Prognostic value of left ventricular and left atrial strain imaging in moderate to severe aortic stenosis: Insights from an Asian population

BACKGROUND

Data regarding the prognostic value of left atrial (LA) strain in aortic stenosis (AS) is scarce, especially in Asian population and moderate AS.

METHOD

Left ventricular global longitudinal strain (LVGLS), LA reservoir strain (LASr), conduit strain (LAScd), and contractile strain (LASct) were measured using automated speckle-tracking echocardiography in consecutive patients with moderate or severe AS. The primary endpoint was a composite of all-cause death (ACD) and major adverse cardiovascular events (MACE; myocardial infarction, syncope, and heart failure hospitalization).

RESULTS

Of 712 patients (mean age, 78 ± 12 years; 370 [52%] moderate AS; 342 [48%] severe AS), average LV ejection fraction (LVEF) was 68 with SD of 12%. At a median follow-up of 18 months (interquartile range, 11-26 months), the primary endpoint occurred in 93 patients (60 deaths and 35 MACEs) and 221 patients underwent surgical or transcatheter aortic valve replacement (AVR). In the entire cohort, separate multivariable models adjusted for age, Charlson index, symptomatic status, time-dependent AVR, AS-severity, LA volume index and LVEF demonstrated that only LASr was associated with MACE+ACD (Hazard ratio, 0.97; P = 0.014). Subgroup analysis for MACE+ACD demonstrated consistent prognostication for LASr in moderate and severe AS; LVGLS was prognostic only in severe AS (all P ≤ 0.023). The optimal MACE+ACD cutoff for LASr from spline curves was 21.3%. Adjusted Kaplan-Meier curves demonstrated better event-free survival in patients with LASr >21.3% versus those with LASr ≤21.3% (P = 0.04).

CONCLUSIONS

In both moderate and severe AS, only LASr robustly predicted outcomes; thus, including LASr in the AS staging algorithm should be considered.

Evaluation of Left Ventricular Function in Patients With Severe Aortic Stenosis Utilizing Automated Cardiac Motion Quantitation Techniques

OBJECTIVE

The objective of this study is to explore the patterns of alteration in left ventricular systolic function among patients with severe aortic stenosis (SAS) through the application of automatic myocardial motion quantification (aCMQ) techniques. Furthermore, we seek to ascertain dependable quantitative markers for the assessment of impaired left ventricular function in patients with SAS and an ejection fraction (EF) ≥ 60%.

METHODS

Seventy patients who underwent echocardiography and received a diagnosis of severe aortic stenosis (SAS) in the hospital from November 2021 to August 2022 were selected for the SAS group and categorized into three subgroups based on ejection fraction (EF)-SAS group with EF ≥ 60%, SAS group with EF ranging from 50% to 59%, and SAS group with EF < 50%. Concurrently, 30 healthy individuals were recruited at the hospital during the same timeframe to serve as the control group. Participants from both groups underwent standard transthoracic echocardiography to assess conventional echocardiographic parameters. Dynamic images were examined using automatic myocardial motion quantification (aCMQ) software to derive longitudinal peak strain (LPS) parameters, which were then subjected to statistical analysis.

RESULTS

In comparison to the control group participants, the measurements of ascending aorta diameter (AoD), left atrium diameter (LAD), interventricular septal end diastolic thickness (IVSd), left ventricular posterior wall end diastolic thickness (LVPWd), peak systolic velocity (Vmax), and mean pressure gradient (MPG) were significantly higher in the SAS groups (p < 0.05). When compared to participants in the SAS group with an EF ≥ 60%, the values of IVSd, LVPWd, Vmax, and MPG in the SAS group with EF ranging from 50% to 59% were significantly elevated (p < 0.05). Similarly, left ventricular end-diastolic diameter (LVEDD), the ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity (E/e'), and the ratio of early to late diastolic mitral inflow velocities (E/A) in the SAS group with EF < 50% were significantly elevated (p < 0.05). The absolute values of longitudinal peak strain (LPS) in the SAS groups were significantly lower in comparison to those in the control group (p < 0.05). Furthermore, all measurements of left ventricular global longitudinal systolic peak strain (GLPS) showed a positive correlation with MPG, a moderate negative correlation with aortic valve area index (AVAI), and a moderate positive correlation with E/A.

CONCLUSIONS

Patients with SAS and an EF < 50% exhibited the most profound impairment in left ventricular myocardial function. Utilizing the aCMQ technique enables the precise and quantitative evaluation of the severity of impaired left ventricular systolic function in patients within the SAS group with an EF ≥ 60%.

Remodeling in Aortic Stenosis With Reduced and Preserved Ejection Fraction: Insight on Motion Abnormality Via 3D + Time Personalized LV Modeling in Cardiac MRI

BACKGROUND

Increased afterload in aortic stenosis (AS) induces left ventricle (LV) remodeling to preserve a normal ejection fraction. This compensatory response can become maladaptive and manifest with motion abnormality. It is a clinical challenge to identify contractile and relaxation dysfunction during early subclinical stage to prevent irreversible deterioration.

PURPOSE

To evaluate the changes of regional wall dynamics in 3D + time domain as remodeling progresses in AS.

STUDY TYPE

Retrospective.

POPULATION

A total of 31 AS patients with reduced and preserved ejection fraction (14 AS_rEF: 7 male, 66.5 [7.8] years old; 17 AS_pEF: 12 male, 67.0 [6.0] years old) and 15 healthy (6 male, 61.0 [7.0] years old).

FIELD STRENGTH/SEQUENCE

1.5 T Magnetic resonance imaging/steady state free precession and late-gadolinium enhancement sequences.

ASSESSMENT

Individual LV models were reconstructed in 3D + time domain and motion metrics including wall thickening (TI), dyssynchrony index (DI), contraction rate (CR), and relaxation rate (RR) were automatically extracted and associated with the presence of scarring and remodeling.

STATISTICAL TESTS

Shapiro-Wilk: data normality; Kruskal-Wallis: significant difference (P < 0.05); ICC and CV: variability; Mann-Whitney: effect size.

RESULTS

AS_rEF group shows distinct deterioration of cardiac motions compared to AS_pEF and healthy groups (TIAS_rEF : 0.92 [0.85] mm, TIAS_pEF : 5.13 [1.99] mm, TIhealthy : 3.61 [1.09] mm, ES: 0.48-0.83; DIAS_rEF : 17.11 [7.89]%, DIAS_pEF : 6.39 [4.04]%, DIhealthy : 5.71 [1.87]%, ES: 0.32-0.85; CRAS_rEF : 8.69 [6.11] mm/second, CRAS_pEF : 16.48 [6.70] mm/second, CRhealthy : 10.82 [4.57] mm/second, ES: 0.29-0.60; RRAS_rEF : 8.45 [4.84] mm/second; RRAS_pEF : 13.49 [8.56] mm/second, RRhealthy : 9.31 [2.48] mm/second, ES: 0.14-0.43). The difference in the motion metrics between healthy and AS_pEF groups were insignificant (P-value = 0.16-0.72). AS_rEF group was dominated by eccentric hypertrophy (47.1%) with concomitant scarring. Conversely, AS_pEF group was dominated by concentric remodeling and hypertrophy (71.4%), which could demonstrate hyperkinesia with slight wall dyssynchrony than healthy. Dysfunction of LV mechanics corresponded to the presence of myocardial scarring (54.9% in AS), which reverted the compensatory mechanisms initiated and performed by LV remodeling.

