Assessment of Subclinical Left Ventricular Dysfunction in Aortic Stenosis

Prognostic value of right ventricular free-wall longitudinal strain in aortic stenosis: A systematic review and meta-analysis

BACKGROUND

Assessment of right ventricular (RV) function in aortic stenosis (AS) may improve risk stratification. However, whether the prognostic value of RV free-wall longitudinal strain (RVfwLS) is better than that of other right heart or pulmonary circulation parameters remains uncertain. This study assessed and compared the prognostic value of RVfwLS with traditional parameters in the AS population using a systematic review and meta-analysis.

METHODS

We selected studies reporting the hazard ratio (HR) of RVfwLS in patients with AS. We also collected data regarding the HR of systolic pulmonary arterial pressure (SPAP), fractional area change (FAC), and tricuspid annulus plane systolic excursion (TAPSE). To ensure comparability, we standardized the HR using within-study standard deviations. The comparison between the prognostic value of RVfwLS and other parameters was conducted as a ratio of HR.

RESULTS

This meta-analysis included 9 studies comprising a total of 2547 patients, with 679 events. The pooled HR of RVfwLS was 1.56 (95 % CI: 1.39-1.75, p < 0.001). When examining the ratio of HR between RVfwLS and conventional parameters, all comparisons were statistically non-significant [RVfwLS/SPAP: 1.28 (95 % CI: 0.99-1.65, p = 0.06); RVfwLS/FAC: 1.24 (95 % CI: 0.90-1.72, p = 0.14); and RVfwLS/TAPSE:1.07 (95 % CI: 0.75-1.52, p = 0.60)].

CONCLUSIONS

This meta-analysis establishes a substantial association between RVfwLS and adverse outcomes in the AS population. However, comparative analysis between RVfwLS and SPAP, FAC, or TAPSE did not support the prognostic superiority of RVfwLS.

Changes in Global Longitudinal Strain after TAVI: Additional Prognostic Value over Cardiac Damage in Patients with Severe Aortic Stenosis

Background: Previous studies demonstrated the prognostic value of baseline cardiac damage staging as well as left ventricular global longitudinal strain (LVGLS) in patients undergoing transcatheter aortic valve implantation (TAVI). The aim of the present study was to evaluate the changes in cardiac damage stage and LVGLS after TAVI and to investigate their prognostic values when integrated into the follow-up assessment. Methods: Patients with severe aortic stenosis undergoing TAVI were hierarchically classified into cardiac damage stages based on echocardiographic criteria before TAVI and at a 6-month follow-up. At the same time, LVGLS was measured. The staging system included stage 0 = no signs of cardiac damage; stage 1 = LV damage; stage 2 = mitral or left atrial damage; stage 3 = pulmonary vasculature or tricuspid damage; and stage 4 = right ventricular damage. The primary endpoint was all-cause mortality. Results: A total of 620 patients were included. At follow-up, LVGLS significantly improved, and the improvement was similar among each baseline cardiac damage stage. Follow-up LVGLS values were divided into quintiles, and each quintile was integrated into the cardiac damage staging, leading to a reclassification of 308 (50%) patients. At the time of a median follow-up at 48 (IQR 31-71) months starting from the 6-month follow-up after TAVI, 262 (38%) patients had died. A multivariable Cox regression model showed that LVGLS-integrated cardiac damage staging at follow-up had an incremental prognostic value over the baseline assessment (HR per 1-stage increase 1.384; 95% CI 1.152-1.663; p < 0.001). Conclusions: The integration of LVGLS with conventional echocardiographic parameters of cardiac damage at a 6-month follow-up after TAVI can improve patient risk-stratification.

Peak atrial longitudinal strain and risk stratification in moderate and severe aortic stenosis

AIMS

We sought to investigate the association of left atrial strain with the outcome in a large cohort of patients with at least moderate aortic stenosis (AS).

METHODS AND RESULTS

We analysed 467 patients (mean age 80.6 ± 8.2 years; 51% men) with at least moderate AS and sinus rhythm. The primary study endpoint was the composite of all-cause mortality and hospitalizations for heart failure. After a median follow-up of 19.2 (inter-quartile range 12.5-24.4) months, 96 events occurred. Using the receiver operator characteristic curve analysis, the cut-off value of peak atrial longitudinal strain (PALS) more strongly associated with outcome was <16% {area under the curve (AUC) 0.70 [95% confidence interval (CI): 0.63-0.78], P < 0.001}. The Kaplan-Meier curves demonstrated a higher rate of events for patients with PALS < 16% (log-rank P < 0.001). On multivariable analysis, PALS [adjusted HR (aHR) 0.95 (95% CI 0.91-0.99), P = 0.017] and age were the only variables independently associated with the combined endpoint. PALS provided incremental prognostic value over left ventricular (LV) global longitudinal strain, LV ejection fraction, and right ventricular function. Subgroup analysis revealed that impaired PALS was also independently associated with outcome in the subgroups of paucisymptomatic patients [aHR 0.98 (95% CI 0.97-0.98), P = 0.048], moderate AS [aHR 0.92, (95% CI 0.86-0.98), P = 0.016], and low-flow AS [aHR 0.90 (95% CI 0.83-0.98), P = 0.020].

CONCLUSION

In our patients with at least moderate AS, PALS was independently associated with outcome. In asymptomatic patients, PALS could be a potential marker of sub-clinical damage, leading to better risk stratification and, potentially, earlier treatment.

Predominant determinants for evaluation of right parasternal approach in transthoracic echocardiography in aortic stenosis: a study based on three-dimensional cardiac computed tomography analysis

The maximum blood flow velocity through the aortic valve (AVmax) using Doppler transthoracic echocardiography (TTE) is important in assessing the severity of aortic stenosis (AS). The right parasternal (RP) approach has been reported to be more useful than the apical approach, but the anatomical rationale has not been studied. We aimed to clarify the influence of the angle formed by the ascending aorta and left ventricle on Doppler analysis by TTE (Sep-Ao angle) and three-dimensional multidetector computed tomography (3D-MDCT) in patients with AS. A total of 151 patients evaluated using the RP approach and 3D-MDCT were included in this study. The Sep-Ao angle determined using TTE was compared with that determined using 3D-MDCT analysis. In MDCT analysis, the left ventricular (LV) axis was measured in two ways and the calcification score was calculated simultaneously. The Sep-Ao angle on TTE was consistent with that measured using 3D-MDCT. In patients with an acute Sep-Ao angle, the Doppler angle in the apical approach was larger, potentially underestimating AVmax. Multivariate analysis revealed that an acute Sep-Ao angle, large Doppler angle in the apical approach, smaller Doppler angle in the RP approach, and low aortic valve calcification were independently associated with a higher AVmax in the RP approach than in the apical approach. The Sep-Ao angle measured using TTE reflected the 3D anatomical angle. In addition to measurements using the RP approach, technical adjustments to minimize the Doppler angle to avoid bulky calcification should always be noted for accurate assessment.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Transcatheter aortic valve implantation in severe aortic stenosis does not necessarily reverse left ventricular myocardial damage: data of long-term follow-up

AIMS

Aortic stenosis (AS) is causing myocardial damage and replacement is mainly indicated based on symptoms. Non-invasive estimation of myocardial work (MW) provides a less afterload-dependent too for assessing myocardial function. We sought to look at the impact of transcatheter aortic valve implantation (TAVI) on the myocardium at long-term follow-up and according to current indications.

