Left ventricular myocardial structure in aortic valve disease before, intermediate, and late after aortic valve replacement

A multicenter prospective clinical study on transcatheter aortic valve implantation for aortic stenosis or pure aortic regurgitation: 5-year outcomes

OBJECTIVE

Currently, there is limited evidence regarding the long-term durability of available transcatheter heart valves (THVs). The purpose of this analysis is to evaluate the 5-year outcomes of using the J-Valve for transcatheter aortic valve implantation (TAVI) in aortic stenosis (AS) and pure aortic regurgitation (AR).

METHODS

From March 2014 to August 2015, all consecutive patients with severe AS and pure AR treated with the J-Valve THV at 3 centers in China were prospectively enrolled in a clinical study. Clinical and echocardiographic follow-up were performed according to study protocol. All results were reported according to the Valve Academic Research Consortium 3 criteria.

RESULTS

At 5-year follow-up, the all-cause mortality rate was 15.31% (16/98), with a cardiovascular mortality rate of 7.14% (7/98). The incidence of stroke was 7.14% (7/98), and the permanent pacemaker implantation rate was 8.16% (8/98). Echocardiographic follow-up showed left ventricular ejection fraction significantly improved at 5 years in both patients with AS (58.98 ± 10.45% vs 61.78 ± 9.07%, P for trend <.01) and pure AR (52.86 ± 10.98% vs 61.45 ± 6.90%, P for trend < .01). Structural or hemodynamic valve deterioration occurred in 3 cases (3.06%). In total, 97.59% of patients had significant improvement in New York Heart Association functional class over the 5-year follow-up, which is associated with significant improvement in quality of life.

CONCLUSIONS

Our study demonstrates that TAVI with the J-Valve THV provides excellent 5-year clinical and echocardiographic outcomes, suggesting TAVI with a dedicated THV is a good alternative treatment for AS and pure AR in selected high-risk patients.

Prognostic value of extracellular volume fraction in myocardial infarction and myocardial infarction with nonobstructive coronary arteries: A multicenter study

RATIONALE AND OBJECTIVES

The aim of the present retrospective study was to evaluate the prognostic role of the extracellular volume fraction (ECV) in patients with myocardial infarction (MI) and myocardial infarction with nonobstructive coronary arteries (MINOCA). The present study hypothesized that ECV is associated with major adverse cardiovascular events (MACEs) in MI and MINOCA patients.

MATERIALS AND METHODS

Cardiac magnetic resonance (CMR) imaging was performed on 351 consecutive patients (mean age: 58 ± 12 years; 252 [71.8%] males) who were diagnosed with MI between October 2015 and November 2023. From CMR imaging, the extent of late gadolinium enhancement (LGE), native T1 and ECV were derived. Patients were categorized into groups according to the degree of coronary artery stenosis, namely, patients with MINOCA and patients with obstructive MI. Follow-up was performed to assess MACEs.

RESULTS

The final cohort consisted of 61 MINOCA patients and 290 obstructive MI patients. During a mean follow-up of 27 ± 16 months, there was no statistically significant difference in the incidence of MACEs between patients with MINOCA and those with obstructive MI, and the two groups of patients had similar ECVs (32.2 ± 3.6 vs. 32.3 ± 6.0, p = 0.864). According to the multivariate Cox regression, ECV was an independent predictor of MACEs (HR: 1.13; p < 0.001) and significantly improved the prognostic value of the baseline multivariate models (C-statistic improvement: 0.816-0.864, p = 0.001). Similarly, ECV maintained an independent association with MACEs in the MINOCA (HR: 1.35; p < 0.001) and obstructive MI (HR: 1.13; p < 0.001) groups.

CONCLUSION

In MI and MINOCA patients, ECV is an independent predictor of MACEs. MINOCA is not a benign disease, and its long-term prognosis is as poor as that of patients with obstructive MI.

Mixed valvular heart disease: diagnosis and management

Mixed valvular diseases (MVDs) are common but have received little attention in the literature, especially regarding the mitral valve (MV) and the right-sided cardiac valves. Whereas echocardiography plays a pivotal diagnostic role, the diagnosis is made difficult due to haemodynamic interactions that may invalidate common indices of severity used in isolated stenosis or regurgitation. The diagnostic strategy should aim at initially separately assessing stenosis and regurgitation, taking into account the diagnostic pitfalls, with complementary use of multimodality imaging in cases of persisting diagnostic uncertainties. Unlike aortic stenosis, the calcium score cannot be used as a surrogate for haemodynamic severity of mixed MV disease. Severe stenosis and/or severe regurgitation are indicative of severe MVD, and management should follow recommendations on the predominant lesion. However, some patients with the combination of moderate stenosis and moderate regurgitation have a poor prognosis when left untreated. Concordant data suggest that, in patients with mixed aortic or MV disease, transvalvular velocities and pressure gradients are more powerful prognostic indicators than valve area or the severity of regurgitation. It is essential to consider the global repercussions that indicate poor outcomes in patients with MVD. However, whereas symptoms and/or ventricular dysfunction are considered as clear indication for intervention, imaging cut-offs have not been validated for balanced moderate regurgitation and stenosis. Although emerging evidence tends to support earlier management, further prospective studies are required, and pending the results of these studies, asymptomatic patients with MVD should be closely monitored.

Longitudinal assessment of left ventricular function and remodelling following surgical replacement of aortic valve in young patients with aortic valve dysfunction: a pilot study

Surgical prosthetic aortic valve replacement has been used for the management of aortic valve dysfunction. Studies in adults after aortic valve replacement report decreased left ventricular function in the early post-operative period. We hypothesised that young adults with aortic valve dysfunction who undergo aortic valve replacement may have incomplete recovery of left ventricular systolic function. This was a retrospective single-centre pilot study of patients with surgical aortic valve replacement at our institution over 20 years. Echocardiograms were analysed pre-operatively, at discharge, 1-year, and 5-year follow-up. Left ventricular systolic function was assessed using fractional shortening and ejection fraction. Speckle tracking measurements were performed for four-chamber longitudinal strain and peak systolic circumferential strain. Repeated-measure ANOVA (SPSS Inc.) was used for analysis. A p-value <0.05 was considered significant. Our cohort included 15 subjects (age 19.1 ± 9.0 years, 73% male). Left ventricular mass indexed to body surface area significantly improved (63.5 ± 25.3 pre-operatively to 41.2 ± 13.1 at 5 years, p = 0.009). Left ventricular longitudinal and circumferential strain measures deteriorated in the early post-operative period compared to pre-aortic valve replacement (-18.2 ± 3.4 versus -11.8 ± 3.3, p = 0.00) and (-25.1 ± 5.4 versus -18.9 ± 5.4, p = 0.06). Longitudinal strain continued to be abnormal at the 1- and 5-year follow-up compared to baseline. Children and young adults undergoing aortic valve replacement for aortic valve dysfunction had a decrease in left ventricular systolic function by strain imaging in the early post-operative period and abnormalities persisted on 5-year follow-up.

Diffuse Interstitial Fibrosis of the Myocardium Predicts Outcome in Moderate and Asymptomatic Severe Aortic Stenosis

BACKGROUND

Patients with moderate or asymptomatic severe aortic stenosis (AS) are at risk of cardiovascular events.

OBJECTIVES

The authors investigated the utility of cardiac magnetic resonance (CMR) to identify drivers of outcome in patients with moderate or asymptomatic severe AS.

METHODS

A prospective, international, multicenter cohort (n = 457) of patients with moderate (aortic valve area [AVA]: 1.0-1.5 cm2) or asymptomatic severe AS (AVA ≤1.0 cm2 and NYHA functional class I-II) patients underwent CMR. Diffuse interstitial fibrosis and scar in the myocardium were analyzed with extracellular volume fraction (ECV%) and late gadolinium enhancement (LGE). The outcome was a composite of mortality and heart failure admission.