DATA CONCLUSION

The proposed 3D + time modeling technique may distinguish regional motion abnormalities between AS_pEF, AS_rEF, and healthy cohorts, aiding clinical diagnosis and monitoring of AS progression. Subclinical myocardial dysfunction is evident in early AS despite of normal EF.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 1.

Association of global longitudinal strain by feature tracking cardiac magnetic resonance imaging with adverse outcomes among community-dwelling adults without cardiovascular disease: The Dallas Heart Study

AIM

Left ventricular (LV) global longitudinal strain (GLS) may detect subtle abnormalities in myocardial contractility among individuals with normal LV ejection fraction (LVEF). However, the prognostic implications of GLS among healthy, community-dwelling adults is not well-established.

METHODS AND RESULTS

Overall, 2234 community-dwelling adults (56% women, 47% Black) with LVEF ≥50% without a history of cardiovascular disease (CVD) from the Dallas Heart Study who underwent cardiac magnetic resonance (CMR) with GLS assessed by feature tracking CMR (FT-CMR) were included. The association of GLS with the risk of incident major adverse cardiovascular events (MACE; composite of incident myocardial infarction, incident heart failure [HF], hospitalization for atrial fibrillation, coronary revascularization, and all-cause death), and incident HF or death were assessed with adjusted Cox proportional hazards models. A total of 309 participants (13.8%) had MACE during a median follow-up duration of 17 years. Participants with the worst GLS (Q4) were more likely male and of the Black race with a history of tobacco use and diabetes with lower LVEF, higher LV end-diastolic volume, and higher LV mass index. Cumulative incidence of MACE was higher among participants with worse (Q4 vs. Q1) GLS (20.4% vs. 9.0%). In multivariable-adjusted Cox models that included clinical characteristics, cardiac biomarkers and baseline LVEF, worse GLS (Q4 vs. Q1) was associated with a significantly higher risk of MACE (hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.07-2.24, p = 0.02) and incident HF or death (HR 1.57, 95% CI 1.03-2.38, p = 0.04).

CONCLUSIONS

Impaired LV GLS assessed by FT-CMR among adults free of cardiovascular disease is associated with a higher risk of incident MACE and incident HF or death independent of cardiovascular risk factors, cardiac biomarkers and LVEF.

Ethnic differences in cardiac structure and function assessed by MRI in healthy South Asian and White European people: A UK Biobank Study

BACKGROUND

Echocardiographic studies indicate South Asian people have smaller ventricular volumes, lower mass and more concentric remodelling than White European people, but there are no data using cardiac MRI (CMR). We aimed to compare CMR quantified cardiac structure and function in White European and South Asian people.

METHODS

Healthy White European and South Asian participants in the UK Biobank Imaging CMR sub-study were identified by excluding those with a history of cardiovascular disease, hypertension, obesity or diabetes. Ethnic groups were matched by age and sex. Cardiac volumes, mass and feature tracking strain were compared.

RESULTS

121 matched pairs (77 male/44 female, mean age 58 ± 8 years) of South Asian and White European participants were included. South Asian males and females had smaller absolute but not indexed left ventricular (LV) volumes, and smaller absolute and indexed right ventricular volumes, with lower absolute and indexed LV mass and lower LV mass:volume than White European participants. Although there were no differences in ventricular or atrial ejection fractions, LV global longitudinal strain was higher in South Asian females than White European females but not males, and global circumferential strain was higher in both male and South Asian females than White European females. Peak early diastolic strain rates were higher in South Asian versus White European males, but not different between South Asian and White European females.

CONCLUSIONS

Contrary to echocardiographic studies, South Asian participants in the UK Biobank study had less concentric remodelling and higher global circumferential strain than White European subjects. These findings emphasise the importance of sex- and ethnic- specific normal ranges for cardiac volumes and function.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Strain Assessment in Aortic Stenosis: Pathophysiology and Clinical Utility

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

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.

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.

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.

Feasibility of Transcatheter Aortic Valve Implantation in Patients With Very Severe Aortic Stenosis

Background: Very severe aortic stenosis (AS) has a poor prognosis even in asymptomatic patients, and asymptomatic very severe AS is a Class IIa indication for aortic valve replacement, although the safety and effectiveness of transcatheter aortic valve implantation (TAVI) for very severe AS is not well-established. Methods and Results: This study included 366 patients undergoing TAVI at a single center, with 85 and 281 patients in the very severe AS (peak velocity ≥5 m/s or mean pressure gradient (PG) ≥60 mmHg) and severe AS groups, respectively. Procedural and clinical outcomes at 1-year follow-up were compared between groups. The calcium scores were significantly higher in the very severe AS group (2,864.5 vs. 1,405.8 arbitrary units [AU] (P<0.001). Although the patient-prosthesis mismatch rate was higher in the very severe AS group (38.3% vs. 25.7%; P=0.029), there was no significant difference in the early safety and clinical efficacy between the groups (16.5% vs. 17.1% and 12.0% vs. 18.9%, respectively). Similarly, there was no significant difference in all-cause mortality at 1 year (4.8% vs. 9.8%). Conclusions: Despite a higher incidence of prosthesis-patient mismatch in those with very severe AS, the procedural and clinical outcomes were comparable to those in patients with severe AS. TAVI may be a reasonable treatment option for very severe AS.

Right vs. left ventricular longitudinal strain for mortality prediction after transcatheter aortic valve implantation

Introduction

This study aims at exploring biventricular remodelling and its implications for outcome in a representative patient cohort with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI).

Methods and results

Pre-interventional echocardiographic examinations of 100 patients with severe AS undergoing TAVI were assessed by speckle tracking echocardiography of both ventricles. Association with mortality was determined for right ventricular global longitudinal strain (RVGLS), RV free wall strain (RVFWS) and left ventricular global longitudinal strain (LVGLS). During a median follow-up of 1,367 [959-2,123] days, 33 patients (33%) died. RVGLS was lower in non-survivors [-13.9% (-16.4 to -12.9)] than survivors [-17.1% (-20.2 to -15.2); P = 0.001]. In contrast, LVGLS as well as the conventional parameters LV ejection fraction (LVEF) and RV fractional area change (RVFAC) did not differ (P = ns). Kaplan-Meier analyses indicated a reduced survival probability when RVGLS was below the -14.6% cutpoint (P < 0.001). Lower RVGLS was associated with higher mortality [HR 1.13 (95% CI 1.04-1.23); P = 0.003] independent of LVGLS, LVEF, RVFAC, and EuroSCORE II. Addition of RVGLS clearly improved the fitness of bivariable and multivariable models including LVGLS, LVEF, RVFAC, and EuroSCORE II with potential incremental value for mortality prediction. In contrast, LVGLS, LVEF, and RVFAC were not associated with mortality.