METHODS AND RESULTS

We conducted an observational, cross-sectional, single-centre study. Patients were selected based on the validated indication for a TAVI. Standardized echocardiographies were repeated. A total of 102 patients were included. The mean age was 85 years, 45% were female, 68% had high blood pressure, and 52% had a coronary disease. One-fifth was suffering from low-flow-low-gradient AS. A follow-up was performed at 22 ± 9.5 months after the TAVI. No TAVI dysfunction was observed. Left ventricular (LV) ejection fraction was stable (62 ± 8%), and global longitudinal strain had improved (-14.0 ± 3.7 vs. -16.0 ± 3.6%, P < 0.0001). No improvement of the MW parameters was noticed (LV global work index 2099 ± 692 vs. 2066 ± 706 mmHg%, P = 0.8, LV global constructive 2463 ± 736 vs. 2463 ± 676 mmHg%, P = 0.8). Global wasted work increased [214 (149; 357) vs. 247 (177; 394) mmHg%, P = 0.0008].

CONCLUSION

In a population of severe symptomatic AS patients who had undergone a TAVI, the non-invasive myocardial indices that assess the LV performance at long-term follow-up did not improve. These results are questioning the timing of the intervention and the need for more attention in the pharmacological management of these AS patients.

Comprehensive Myocardial Assessment by Computed Tomography: Impact on Short-Term Outcomes After Transcatheter Aortic Valve Replacement

BACKGROUND

Quantification of myocardial changes in severe aortic stenosis (AS) is prognostically important. The potential for comprehensive myocardial assessment pre-transcatheter aortic valve replacement (TAVR) by computed tomography angiography (CTA) is unknown.

OBJECTIVES

This study sought to evaluate whether quantification of left ventricular (LV) extracellular volume-a marker of myocardial fibrosis-and global longitudinal strain-a marker of myocardial deformation-at baseline CTA associate with post-TAVR outcomes.

METHODS

Consecutive patients with symptomatic severe AS between January 2021 and June 2022 who underwent pre-TAVR CTA were included. Computed tomography extracellular volume (CT-ECV) was derived from septum tracing after generating the 3-dimensional CT-ECV map. Computed tomography global longitudinal strain (CT-GLS) used semi-automated feature tracking analysis. The clinical endpoint was the composite outcome of all-cause mortality and heart failure hospitalization.

RESULTS

Among the 300 patients (80.0 ± 9.4 years of age, 45% female, median Society of Thoracic Surgeons Predicted Risk of Mortality score 2.80%), the left ventricular ejection fraction (LVEF) was 58% ± 12%, the median CT-ECV was 28.5% (IQR: 26.2%-32.1%), and the median CT-GLS was -20.1% (IQR: -23.8% to -16.3%). Over a median follow-up of 16 months (IQR: 12-22 months), 38 deaths and 70 composite outcomes occurred. Multivariable Cox proportional hazards model, accounting for clinical and echocardiographic variables, demonstrated that CT-ECV (HR: 1.09 [95% CI: 1.02-1.16]; P = 0.008) and CT-GLS (HR: 1.07 [95% CI: 1.01-1.13]; P = 0.017) associated with the composite outcome. In combination, elevated CT-ECV and CT-GLS (above median for each) showed a stronger association with the outcome (HR: 7.14 [95% CI: 2.63-19.36]; P < 0.001).

CONCLUSIONS

Comprehensive myocardial quantification of CT-ECV and CT-GLS associated with post-TAVR outcomes in a contemporary low-risk cohort with mostly preserved LVEF. Whether these imaging biomarkers can be potentially used for the decision making including timing of AS intervention and post-TAVR follow-up will require integration into future clinical trials.

Left ventricular global work index and prediction of cardiovascular mortality after transcatheter aortic valve implantation

INTRODUCTION

Echocardiography is used for assessment of patients after transcatheter aortic valve implantation (TAVI). Global work index (GWI) integrates LV deformation throughout the cardiac cycle and LV afterload and may be advantageous for long-term follow-up.

METHODS

We analysed 144 patients with severe aortic stenosis who underwent TAVI and echocardiography within two weeks afterwards. GE EchoPAC v2.6 was applied for determining LV ejection fraction, global longitudinal strain (GLS), stroke work (SW), cardiac power output (CPO), and GWI. The endpoint was cardiovascular mortality.

RESULTS

During median follow-up of 625 [IQR: 511-770] days, 20 (14%) patients died. Clinical baseline characteristics were comparable between non-survivors and survivors. GWI (p = 0.003) and LVEF (p = 0.039) were lower in non-survivors, while GLS, SW, and CPO were not different. In Kaplan-Meier analysis patients with GWI ≤1234 mmHg% exhibited a lower survival probability (P = 0.006). In univariable Cox regression, a significant mortality association was identified for GWI (P = 0.004), weaker for LVEF (P = 0.014), but not for the other parameters. In multivariable Cox regression, GWI independently improved an LV systolic function model including LVEF and GLS. Similarly, GWI but not LVEF independently improved outcome association of different clinical models.

CONCLUSIONS

GWI was lower in non-survivors than survivors, differentiated non-survivors from survivors, was associated with mortality independent of clinical or LV parameters, and improved the fitness of clinical or LV prediction models. In contrast, GLS, SW, and CPO did not show any of these properties. GWI provides added value for follow-up after TAVI possibly by integrating LV deformation throughout the cardiac cycle.

Additive Prognostic Value of Left Ventricular Dispersion and Deformation in Patients With Severe Aortic Stenosis

BACKGROUND

Speckle tracking strain echocardiography allows one to visualize the timing of maximum regional strain and quantifies left ventricular-mechanical dispersion (LV-MD). Whether LV-MD and LV-global longitudinal strain (LV-GLS) provide similar or complementary information in mortality risk stratification in patients with severe aortic stenosis (SAS) remains unknown.

OBJECTIVES

The authors hypothesized that LV mechanical dyssynchrony assessed by LV-MD is associated with an increased risk of mortality and provides additional prognostic information on top of LV-GLS in patients with SAS.

METHODS

A total of 364 patients with SAS (aortic valve area indexed ≤0.6 cm2/m2 and/or aortic valve area ≤1 cm2), LV ejection fraction ≥50% and no or mild symptoms were enrolled. The endpoint was overall mortality.

RESULTS

During a median follow-up period of 41 months, 149 patients died. After adjustment, LV-MD ≥68 ms was significantly associated with an increased risk of mortality (adjusted HR: 1.41; 95% CI: 1.01-1.96; P = 0.044). Adding LV-MD ≥68 ms to a multivariable Cox regression model including LV-GLS ≥-15% improved predictive performance in terms of overall mortality, with improved global model fit, reclassification, and better discrimination. Patients with both criteria had an important increase in mortality compared to patients with none or one criterion (adjusted HR: 2.02; 95% CI: 1.34-3.03; P = 0.001). Interobserver reproducibility of LV-MD was good with an intraclass correlation coefficient of 0.90 (95% CI: 0.72-0.97).