RESULTS

Median ECV% was 26.6% (IQR: 24.4%-29.9%), and LGE was present in 31.5% (median 0.8%; IQR: 0.1%-1.7%). Greater AS severity was associated with greater left ventricular mass and diastolic dysfunction, but not with ECV% or LGE. During a median 5.7 years of follow-up, 83 events occurred. Patients with events had higher ECV% (median ECV% 26.3% vs 28.2%; P = 0.003). Patients in the highest ECV% tertiles (ECV% >28.6%) had worse outcomes both in the entire cohort and in those with NYHA functional class I moderate or severe AS, and ECV% was independently associated with outcome (adjusted HR: 1.05; P = 0.039). The ECV% had significant incremental prognostic value when added to parameters of AS severity and cardiac function, comorbidities, aortic valve replacement, and LGE (P < 0.05).

CONCLUSIONS

Increased diffuse interstitial fibrosis of the myocardium is associated with poor outcomes in patients with moderate and asymptomatic severe AS and can help identify those who require closer surveillance for adverse outcomes.

Early Intervention in Patients With Asymptomatic Severe Aortic Stenosis and Myocardial Fibrosis: The EVOLVED Randomized Clinical Trial

Importance

Development of myocardial fibrosis in patients with aortic stenosis precedes left ventricular decompensation and is associated with an adverse long-term prognosis.

Objective

To investigate whether early valve intervention reduced the incidence of all-cause death or unplanned aortic stenosis-related hospitalization in asymptomatic patients with severe aortic stenosis and myocardial fibrosis.

Design, Setting, and Participants

This prospective, randomized, open-label, masked end point trial was conducted between August 2017 and October 2022 at 24 cardiac centers across the UK and Australia. Asymptomatic patients with severe aortic stenosis and myocardial fibrosis were included. The final date of follow-up was July 26, 2024.

Intervention

Early valve intervention with transcatheter or surgical aortic valve replacement or guideline-directed conservative management.

Main Outcomes and Measures

The primary outcome was a composite of all-cause death or unplanned aortic stenosis-related hospitalization in a time-to-first-event intention-to-treat analysis. There were 9 secondary outcomes, including the components of the primary outcome and symptom status at 12 months.

Results

The trial enrolled 224 eligible patients (mean [SD] age, 73 [9] years; 63 women [28%]; mean [SD] aortic valve peak velocity of 4.3 [0.5] m/s) of the originally planned sample size of 356 patients. The primary end point occurred in 20 of 113 patients (18%) in the early intervention group and 25 of 111 patients (23%) in the guideline-directed conservative management group (hazard ratio, 0.79 [95% CI, 0.44-1.43]; P = .44; between-group difference, -4.82% [95% CI, -15.31% to 5.66%]). Of 9 prespecified secondary end points, 7 showed no significant difference. All-cause death occurred in 16 of 113 patients (14%) in the early intervention group and 14 of 111 (13%) in the guideline-directed group (hazard ratio, 1.22 [95% CI, 0.59-2.51]) and unplanned aortic stenosis hospitalization occurred in 7 of 113 patients (6%) and 19 of 111 patients (17%), respectively (hazard ratio, 0.37 [95% CI, 0.16-0.88]). Early intervention was associated with a lower 12-month rate of New York Heart Association class II-IV symptoms than guideline-directed conservative management (21 [19.7%] vs 39 [37.9%]; odds ratio, 0.37 [95% CI, 0.20-0.70]).

Conclusions and Relevance

In asymptomatic patients with severe aortic stenosis and myocardial fibrosis, early aortic valve intervention had no demonstrable effect on all-cause death or unplanned aortic stenosis-related hospitalization. The trial had a wide 95% CI around the primary end point, with further research needed to confirm these findings.

Trial Registration

ClinicalTrials.gov Identifier: NCT03094143.

Electrocardiographic Strain and Relationship with Left Ventricular Remodelling and Clinical Outcomes in Patients with Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation

INTRODUCTION

Left ventricular (LV) remodelling and fibrosis are known to occur in patients with aortic stenosis (AS) and are linked to post-intervention outcomes. These myocardial changes may be detected upon the routine 12-lead electrocardiogram (ECG) by the presence of a LV strain pattern (LVS-ECG). Although LVS-ECG has been related to excessive cardiovascular morbidity and mortality in multiple patient populations, there is currently a dearth of data upon its impact in patients undergoing transcatheter aortic valve implantation (TAVI). The aim of the current study was to investigate the prevalence, predictors, and prognostic value of LVS-ECG.

METHODS

Between 2012 and 2019, 640 consecutive patients underwent TAVI at Haukeland University Hospital, Bergen. Of these, 600 patients with severe AS were included in the TAVI-NOR study. Patients with known bundle branch block (n = 85) or permanent pacing (n = 25) were excluded, leaving 490 patients (mean age 81 ± 6 years, 52% females) eligible for the analyses. LVS-ECG was defined as down-sloping, convex ST-segment depression with asymmetric T-wave inversion in V5 or V6.

RESULTS

LVS-ECG was present in 25.7% patients. Higher levels of NT-proBNP (OR 1.96; 95% CI: 1.08-3.55, p = 0.028), left ventricular ejection fraction (LVEF) <50% (OR 3.14; 95% CI: 1.61-6.13, p = 0.001), increase in LV mass index per SD (32 g/m2) (OR 1.37; 95 CI: 1.06-1.76, p = 0.014), and the presence of LV hypertrophy on ECG (OR 3.23; 95% CI: 1.97-5.32, p < 0.001) were independent predictors of LVS-ECG in the multivariable-adjusted analysis. Although all-cause mortality was significantly higher in patients with LVS-ECG compared to those without (54.8% vs. 44.2%, p = 0.041), the presence of LVS-ECG did not predict all-cause mortality during a mean follow-up of 64 ± 24 months (HR 1.05; 95% CI: 0.79-1.39, p = 0.742). Patients with LVEF <50% and concomitant LVS-ECG had a worse prognosis than those with LVEF >50% and no LVS-ECG (p < 0.001).

CONCLUSIONS

LVS-ECG may represent a simple marker of structural and functional LV remodelling that signals a propensity to excess mortality during long-term follow-up after TAVI, as it is strongly associated with other prognosticators such as reduced LVEF and increased levels of NT-proBNP.

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.

Quantification of Replacement Fibrosis in Aortic Stenosis: A Narrative Review on the Utility of Cardiovascular Magnetic Resonance Imaging

Aortic stenosis (AS) is associated with the development of replacement myocardial fibrosis/scar. Given the dose-dependent relationship between scar and clinical outcomes after aortic valve replacement (AVR) surgery, scar quantity may serve as an important risk-stratification tool to aid decision-making on the optimal timing of AVR. Scar is non-invasively assessed and quantified by cardiovascular magnetic resonance (CMR) imaging. Several quantification techniques exist, and consensus on the optimal technique is lacking. These techniques range from a visual manual method to fully automated ones. This review describes the different scar quantification techniques used and highlights their strengths and shortfalls within the context of AS. The two most commonly used techniques in AS include the semi-automated signal threshold versus reference mean (STRM) and full-width half-maximum (FWHM) techniques. The accuracy and reproducibility of these techniques may be hindered in AS by the coexistence of diffuse interstitial fibrosis and the presence of relatively small, non-bright scars. The validation of these techniques against histology, which is the current gold standard for scar quantification in AS, is limited. Based on the best current evidence, the STRM method using a threshold of three standard deviations above the mean signal intensity of remote myocardium is recommended. The high reproducibility of the FWHM technique in non-AS cohorts has been shown and merits further evaluation within the context of AS. Future directions include the use of quantitative T1 mapping for the detection and quantification of scar, as well as the development of serum biomarkers that reflect the fibrotic status of the myocardium in AS.

Human epididymis protein 4 is a useful predictor of post-operative prognosis in patients with severe aortic stenosis

AIMS

The human epididymis protein 4 (HE4), a novel fibrosis marker, is expressed only in activated fibroblasts and is thought to reflect ongoing left ventricular (LV) fibrosis. LV fibrosis is a feature of severe aortic stenosis (AS) and is related to the post-operative outcome of patients with AS. We investigated the relationship between serum levels of HE4 and the post-operative prognosis of patients with severe AS.