Discussion

In patients with severe AS undergoing TAVI, RVGLS but not LVGLS was reduced in non-survivors compared to survivors, differentiated non-survivors from survivors, was independently associated with mortality, and exhibited potential incremental value for outcome prediction. RVGLS appears to be more suitable than LVGLS for risk stratification in AS and timely valve replacement.

Aortic Valve Area and Strain Measurements by Cardiac MRI and Transthoracic Echocardiography in Severe Aortic Stenosis with Normal Left Ventricular Function

Background

Transthoracic echocardiography (TTE) is the recommended imaging technique for the evaluation of patients with aortic stenosis (AS). However, in cases with inconclusive findings, cardiac magnetic resonance (CMR) planimetry is used to grade AS severity. This study aimed to compare the results derived from TTE and CMR in patients with severe AS with normal left ventricular (LV) function.

Methods

In a prospective study, 20 patients with severe AS were recruited and data derived from TTE and CMR modalities were compared with the archived records of 28 age- and sex-matched healthy controls. The data included aortic valve area (AVA), MRI-derived biventricular global strains, and TTE-derived global longitudinal strain (GLS). SPSS software was used to analyze the data with independent samples t test, intraclass correlation coefficient (ICC), and Pearson correlation. P<0.05 was considered statistically significant.

Results

An excellent agreement was found in AVA values derived from CMR and TTE with an average ICC of 0.932 (95% CI=0.829-0.973). There was a significant difference in LV-GLS, LV global radial strain (GRS), right ventricular (RV) GRS, and RV global circumferential strain between the groups. A good correlation was found between CMR- and TTE-derived GLS with an average ICC of 0.721 (95% C=0.255-0.896). The mean aortic valve pressure gradient in TTE had a significant inverse linear correlation with LV-GRS in CMR (r=-0.537). All P values were <0.05.

Conclusion

There was a good agreement between AVA and strain values derived from cardiac MRI and TTE. The myocardial strain was impaired in patients with severe AS and normal LV function and correlated with disease severity.

The Interfield Strength Agreement of Left Ventricular Strain Measurements at 1.5 T and 3 T Using Cardiac MRI Feature Tracking

BACKGROUND

Left ventricular (LV) strain measurements can be derived using cardiac MRI from routinely acquired balanced steady-state free precession (bSSFP) cine images.

PURPOSE

To compare the interfield strength agreement of global systolic strain, peak strain rates and artificial intelligence (AI) landmark-based global longitudinal shortening at 1.5 T and 3 T.

STUDY TYPE

Prospective.

SUBJECTS

A total of 22 healthy individuals (mean age 36 ± 12 years; 45% male) completed two cardiac MRI scans at 1.5 T and 3 T in a randomized order within 30 minutes. FIELD STRENGTH/SEQUENCE: bSSFP cine images at 1.5 T and 3 T.

ASSESSMENT

Two software packages, Tissue Tracking (cvi42, Circle Cardiovascular Imaging) and QStrain (Medis Suite, Medis Medical Imaging Systems), were used to derive LV global systolic strain in the longitudinal, circumferential and radial directions and peak (systolic, early diastolic, and late diastolic) strain rates. Global longitudinal shortening and mitral annular plane systolic excursion (MAPSE) were measured using an AI deep neural network model.

STATISTICAL TESTS

Comparisons between field strengths were performed using Wilcoxon signed-rank test (P value < 0.05 considered statistically significant). Agreement was determined using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

RESULTS

Minimal bias was seen in all strain and strain rate measurements between field strengths. Using Tissue Tracking, strain and strain rate values derived from long-axis images showed poor to fair agreement (ICC range 0.39-0.71), whereas global longitudinal shortening and MAPSE showed good agreement (ICC = 0.81 and 0.80, respectively). Measures derived from short-axis images showed good to excellent agreement (ICC range 0.78-0.91). Similar results for the agreement of strain and strain rate measurements were observed with QStrain.

CONCLUSION

The interfield strength agreement of short-axis derived LV strain and strain rate measurements at 1.5 T and 3 T was better than those derived from long-axis images; however, the agreement of global longitudinal shortening and MAPSE was good.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Prognostic Value of Preprocedural LV Global Longitudinal Strain for Post-TAVR-Related Morbidity and Mortality: A Meta-Analysis

BACKGROUND

Left ventricular ejection fraction (LVEF) demonstrates limited prognostic value for post-transcatheter aortic valve replacement (TAVR) outcomes. Evidence regarding the potential role of left ventricular global longitudinal strain (LV-GLS) in this setting is inconsistent.

OBJECTIVES

The aim of this systematic review and meta-analysis of aggregated data was to evaluate the prognostic value of preprocedural LV-GLS for post-TAVR-related morbidity and mortality.

METHODS

The authors searched PubMed, Embase, and Web of Science for studies investigating the association between preprocedural 2-dimensional speckle-tracking-derived LV-GLS and post-TAVR clinical outcomes. An inversely weighted random effects meta-analysis was adopted to investigate the association between LV-GLS vs primary (ie, all-cause mortality) and secondary (ie, major cardiovascular events [MACE]) post-TAVR outcomes.

RESULTS

Of the 1,130 identified records, 12 were eligible, all of which had a low-to-moderate risk of bias (Newcastle-Ottawa scale). On average, 2,049 patients demonstrated preserved LVEF (52.6% ± 1.7%), but impaired LV-GLS (-13.6% ± 0.6%). Patients with a lower LV-GLS had a higher all-cause mortality (pooled HR: 2.01; 95% CI: 1.59-2.55) and MACE (pooled odds ratio [OR]: 1.26; 95% CI: 1.08-1.47) risk compared with patients with higher LV-GLS. In addition, each percentage point decrease of LV-GLS (ie, toward 0%) was associated with an increased mortality (HR: 1.06; 95% CI: 1.04-1.08) and MACE risk (OR: 1.08; 95% CI: 1.01-1.15).

CONCLUSIONS

Preprocedural LV-GLS was significantly associated with post-TAVR morbidity and mortality. This suggests a potential clinically important role of pre-TAVR evaluation of LV-GLS for risk stratification of patients with severe aortic stenosis. (Prognostic value of left ventricular global longitudinal strain in patients with aortic stenosis undergoing Transcatheter Aortic Valve Implantation: a meta-analysis; CRD42021289626).

Incremental value of left ventricular global longitudinal strain in moderate aortic stenosis and reduced left ventricular ejection fraction

BACKGROUND

Moderate aortic stenosis (AS) often coexists with left ventricular (LV) systolic dysfunction and may affect survival through afterload mismatch. Because outcomes are ultimately driven by the condition of the LV, accurate assessment of LV performance is crucial to improve risk stratification. This study investigated the prognostic value of LV global longitudinal strain (GLS) in patients with moderate AS and reduced LV systolic dysfunction.