CONCLUSIONS

LV-MD is a reproducible parameter independently associated with an increased risk of mortality in SAS. Increased LV-MD associated with depressed LV-GLS identifies a subgroup of patients with an increased mortality risk. Whether early aortic valve replacement improves the outcome of these patients deserves further studies.

Quantifying the Survival Loss Linked to Late Therapeutic Indication in High-Gradient Severe Aortic Stenosis

Background

International guidelines recommend aortic valve replacement (AVR) as Class I triggers in high-gradient severe aortic stenosis (HGSAS) patients with symptoms and/or left ventricular ejection fraction (LVEF) <50%. The association between waiting for these triggers and postoperative survival penalty is poorly studied.

Objectives

The purpose of this study was to examine the impact of guideline-based Class I triggers on long-term postoperative survival in HGSAS patients.

Methods

2,030 patients operated for HGSAS were included and classified as follows: no Class I triggers (no symptoms and LVEF >50%, n = 853), symptoms with LVEF >50% (n = 965), or LVEF <50% regardless of symptoms (n = 212). Survival was compared after matching (inverse probability weighting) for clinical differences. Restricted mean survival time was analyzed to quantify lifetime loss.

Results

Ten-year survival was better without any Class I trigger than with symptoms or LVEF <50% (67.1% ± 3% vs 56.4% ± 3% vs 53.1% ± 7%, respectively, P < 0.001). Adjusted death risks increased significantly in operated patients with symptoms (HR: 1.45 [95% CI: 1.15-1.82]) or LVEF <50% (HR: 1.47 [95% CI: 1.05-2.06]) than in those without Class I triggers. Performing AVR with LVEF >60% produced similar outcomes to that of the general population, whereas operated patients with LVEF <60% was associated with a 10-year postoperative survival penalty. Furthermore, according to restricted mean survival time analyses, operating on symptomatic patients or with LVEF <60% led to 8.3- and 11.4-month survival losses, respectively, after 10 years, compared with operated asymptomatic patients with a LVEF >60%.

Conclusions

Guideline-based Class I triggers for AVR in HGSAS have profound consequences on long-term postoperative survival, suggesting that HGSAS patients should undergo AVR before trigger onset. Operating on patients with LVEF <60% is already associated with a 10-year postoperative survival penalty questioning the need for an EF threshold recommending AVR in HGSAS patients.

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

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

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Cardiac amyloidosis and aortic stenosis: a state-of-the-art review

Cardiac amyloidosis is caused by the extracellular deposition of amyloid fibrils in the heart, involving not only the myocardium but also any cardiovascular structure. Indeed, this progressive infiltrative disease also involves the cardiac valves and, specifically, shows a high prevalence with aortic stenosis. Misfolded protein infiltration in the aortic valve leads to tissue damage resulting in the onset or worsening of valve stenosis. Transthyretin cardiac amyloidosis and aortic stenosis coexist in patients > 65 years in about 4-16% of cases, especially in those undergoing transcatheter aortic valve replacement. Diagnostic workup for cardiac amyloidosis in patients with aortic stenosis is based on a multi-parametric approach considering clinical assessment, electrocardiogram, haematologic tests, basic and advanced echocardiography, cardiac magnetic resonance, and technetium labelled cardiac scintigraphy like technetium-99 m (99mTc)-pyrophosphate, 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid, and 99mTc-hydroxymethylene diphosphonate. However, a biopsy is the traditional gold standard for diagnosis. The prognosis of patients with coexisting cardiac amyloidosis and aortic stenosis is still under evaluation. The combination of these two pathologies worsens the prognosis. Regarding treatment, mortality is reduced in patients with cardiac amyloidosis and severe aortic stenosis after undergoing transcatheter aortic valve replacement. Further studies are needed to confirm these findings and to understand whether the diagnosis of cardiac amyloidosis could affect therapeutic strategies. The aim of this review is to critically expose the current state-of-art regarding the association of cardiac amyloidosis with aortic stenosis, from pathophysiology to treatment.

Association of acute improvement in left ventricular longitudinal function after transcatheter aortic valve implantation with outcomes for severe aortic stenosis and preserved ejection fraction

BACKGROUND

Global longitudinal strain (GLS) is reportedly a sensitive marker for early subtle abnormalities in left ventricular (LV) performance of asymptomatic patients with severe aortic stenosis (AS) and preserved LV ejection fraction (LVEF). For symptomatic patients with severe AS and preserved LVEF, however, the association of immediate improvement in GLS after transcatheter aortic valve implantation (TAVI) with long-term outcomes remains uncertain.

METHODS

This study concerned 151 symptomatic patients with severe AS and preserved LVEF who had undergone TAVI. Echocardiography was performed before TAVI and 7 (7-9) days after TAVI. GLS was determined by means of a two-dimensional speckle-tracking strain using current guidelines. The primary endpoint was defined as a composite endpoint comprising cardiovascular death or re-hospitalization for HF after TAVI over a median follow-up period of 27.7 (11.9-51.4) months.

RESULTS

Mean LVEF and GLS were 65 ± 7 % and 12.8 ± 3.4 %, respectively. The Kaplan-Meier curve indicated that patients with acute improvement in GLS after TAVI experienced fewer cardiovascular events than those without such improvement (log-rank P = 0.02). Multivariate analysis showed that non-acute improvement in GLS after TAVI was independently associated with worse outcomes as well as deterioration of the mean transaortic pressure gradient.

CONCLUSION

Assessment of GLS immediately after TAVI is a valuable additional parameter for better management of symptomatic patients with severe AS and preserved LVEF who are scheduled for TAVI.

Assessing Complex Left Ventricular Adaptations in Aortic Stenosis Using Personalized 3D + time Cardiac MRI Modeling

Left ventricular adaptations can be a complex process under the influence of aortic stenosis (AS) and comorbidities. This study proposed and assessed the feasibility of using a motion-corrected personalized 3D + time LV modeling technique to evaluate the adaptive and maladaptive LV response to aid treatment decision-making. A total of 22 AS patients were analyzed and compared against 10 healthy subjects. The 3D + time analysis showed a highly distinct and personalized pattern of remodeling in individual AS patients which is associated with comorbidities and fibrosis. Patients with AS alone showed better wall thickening and synchrony than those comorbid with hypertension. Ischemic heart disease in AS caused impaired wall thickening and synchrony and systolic function. Apart from showing significant correlations to echocardiography and clinical MRI measurements (r: 0.70-0.95; p < 0.01), the proposed technique helped in detecting subclinical and subtle LV dysfunction, providing a better approach to evaluate AS patients for specific treatment, surgical planning, and follow-up recovery.

Impact of aortic valve stenosis on myocardial deformation in different left ventricular levels: A three-dimensional speckle tracking echocardiography study

BACKGROUND

Global systolic left ventricular (LV) myocardial function progressively declines as degenerative aortic valve stenosis (AS) progresses. Whether this results in uniformly distributed deformation changes from base to apex has not been investigated.