METHODS AND RESULTS

We measured the serum HE4 levels of 55 participants (80.8 ± 8.0 years old, male n = 26, 46%) with severe AS prior to surgical aortic valve replacement (n = 31, 56%) or transcatheter aortic valve implantation (n = 24, 44%) at Kumamoto University Hospital in 2018. We followed them for cardiovascular (CV) death or hospitalization for heart failure (HF) for 3 years. Serum HE4 levels were positively correlated with computed tomography-extracellular volume (CT-ECV) values (r = 0.53, P = 0.004). Kaplan-Meier curves demonstrated a significantly higher probability of hospitalization for HF or CV-related death in the patients with high HE4 (greater than the median HE4 value) compared with the patients with low HE4 (lower than the median HE4 value) (log-rank P = 0.003). Multivariate analysis showed HE4 (log(HE4)) to be an independent prognostic factor [hazard ratio (HR): 7.50; 95% confidence interval (CI): 1.81-31.1; P = 0.005]. Receiver operating characteristic (ROC) curve analysis suggested that HE4 is a marker of increased risk of CV-related death or hospitalization for HF at 3 years after surgery, with an area under the curve (AUC) of 0.76 (95% CI: 0.62-0.90; P = 0.003).

CONCLUSIONS

We found that HE4 is a potentially useful biomarker for predicting future CV events in patients scheduled for AS surgery. Measuring serum HE4 values could help consider AS surgery.

Histopathological myocardial changes in patients with severe aortic stenosis referred for surgical valve replacement: a cardiac magnetic resonance correlation study

AIMS

Myocardial fibrosis (MF) takes part in left ventricular (LV) remodelling in patients with aortic stenosis (AS), driving the transition from hypertrophy to heart failure. The structural changes that occur in this transition are not fully enlightened. The aim of this study was to describe histopathological changes at endomyocardial biopsy (EMB) in patients with severe AS referred to surgical aortic valve replacement (AVR) and to correlate them with LV tissue characterization from pre-operative cardiac magnetic resonance (CMR).

METHODS AND RESULTS

One-hundred fifty-eight patients [73 (68-77) years, 50% women] were referred for surgical AVR because of severe symptomatic AS, with pre-operative CMR (n = 143) with late gadolinium enhancement (LGE), T1, T2 mapping, and extracellular volume fraction (ECV) quantification. Intra-operative septal EMB was obtained in 129 patients. MF was assessed through Masson's Trichrome histochemistry. Immunohistochemistry was performed for both inflammatory cells and extracellular matrix (ECM) characterization (Type I Collagen, Fibronectin, Tenascin C). Non-ischaemic LGE was present in 106 patients (67.1%) [median fraction: 5.0% (2.0-9.7)]. Native T1 was above normal [1053 ms (1024-1071)] and T2 within the normal range [39.3 ms (37.3-42.0)]. Median MF was 11.9% (6.54-19.97), with predominant type I collagen perivascular distribution (95.3%). Sub-endocardial cardiomyocyte ischaemic-like changes were identified in 45% of EMB. There was no inflammation, despite ECM remodelling expression. MF quantification at EMB was correlated with LGE mass (P = 0.008) but not with global ECV (P = 0.125).

CONCLUSION

Patients with severe symptomatic AS referred for surgical AVR have unspecific histological myocardial changes, including signs of cardiomyocyte ischaemic insult. ECM remodelling is ongoing, with MF heterogeneity. These features may be recognized by comprehensive CMR protocols. However, no single CMR parameter captures the burden of MF and histological myocardial changes in this setting.

Role of macrophages in regression of myocardial fibrosis following alleviation of left ventricular pressure overload

Sustained hemodynamic pressure overload (PO) produced by murine transverse aortic constriction (TAC) causes myocardial fibrosis; removal of TAC (unTAC) returns left ventricle (LV) hemodynamic load to normal and results in significant, but incomplete regression of myocardial fibrosis. However, the cellular mechanisms that result in these outcomes have not been defined. The objective was to determine temporal changes in myocardial macrophage phenotype in TAC and unTAC and determine whether macrophage depletion alters collagen degradation after unTAC. Myocardial macrophage abundance and phenotype were assessed by immunohistochemistry, flow cytometry, and gene expression by RT-PCR in control (non-TAC), 2 wk, 4 wk TAC, and 2 wk, 4 wk, and 6 wk unTAC. Myocardial cytokine profiles and collagen-degrading enzymes were determined by immunoassay and immunoblots. Initial collagen degradation was detected with collagen-hybridizing peptide (CHP). At unTAC, macrophages were depleted with clodronate liposomes, and endpoints were measured at 2 wk unTAC. Macrophage number had a defined temporal pattern: increased in 2 wk and 4 wk TAC, followed by increases at 2 wk unTAC (over 4 wk TAC) that then decreased at 4 wk and 6 wk unTAC. At 2 wk unTAC, macrophage area was significantly increased and was regionally associated with CHP reactivity. Cytokine profiles in unTAC reflected a proinflammatory milieu versus the TAC-induced profibrotic milieu. Single-cell sequencing analysis of 2 wk TAC versus 2 and 6 wk unTAC revealed distinct macrophage gene expression profiles at each time point demonstrating unique macrophage populations in unTAC versus TAC myocardium. Clodronate liposome depletion at unTAC reduced CHP reactivity and decreased cathepsin K and proMMP2. We conclude that temporal changes in number and phenotype of macrophages play a critical role in both TAC-induced development and unTAC-mediated partial, but incomplete, regression of myocardial fibrosis.NEW & NOTEWORTHY Our novel findings highlight the dynamic changes in myocardial macrophage populations that occur in response to PO and after alleviation of PO. Our data demonstrated, for the first time, a potential benefit of macrophages in contributing to collagen degradation and the partial regression of interstitial fibrosis following normalization of hemodynamic load.

Histologically Validated Myocardial Fibrosis in Relation to Left Ventricular Geometry and Its Function in Aortic Stenosis

Background and Objectives: The combination of aortic valve stenosis (AS) and ischemic heart disease (IHD) is quite common and is associated with myocardial fibrosis (MF). The purpose of this study was to evaluate the association between the histologically verified left ventricular (LV) MF and its geometry and function in isolated AS and AS within IHD groups. Materials and Methods: In a single-center, prospective trial, 116 patients underwent aortic valve replacement (AVR) with/without concomitant surgery. The study population was divided into groups of isolated AS with/without IHD. Echocardiography was used, and LV measurements and aortic valve parameters were obtained from all patients. Myocardial tissue was procured from all study patients undergoing elective surgery. Results: There were no statistical differences between isolated AS and AS+IHD groups in LV parameters or systolic and diastolic functions during the study periods. The collagen volume fraction was significantly different between the isolated AS and AS+IHD groups and was 7.3 ± 5.6 and 8.3 ± 6.4, respectively. Correlations between MF and left ventricular end-diastolic diameter (LVEDD) (r = 0.59, p = < 0.001), left ventricular mass (LVM) (r = 0.42, p = 0.011), left ventricular ejection fraction (LVEF) (r = -0.67, p < 0.001) and an efficient orifice area (EOA) (r = 0.371, p = 0.028) were detected in isolated AS during the preoperative period; the same was observed for LVEDD (r = 0.45, p = 0.002), LVM (r = 0.36, p = 0.026), LVEF (r = -0.35, p = 0.026) and aortic annulus (r = 0.43, p = 0.018) in the early postoperative period; and LVEDD (r = 0.35, p ≤ 0.05), LVM (r = 0.43, p = 0.007) and EOA (r = 0.496, p = 0.003) in the follow-up period. In the group of AS and IHD, correlations were found only with LV posterior wall thickness (r = 0.322, p = 0.022) in the follow-up period. Conclusions: Histological MF in AS was correlated with LVM and LVEDD in all study periods. No correlations between MF and LV parameters were found in aortic stenosis in the ischemic heart disease group across all study periods.