METHODS

Patients with moderate AS (aortic valve area 1.0-1.5 cm²) and reduced LV ejection fraction (EF) (<50%) were identified. LVGLS was evaluated with speckle-tracking echocardiography. Patients were divided into 2 groups according to an LVGLS value of 11%, based on spline curve analysis. The primary endpoint was all-cause mortality.

RESULTS

A total of 166 patients (mean age 73 ± 11 years, 71% male) were included. The cumulative 1- and 5-year mortality rates were higher in patients with LVGLS <11% (25% and 60%) versus LVGLS ≥11% (10% and 27%) (p < 0.001). On multivariable analysis, LVGLS as a continuous variable (HR 0.753; 95% CI 0.673-0.843; p < 0.001) and as a categorical variable (<11%) (HR 3.028; 95% CI 1.623-5.648; p < 0.001) were independently associated with outcomes, whereas LVEF was not. LVGLS provided additional prognostic information in patients with/without coronary artery disease and with mildly versus severely reduced LVEF. In addition, LVGLS had incremental prognostic value over established risk factors, including LVEF.

CONCLUSION

The combination of moderate AS and reduced LV systolic dysfunction is associated with a high mortality risk. LVGLS, but not LVEF, is independently associated with mortality and provides incremental prognostic value over established risk factors in patients with moderate AS and reduced LVEF.

Managing Patients With Moderate Aortic Stenosis

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

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.

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.

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.

Characterization of myocardial mechanics and its prognostic significance in patients with severe aortic stenosis undergoing aortic valve replacement

AIMS

Aortic stenosis (AS) induces characteristic changes in left ventricular (LV) mechanics that can be reversed after aortic valve replacement (AVR). We aimed to comprehensively characterize LV mechanics before and after AVR in patients with severe AS and identify predictors of short-term functional recovery and long-term survival.

METHODS AND RESULTS

We prospectively performed comprehensive strain analysis by 2D speckle-tracking echocardiography in 88 patients with severe AS and LV ejection fraction ≥50% (mean age 71 ± 12 years, 42% female) prior to and within 7 days after AVR. Patients were followed for up to 5.2 years until death from any cause or last encounter. Within days after AVR, we observed an absolute increase in global longitudinal strain (GLS) (-16.0 ± 2.0% vs. -18.5 ± 2.1%, P<0.0001) and a decrease in apical rotation (10.5 ± 4.0° vs. 8.3 ± 2.8°, P = 0.0002) and peak systolic twist (18.2 ± 5.0° vs. 15.5 ± 3.8°, P = 0.0008). A baseline GLS is less negative than -16.2% was 90% sensitive and 67% specific in predicting a ≥ 20% relative increase in GLS. During a median follow-up of 3.8 years, a global circumferential systolic strain rate (GCSRs) less negative than -1.9% independently predicted lower survival.

CONCLUSION

In patients with severe AS, a reversal in GLS, apical rotation, and peak systolic twist abnormalities towards normal occurs within days of AVR. Baseline GLS is the strongest predictor of GLS recovery but neither was associated with long-term survival. In contrast, abnormal baseline GCSRs are associated with worse outcomes.

Post-cardiopulmonary bypass longitudinal strain provides higher prognostic ability than baseline strain or change in strain

CONTEXT

Global longitudinal strain (GLS) measured by speckle-tracking echocardiography demonstrates excellent prognostic ability in predicting major adverse cardiac events after cardiac surgery. However, the optimal timing of intraoperative GLS measurement that provides the best prognostic value is unclear.

AIM

Our goal was to evaluate whether GLS measured prior to cardiopulmonary bypass (pre-CPB GLS), following CPB (post-CPB GLS), or change in GLS provides the strongest association with postoperative complications.

SETTING AND DESIGN

Post hoc analysis of prospectively collected data from a clinical trial (NCT01187329). 72 patients with aortic stenosis undergoing elective AVR ± coronary artery bypass grafting between January 2011 and August 2013.

MATERIAL AND METHODS

Myocardial deformation analysis from standardized transesophageal echocardiographic examinations were performed after anesthetic induction and chest closure. We evaluated the association between pre-CPB GLS, post-CPB GLS, and change in GLS (percent change from pre-CPB baseline) with postoperative atrial fibrillation and hospitalization >7 days. The association of post-CPB GLS with duration of mechanical ventilation, N-terminal pro-BNP (NT-proBNP) and troponin T were also assessed.

STATISTICAL ANALYSIS

Multivariable logistic regression.

RESULTS

Risk-adjusted odds (OR[97.5%CI] of prolonged hospitalization increased an estimated 27% (1.27[1.01 to 1.59];P_adj =0.035) per 1% decrease in absolute post-CPB GLS. Mean[98.3%CI] NT-proBNP increased 98.4[20 to 177]pg/mL; P_adj =0.008), per 1% decrease in post-CPB GLS. Pre-CPB GLS or change in GLS were not associated with any outcomes.

CONCLUSIONS

Post-CPB GLS provides the best prognostic value in predicting postoperative outcomes. Measuring post-CPB GLS may improve risk stratification and assist in future study design and patient outcome research.

Quantification of left ventricular strain and torsion by joint analysis of 3D tagging and cine MR images

Cardiovascular magnetic resonance (CMR) imaging is the gold standard for the non-invasive assessment of left-ventricular (LV) function. Prognostic value of deformation metrics extracted directly from regular SSFP CMR images has been shown by numerous studies in the clinical setting, but with some limitations to detect torsion of the myocardium. Tagged CMR introduces trackable features in the myocardium that allow for the assessment of local myocardial deformation, including torsion; it is, however, limited in the quantification of radial strain, which is a decisive metric for assessing the contractility of the heart. In order to improve SSFP-only and tagged-only approaches, we propose to combine the advantages of both image types by fusing global shape motion obtained from SSFP images with the local deformation obtained from tagged images. To this end, tracking is first performed on SSFP images, and subsequently, the resulting motion is utilized to mask and track tagged data. Our implementation is based on a recent finite element-based motion tracking tool with mechanical regularization. Joint SSFP and tagged images registration performance is assessed based on deformation metrics including LV strain and twist using human and in-house porcine datasets. Results show that joint analysis of SSFP and 3DTAG images provides better quantification of LV strain and twist as either data source alone.

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.

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.