METHODS

Eighty-five AS patients underwent three-dimensional (3D) echocardiography in this cross-sectional study. Patients were grouped by peak jet velocity into mild (n = 32), moderate (n = 31), and severe (n = 22) AS. 3D speckle tracking derived strain, rotation, twist, and torsion were obtained to assess global LV function and myocardial function at the apical, mid, and basal levels.

RESULTS

Global longitudinal strain (GLS) was lower in patients with severe AS (-16.1 ± 2.4% in mild, -15.5 ± 2.5% in moderate, and -13.5 ± 3.0% in severe AS [all p < .01]). Peak basal and mid longitudinal strain (LS), basal rotation and twist from apical to basal level followed the same pattern, while peak apical LS was higher in moderate AS compared to severe AS (all p < .05). In multivariate analyses, lower GLS was particularly associated with male sex, higher body mass index and peak aortic jet velocity, lower basal LS with higher filling pressure (E/e') and LV mass, lower mid LS with higher RWT and presence of AS symptoms, and lower apical LS with male sex and higher systolic blood pressure, respectively (all p < .05).

CONCLUSION

Using 3D speckle tracking echocardiography reveals regional and global changes in LV mechanics in AS related to the severity of AS, LV remodeling and presence of cardiovascular risk factors.

Assessment of subclinical left ventricular systolic dysfunction in patients with asymptomatic severe aortic stenosis with preserved left ventricular systolic function by three-dimensional speckle tracking echocardiography

OBJECTIVES

Left ventricular dysfunction and remodeling can occur as a result of aortic valve stenosis (AS). Three-dimensional speckle tracking echocardiography (3D-STE) can detect early left ventricular myocardial dysfunction even before ejection fraction declines. The purpose of this study was to look at the relationship between various myocardial strain parameters measured by 3D-STE in asymptomatic severe AS patients from Bangladesh.

METHODS

This study included 46 patients with asymptomatic severe AS but preserved LV systolic function (mean age 50.11 ± 12.66 years, LVEF 63.78 ± 3.95%, AS group) and 33 healthy subjects with no cardiovascular disease (mean age 48.21 ± 4.53 years, LVEF 65.15 ± 3.13%, control group). 3D-STE was used to measure left ventricular global myocardial strain parameters such as peak systolic longitudinal strain (PSLS), circumferential strain, radial strain, and area strain.

RESULTS

The AS group had significantly thicker interventricular septum and posterior ventricular wall than the control group (1.49 ± .19 cm vs. .81 ± .09 cm, p < .001; 1.73 ± 1.71 cm vs. .81 ± .10 cm, p = .003, respectively.) In the AS group, the Indexed Aortic Valve Area (AVA) was significantly lower than in the control group. (.29 ± .10 vs. 2.03 ± .18, p < .001, respectively). In terms of LVEF (p = .102), left ventricular end diastolic volume (p = .075), or left ventricular end systolic volume (p = .092), no significant inter-group difference was found. However, global PSLS (-10.75 ± 2.27 vs. -16.42 ± 2.76, p < .001), circumferential strain (-14.26 ± 3.40 vs. -16.64 ± 2.56, p = .001), area strain (-22.70 ± 4.19 vs. -26.45 ± 9.90, p = .024) and radial strain (32.20 ± 8.77 vs. 41.00 ± 7.52, p < .001) in the AS group were significantly lower than in the control group.

CONCLUSION

Our findings showed reductions in left ventricular global myocardial strains, particularly PSLS in patients suffering from asymptomatic severe AS in Bangladesh; this is consistent with other studies. Reduced area strain, detectable with 3D-STE, is also consistent with that pattern.

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

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

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

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

Myocardial Work in Echocardiography

Myocardial work is an emerging tool in echocardiography that incorporates left ventricular afterload into global longitudinal strain analysis. Myocardial work correlates with myocardial oxygen consumption, and work efficiency can also be assessed. Myocardial work has been evaluated in a variety of clinical conditions to assess the added value of myocardial work compared to left ventricular ejection fraction and global longitudinal strain. This review showcases the current use of myocardial work in adult echocardiography and its possible role in cardiac pathologies.

Identification of early cardiac dysfunction and heterogeneity after pressure and volume overload in mice by high-frequency echocardiographic strain imaging

Object

Aortic stenosis and regurgitation are clinically important conditions characterized with different hypertrophic types induced by pressure or volume overload, respectively, but with comparable cardiac function in compensated stage. Speckle-tracking based strain imaging has been applied to assess subtle alterations in cardiac abnormality, but its application in differentiating these two types of ventricular hypertrophy is still sparse. Here, we performed strain imaging analysis of cardiac remodeling in these two loading conditions.

Methods

C57BL/6J mice were subjected to transverse aortic constriction (TAC)-induced pressure overload or aortic regurgitation (AR)-induced volume overload. Conventional echocardiography and strain imaging were comprehensively assessed to detect stimulus-specific alterations in TAC and AR hearts.

Results

Conventional echocardiography did not detect significant changes in left ventricular systolic (ejection fraction and fractional shortening) and diastolic (E/E') function in either TAC or AR mice. On the contrary, global strain analysis revealed global longitudinal strain and strain rate were remarkably impaired in TAC while preserved in AR mice, although global radial, and circumferential strain and strain rate were significantly reduced in both models. Regional strain analysis in the long axis demonstrated that longitudinal strain and strain rate in all or most segments were decreased in TAC but maintained or slightly dented in AR mice, while radial strain and strain rate indicated overt decline in both models. Moreover, decreased radial and circumferential strain and strain rate were observed in most segments of TAC and AR mice in the short axis.

Conclusion

Strain imaging is superior to conventional echocardiography to detect subtle changes in myocardial deformation, with longitudinal strain and strain rate indicating distinct functional changes in pressure versus volume overload myocardial hypertrophy, making it potentially an advanced approach for early detection and differential diagnosis of cardiac dysfunction.

Valvular heart disease: shifting the focus to the myocardium

Adverse cardiac remodelling is the main determinant of patient prognosis in degenerative valvular heart disease (VHD). However, to give an indication for valvular intervention, current guidelines include parameters of cardiac chamber dilatation or function which are subject to variability, do not directly reflect myocardial structural changes, and, more importantly, seem to be not sensitive enough in depicting early signs of myocardial dysfunction before irreversible myocardial damage has occurred. To avoid irreversible myocardial dysfunction, novel biomarkers are advocated to help refining indications for intervention and risk stratification. Advanced echocardiographic modalities, including strain analysis, and magnetic resonance imaging have shown to be promising in providing new tools to depict the important switch from adaptive to maladaptive myocardial changes in response to severe VHD. This review, therefore, summarizes the current available evidence on the role of these new imaging biomarkers in degenerative VHD, aiming at shifting the clinical perspective from a valve-centred to a myocardium-focused approach for patient management and therapeutic decision-making.