Paravalvular regurgitation after transcatheter aortic valve replacement: incidence, quantification, and prognostic impact

Transcatheter aortic valve replacement (TAVR) is the standard of care in aortic stenosis with results comparable to surgical aortic valve replacement. However, paravalvular regurgitation (PVR) is more common after TAVR. With the alteration of devices and implantation techniques, the incidence of moderate or more PVR has declined. Mild PVR is still common in around 30% of TAVR patients in low-risk trials. Progression of AS causes myocardial hypertrophy and varying degrees of diastolic dysfunction which may cause heart failure even in combination with small volumes of PVR. Any degree of PVR is associated with an increased risk of overall and cardiovascular mortality. Predictors of PVR are annular eccentricity, severe calcification of the aortic valve, bicuspid aortic valves, and type of prosthesis where balloon-expandable devices are associated with less PVR. PVR is diagnosed using echocardiography, aortic angiogram with or without videodensitometry, haemodynamic parameters, or cardiac magnetic resonance. PVR can be treated using post-dilation, interventional treatment using a vascular plug, or implantation of a second device. Successful post-dilation depends on balloon size which should at least be equal to or >95% of the mean annulus diameter. Implantation of a second device to reduce PVR is successful in ∼90% of cases, either through lengthening of the sealing skirt in case of inadequate position or through further expansion of the index device. Implantation of a vascular plug can successfully reduce PVR and reduce mortality.

The impact of water exchange on estimates of myocardial extracellular volume calculated using contrast enhanced T1 measurements: A preliminary analysis in patients with severe aortic stenosis

PURPOSE

Guidelines recommend measuring myocardial extracellular volume (ECV) using T1 -mapping before and 10-30 min after contrast agent administration. Data are then analyzed using a linear model (LM), which assumes fast water exchange (WX) between the ECV and cardiomyocytes. We investigated whether limited WX influences ECV measurements in patients with severe aortic stenosis (AS).

METHODS

Twenty-five patients with severe AS and 5 healthy controls were recruited. T1 measurements were made on a 3 T Siemens system using a multiparametric saturation-recovery single-shot acquisition (a) before contrast; (b) 4 min post 0.05 mmol/kg gadobutrol; and (c) 4 min, (d) 10 min, and (e) 30 min after an additional gadobutrol dose (0.1 mmol/kg). Three LM-based ECV estimates, made using paired T1 measurements (a and b), (a and d), and (a and e), were compared to ECV estimates made using all 5 T1 measurements and a two-site exchange model (2SXM) accounting for WX.

RESULTS

Median (range) ECV estimated using the 2SXM model was 25% (21%-39%) for patients and 26% (22%-29%) for controls. ECV estimated in patients using the LM at 10 min following a cumulative contrast dose of 0.15 mmol/kg was 21% (17%-32%) and increased significantly to 22% (19%-35%) at 30 min (p = 0.0001). ECV estimated using the LM was highest following low dose gadobutrol, 25% (19%-38%).

CONCLUSION

Current guidelines on contrast agent dose for ECV measurements may lead to underestimated ECV in patients with severe AS because of limited WX. Use of a lower contrast agent dose may mitigate this effect.

Non-invasive assessment of left ventricular filling pressure in aortic stenosis

BACKGROUND

The assessment of left ventricular (LV) filling pressure (FP) is important for the management of aortic stenosis (AS) patients. Although, it is often restricted for predict LV FP in AS because of mitral annular calcification and a certain left ventricular hypertrophy. Thus, we tested the predictive ability of the algorithm for elevated LV FP in AS patients and also applied a recently-proposed echocardiographic scoring system of LV FP, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score.

METHODS

We enrolled consecutive 116 patients with at least moderate AS in sinus rhythm who underwent right heart catheterization and echocardiography within 7 days. Mean pulmonary artery wedge pressure (PAWP) was measured as invasive parameter of LV FP. LV diastolic dysfunction (DD) was graded according to the ASE/EACVI guidelines. The VMT score was defined as follows: time sequence of opening of mitral and tricuspid valves was scored to 0-2 (0: tricuspid valve first, 1: simultaneous, 2: mitral valve first). When the inferior vena cava was dilated, one point was added and VMT score was finally calculated as 0-3.

RESULTS

Of the 116 patients, 29 patients showed elevated PAWP. Ninety patients (93%) and 67 patients (63%) showed increased values for left atrium volume index (LAVI) and E/e', respectively when the cut-off values recommended by the guidelines were applied and thus the algorism predicted elevated PAWP with a low specificity and positive predictive value (PPV). VMT ≥ 2 predicted elevated PAWP with a sensitivity of 59%, specificity of 90%, PPV of 59%, and negative predictive value of 89%. An alternative algorithm that applied tricuspid regurgitation velocity and VMT scores was tested, and its predictive ability was markedly improved.

CONCLUSION

VMT score was applicable for AS patients. Alternative use of VMT score improved diagnostic accuracy of guideline-recommended algorism.

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.

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.

Hypertrophy of the right ventricle by pulmonary artery banding in rats: a study of structural, functional, and transcriptomics alterations in the right and left ventricles

Introduction: Right ventricular remodeling with subsequent functional impairment can occur in some clinical conditions in adults and children. The triggering factors, molecular mechanisms, and, especially, the evolution over time are still not well known. Left ventricular (LV) changes associated with right ventricular (RV) remodeling are also poorly understood. Objectives: The study aimed to evaluate RV morphological, functional, and gene expression parameters in rats submitted to pulmonary artery banding compared to control rats, with the temporal evolution of these parameters, and to analyze the influence of RV remodeling by pulmonary artery banding in rats and their controls over time on LV geometry, histology, gene expression, and functional performance. Methods: Healthy 6-week-old male Wistar-EPM rats weighing 170-200 g were included. One day after the echocardiogram, depending on the animals undergoing the pulmonary artery banding (PAB) procedure or not (control group), they were then randomly divided into subgroups according to the follow-up time: 72 h, or 2, 4, 6, or 8 weeks. In each subgroup, the following were conducted: a new echocardiogram, a hemodynamic study, the collection of material for morphological analysis (hypertrophy and fibrosis), and molecular biology (gene expression). The results were presented as the mean ± standard deviation of the mean. A two-way ANOVA and Tukey post-test compared the variables of the subgroups and evolution follow-up times. The adopted significance level was 5%. Results: There was no significant difference among the subgroups in the percentage of water in both the lungs and the liver (the percentage of water in the lungs ranged from 76% to 78% and that of the liver ranged from 67% to 71%). The weight of the right chambers was significantly higher in PAB animals in all subgroups (RV PAB weighed from 0.34 to 0.48 g, and control subjects, from 0.17 to 0.20 g; right atrium (RA) with PAB from 0.09 to 0.14 g; and control subjects from 0.02 to 0.03 g). In the RV of PAB animals, there was a significant increase in myocyte nuclear volume (97 μm3-183.6 μm3) compared to control subjects (34.2 μm3-57.2 μm3), which was more intense in subgroups with shorter PAB follow-up time, and the fibrosis percentage (5.9%-10.4% vs. 0.96%-1.18%) was higher as the PAB follow-up time was longer. In the echocardiography result, there was a significant increase in myocardial thickness in all PAB groups (0.09-0.11 cm compared to control subjects-0.04-0.05 cm), but there was no variation in RV diastolic diameter. From 2 to 8 weeks of PAB, the S-wave (S') (0.031 cm/s and 0.040 cm/s), and fractional area change (FAC) (51%-56%), RV systolic function parameters were significantly lower than those of the respective control subjects (0.040 cm/s to 0.050 cm/s and 61%-67%). Furthermore, higher expression of genes related to hypertrophy and extracellular matrix in the initial subgroups and apoptosis genes in the longer follow-up PAB subgroups were observed in RV. On the other hand, LV weight was not different between animals with and without PAB. The nuclear volume of the PAB animals was greater than that of the control subjects (74 μm3-136 μm3; 40.8 μm3-46.9 μm3), and the percentage of fibrosis was significantly higher in the 4- and 8-week PAB groups (1.2% and 2.2%) compared to the control subjects (0.4% and 0.7%). Echocardiography showed that the diastolic diameter and LV myocardial thickness were not different between PAB animals and control subjects. Measurements of isovolumetric relaxation time and E-wave deceleration time at the echocardiography were different between PAB animals and control subjects in all subgroups, but there were no changes in diastolic function in the hemodynamic study. There was also increased expression of genes related to various functions, particularly hypertrophy. Conclusion: 1) Rats submitted to pulmonary artery banding presented RV remodeling compatible with hypertrophy. Such alterations were mediated by increased gene expression and functional alterations, which coincide with the onset of fibrosis. 2) Structural changes of the RV, such as weight, myocardial thickness, myocyte nuclear volume, and degree of fibrosis, were modified according to the time of exposure to pulmonary artery banding and related to variations in gene expression, highlighting the change from an alpha to a beta pattern from early to late follow-up times. 3) The study suggests that the left ventricle developed histological alterations accompanied by gene expression modifications simultaneously with the alterations found in the right ventricle.