One and Five-Year Mortality Risk Prediction in Patients with Moderate and Severe Aortic Stenosis

(1) Background: Our goal was to develop a risk prediction model for mortality in patients with moderate and severe aortic stenosis (AS). (2) Methods: All patients aged 40−95 years, with echocardiographic evidence of moderate and severe AS at a single institution, were studied over a median of 2.8 (1.5−4.8) years, between 2013−2018. Patient characteristics and mortality were compared using Chi-squares, t-tests, and Kaplan−Meier (KM) curves, as appropriate. The risk calculation for mortality was derived using the Cox proportional hazards model. A risk score was calculated for each parameter, and the total sum of scores predicted the individualized risks of 1-and 5-year mortality. (3) Results: A total of 1991 patients with severe and 2212 with moderate AS were included. Severe AS patients were older, had a lower ejection fraction %, were more likely to be Caucasian, and had lower rates of obesity and smoking, but had higher rates of cardiac comorbidities and AVR (49.3% vs. 2.8%, p < 0.0001). The unadjusted overall mortality was 41.7% vs. 41%, p = 0.6530, and was not different using KM curves (log rank, p = 0.0853). The models included only patients with complete follow-up (3966 in the 1-year, and 816 in the 5-year model) and included 13 variables related to patient characteristics, degree of AS, and AVR. The C-statistic was 0.75 and 0.72 for the 1-year and the 5-year models, respectively. (4) Conclusions: Patients with moderate and severe AS experience high morbidity and mortality. The usage of a risk prediction model may provide guidance for clinical decision making in complex patients.

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.

Echocardiographic Global Longitudinal Strain Is Associated With Myocardial Fibrosis and Predicts Outcomes in Aortic Stenosis

Aims: Left ventricular ejection fraction is the conventional measure used to guide heart failure management, regardless of underlying etiology. Left ventricular global longitudinal strain (LV-GLS) by speckle tracking echocardiography (STE) is a more sensitive measure of intrinsic myocardial function. We aim to establish LV-GLS as a marker of replacement myocardial fibrosis on cardiovascular magnetic resonance (CMR) and validate the prognostic value of LV-GLS thresholds associated with fibrosis.

Methods and results: LV-GLS thresholds of replacement fibrosis were established in the derivation cohort: 151 patients (57 ± 10 years; 58% males) with hypertension who underwent STE to measure LV-GLS and CMR. Prognostic value of the thresholds was validated in a separate outcome cohort: 261 patients with moderate-severe aortic stenosis (AS; 71 ± 12 years; 58% males; NYHA functional class I–II) and preserved LVEF ≥50%. Primary outcome was a composite of cardiovascular mortality, heart failure hospitalization, and myocardial infarction. In the derivation cohort, LV-GLS demonstrated good discrimination (c-statistics 0.74 [0.66–0.83]; P < 0.001) and calibration (Hosmer-Lemeshow χ² = 6.37; P = 0.605) for replacement fibrosis. In the outcome cohort, 47 events occurred over 16 [3.3, 42.2] months. Patients with LV-GLS > −15.0% (corresponding to 95% specificity to rule-in myocardial fibrosis) had the worst outcomes compared to patients with LV-GLS < −21.0% (corresponding to 95% sensitivity to rule-out myocardial fibrosis) and those between −21.0 and −15.0% (log-rank P < 0.001). LV-GLS offered independent prognostic value over clinical variables, AS severity and echocardiographic LV mass and E/e′.

Conclusion: LV-GLS thresholds associated with replacement myocardial fibrosis is a novel approach to risk-stratify patients with AS and preserved LVEF.

Role of myocardial strain and rotation for predicting prosthetic aortic valve stenosis

Pressure overload due to aortic stenosis leads to subclinical left ventricular (LV) dysfunction and global longitudinal strain (GLS) impairment even if ejection fraction is preserved. However, little is known about LV mechanics in aortic prosthetic valve (APV) stenosis. The study aimed to determine the role of myocardial strain and rotation in predicting prosthetic valve stenosis in mechanical APV patients. 60 patients with mechanical APV and 30 healthy individuals were evaluated. APV patients were analyzed in two groups; aortic valve mean gradient < 20 mmHg (27 normal gradient patients) and ≥ 20 mmHg (33 high gradient patients). Strain, rotation, and twist values were assessed using the speckle tracking method, and brain natriuretic peptide (BNP) levels were measured. Four-chamber (p < 0.001) and two-chamber (p = 0.008) longitudinal strain (LS) were higher in the control group. GLS was lower in the high gradient group than control and normal gradient groups (p < 0.001, p = 0.022). LS of lateral wall's basal and mid segments were lower in normal and high gradient groups than the control group (p = 0.003, p = 0.008). While basal rotation was lower in the high gradient group than the control group (p = 0.048), there was no difference between the groups in terms of apical rotation, and twist. BNP levels were significantly different between the groups (p = 0.048). No correlation was found between aortic valve mean gradient and GLS, basal rotation, and BNP. In conclusions, LV GLS and basal rotation are depressed in high APV gradient patients; however, these parameters are not independent predictors of gradient increment.

Role of Exercise Testing and Speckle Tracking Echocardiography in Paradoxical Severe Aortic Stenosis

Introduction The clinical behavior and prognosis of patients with asymptomatic paradoxical low-gradient aortic stenosis (PLGAS) still remain controversial. Some authors consider PLGAS as an echocardiographically poorly quantified moderate AS (MAS). We aimed to investigate the clinical behavior of PLGAS by comparing it with that of asymptomatic high-gradient aortic stenosis (HG-AS) and MAS using transthoracic echocardiography (TTE) with speckle tracking imaging (STI) and cardiopulmonary exercise testing (CPET). The hypothesis of our study is, unlike that described by other authors, to demonstrate the existence of clinical and echocardiographic differences between PLGAS and MAS. Methods A cohort of 113 patients was included and categorized into three groups according to AS type: MAS (n=63), HG-AS (n=29), and PLGAS (n=21). Patients' clinical data were obtained. Patients underwent 2D TTE with STI and CPET. Results There were no significant differences in the clinical variables between the three AS groups. In the multivariate multinomial logistic regression analysis, with PLGAS being the reference category, the most powerful variable for establishing a difference with HG-AS was the left ventricular mass (LVM) indexed by body-surface area (odds ratio [OR]=1.04, confidence interval (CI)=1.01-1.06, p<0.05). The MAS group showed less abnormal CPET (OR=0.198, CI=0.06-0.69, p<0.05), and higher left ventricle global longitudinal strain rate (GLSR) (OR=0.003, CI=0.00-0.35, p<0.05) than the PLGAS group. Conclusions TTE with STI and CPET established the clear differences between patients with asymptomatic PLGAS and those with asymptomatic MAS, as well as the similarities between patients with PLGAS and those with HG-AS. Our data identify PLGAS as a completely different entity from MAS.

Incremental value of left ventricular global longitudinal strain in a newly proposed staging classification based on cardiac damage in patients with severe aortic stenosis

AIMS

Cardiac damage in severe aortic stenosis (AS) can be classified according to a recently proposed staging classification. The present study investigated the incremental prognostic value of left ventricular (LV) global longitudinal strain (GLS) over stages of cardiac damage in patients with severe AS.