Prognostic implications of residual left ventricular hypertrophy and systolic dysfunction in aortic stenosis following transcatheter aortic valve replacement

The impact of left ventricle (LV) hypertrophy (LVH) regression on contractility-associated measures, the extent of residual cardiac dysfunction and prognostic implications after the initial remodeling process after transcatheter aortic valve replacement (TAVR) has not been investigated. We aimed to assess whether greater LV mass regression from pre-TAVR to 12-months after TAVR was associated with increased systolic function; and assess the prognostic value of residual LVH, systolic function and contractility-associated measures 12-months after TAVR. A total of 439 symptomatic patients were included and examined by echocardiography. LVH regression was assessed as percentage change in LV mass index (LVMi) from baseline to 12-months after TAVR. Midwall fractional shortening (mFS) and stress-corrected (SC-mFS) were used as contractility-associated measures. Primary outcome was all-cause mortality. SC-mFS increased from 0.94 (0.7) at baseline (BS) to 1.22 (0.7) (p < 0.05) 12-months after TAVR for patients with the most LVH regression, compared to patients with no LV regression (BS 1.06 (0.7) to 1.04 (0.5), NS). At 12-months after TAVR, multivariate analysis showed independent prognostic value of LVEF < 50% or GLS < 15% (HR 1.59, p = 0.049) and mFS < 14% (HR 1.99, p = 0.002) for future all cause death. LVH regression in AS after TAVR is associated with significant improvements of LV systolic function in contrast to patients without LV regression. Residual LVH and subsequent LV systolic dysfunction is substantial 12 months after TAVR and are associated with reduced survival. Impaired mFS and the combination of abnormal LVEF or GLS independently predicted all-cause mortality beyond 12 months after TAVR.

Prognostic Value of Left Atrial Strain in Aortic Stenosis: A Competing Risk Analysis

BACKGROUND

The role of left atrial (LA) strain as an imaging biomarker in aortic stenosis is not well established. The aim of this study was to investigate the prognostic performance of phasic LA strain in relation to clinical and echocardiographic variables and N-terminal pro-B-type natriuretic peptide in asymptomatic and minimally symptomatic patients with moderate to severe aortic stenosis and left ventricular ejection fraction > 50%.

METHODS

LA reservoir strain (LASr), LA conduit strain (LAScd), and LA contractile strain (LASct) were measured using speckle-tracking echocardiography. The primary outcome was a composite of all-cause mortality, heart failure hospitalization, progression to New York Heart Association functional class III or IV, acute coronary syndrome, or syncope. Secondary outcomes 1 and 2 comprised the same end points but excluded acute coronary syndrome and additionally syncope, respectively. The prognostic performance of phasic LA strain cutoffs was evaluated in competing risk analyses, aortic valve replacement being the competing risk.

RESULTS

Among 173 patients (mean age, 69 ± 11 years; mean peak transaortic velocity, 4.0 ± 0.8 m/sec), median LASr, LAScd, and LASct were 27% (interquartile range [IQR], 22%-32%), 12% (IQR, 8%-15%), and 16% (IQR, 13%-18%), respectively. Over a median of 2.7 years (IQR, 1.4-4.6 years), the primary outcome and secondary outcomes 1 and 2 occurred in 66 (38%), 62 (36%), and 59 (34%) patients, respectively. LASr < 20%, LAScd < 6%, and LASct < 12% were identified as optimal cutoffs of the primary outcome. In competing risk analyses, progressing from echocardiographic to echocardiographic-clinical and combined models incorporating N-terminal pro-B-type natriuretic peptide, LA strain parameters outperformed other key echocardiographic variables and significantly predicted clinical outcomes. LASr < 20% was associated with the primary outcome and secondary outcome 1, LAScd < 6% with all clinical outcomes, and LASct < 12% with secondary outcome 2. LAScd < 6% had the highest specificity (95%) and positive predictive value (82%) for the primary outcome, and competing risk models incorporating LAScd < 6% had the best discriminative value.

CONCLUSIONS

In well-compensated patients with moderate to severe aortic stenosis and preserved left ventricular ejection fractions, LA strain was superior to other echocardiographic indices and incremental to N-terminal pro-B-type natriuretic peptide for risk stratification. LAScd < 6%, LASr < 20%, and LASct < 12% identified patients at higher risk for adverse outcomes.

How myocardial work could be relevant in patients with an aortic valve stenosis?

AIMS

Myocardial work (MW) calculation is an attractive method to assess left ventricular (LV) myocardial function. In case of aortic stenosis (AS), assessment of work indices is challenging because it requires an accurate evaluation of LV-pressure curves. We sought to evaluate the performances of two distinct methods and to provide a quantitative comparison with invasive data.

METHODS AND RESULTS

Model-based and template-based methods were defined and applied for the evaluation of LV-pressures on 67 AS-patient. Global Constructive (GCW), Wasted (GWW), Positive (GPW), Negative (GNW) MW and Global Work Efficiency (GWE), and Index (GWI) parameters were calculated using the available software computing the indices using brachial blood-pressure and trans-aortic mean pressure gradient (MPG) for estimating the LV-pressures vs. using a model-based and homemade software. A complete comparison was performed with invasive measurements. Patients were characterized by MPG of 49.8 ± 14.8 mmHg, the global longitudinal strain (GLS) was -15.0 ± 4.04%, GCW was 2107 ± 800 mmHg.% (model-based) and 2483 ± 1068 mmHg.% (template-based). The root mean square error (RMSE) and correlation were calculated for each patient and pressure estimation methods. The mean RMSE are 33.9 mmHg and 40.4 mmHg and the mean correlation coefficients are 0.81 and 0.72 for the model-based and template-based methods, respectively. The two methods present correlation coefficient r2 >0.75 for all the indices.

CONCLUSION

The two non-invasive methods of LV pressure estimation and work indices computation correlate with invasive measurements. Although the model-based approach requires less information and is associated with slightly better performances, the implementation of template-based method is easier and is appropriate for clinical practice.

Transcatheter and surgical aortic valve replacement in patients with left ventricular dysfunction

BACKGROUND

Patients with severe aortic stenosis and left ventricular systolic dysfunction have a poor prognosis, and this may result in inferior survival also after aortic valve replacement. The outcomes of transcatheter and surgical aortic valve replacement were investigated in this comparative analysis.

METHODS

The retrospective nationwide FinnValve registry included data on patients who underwent transcatheter or surgical aortic valve replacement with a bioprosthesis for severe aortic stenosis. Propensity score matching was performed to adjust the outcomes for baseline covariates of patients with reduced (≤ 50%) left ventricular ejection fraction.

RESULTS

Within the unselected, consecutive 6463 patients included in the registry, the prevalence of reduced ejection fraction was 20.8% (876 patients) in the surgical cohort and 27.7% (452 patients) in the transcatheter cohort. Reduced left ventricular ejection fraction was associated with decreased survival (adjusted hazards ratio 1.215, 95%CI 1.067-1.385) after a mean follow-up of 3.6 years. Among 255 propensity score matched pairs, 30-day mortality was 3.1% after transcatheter and 7.8% after surgical intervention (p = 0.038). One-year and 4-year survival were 87.5% and 65.9% after transcatheter intervention and 83.9% and 69.6% after surgical intervention (restricted mean survival time ratio, 1.002, 95%CI 0.929-1.080, p = 0.964), respectively.

