural programs in the world have been suspended during this period. We sought to evaluate and compare clinical outcomes in patients undergoing TAVI in pandemic versus nonpandemic era. In a single center, we compared 198 TAVI patients performed during 2019 to 59 patients performed during the COVID-19 pandemic period (March 1st to June 30th, 2020). Primary outcome was procedural success according to VARC criteria and 30-day mortality rates. VARC-defined procedural success was high in both groups (93.3% vs 96.6%; p = 0.53). There were no differences in any vascular complications (26% vs 19%; p = 0.3), permanent pacemaker implantation (11.8% vs 15.3%; p = 0.63), and length of hospital stay (5.2 vs 4.2 days; p = 0.29). Thirty-day mortality was similar (3% vs 3.4%; p = 1.0). We had no documented COVID-19 disease in our patients during follow up. In conclusion, TAVI procedures can be performed effectively and safely during the COVID-9 pandemic, using a minimalist approach, early discharge, and by maintaining proper use of personal protective equipment.

A risk prediction model in asymptomatic patients with severe aortic stenosis: CURRENT-AS risk score

AIMS

Early aortic valve replacement (AVR) might be beneficial in selected high-risk asymptomatic patients with severe aortic stenosis (AS), considering their poor prognosis when managed conservatively. This study aimed to develop and validate a clinical scoring system to predict AS-related events within 1 year after diagnosis in asymptomatic severe AS patients.

METHODS AND RESULTS

We analysed 1274 asymptomatic severe AS patients derived from a retrospective multicentre registry enrolling consecutive patients with severe AS in Japan (CURRENT AS registry), who were managed conservatively and completed 1-year follow-up without AVR. From a randomly assigned derivation set (N = 849), we developed CURRENT AS risk score for the AS-related event (a composite of AS-related death and heart failure hospitalization) within 1 year using a multivariable logistic regression model. The risk score comprised independent risk predictors including left ventricular ejection fraction <60%, haemoglobin ≤11.0 g/dL, chronic lung disease (2 points), diabetes mellitus, haemodialysis, and any concomitant valve disease (1 point). The predictive accuracy of the model was good with the area under the curve of 0.79 and 0.77 in the derivation and validation sets (N = 425). In the validation set, the 1-year incidence of AS-related events was much higher in patients with score ≥2 than in patients with score ≤1 (Score 0: 2.2%, Score 1: 1.9%, Score 2: 13.4%, Score 3: 14.3%, and Score ≥4: 22.7%, P < 0.001).

CONCLUSION

The CURRENT-AS risk score integrating clinical and echocardiographic factors well-predicted the risk of AS-related events at 1 year in asymptomatic patients with severe AS and was validated internally.

Asymptomatic Patients with Severe Aortic Stenosis and the Impact of Intervention

Objectives the exact timing of aortic valve replacement (AVR) in asymptomatic patients with severe aortic stenosis (AS) remains a matter of debate. Therefore, we described the natural history of asymptomatic patients with severe AS, and the effect of AVR on long-term survival. Methods: Asymptomatic patients who were found to have severe AS between June 2006 and May 2009 were included. Severe aortic stenosis was defined as peak aortic jet velocity Vmax ≥ 4.0 m/s or aortic valve area (AVA) ≤ 1 cm². Development of symptoms, the incidence of AVR, and all-cause mortality were assessed. Results: A total of 59 asymptomatic patients with severe AS were followed, with a mean follow-up of 8.9 ± 0.4 years. A total of 51 (86.4%) patients developed AS related symptoms, and subsequently 46 patients underwent AVR. The mean 1-year, 2-year, 5-year, and 10-year overall survival rates were higher in patients receiving AVR compared to those who did not undergo AVR during follow-up (100%, 93.5%, 89.1%, and 69.4%, versus 92.3%, 84.6%, 65.8%, and 28.2%, respectively; p < 0.001). Asymptomatic patients with severe AS receiving AVR during follow-up showed an incremental benefit in survival of up to 31.9 months compared to conservatively managed patients (p = 0.002). Conclusions: The majority of asymptomatic patients turn symptomatic during follow-up. AVR during follow-up is associated with better survival in asymptomatic severe AS patients.

Local Use of Hydrogel with Amiodarone in Cardiac Surgery: Experiment and Translation to the Clinic