METHODS AND RESULTS

From an ongoing registry, a total of 616 severe symptomatic AS patients with available LV GLS by speckle tracking echocardiography were selected and retrospectively analysed. Patients were categorized according to cardiac damage on echocardiography: Stage 0 (no damage), Stage 1 (LV damage), Stage 2 (mitral valve or left atrial damage), Stage 3 (tricuspid valve or pulmonary artery vasculature damage), or Stage 4 (right ventricular damage). LV GLS was divided by quintiles and assigned to the different stages. The endpoint was all-cause mortality. Over a median follow-up of 44 [24-89] months, 234 (38%) patients died. LV GLS was associated with all-cause mortality independent of stage of cardiac damage. After incorporation of LV GLS by quintiles into the staging classification, Stages 2-4 were independently associated with outcome. LV GLS showed incremental prognostic value over clinical characteristics and stages of cardiac damage.

CONCLUSION

In this large single-centre cohort of severe AS patients, incorporation of LV GLS by quintiles in a novel proposed staging classification resulted in refinement of risk stratification by identifying patients with more advanced cardiac damage. LV GLS was shown to provide incremental prognostic value over the originally proposed staging classification.

Echocardiographic assessment of aortic stenosis: a practical guideline from the British Society of Echocardiography

The guideline provides a practical step-by-step guide in order to facilitate high-quality echocardiographic studies of patients with aortic stenosis. In addition, it addresses commonly encountered yet challenging clinical scenarios and covers the use of advanced echocardiographic techniques, including TOE and Dobutamine stress echocardiography in the assessment of aortic stenosis.

Segmentally impaired left ventricular longitudinal strain: a new predictive diagnostic parameter for asymptomatic patients with severe aortic stenosis and preserved ejection fraction

INTRODUCTION

This study aims to investigate the correlation between severe aortic stenosis (sAS) and impairment of left ventricular global longitudinal strain (LVGLS) in particular segments, using two-dimensional speckle tracking echocardiography in patients with sAS and normal ejection fraction of left ventricle (LVEF).

METHODS

The study included 53 consecutive patients with asymptomatic sAS and preserved LVEF. The regional longitudinal systolic LV wall strain was evaluated at the area opposite of the aorta as the median strain value of the basal, middle, and apical segments of the lateral and posterior walls and was compared to the average strain value of the interventricular septum (IVS) at the same views.

RESULTS

LVGLS was decreased and was not statistically different between three- and four-chamber views (-12.5 ± 3.6 vs -11.4 ± 5.5%, p = 0.2). The average strain values of the lateral and posterior walls were statistically reduced compared to the average value of the IVS (lateral vs IVS: -7.8 ± 3.7 vs -10 ± 5.3%, p = 0.005, posterior vs IVS: -7.7 ± 4.2 vs -10.3 ± 3.8%, p < 0.0001). There was no significant difference between lateral and posterior walls (-7.8 ± 3.7 vs -7.7 ± 4.2%, p = 0.9).

CONCLUSIONS

The strain of lateral and posterior walls of left ventricle, which lay just opposite to the aortic valve seem to be more reduced compared to other walls in patients with sAS and preserved LVEF possibly due to their anatomical position. This impairment seems to be the reason of the overall LVGLS reduction. Regional strain could be used as an extra tool for the estimation of the severity of AS as well as for prognostic information in asymptomatic patients.

Clinical Utility of Echocardiographic Strain and Strain Rate Measurements

PURPOSE OF REVIEW

Assessment of left ventricular function is pivotal in many decisions, but ejection fraction has fundamental limitations for assessment of mild dysfunction, and especially for repeated assessments. Myocardial deformation imaging using speckle-tracking is widely available on modern echocardiography systems, and is now feasible as a clinical, rather than purely a research tool. Strain can be measured in all cardiac chambers, most commonly as a systolic parameter, although it can be measured in diastole. Generally, speckle tracking is more effective at measuring strain than strain-rate, which requires a higher temporal resolution. The purpose of this review is to help clinicians understand the main situations where strain provides incremental value to standard echocardiographic measurements.

RECENT FINDINGS

The normal range of LV global longitudinal strain (GLS) has now been defined as -18% and lower (ie more negative), abnormal as -16% or higher (ie less negative), with -16 to -18% being borderline. The variation between different vendors is now small for global parameters, but regional strain measurement remains unreliable - and therefore its use for stress echocardiography remains problematic. The most valuable indications for measuring strain are subclinical LV dysfunction (eg., GLS in HFpEF, stage B heart failure, aortic stenosis, mitral regurgitation), RV dysfunction (RV strain in pulmonary hypertension), atrial fibrillation (LA strain) and sequential follow-up (cardiotoxicity). Strain measurements have clinical utility in a number of settings and should be considered as part of the standard echocardiogram.

Quantification of Biventricular Myocardial Strain Using CMR Feature Tracking: Reproducibility in Small Animals

Myocardial strain is a well-validated parameter for evaluating myocardial contraction. Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a novel method for the quantitative measurements of myocardial strain from routine cine acquisitions. In this study, we investigated the influence of temporal resolution on tracking accuracy of CMR-FT and the intraobserver, interobserver, and interstudy reproducibilities for biventricular strain analysis in mice from self-gated CMR at 11.7 T. 12 constitutive nexilin knockout (Nexn-KO) mice, heterozygous (Het, N = 6) and wild-type (WT, N = 6), were measured with a well-established self-gating sequence twice within two weeks. CMR-FT measures of biventricular global and segmental strain parameters were derived. Interstudy, intraobserver, and interobserver reproducibilities were investigated. For the assessment of the impact of the temporal resolution for the outcome in CMR-FT, highly oversampled semi-4 chamber and midventricular short-axis data were acquired and reconstructed with 10 to 80 phases per cardiac cycle. A generally reduced biventricular myocardial strain was observed in Nexn-KO Het mice. Excellent intraobserver and interobserver reproducibility was achieved in all global strains (ICC range from 0.76 to 0.99), where global right ventricle circumferential strain (RCSSAX) showed an only good interobserver reproducibility (ICC 0.65, 0.11-0.89). For interstudy reproducibility, left ventricle longitudinal strain (LLSLAX) was the most reproducible measure of strain (ICC 0.90, 0.71-0.97). The left ventricle radial strain (LRSSAX) (ICC 0.50, 0.10-0.83) showed fair reproducibility and RCSSAX (ICC 0.36, 0.14-0.74) showed only poor reproducibility. In general, compared with global strains, the segmental strains showed relatively lower reproducibility. A minimal temporal resolution of 20 phases per cardiac cycle appeared sufficient for CMR-FT strain analysis. The analysis of myocardial strain from high-resolution self-gated cine images by CMR-FT provides a highly reproducible method for assessing myocardial contraction in small rodent animals. Especially, global LV longitudinal and circumferential strain revealed excellent reproducibility of intra- and interobserver and interstudy measurements.