CONCLUSIONS

Reduced left ventricular ejection fraction was associated with increased morbidity and mortality after surgical and transcatheter aortic valve replacement. Thirty-day mortality was higher after surgery, but intermediate-term survival was comparable to transcatheter intervention. Trial registration The FinnValve registry ClinicalTrials.gov Identifier: NCT03385915.

Absolute coronary flow and microvascular resistance reserve in patients with severe aortic stenosis

BACKGROUND

Development of left ventricle (LV) hypertrophy in aortic stenosis (AS) is accompanied by adaptive coronary flow regulation. We aimed to assess absolute coronary flow, microvascular resistance, coronary flow reverse (CFR) and microvascular resistance reserve (MRR) in patients with and without AS.

METHODS

Absolute coronary flow and microvascular resistance were measured by continuous thermodilution in 29 patients with AS and 29 controls, without AS, matched for age, gender, diabetes and functional severity of epicardial coronary lesions. Myocardial work, total myocardial mass and left anterior descending artery (LAD)-specific mass were quantified by echocardiography and cardiac-CT.

RESULTS

Patients with AS presented a significantly positive LV remodelling with lower global longitudinal strain and global work efficacy compared with controls. Total LV myocardial mass and LAD-specific myocardial mass were significantly higher in patients with AS (p=0.001). Compared with matched controls, absolute resting flow in the LAD was significantly higher in the AS cohort (p=0.009), resulting into lower CFR and MRR in the AS cohort compared with controls (p<0.005 for both). No differences were found in hyperaemic flow and resting and hyperaemic resistances. Hyperaemic myocardial perfusion (calculated as the ratio between the absolute coronary flow subtended to the LAD, expressed in mL/min/g), but not resting, was significantly lower in the AS group (p=0.035).

CONCLUSIONS

In patients with severe AS and non-obstructive coronary artery disease, with the progression of LV hypertrophy, the compensatory mechanism of increased resting flow maintains adequate perfusion at rest, but not during hyperaemia. As a consequence, both CFR and MRR are significantly impaired.

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.

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.

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

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

The effects of levosimendan in patients undergoing transcatheter aortic valve replacement- a retrospective analysis

Background: Aortic stenosis (AS) increases left ventricular afterload, leading to cardiac damage and heart failure (HF). Transcatheter aortic valve replacement (TAVR) is an effective therapy for AS. No inotropic agents including levosimendan have been evaluated in patients undergoing TAVR.

Methods: A total of 285 patients underwent TAVR between 2014 and 2019; 210 were included in the matched analysis and 105 received 0.1 μg/kg body weight/min levosimendan immediately after the prosthesis had been successfully implanted. Medical history, laboratory tests, and echocardiography results were analyzed. Endpoints including 2-year all-cause mortality, stroke, or HF-related hospitalization, and a combination of the above were analyzed by Cox proportional hazard models.

Results: The levosimendan group had no difference in 2-year mortality compared with the control group (hazard ratio [HR]: 0.603, 95% confidence interval [CI]: 0.197–1.844; p = 0.375). However, levosimendan reduced stroke or HF-related hospitalization (HR: 0.346; 95% CI: 0.135–0.884; p = 0.027) and the combined endpoint (HR: 0.459, 95% CI: 0.215–0.980; p = 0.044). After adjusting for multiple variants, levosimendan still reduced stroke or HF-related hospitalization (HR: 0.346, 95% CI: 0.134–0.944; p = 0.038).

Conclusion: Prophylactic levosimendan administration immediately after valve implantation in patients undergoing TAVR can reduce stroke or HF-related hospitalization but does not lower all-cause mortality.

Global Longitudinal Strain and Biomarkers of Cardiac Damage and Stress as Predictors of Outcomes After Transcatheter Aortic Valve Implantation

Background Global longitudinal strain (GLS) is a sensitive measure of left ventricular function and a risk marker in severe aortic stenosis. We sought to determine whether biomarkers of cardiac damage (cardiac troponin) and stress (NT-proBNP [N-terminal pro-B-type natriuretic peptide]) could complement GLS to identify patients with severe aortic stenosis at highest risk. Methods and Results From a multicenter prospective cohort of patients with symptomatic severe aortic stenosis who underwent transcatheter aortic valve implantation, we measured absolute GLS (aGLS), cardiac troponin, and NT-proBNP at baseline in 499 patients. Left ventricular ejection fraction <50% was observed in 19% and impaired GLS (aGLS <15%) in 38%. Elevations in cardiac troponin and NT-proBNP were present in 79% and 89% of those with impaired GLS, respectively, as compared with 63% and 60% of those with normal GLS, respectively (P<0.001 for each). aGLS <15% was associated with increased mortality in univariable analysis (P=0.009), but, in a model with both biomarkers, aGLS, and clinical covariates included, aGLS was not associated with mortality; elevation in each biomarker was associated with an increased hazard of mortality (adjusted hazard ratio, >2; P≤0.002 for each) when the other biomarker was elevated, but not when the other biomarker was normal (interaction P=0.015). Conclusions Among patients with symptomatic severe aortic stenosis undergoing transcatheter aortic valve implantation, elevations in circulating cardiac troponin and NT-proBNP are more common as GLS worsens. Biomarkers of cardiac damage and stress are independently associated with mortality after transcatheter aortic valve implantation, whereas GLS is not. These findings may have implications for risk stratification of asymptomatic patients to determine optimal timing of valve replacement.

Impact of Right Ventricle-Pulmonary Artery Coupling on Clinical Outcomes in the PARTNER 3 Trial

BACKGROUND

Physiologic right ventricle-pulmonary artery (RV-PA) coupling may be impaired in patients with aortic stenosis (AS).

OBJECTIVES

This study aimed to assess the incidence and prognostic significance of impaired RV-PA coupling in low-risk patients with symptomatic severe AS undergoing transcatheter aortic valve replacement or surgical aortic valve replacement.

METHODS

RV-PA coupling was measured by transthoracic echocardiography as the ratio of tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) in patients in the PARTNER (Placement of Aortic Transcatheter Valve) 3 trial. The primary endpoint was the composite of all-cause mortality, stroke, and rehospitalization at the 2-year follow-up.

RESULTS

Among 570 low-risk patients included in the analysis, RV-PA uncoupling was defined by a TAPSE/PASP ratio ≤ 0.55 mm/mm Hg. At baseline, 222 of 570 (38.9%) patients had RV-PA uncoupling. At 2 years, patients with baseline RV-PA uncoupling had an increased incidence of the primary endpoint (19.1% vs 9.9%, P = 0.002), all-cause mortality (5.9% vs 0.6%, P < 0.001), cardiovascular mortality (4.1% vs 0.6%, P = 0.003), and rehospitalization (13.5% vs 7.3%, P = 0.018). On multivariable analysis, baseline RV-PA uncoupling remained an independent predictor of the primary endpoint at 2 years (HR: 1.92; 95% CI: 1.04-3.57; P = 0.038).