The objective of this study was to study the use of the hydrogel biopolymer based on sodium alginate ("Colegel") with a drug substance-amiodarone-for the prevention of postoperative atrial fibrillation (POAF) in cardiac surgery. The experimental part of the study was performed on 46 rabbits. Five groups were formed: in the first group, the dose of amiodarone in hydrogel was 1 mg; in the second group-3 mg; in the third group-6 mg; in the fourth group, hydrogel was used without amiodarone; in the fifth group, 60 mg amiodarone was administered intravenously. The animals from each group were removed from the experiment for the pathomorphological study of the heart after 3, 7 and 14 days. The studied endpoints were: the heart rate control; the development of the blockades of the conduction system of the heart; and the development of inflammation according to laboratory pathomorphological studies. The translational clinical part involved a randomized clinical trial which included 60 patients, with an average age of 62 ± 8.5 years. All patients were randomized into two groups: the study group (n = 30, with the application of amiodarone hydrogel) and the control group (n = 30, without the application of amiodarone hydrogel). The dose of amiodarone in the hydrogel material was 60 mg for all patients. The heart rhythm was monitored during 5 days. The primary endpoint was the development of POAF. Secondary endpoints were: the dynamics of heart rate; the duration of the QT and PQ intervals; the development of blockades of the cardiac conduction system; as well as the dynamics of AST and ALT. According to the results of the experimental part, it was found that the method of the local epicardial delivery of amiodarone by the hydrogel material was safe. Hydrogel with amiodarone is effective for reducing the heart rate in the animal experiment in comparison to the control group and the group with the intravenous administration of the drug. The optimal dose of amiodarone in hydrogel was 1 mg per 1 kg. According to the results of the clinical part, it was found that the method of the local epicardial delivery of amiodarone as a hydrogel material proved its safety. Hydrogel with amiodarone at a dose of 60 mg was effective in preventing POAF in patients after coronary artery bypass grafting (CABG) operations in comparison to the control group (p < 0.001). The age and procedure of application of the amiodarone gel were significantly associated with POAF (p = 0.009 and p = 0.011, respectively). The use of hydrogel with amiodarone reduced the probability of developing POAF 18.9-fold. The method of the local epicardial delivery of amiodarone in the form of a hydrogel material is safe. The use of hydrogel with amiodarone after CABG reduced the probability of developing POAF.

Left atrial functional assessment and mortality in patients with severe aortic stenosis with sinus rhythm

BACKGROUND

Aortic valve stenosis (AS) is the most common primary valvular heart disease leading to surgical or percutaneous aortic valve replacement (AVR) in Europe and its prevalence keeps growing. While other risk factors in severe AS are well documented, little is known about the prognostic value of left atrial (LA) function in AS. Our aim is to clarify the relationship between LA function measured at severe AS diagnosis (evaluated by means of volumetric assessment) and all-cause mortality during follow-up.

METHODS

We retrospectively evaluated patients diagnosed with severe AS for the first time at our echocardiography laboratory. We evaluated LA reservoir, conduit and pump function by measuring LA volumes at different timings of cardiac cycle. Treatment strategy was decided according to heart team consensus and patient decision. We divided patients into groups according to terciles of LA reservoir, conduit and pump function. Primary outcome was defined by the occurrence of all-cause mortality during follow-up.

RESULTS

A total of 408 patients were included in the analysis, with a median follow-up time of 45 months (interquartile range 54 months). 57.9% of patients underwent AVR and 44.9% of patients registered the primary outcome during follow-up. Left atrial emptying fraction (LAEF) was the best LA functional parameter and the best overall parameter in discriminating primary outcome (AUC 0.845, 95%CI 0.81-0.88, P < 0.001). After adjustment for clinical, demographic and echocardiographic variables, cumulative survival of patients with LAEF < 37% and LAEF 37 to 53% relative to patients with LAEF ≥54% remained significantly lower (HR 13.91, 95%CI 6.20-31.19, P < 0.001 and HR 3.40, 95%CI 1.57-7.37, P = 0.002, respectively). After adjustment for AVR, excess risk of LAEF < 37% and LAEF 37 to 53% relative to LAEF ≥54% remained significant (HR 11.71, 95%CI 5.20-26.40, P < 0.001 and HR 3.59, 95%CI 1.65-7.78, P = 0.001, respectively).

CONCLUSIONS

In patients with a first diagnosis of severe AS, LA function, evaluated by means of volumetric assessment, is an independent predictor of all-cause mortality and a more potent predictor of death compared to classical severity parameters. These data can be useful to identify high-risk patients who might benefit of AVR.

Watchful waiting care or early intervention in asymptomatic severe aortic stenosis: Where we are

Aortic stenosis, the most common valvular heart disease in Western countries, affects predominantly older people. Prompt aortic valve replacement is undoubtedly indicated in symptomatic patients. Management of asymptomatic patients is nowadays shifting from a conservative approach to early aortic valve replacement, as multimodality imaging is increasingly available. However, multimodality imaging has led to multiple prognostic parameters and complex algorithms, as well as a new staging classification that has left patients and physicians somewhat puzzled. We highlight the value of thorough serial clinical examinations, Doppler echocardiography and exercise testing when caring for a growing aortic stenosis population, including that has no or limited access to multimodality imaging. Evidence for early aortic valve replacement versus conservative management in asymptomatic patients with severe aortic stenosis is biased by the lack of serial stress testing evaluation; 30% of so-called asymptomatic patients were in fact symptomatic, and thus were clear candidates for aortic valve replacement in the above-mentioned studies. Randomized trials of aortic valve replacement versus conservative management that include serial stress testing evaluation are needed to ascertain whether early aortic valve replacement actually improves clinical outcome in asymptomatic patients with severe aortic stenosis. Less interventional medicine and healthcare resource utilization can result in better health.