Distribution and prognostic value of left ventricular global longitudinal strain in elderly patients with symptomatic severe aortic stenosis undergoing transcatheter aortic valve replacement

Aims

The aim of present study was to examine the preoperative prevalence and distribution of impaired left ventricular global longitudinal strain (LVGLS) in elderly patients with symptomatic aortic stenosis (AS) undergoing transcutaneous aortic valve replacement (TAVR) and to determine the predictive value of LVGLS on survival.

Methods

We included 411 patients with symptomatic severe AS treated with TAVR during a 5-year period, where a baseline echocardiography including LVGLS assessment was available.

Results

Mean age was 80.1 ± 7.1 years and aortic valve area (AVA) index 0.4 ± 0.1 cm². 78 patients died during a median follow-up of 762 days. Mean left ventricular ejection fraction (LVEF) was 50 ± 13% and mean LVGLS was − 14.0%. LVEF was preserved in 60% of patients, while impaired LVGLS > − 18% was seen in 75% of the patients. Previous myocardial infarction, LVEF < 50%, LVGLS > − 14%, low gradient AS (< 4.0 m/s), tricuspid regurgitant gradient > 30 mmHg were identified as significant univariate predictors of all-cause mortality. On multivariate analysis LVGLS > − 14% (HR 1.79 [1.02–3.14], p = 0.04) was identified as the only independent variable associated with all-cause mortality. Reduced survival was observed with an impaired LVGLS > − 14% in the total population (p < 0.002) but also in patients with high AS gradient with preserved LVEF. LVGLS provided incremental prognostic value with respect to clinical characteristics, AVA and LVEF (χ² 19.9, p = 0.006).

Conclusions

In patients with symptomatic AS undergoing TAVR, impaired LVGLS was highly prevalent despite preserved LVEF. LVGLS > − 14% was an independent predictor of all-cause mortality, and survival was reduced if LVGLS > − 14%.

Left ventricular myocardial deformation as measure of hemodynamic burden in congenital valvular aortic stenosis

BACKGROUND

Changes in 2D echocardiography (2DE) speckle tracking imaging (STI) derived left ventricular (LV) strain (S) and strain rate (SR) precedes diminution of LV ejection fraction (LVEF) in adult valvular aortic stenosis (AS). We prospectively examined whether 2DE-STI derived multidirectional LV S and SR correlate with AS severity in children using LV mass index (MI) as the principal outcome variable.

METHODS

52 children (10.4 ± 7.3 years) with isolated congenital AS were included; 13 mild (2.5 m/s < V_max < 3.0 m/s), 25 moderate (3.0 m/s < V_max < 4.0 m/s), and 14 severe (V_max > 4.0 m/s). 2DE including Doppler and STI longitudinal strain (LS), strain rate (LSR), circumferential strain (CS), and strain rate (CSR) were measured. Univariate and multivariable linear regressions identified correlations between LVMI and strain indices.

RESULTS

Three clinical and 2DE variables, and four strain indices were independently associated with LVMI. LVMI correlated positively with systolic blood pressure and aortic regurgitation, and negatively with LVEF. LVMI correlated positively with LSR (four-chamber) and CSR (basal), and negatively with segmental CS in the inferior (basal) and anteroseptal (distal) segments. LVMI showed significant inverse association with LS (P = .05), LSR (P < .001), CS (P < .005), and CSR (P < .0001), independent of AS severity.

CONCLUSIONS

Independent of clinical and 2DE findings including contemporaneous Doppler estimates of AS gradient, both longitudinal and circumferential strain indices correlate with LVMI as a measure of cumulative hemodynamic burden. This association implies subclinical LV dysfunction.

Dissecting myocardial mechanics in patients with severe aortic stenosis: 2-dimensional vs 3-dimensional-speckle tracking echocardiography

Background

Aortic stenosis (AS) causes left ventricular (LV) pressure overload, leading to adverse LV remodeling and dysfunction. Identifying early subclinical markers of LV dysfunction in patients with significant AS is critical as this could provide support for earlier intervention, which may result in improved long-term outcomes. We therefore examined the impact of severe AS and its consequent increase in LV afterload on myocardial deformation and rotational mechanics by 2-dimensional (2D) and 3-dimensional (3D) speckle-tracking echocardiography.

Methods

We prospectively measured various strain parameters in 168 patients (42% female, mean age 72 ± 12 years) with severe AS and LV ejection fraction (EF) ≥50%, and compared them to normal values found in literature. 2D and 3D images were analyzed for global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), basal rotation, apical rotation, and peak systolic twist. We further assessed the degree of concordance between 2D and 3D strain, and examined their association with measures of LV preload and afterload.

Results

Patients with severe AS exhibited significantly lower GLS and GRS but higher GCS, apical rotation, and twist by 2D and 3D echocardiography compared with published normal values (P = 0.003 for 3D twist, P < 0.001 for all others). Agreement between 2D- and 3D-GLS by concordance correlation coefficient was 0.49 (95% confidence interval: 0.39–0.57). GLS was correlated with valvulo-arterial impedance, a measure of LV afterload (r = 0.34, p < 0.001 and r = 0.23, p = 0.003, respectively).

Conclusion

Patients with severe AS demonstrated lower-than-normal GLS and GRS but appear to compensate with higher-than-normal GCS, apical rotation, and twist in order to maintain a preserved LVEF. GLS showed a modest correlation with valvulo-arterial impedance.

Time course of left ventricular remodelling and mechanics after aortic valve surgery: aortic stenosis vs. aortic regurgitation

Aims

Pressure overload in aortic stenosis (AS) and both pressure and volume overload in aortic regurgitation (AR) induce concentric and eccentric hypertrophy, respectively. These structural changes influence left ventricular (LV) mechanics, but little is known about the time course of LV remodelling and mechanics after aortic valve surgery (AVR) and its differences in AS vs. AR. The present study aimed to characterize the time course of LV mass index (LVMI) and LV mechanics [by LV global longitudinal strain (LV GLS)] after AVR in AS vs. AR.

Methods and results

Two hundred and eleven (61 ± 14 years, 61% male) patients with severe AS (63%) or AR (37%) undergoing surgical AVR with routine echocardiographic follow-up at 1, 2, and/or 5 years were evaluated. Before AVR, LVMI was larger in AR patients compared with AS. Both groups showed moderately impaired LV GLS, but preserved LV ejection fraction. After surgery, both groups showed LV mass regression, although a more pronounced decline was seen in AR patients. Improvement in LV GLS was observed in both groups, but characterized by an initial decline in AR patients while LV GLS in AS patients remained initially stable.

Conclusion

In severe AS and AR patients undergoing AVR, LV mass regression and changes in LV GLS are similar despite different LV remodelling before AVR. In AR, relief of volume overload led to reduction in LVMI and an initial decline in LV GLS. In contrast, relief of pressure overload in AS was characterized by a stable LV GLS and more sustained LV mass regression.

Structural and Functional Correlates of Gradient-Area Patterns in Severe Aortic Stenosis and Normal Ejection Fraction

OBJECTIVES

The authors sought to characterize the functional and structural myocardial phenotypes of patients with moderate-to-severe aortic stenosis (AS) and to determine whether severe paradoxical low-gradient AS (LG-AS) is specifically associated with left ventricular (LV) remodeling and fibrosis.