Sex differences in myocardial remodeling and extracellular volume in aortic regurgitation

Whether sex differences exist in the cardiac remodeling related to aortic regurgitation (AR) is unclear. Cardiac magnetic resonance (CMR) is the current non-invasive reference standard for cardiac remodeling assessment and can evaluate tissue characteristics. This prospective cohort included patients with AR undergoing CMR between 2011 and 2020. We excluded patients with confounding causes of remodeling. We quantified left ventricular (LV) volume, mass, AR severity, replacement fibrosis by late Gadolinium enhancement (LGE), and extracellular expansion by extracellular volume fraction (ECV). We studied 280 patients (109 women), median age 59.5 (47.2, 68.6) years (P for age = 0.25 between sexes). Women had smaller absolute LV volume and mass than men across the spectrum of regurgitation volume (RVol) (P ≤ 0.01). In patients with ≥ moderate AR and with adjustment for body surface area, indexed LV end-diastolic volume and mass were not significantly different between sexes (all P > 0.5) but men had larger indexed LV end systolic volume and lower LV ejection fraction (P ≥ 0.01). Women were more likely to have NYHA class II or greater symptoms than men but underwent surgery at a similar rate. Prevalence and extent of LGE was not significantly different between sexes or across RVol. Increasing RVol was independently associated with increasing ECV in women, but not in men (adjusted P for interaction = 0.03). In conclusion, women had lower LV volumes and mass than men across AR severity  but their ECV increased with higher regurgitant volume, while ECV did not change in men. Indexing to body surface area did not fully correct for the cardiac remodeling differences between men and women. Women were more likely to have symptoms but underwent surgery at a similar rate to men. Further research is needed to determine if differences in ECV would translate to differences in the course of AR and outcomes.

Syncope in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

No data exist on the clinical and prognostic significance of syncope in patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis.

METHODS

A total of 1705 consecutive patients with severe aortic stenosis undergoing TAVR in a tertiary university centre between 2007 and 2021 were included and classified according to the presence of syncope before the TAVR procedure. Baseline, procedural, and follow-up data were collected prospectively in a dedicated database.

RESULTS

A total of 115 patients (7%) presented with syncope before the TAVR procedure. Of these, 15 patients (13%) showed arrhythmic episodes as the probable cause of the syncope, and all of them had pacemakers implanted at a median of 13 (6 to 53) days before the TAVR procedure. Patients with syncope were older (82 ± 8 years vs 80 ± 8 years, P = 0.001) and had a higher rate of pacemaker implantation before the TAVR procedure (27% vs 14%, P < 0.001), with no differences between groups regarding the severity of aortic stenosis (transvalvular gradient, valve area). There were no differences between groups in 30-day (adjusted hazard ratio [HR], 1.28; 95% confidence interval [CI], 0.46-3.60) and 1-year (adjusted HR, 0.71; 95% CI, 0.0.35-1.45) mortality following TAVR.

CONCLUSIONS

Syncope was not associated with a more advanced valvular disease and had no significant prognostic impact on patients undergoing TAVR. However, arrhythmias and conduction-system disturbances were more common in patients with previous syncope and might play a relevant role in the pathogenesis of syncope in patients with aortic stenosis.

Cardiac T1 mapping enables risk prediction of LV dysfunction after surgery for aortic regurgitation

Background

To assess whether cardiac T1 mapping for detecting myocardial fibrosis enables preoperative identification of patients at risk for early left ventricular dysfunction after surgery of aortic regurgitation.

Methods

1.5 Tesla cardiac magnetic resonance imaging was performed in 40 consecutive aortic regurgitation patients before aortic valve surgery. Native and post-contrast T1 mapping was performed using a modified Look-Locker inversion-recovery sequence. Serial echocardiography was performed at baseline and 8 ± 5 days after aortic valve surgery to quantify LV dysfunction. Receiver operating characteristic analysis was performed to determine the diagnostic accuracy of native T1 mapping and extracellular volume for predicting postoperative LV ejection fraction decrease >-10% after aortic valve surgery.

Results

Native T1 was significantly increased in patients with a postoperatively decreased LVEF (n = 15) vs. patients with a preserved postoperative LV ejection fraction (n = 25) (i.e., 1,071 ± 67 ms vs. 1,019 ± 33 ms, p = .001). Extracellular volume was not significantly different between patients with preserved vs. decreased postoperative LV ejection fraction. With a cutoff-of value of 1,053 ms, native T1 yielded an area under the curve (AUC) of .820 (95% CI: .683-.958) for differentiating between patients with preserved vs. reduced LV ejection fraction with 70% sensitivity and 84% specificity.

Conclusion

Increased preoperative native T1 is associated with a significantly higher risk of systolic LV dysfunction early after aortic valve surgery in aortic regurgitation patients. Native T1 could be a promising tool to optimize the timing of aortic valve surgery in patients with aortic regurgitation to prevent early postoperative LV dysfunction.

Homoarginine in the cardiovascular system: Pathophysiology and recent developments

Upcoming experimental and epidemiological data have identified the endogenous non-proteinogenic amino acid L-homoarginine (L-hArg) not only as a novel biomarker for cardiovascular disease but also as being directly involved in the pathogenesis of cardiac dysfunction. The association of low L-hArg levels with adverse cardiovascular events and mortality has proposed the idea of nutritional supplementation to rescue pathways inversely associated with cardiovascular health. Subsequent clinical and experimental studies contributed significantly to our knowledge of potential effects on the cardiorenal axis, acting either as a biomarker or a cardiovascular active agent. In this review article, we provide a comprehensive summary of the L-hArg metabolism, pathophysiological aspects, and current developments in the field of experimental and clinical evidence in favor of protective cardiovascular effects. Establishing a reliable biomarker to identify patients at high risk to die of cardiovascular disease represents one of the main goals for tackling this disease and providing individual therapeutic guidance.

LGE prevalence and patterns in severe aortic stenosis: When "junctional" means the same

BACKGROUND

Left ventricular (LV) remodeling in severe aortic valve stenosis (AS) is a complex process that goes beyond hypertrophic response. Reparative/replacement fibrosis is considered irreversible and has recognized value in both risk stratification and prognosis. Currently, cardiac magnetic resonance (CMR) is the gold-standard imaging technique for fibrosis identification through late gadolinium enhancement (LGE) assessment. However, its prevalence and distribution are quite variable among series. Our goal was to assess LGE prevalence and patterns in severe AS.

METHODOLOGY

Single-center prospective cohort of 140 patients with severe symptomatic high-gradient AS (mean age 72 ± 8 years; mean valvular transaortic gradient 61 ± 18 mmHg; mean LV ejection fraction by echocardiogram 58 ± 9%) undergoing surgical aortic valve replacement. Those with previous myocardial infarction and/or non-ischemic cardiomyopathy were excluded. All patients performed 1.5 T LGE-CMR prior to surgery.