CONCLUSIONS

In patients with symptomatic severe AS at low surgical risk undergoing transcatheter aortic valve replacement or surgical aortic valve replacement, baseline RV-PA uncoupling defined by TAPSE/PASP ≤ 0.55 mm Hg was associated with adverse clinical outcomes at 2 years, including all-cause mortality, cardiovascular mortality, and rehospitalization.

Associations between Subclinical Myocardial Dysfunction and Premature Fusion of Early and Late Diastolic Filling with Uncertain Cause

PURPOSE

The fusion of early (E) and late diastolic filling (A) on mitral inflow Doppler, even in the absence of tachycardia, is often found during assessment of left ventricular (LV) diastolic function. We evaluated the echocardiographic characteristics and clinical implications of premature E-A fusion of uncertain cause in the absence of tachycardia.

MATERIALS AND METHODS

We identified 1014 subjects who showed E-A fusion and normal LV ejection fraction (LVEF) between January 2019 and June 2021 at two tertiary hospitals. Among these, 105 (10.4%) subjects showed premature E-A fusion at heart rates less than 100 beats per minute (bpm). The conventional echocardiographic parameters and LV global longitudinal strain (GLS) were compared with 1:1 age-, sex-, and heart rate-matched controls without E-A fusion.

RESULTS

The premature E-A fusion group had a heart rate of 96.4±3.7 bpm. Only 4 (3.8%) subjects were classified as having LV diastolic dysfunction according to current guidelines. The group showed prolonged isovolumic relaxation time (107.2±25.3 msec vs. 61.6±15.6 msec, p<0.001), increased Tei index (0.76±0.19 vs. 0.48±0.10, p<0.001), lower LVEF (63.8±7.0% vs. 67.3±5.6%, p<0.001) and lower absolute LV GLS (|LV GLS|) (17.0±4.2% vs. 19.7±3.3%, p<0.001) than controls. As the E-A fusion occurred at lower heart rate, the |LV GLS| was also lower (p for trend=0.002).

CONCLUSION

Premature E-A fusion at heart rates less than 100 bpm is associated with subclinical LV dysfunction. Time-based indices and LV GLS are helpful for evaluating this easily overlooked population.

Left ventricular dyssynchrony as marker of early dysfunction in premature ventricular contraction-induced cardiomyopathy

Background

Strain imaging has been suggested as a tool to detect early left ventricular (LV) dysfunction due to frequent premature ventricular contractions (PVCs) in patients with preserved LV ejection fraction (EF). However, the progression of intraventricular dyssynchrony (IVD), radial, and circumferential strain (RS, CS) in PVC-cardiomyopathy (CM) are unknown. The aim of this study was to elucidate the progression patterns of CS, IVD, and electro-mechanical latency (EML) in PVC-CM.

Methods and results

Pacemakers were implanted in 20 canines to reproduce ventricular bigeminy at 200ms (PVCs n = 11) for 12 weeks and compared to a sham group (n = 9). We obtained echocardiograms at baseline, 4-, 8- and 12-weeks. RS and CS were obtained at the LV mid-cavitary level. IVD was defined as the time between the earliest and latest peak RS. EML was defined as the time between the onset of QRS and the earliest peak RS. LVEF (62 ± 5 to 42 ± 7%, p < 0.01), CS (-18 ± 3 to -12 ± 3, p < 0.01), and EML (219 ± 37 to 283 ± 46ms, p = 0.02) changed significantly in the PVC group. Peak CS (-18 ± 3 to -14 ± 4, p = 0.02) and IVD (49 ± 31 to 122 ± 103, p = 0.05) had a significant change at 4-weeks despite preserved LVEF (51 ± 5%). IVD normalized while EML increased at weeks 8 and 12.

Conclusion

Our findings consolidate the existing theory that changes in strain precede changes in LVEF in PVC-CM. While IVD becomes abnormal early in the development of PVC-CM, it pseudo-normalizes at advanced stages due to further increases in EML suggestive of cardiac contractility remodeling. These findings are consistent with recent published data where abnormal LV mechanics could be part of a substrate that can predispose to worse outcome in PVC-Cardiomyopathy.

Prognostic value of ventricular longitudinal strain in patients undergoing transcatheter aortic valve replacement: A systematic review and meta-analysis

Introduction

Strain obtained by speckle tracking echocardiography (STE) can detect subclinical myocardial impairment due to myocardial fibrosis (MF) and is considered a prognostic marker. Aortic stenosis (AS) is not only a valve disease, but also a cardiomyopathy characterized by MF. The purpose of this study was to systematically review and analyze ventricular strain as a predictor of adverse outcomes in patients with AS undergoing transcatheter aortic valve replacement (TAVR).

Methods

PubMed, Embase, and the Cochrane library were searched for studies that investigated the prognostic value of impaired ventricular strain on patients with AS undergoing TAVR with all-cause mortality (ACM) and major adverse cardiovascular events (MACE). Pooled odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) were calculated to assess the role of left (LVLS) and right (RVLS) ventricular longitudinal strain in the prognostic prediction of patients with AS undergoing TAVR. Sensitivity and subgroup analysis was performed to assess heterogeneity.

Results

Twelve studies were retrieved from 571 citations for analysis. In total, 1,489 patients with a mean age of 82 years and follow-up periods varying between 1 year and 8.5 years were included. Meta-analysis showed the impaired LVLS from eight studies was associated with an increased risk for combined ACM and MACE (OR: 1.08, 95% CI: 1–1.16; p = 0.037), and ACM alone (HR: 1.08, 95% CI: 1.01–1.16; p = 0.032). Impaired RVLS from four studies was associated with an increased risk of combined ACM and MACE (OR: 1.08, 95% CI: 1.02–1.14; p < 0.01), and ACM alone (HR: 1.07, 95% CI: 1.02–1.12; p < 0.01).

Conclusions

This meta-analysis demonstrated that ventricular strain, including LVLS and RVLS, had a substantial prognostic value in ACM or combined ACM and MACE, which could be used as a valid marker for risk stratification in patients with AS undergoing TAVR.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

Highlighting the role of global longitudinal strain assessment in valvular heart disease

Background

Echocardiography has been the choice for imaging modality for valvular heart disease. It is less invasive, widely available, and allows valvular structure visualization. Echocardiographic assessment often also determines the management. Left ventricular ejection fraction is the most commonly used indicator during echocardiography assessment. It shows signs of left ventricular dysfunction in patients with valve disease. However, most of the time, the ongoing process of cardiac damage may already occur even with preserved cardiac function; further deteriorated ejection fraction will show irreversible cardiac damage. There is a need for a more advanced diagnostic tool to detect early cardiac dysfunction, to prevent further damage.

Main body

Advanced echocardiography imaging using strain imaging allows a physician to evaluate cardiac function more precisely. A more sensitive parameter than left ventricular ejection fraction, global longitudinal strain, can evaluate subclinical myocardial dysfunction before the symptoms occur by evaluating complex cardiac mechanisms. Global longitudinal strain evaluation provides the chance for physicians to determine the intervention needed to prevent further deterioration and permanent cardiac dysfunction. Global longitudinal strain is proven to be beneficial in many types of valvular heart diseases, especially in mitral and aortic valve diseases. It has an excellent diagnostic and prognostic value for patients with valve disease. This review aims to present the superiority of global longitudinal strain compared to left ventricular ejection fraction in assessing cardiac function in patients with valvular heart disease. Clinical usage of global longitudinal strain in several valvular heart diseases is also presented in this review.