BACKGROUND

Recently, it was suggested that severe paradoxical LG-AS is a more advanced form of AS, with greater reduction of longitudinal deformation, adverse LV remodeling, and more interstitial fibrosis.

METHODS

The study population includes 147 patients with moderate-to-severe AS and a normal LV ejection fraction, and 75 normal control subjects. They prospectively underwent 2-dimensional speckle-tracking echocardiography and cardiac magnetic resonance to evaluate myocardial deformation, LV remodeling, and age- and sex-adjusted extravascular volume fraction (ECV, %). Among AS patients, 18 had moderate AS, 74 had severe high-gradient AS (HG-AS), and 55 had severe paradoxical LG-AS.

RESULTS

Reduced longitudinal and circumferential deformation was observed in 21% and 6% of the AS patients, respectively. Multivariate analyses identified increased ECV (ß = 1.99; p = 0.001) and the absence of normal LV geometry (ß = -1.37; p = 0.007) and as independent predictors of reduced longitudinal deformation. Increased ECV was an independent predictor of reduced circumferential deformation (ß = 2.19; p = 0.001). Over a median follow-up of 29 months, reduced longitudinal deformation (hazard ratio: 0.82; p = 0.023) and higher transvalvular gradients (hazard ratio: 1.05; p < 0.001) increased the risk of death or need for aortic valve replacement. LV hypertrophy was more frequently observed among patients with severe HG-AS (65%) than among the other AS patients (14%; p < 0.001). On average, ECV was within normal limits and did not differ among gradient-area subgroups. When present, increased ECV was associated with reduced longitudinal deformation.

CONCLUSIONS

This study's data show that patients with severe paradoxical LG-AS less frequently display reduced longitudinal deformation, LV hypertrophy, or myocardial fibrosis than patients with HG-AS. Also, interstitial fibrosis only occurs when reduced longitudinal deformation and severe HG-AS are present together. Finally, this study suggests that reduced longitudinal deformation and higher transvalvular gradients adversely affect patients' outcomes.

Determinants and prognostic implications of left ventricular mechanical dispersion in aortic stenosis

AIMS

The present study aimed at investigating the association between left ventricular (LV) mechanical dispersion measured with speckle tracking echocardiography and severity of aortic stenosis (AS) and its impact on prognosis.

METHODS AND RESULTS

This retrospective study included 630 patients [age 72 (62-78) years, 61.4% men] with various grades of AS (mild AS, 19.8%; moderate AS, 37.0%; severe AS, 43.2%). LV mechanical dispersion (defined as standard deviation of time from Q/R on electrocardiogram to peak longitudinal strain in 17 LV segments) was assessed by speckle tracking echocardiography. Clinical, electrocardiographic, and echocardiographic determinants of increased LV mechanical dispersion were evaluated. During a follow-up of 107 (43-133) months, the independent association between LV mechanical dispersion and all-cause mortality (n = 302, 48%) was evaluated including aortic valve replacement as time-dependent co-variate. LV mechanical dispersion increased significantly with increasing severity of AS (mild AS, 54.5 ± 17.2 ms; moderate AS, 56.7 ± 19.3 ms; severe AS, 70.9 ± 24.3 ms; P < 0.001). Independent determinants of increased mechanical dispersion included older age (β = 0.28; P = 0.003), lower LV ejection fraction (β = -0.24; P = 0.020), smaller aortic valve area (β = -8.55; P = 0.001), larger LV mass index (β = 0.20; P < 0.001), and longer QRS duration (β = 1.12 per each 10 ms increase; P = 0.012). LV mechanical dispersion showed incremental prognostic value for all-cause mortality (hazard ratio 1.10 per each 10 ms increase, 95% confidence interval 1.04-1.15; P < 0.001).

CONCLUSION

LV mechanical dispersion assessed by speckle tracking echocardiography increases significantly with severity of AS and is significantly associated with all-cause mortality.

Early Surgery versus Watchful Waiting in Patients with Moderate Aortic Stenosis and Left Ventricular Systolic Dysfunction

Background and Objectives

Severe aortic stenosis (AS) with left ventricular systolic dysfunction (LVSD) is a class I indication for aortic valve replacement (AVR) but this recommendation is not well established in those at the stage of moderate AS. We investigate the clinical impact of AVR among patients with moderate AS and LVSD.

Methods

From 2001 to 2017, we consecutively identified patients with moderate AS and LVSD, defined as aortic valve area 1.0–1.5 cm² and left ventricular ejection fraction <50%. The primary outcome was all-cause death. The outcomes were compared between those who underwent early surgical AVR (within 2 years of index echocardiography) at the stage of moderate AS versus those who were followed medically without AVR at the outpatient clinic.

Results

Among 255 patients (70.1±11.3 years, male 62%), 37 patients received early AVR. The early AVR group was younger than the medical observation group (63.1±7.9 vs. 71.3±11.4) with a lower prevalence of hypertension and chronic kidney disease. During a median 1.8-year follow up, 121 patients (47.5%) died, and the early AVR group showed a significantly lower all-cause death rate than the medical observation group (5.03PY vs. 18.80PY, p<0.001). After multivariable Cox-proportional hazard regression adjusting for age, sex, comorbidities, and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of death (hazard ratio, 0.43; 95% confidence interval 0.20–0.91; p=0.028).

Conclusions

In patients with moderate AS and LVSD, AVR reduces the risk of all-cause death. A prospective randomized trial is warranted to confirm our findings.

Management of patients with combined arterial hypertension and aortic valve stenosis: a consensus document from the Council on Hypertension and Council on Valvular Heart Disease of the European Society of Cardiology, the European Association of Cardiovascular Imaging (EACVI), and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Aortic valve stenosis (AS) is the third most common cardiovascular disease. The prevalence of both AS and arterial hypertension increases with age, and the conditions therefore often co-exist. Co-existence of AS and arterial hypertension is associated with higher global left ventricular (LV) pressure overload, more abnormal LV geometry and function, and more adverse cardiovascular outcome. Arterial hypertension may also influence grading of AS, leading to underestimation of the true AS severity. Current guidelines suggest re-assessing patients once arterial hypertension is controlled. Management of arterial hypertension in AS has historically been associated with prudence and concerns, mainly related to potential adverse consequences of drug-induced peripheral vasodilatation combined with reduced stroke volume due to the fixed LV outflow obstruction. Current evidence suggests that patients should be treated with antihypertensive drugs blocking the renin-angiotensin-aldosterone system, adding further drug classes when required, to achieve similar target blood pressure (BP) values as in hypertensive patients without AS. The introduction of transcatheter aortic valve implantation has revolutionized the management of patients with AS, but requires proper BP management during and following valve replacement. The purpose of this document is to review the recent evidence and provide practical expert advice on management of hypertension in patients with AS.