RESULTS

Overall, 103 patients (74%) had non-ischemic LGE (median LGE mass 2.8 g [IQR 0.0-7.8] g), many of them with combined mid-wall and junctional enhancement pattern (36%). LGE was most frequently observed in the mid-basal segments of the interventricular septum. Seventy-four patients (53%) had non-exclusively junctional LGE. Contrary to those with junctional enhancement, patients with non-exclusively junctional LGE had higher LV volumes/mass, worse LV ejection fraction and worse global longitudinal strain.

CONCLUSION

Among patients with severe, symptomatic, high-gradient AS, LGE is frequent, primarily affecting the mid-basal interventricular septum. Contrary to junctional LGE, the presence of non-junctional LGE seems to correlate with adverse markers of LV remodeling.

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.

Mechanically induced alterations in chromatin architecture guide the balance between cell plasticity and mechanical memory

Phenotypic plasticity, or adaptability, of a cell determines its ability to survive and function within changing cellular environments. Changes in the mechanical environment, ranging from stiffness of the extracellular matrix (ECM) to physical stress such as tension, compression, and shear, are critical environmental cues that influence phenotypic plasticity and stability. Furthermore, an exposure to a prior mechanical signal has been demonstrated to play a fundamental role in modulating phenotypic changes that persist even after the mechanical stimulus is removed, creating stable mechanical memories. In this mini review, our objective is to highlight how the mechanical environment alters both phenotypic plasticity and stable memories through changes in chromatin architecture, mainly focusing on examples in cardiac tissue. We first explore how cell phenotypic plasticity is modulated in response to changes in the mechanical environment, and then connect the changes in phenotypic plasticity to changes in chromatin architecture that reflect short-term and long-term memories. Finally, we discuss how elucidating the mechanisms behind mechanically induced chromatin architecture that lead to cell adaptations and retention of stable mechanical memories could uncover treatment methods to prevent mal-adaptive permanent disease states.

Incidence and Risk Factors for Long-Term Persistence of Diastolic Dysfunction after Aortic Valve Replacement for Aortic Stenosis Compared with Aortic Regurgitation

(1) Background: Severe left ventricular (LV) diastolic dysfunction with a restrictive diastolic pattern (LVDFP) is generally associated with a worse prognosis. Its evolution and reversibility in the short- and medium-term after aortic valve replacement (AVR) has been little-studied. We aimed to evaluate the evolution of LV remodeling and LV systolic and diastolic function after AVR in aortic stenosis (AS) patients compared to aortic regurgitation (AR). Moreover, we tried to identify the main predictive parameters for postoperative evolution (cardiovascular hospitalization or death and quality of life) and the independent predictors for the persistence of restrictive LVDFP after AVR. (2) Methods: A five-year prospective study on 397 patients undergoing AVR for AS (226 pts) or AR (171 pts), evaluated clinically and by echocardiography preoperatively and until 5 years postoperatively. (3) Results: 1. In patients with AS, early post AVR, LV dimensions decreased and diastolic filling and LV ejection fraction (LVEF) improved more rapidly compared to patients with AR. At 1 year postoperatively, persistent restrictive LVDFP was found especially in the AR group compared to the AS group (36.84% vs. 14.16%). 2. Cardiovascular event-free survival at the 5-year follow-up was lower in the AR group (64.91% vs. 87.17% in the AS group). The main independent predictors of short- and medium-term prognosis after AVR were: restrictive LVDFP, severe LV systolic dysfunction, severe pulmonary hypertension (PHT), advanced age, severe AR, and comorbidities. 3. The persistence of restrictive LVDFP after AVR was independently predicted by: preoperative AR, the E/Ea ratio > 12, the LA dimension index > 30 mm/m², an LV endsystolic diameter (LVESD) > 55 mm, severe PHT, and associated second-degree MR (p < 0.05). (4) Conclusions: AS patients had an immediate postoperative evolution in terms of LV remodeling, and LV systolic and diastolic function were more favorable compared to those with AR. The restrictive LVDFP was reversible, especially after the AVR for AS. The main prognostic predictors were the presence of restrictive LVDFP, advanced age, preoperative AR, severe LV systolic dysfunction, and severe PHT.

Proteomic Analysis in Valvular Cardiomyopathy: Aortic Regurgitation vs. Aortic Stenosis

Left ventricular (LV) reverse remodeling after aortic valve (AV) surgery is less predictable in chronic aortic regurgitation (AR) than in aortic stenosis (AS). We aimed to disclose specific LV myocardial protein signatures possibly contributing to differential disease progression. Global protein profiling of LV myocardial samples excised from the subaortic interventricular septum in patients with isolated AR or AS undergoing AV surgery was performed using liquid chromatography-electrospray ionization-tandem mass spectrometry. Based on label-free quantitation protein intensities, a logistic regression model was calculated and adjusted for age, sex and protein concentration. Web-based functional enrichment analyses of phenotype-associated proteins were performed utilizing g:Profiler and STRING. Data are available via ProteomeXchange with identifier PXD039662. Lysates from 38 patients, including 25 AR and 13 AS samples, were analyzed. AR patients presented with significantly larger LV diameters and volumes (end-diastolic diameter: 61 (12) vs. 48 (13) mm, p < 0.001; end-diastolic volume: 180.0 (74.6) vs. 92.3 (78.4), p = 0.001). A total of 171 proteins were associated with patient phenotype: 117 were positively associated with AR and the enrichment of intracellular compartment proteins (i.e., assigned to carbohydrate and nucleotide metabolism, protein biosynthesis and the proteasome) was detected. Additionally, 54 were positively associated with AS and the enrichment of extracellular compartment proteins (i.e., assigned to the immune and hematopoietic system) was observed. In summary, functional enrichment analysis revealed specific AR- and AS-associated signatures of LV myocardial proteins.

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.

Association between proteomic biomarkers and myocardial fibrosis measured by MRI: the multi-ethnic study of atherosclerosis

BACKGROUND

Cardiac magnetic resonance imaging (CMR) determines the extent of interstitial fibrosis, measured by increased extracellular volume (ECV), and replacement fibrosis with late gadolinium myocardial enhancement (LGE). Despite advances in detection, the pathophysiology of subclinical myocardial fibrosis is incompletely understood. Targeted proteomic discovery technologies enable quantification of low abundance circulating proteins to elucidate cardiac fibrosis mechanisms.

METHODS

Using a cross-sectional design, we selected 92 LGE+ cases and 92 LGE- demographically matched controls from the Multi-Ethnic Study of Atherosclerosis. Similarly, we selected 156 cases from the highest ECV quartile and matched with 156 cases from the lowest quartile. The plasma serum proteome was analyzed using proximity extension assays to determine differential regulation of 92 proteins previously implicated with cardiovascular disease. Results were analyzed using volcano plots of statistical significance vs. magnitude of change and Bayesian additive regression tree (BART) models to determine importance.

FINDINGS

After adjusting for false discovery, higher ECV was significantly associated with 17 proteins. Using BART, Plasminogen activator inhibitor 1, Insulin-like growth factor-binding protein 1, and N-terminal pro-B-type natriuretic peptide were associated with higher ECV after accounting for other proteins and traditional cardiovascular risk factors. In contrast, no circulating proteins were associated with replacement fibrosis.

INTERPRETATIONS

Our results suggest unique circulating proteomic signatures associated with interstitial fibrosis emphasizing its systemic influences. With future validation, protein panels may identify patients who may develop interstitial fibrosis with progression to heart failure.

FUNDING

This research was supported by contracts and grants from NHLBI, NCATS and the Inova Heart and Vascular Institute.

Clinical Utility of Strain Imaging in Assessment of Myocardial Fibrosis

Myocardial fibrosis (MF) is a non-reversible process that occurs following acute or chronic myocardial damage. MF worsens myocardial deformation, remodels the heart and raises myocardial stiffness, and is a crucial pathological manifestation in patients with end-stage cardiovascular diseases and closely related to cardiac adverse events. Therefore, early quantitative analysis of MF plays an important role in risk stratification, clinical decision, and improvement in prognosis. With the advent and development of strain imaging modalities in recent years, MF may be detected early in cardiovascular diseases. This review summarizes the clinical usefulness of strain imaging techniques in the non-invasive assessment of MF.