Conclusions

The superiority of global longitudinal strain to left ventricular ejection fraction relies on the mechanism where other strains would compensate for the deterioration of longitudinal strain, which is more vulnerable to damage, so the cardiac function is preserved. Therefore, examination of longitudinal strain would give the physician early signs of cardiac function impairment, and prompt management can be conducted.

Impaired Left Ventricular Circumferential Midwall Systolic Performance Appears Linked to Depressed Preload, but Not Intrinsic Contractile Dysfunction or Excessive Afterload, in Paradoxical Low-Flow/Low-Gradient Severe Aortic Stenosis

Paradoxical low-flow/low-gradient aortic stenosis (P-LFLG-AS) occurs in about one-third of patients with severe AS and preserved left ventricular (LV) ejection fraction (EF). Our aim was to differentiate between altered LV loading conditions and contractility as determinants of subtle LV systolic dysfunction in P-LFLG-AS. We retrospectively analyzed medical records of patients with isolated severe degenerative AS and preserved EF (30 subjects with P-LFLG-AS and 30 patients with normal-flow/high-gradient severe AS (NFHG-AS)), without relevant coexistent diseases (e.g., diabetes, coronary artery disease and chronic kidney disease) or any abnormalities which could account for a low-flow state. Patients with P-LFLG-AS and NFHG-AS did not differ in aortic valve area index and most clinical characteristics. Compared to NFHG-AS, subjects with P-LFLG-AS exhibited smaller LV end-diastolic diameter (LVd) (44 ± 5 vs. 54 ± 5 mm, p < 0.001) (consistent with lower LV preload) with pronounced concentric remodeling, higher valvulo-arterial impedance (3.8 ± 1.1 vs. 2.2 ± 0.5 mmHg per mL/m2, p < 0.001) and diminished systemic arterial compliance (0.45 ± 0.11 vs. 0.76 ± 0.23 mL/m2 per mmHg, p < 0.001), while circumferential end-systolic LV midwall stress (cESS), an estimate of afterload at the LV level, was similar in P-LFLG-AS and NFHG-AS (175 ± 83 vs. 198 ± 69 hPa, p = 0.3). LV midwall fractional shortening (mwFS) was depressed in P-LFLG-AS vs. NFHG-AS (12.3 ± 3.5 vs. 14.7 ± 2.9%, p = 0.006) despite similar EF (61 ± 6 vs. 59 ± 8%, p = 0.4). By multiple regression, the presence of P-LFLG-AS remained a significant predictor of lower mwFS compared to NFHG-AS upon adjustment for cESS (β ± SEM: −2.35 ± 0.67, p < 0.001); however, the significance was lost after further correction for LVd (β = −1.10 ± 0.85, p = 0.21). In conclusion, the association of P-LFLG-AS with a lower cESS-adjusted mwFS, an index of afterload-corrected LV circumferential systolic function at the midwall level, appears secondary to a smaller LV end-diastolic cavity size according to the Frank−Starling law. Thus, low LV preload, not intrinsic contractile dysfunction or excessive afterload, may account for impaired LV circumferential midwall systolic performance in P-LFLG-AS.

SS31 Alleviates Pressure Overload-Induced Heart Failure Caused by Sirt3-Mediated Mitochondrial Fusion

Heart failure caused by pressure overload is one of the leading causes of heart failure worldwide, but its pathological origin remains poorly understood. It remains critical to discover and find new improvements and treatments for pressure overload-induced heart failure. According to previous studies, mitochondrial dysfunction and myocardial interstitial fibrosis are important mechanisms for the development of heart failure. The oligopeptide Szeto-Schiller Compound 31 (SS31) can specifically interact with the inner mitochondrial membrane and affect the integrity of the inner mitochondrial membrane. Whether SS31 alleviates pressure overload-induced heart failure through the regulation of mitochondrial fusion has not yet been confirmed. We established a pressure-overloaded heart failure mouse model through TAC surgery and found that SS31 can significantly improve cardiac function, reduce myocardial interstitial fibrosis, and increase the expression of optic atrophy-associated protein 1 (OPA1), a key protein in mitochondrial fusion. Interestingly, the role of SS31 in improving heart failure and reducing fibrosis is inseparable from the presence of sirtuin3 (Sirt3). We found that in Sirt3KO mice and fibroblasts, the effects of SS31 on improving heart failure and improving fibroblast transdifferentiation were disappeared. Likewise, Sirt3 has direct interactions with proteins critical for mitochondrial fission and fusion. We found that SS31 failed to increase OPA1 expression in both Sirt3KO mice and fibroblasts. Thus, SS31 can alleviate pressure overload-induced heart failure through Sirt3-mediated mitochondrial fusion. This study provides new directions and drug options for the clinical treatment of heart failure caused by pressure overload.

Change and impact of left ventricular global longitudinal strain during transcatheter aortic valve implantation

BACKGROUND

Although transcatheter aortic valve implantation (TAVI) is a safe and effective treatment for aortic stenosis, it still carries some risks, such as valve leaks, stroke, and even death. The left ventricular global longitudinal strain (LVGLS) measurement may be useful for the prediction of adverse events during this operation.

AIM

To explore the change of LVGLS during TAVI procedure and the relationship between LVGLS and perioperative adverse events.

METHODS

In this study, 61 patients who had undergone percutaneous transfemoral TAVI were evaluated by transthoracic echocardiography. Before surgery, data on left ventricular ejection fraction (LVEF) and LVGLS were collected separately following balloon expansion and stent implantation. Difference in values of LVGLS and LVEF during preoperative balloon expansion (pre-ex), preoperative stent implantation (pre-im) and balloon expansion-stent implantation (ex-im) were also examined. Adverse events were defined as perioperative death, cardiac rupture, heart arrest, moderate or severe perivalvular leakage, significant mitral regurgitation during TAVI, perioperative moderate or severe mitral regurgitation, perioperative left ventricular outflow tract obstruction, reoperation, and acute heart failure.

RESULTS

The occurrence of perioperative adverse events was associated with differences in pre-ex LVGLS, but not with difference in pre-ex LVEF. There were significant differences between pre-LVGLS and ex-LVGLS, and between pre-LVGLS and im-LVGLS (P = 0.037 and P = 0.020, respectively). However, differences in LVEF were not significant (P = 0.358, P = 0.254); however differences in pre-ex LVGLS were associated with pre-LVGLS (P = 0.045). Compared to LVEF, LVGLS is more sensitive as a measure of left heart function during TAVI and the perioperative period. Moreover, the differences in LVGLS were associated with the occurrence of perioperative adverse events, and changes in LVGLS were apparent in patients with undesirable LVGLS before the surgery. Furthermore, LVGLS is useful to predict changes in cardiac function during TAVI.

CONCLUSION

Greater attention should be paid to the patients who plan to undergo TAVI with normal LVEF but poor LVGLS.