Multimodality imaging in aortic stenosis: new diagnostic and therapeutic frontiers

The advent of transcatheter aortic valve implantation has revolutionized the treatment of calcific aortic valve stenosis. Elderly patients who were previously considered inoperable have currently an efficacious and safe therapy that provides better survival. In addition, current practice guidelines tend to recommend earlier intervention to avoid the irreversible consequences of long-lasting pressure overload caused by the stenotic aortic valve. Appropriate timing of the intervention relies significantly on imaging techniques that provide information on the severity of the aortic stenosis as well as on the hemodynamic consequences and cardiac remodeling. While left ventricular ejection fraction remains one of the main functional parameters for risk stratification in patients with severe aortic stenosis, advances in imaging techniques have provided new structural and functional parameters that allow the identification of patients who will benefit from intervention before the occurrence of symptoms or irreversible cardiac damage. Furthermore, ongoing research aiming to identify the medical therapies that can effectively halt the progression of aortic stenosis relies heavily on imaging endpoints, and new imaging techniques that characterize the metabolic activity of calcific aortic stenosis have been proposed to monitor the effects of these therapies. The present review provides an up-to-date overview of the imaging advances that characterizes the pathophysiology and that have changed the management paradigm of aortic stenosis.

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.

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

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

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.

Multiparametric Strategy to Predict Early Disease Decompensation in Asymptomatic Severe Aortic Regurgitation

BACKGROUND

Use of the current echocardiography-based indications for aortic regurgitation (AR) surgery might result in late valve replacement at the stage of irreversible myocardial damage. Therefore, we aimed to identify simple models combining multiple echocardiography or magnetic resonance imaging (MRI)-derived indices and natriuretic peptides (BNP [brain natriuretic peptide] or NT-proBNP [N-terminnal pro-B type natriuretic peptide]) to predict early disease decompensation in asymptomatic severe AR.

METHODS

This prospective and multicenter study included asymptomatic patients with severe AR, preserved left ventricular ejection fraction (>50%), and sinus rhythm. The echocardiography and MRI images were analyzed centrally in the CoreLab. The study end point was the onset of indication for aortic valve surgery as per current guidelines.

RESULTS

The derivative cohort consisted of 127 asymptomatic patients (age 45±14 years, 84% males) with 41 (32%) end points during a median follow-up of 1375 (interquartile range, 1041-1783) days. In multivariable Cox regression analysis, age, BNP, 3-dimensional vena contracta area, MRI left ventricular end-diastolic volume index, regurgitant volume, and a fraction were identified as independent predictors of end point (all P<0.05). However, a combined model including one parameter of AR assessment (MRI regurgitant volume or regurgitant fraction or 3-dimensional vena contracta area), 1 parameter of left ventricular remodeling (MRI left ventricular end-diastolic volume index or echocardiography 2-dimensional global longitudinal strain or E wave), and BNP showed significantly higher predictive accuracy (area under the curve, 0.74-0.81) than any parameter alone (area under the curve, 0.61-0.72). These findings were confirmed in the validation cohort (n=100 patients, 38 end points).

CONCLUSIONS

In asymptomatic severe AR, multimodality and multiparametric model combining 2 imaging indices with natriuretic peptides, showed high accuracy to identify early disease decompensation. Further prospective studies are warranted to explore the clinical benefit of implementing these models to guide patient management.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02910349.

Aortic valve sclerosis and subclinical LV dysfunction in the general population with normal LV geometry

AIMS

Aortic valve sclerosis (AVS) without hemodynamically significant obstruction is related to cardiovascular morbidity and mortality independent of left ventricular (LV) hypertrophy, although the underlying mechanisms remain unknown. This study investigated the prevalence of AVS and its association with subclinical LV systolic and diastolic dysfunction in individuals with normal LV geometry free of cardiovascular disease.

METHODS

We examined 962 participants with normal LV geometry and free from significant AV stenosis who underwent standard and speckle-tracking echocardiography. AVS was categorized into 4 groups as follows: no AVS, AV thickening, calcification on one leaflet and calcification on ≥2 leaflets.

RESULTS

Among the 962 participants, 767 (79.7%) individuals were classified as no AVS, 74 (7.7%) as AV thickening, 87 (9.0%) as calcification on one leaflet, and 34 (3.5%) as calcification on ≥2 leaflets. The prevalence of subclinical LV diastolic dysfunction (E/e' ratio ≥13) and systolic dysfunction (LV global longitudinal strain (GLS) > -17.0% for men and > -18.0% for women) were greater in AVS groups than those in no AVS group. Subclinical LV diastolic impairment was evident from AV thickening and systolic dysfunction was observed at AV calcification. Multivariable logistic regression analysis demonstrated that AV thickening as well as calcification were independently associated with subclinical LV diastolic impairment (all p < 0.05), while only AV calcification on ≥2 leaflets conferred significant increased risk of impaired LVGLS.

CONCLUSIONS

AVS was observed in approximately 20% individuals without cardiac disease and was associated with subclinical LV diastolic and systolic function even in the absence of LV morphological change.

Cellular Senescence, Aging and Non-Aging Processes in Calcified Aortic Valve Stenosis: From Bench-Side to Bedside

Aortic valve stenosis (AS) is the most common valvular heart disease. The incidence of AS increases with age, however, a significant proportion of elderly people have no significant AS, indicating that both aging and nonaging pathways are involved in the pathomechanism of AS. Age-related and stress-induced cellular senescence accompanied by further active processes represent the key elements of AS pathomechanism. The early stage of aortic valve degeneration involves dysfunction and disruption of the valvular endothelium due to cellular senescence and mechanical stress on blood flow. These cells are replaced by circulating progenitor cells, but in an age-dependent decelerating manner. When endothelial denudation is no longer replaced by progenitor cells, the path opens for focal lipid deposition, initiating subsequent oxidation, inflammation and micromineralisation. Later stages of AS feature a complex active process with extracellular matrix remodeling, fibrosis and calcification. Echocardiography is the gold standard method for diagnosing aortic valve disease, although computed tomography and cardiac magnetic resonance are useful additional imaging methods. To date, no medical treatment has been proven to halt the progression of AS. Elucidation of differences and similarities between vascular and valvular calcification pathomechanisms may help to find effective medical therapy and reduce the increasing health burden of the disease.

Frühe Herzklappentherapie bei asymptomatischen Patienten – was gilt schon jetzt?

Bei einer asymptomatischen hochgradigen Aortenklappenstenose (AS) mit normaler linksventrikulärer Funktion sollte eine „Watchful-Waiting“-Strategie verfolgt werden. Asymptomatische Patienten mit Risikofaktoren, wie sehr schwere AS, schwere kalzifizierter AS oder 3-fach erhöhtem proBNP-Level, können bei niedrigem operativem Risiko eine Intervention erhalten. Erste randomisierte Studien weisen auf einen Vorteil des frühzeitigen Aortenklappenersatzes bei niedrigem OP-Risiko hin.

Für Patienten mit einer asymptomatischen hochgradigen Aortenklappeninsuffizienz sollte bei niedrigem operativem Risiko bereits frühzeitig eine OP erwogen werden, wenn sich Zeichen der linksventrikulären Schädigung zeigen.

Bei asymptomatischer primärer Mitralklappeninsuffizienz (MI) kann die chirurgische Mitralklappenrekonstruktion bereits vor dem Auftreten einer linksventrikulären Dilatation oder anderweitigen Folgeschäden erwogen werden, falls mit einer hohen Rekonstruktionswahrscheinlichkeit zu rechnen ist.

Left Ventricular Global Longitudinal Strain in Patients with Moderate Aortic Stenosis

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

Mechanisms that limit regression of myocardial fibrosis following removal of left ventricular pressure overload

Left ventricular pressure overload (LVPO) can develop from antecedent diseases such as aortic valve stenosis and systemic hypertension and is characterized by accumulation of myocardial extracellular matrix (ECM). Evidence from patient and animal models supports limited reductions in ECM following alleviation of PO, however, mechanisms that control the extent and timing of ECM regression are undefined. LVPO, induced by 4 wk of transverse aortic constriction (TAC) in mice, was alleviated by removal of the band (unTAC). Cardiomyocyte cross-sectional area, collagen volume fraction (CVF), myocardial stiffness, and collagen degradation were assessed for: control, 2-wk TAC, 4-wk TAC, 4-wk TAC + 2-wk unTAC, 4-wk TAC + 4-wk unTAC, and 4-wk TAC + 6-wk unTAC. When compared with 4-wk TAC, 2-wk unTAC resulted in increased reactivity of collagen hybridizing peptide (CHP) (representing initiation of collagen degradation), increased levels of collagenases and gelatinases, decreased levels of collagen cross-linking enzymes, but no change in CVF. When compared with 2-wk unTAC, 4-wk unTAC demonstrated decreased CVF, which did not decline to control values. At 4-wk and 6-wk unTAC, CHP reactivity and mediators of ECM degradation were reduced versus 2-wk unTAC, whereas levels of tissue inhibitor of metalloproteinase (TIMP)-1 increased. ECM homeostasis changed in a time-dependent manner after removal of LVPO and is characterized by early increases in collagen degradation, followed by a later dampening of this process. Tempered ECM degradation with time is predicted to contribute to the finding that normalization of hemodynamic overload alone does not completely regress myocardial fibrosis.NEW & NOTEWORTHY In this study, a murine model demonstrated persistent interstitial fibrosis and myocardial stiffness following alleviation of pressure overload.

Current and new imaging techniques in risk stratification of asymptomatic severe aortic stenosis

Aortic stenosis (AS) is one of the most common valvular diseases in clinical practice. The prevalence of calcified AS with moderate or severe stenosis exceeds 2% after 75 years. The optimal timing of intervention for asymptomatic severe AS is uncertain and controversial. Identification of high-risk patients is based on echocardiographic parameters (left ventricular dysfunction, AS severity and progression), hemodynamic response to exercise, pulmonary hypertension, and elevated brain natriuretic peptides. However, early surgical aortic valve replacement (AVR), when compared to the watchful waiting approach, was associated with survival advantage. Moreover, new insights into pathophysiology of AS and advances in imaging modalities were helpful in the management of asymptomatic AS. In this report, we detail the potential role of echocardiography to guide timing of surgery and we discussed the use of early risk features based on recent imaging modalities.

Differential Diagnosis of Thick Myocardium according to Histologic Features Revealed by Multiparametric Cardiac Magnetic Resonance Imaging

Left ventricular (LV) wall thickening, or LV hypertrophy (LVH), is common and occurs in diverse conditions including hypertrophic cardiomyopathy (HCM), hypertensive heart disease, aortic valve stenosis, lysosomal storage disorders, cardiac amyloidosis, mitochondrial cardiomyopathy, sarcoidosis and athlete's heart. Cardiac magnetic resonance (CMR) imaging provides various tissue contrasts and characteristics that reflect histological changes in the myocardium, such as cellular hypertrophy, cardiomyocyte disarray, interstitial fibrosis, extracellular accumulation of insoluble proteins, intracellular accumulation of fat, and intracellular vacuolar changes. Therefore, CMR imaging may be beneficial in establishing a differential diagnosis of LVH. Although various diseases share LV wall thickening as a common feature, the histologic changes that underscore each disease are distinct. This review focuses on CMR multiparametric myocardial analysis, which may provide clues for the differentiation of thickened myocardium based on the histologic features of HCM and its phenocopies.

Impact of elevated left ventricular filling pressure on long-term outcomes after transcatheter aortic valve replacement

BACKGROUND

Increase in left ventricular filling pressure (FP) and diastolic dysfunction are established consequences of progressive aortic stenosis (AS). However, the impact of elevated FP as detected by pretranscatheter aortic valve replacement (TAVR) echocardiogram on long-term outcomes after TAVR remains unclear.

OBJECTIVE

To understand the impact of elevated FP in patients with severe AS who undergo TAVR.

METHODS

This was a retrospective study of all patients who underwent TAVR between 1 January 2014 and 31 December 2017. The presence of elevated FP was determined in accordance with the latest guidelines using the last available comprehensive echocardiogram prior to TAVR.

RESULTS

Of 983 patients who were included in our study, 422 patients (43%) were found to have elevated FP and 561 patients (57%) had normal FP prior to TAVR. Patients with elevated FP had a mean age of 81.2±8.6 years and were more likely to be males (62%), diabetic (41% vs 35%, p=0.046), and have a higher prevalence of atrial fibrillation (Afib) (53% vs 39%, p<0.001). The 5-year all-cause mortality after TAVR was significantly higher in patients with elevated FP when compared with patients with normal FP (32% vs 24%, p=0.006). The presence of elevated FP, history of Afib and prior PCI emerged as independent predictors of long-term mortality after TAVR.

CONCLUSION

Elevated FP is associated with increased mortality in patients with severe AS undergoing TAVR. Assessment of FP should be incorporated into the risk assessment of AS patients to identify those who may benefit from early intervention.

Remodelling of adult cardiac tissue subjected to physiological and pathological mechanical load in vitro

AIMS

Cardiac remodelling is the process by which the heart adapts to its environment. Mechanical load is a major driver of remodelling. Cardiac tissue culture has been frequently employed for in vitro studies of load-induced remodelling; however, current in vitro protocols (e.g. cyclic stretch, isometric load, and auxotonic load) are oversimplified and do not accurately capture the dynamic sequence of mechanical conformational changes experienced by the heart in vivo. This limits translational scope and relevance of findings.

METHODS AND RESULTS

We developed a novel methodology to study chronic load in vitro. We first developed a bioreactor that can recreate the electromechanical events of in vivo pressure-volume loops as in vitro force-length loops. We then used the bioreactor to culture rat living myocardial slices (LMS) for 3 days. The bioreactor operated based on a 3-Element Windkessel circulatory model enabling tissue mechanical loading based on physiologically relevant parameters of afterload and preload. LMS were continuously stretched/relaxed during culture simulating conditions of physiological load (normal preload and afterload), pressure-overload (normal preload and high afterload), or volume-overload (high preload & normal afterload). At the end of culture, functional, structural, and molecular assays were performed to determine load-induced remodelling. Both pressure- and volume-overloaded LMS showed significantly decreased contractility that was more pronounced in the latter compared with physiological load (P < 0.0001). Overloaded groups also showed cardiomyocyte hypertrophy; RNAseq identified shared and unique genes expressed in each overload group. The PI3K-Akt pathway was dysregulated in volume-overload while inflammatory pathways were mostly associated with remodelling in pressure-overloaded LMS.

CONCLUSION

We have developed a proof-of-concept platform and methodology to recreate remodelling under pathophysiological load in vitro. We show that LMS cultured in our bioreactor remodel as a function of the type of mechanical load applied to them.

Detection of myocardial fibrosis by speckle-tracking echocardiography: from prediction to clinical applications

Myocardial fibrosis (MF) represents the underlying pathologic condition of many cardiac disease, leading to cardiac dysfunction and heart failure (HF). Biopsy studies have shown the presence of MF in patients with decompensating HF despite apparently normal cardiac function. In fact, basic indices of left ventricular (LV) function, such as LV ejection fraction (EF), fail to recognize subtle LV dysfunction caused by MF. Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) is currently recognized as the gold standard imaging investigation for the detection of focal and diffuse cardiac chambers MF; however, its use is limited by its availability and the use of contrast agents, while echocardiography remains the first level cardiac imaging technique due to its low cost, portability and high accessibility. Advanced echocardiographic techniques, above all speckle-tracking echocardiography (STE), have demonstrated reliability for early detection of structural myocardial abnormalities and for the prediction of prognosis in acute and chronic HF. Myocardial strain of both ventricles and also left atrium has been shown to correlate with the degree of MF, providing useful prognostic information in several diseases, such as HF, cardiomyopathies and valvular heart disease. This paper aims to provide an overview of the pathophysiology of MF and the clinical application of STE for the prediction of left and right heart chambers MF in HF patients.