Global Strain in Severe Aortic Valve Stenosis: Relation to Clinical Outcome After Aortic Valve Replacement

Myocardial Strain Imaging: Theory, Current Practice, and the Future

Myocardial strain imaging by echocardiography or cardiac magnetic resonance (CMR) is a powerful method to diagnose cardiac disease. Strain imaging provides measures of myocardial shortening, thickening, and lengthening and can be applied to any cardiac chamber. Left ventricular (LV) global longitudinal strain by speckle-tracking echocardiography is the most widely used clinical strain parameter. Several CMR-based modalities are available and are ready to be implemented clinically. Clinical applications of strain include global longitudinal strain as a more sensitive method than ejection fraction for diagnosing mild systolic dysfunction. This applies to patients suspected of having heart failure with normal LV ejection fraction, to early systolic dysfunction in valvular disease, and when monitoring myocardial function during cancer chemotherapy. Segmental LV strain maps provide diagnostic clues in specific cardiomyopathies, when evaluating LV dyssynchrony and ischemic dysfunction. Strain imaging is a promising modality to quantify right ventricular function. Left atrial strain may be used to evaluate LV diastolic function and filling pressure.

Metabolic profiling of aortic stenosis and hypertrophic cardiomyopathy identifies mechanistic contrasts in substrate utilization

Aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM) are distinct disorders leading to left ventricular hypertrophy (LVH), but whether cardiac metabolism substantially differs between these in humans remains to be elucidated. We undertook an invasive (aortic root, coronary sinus) metabolic profiling in patients with severe AS and HCM in comparison with non-LVH controls to investigate cardiac fuel selection and metabolic remodeling. These patients were assessed under different physiological states (at rest, during stress induced by pacing). The identified changes in the metabolome were further validated by metabolomic and orthogonal transcriptomic analysis, in separately recruited patient cohorts. We identified a highly discriminant metabolomic signature in severe AS in all samples, regardless of sampling site, characterized by striking accumulation of long-chain acylcarnitines, intermediates of fatty acid transport across the inner mitochondrial membrane, and validated this in a separate cohort. Mechanistically, we identify a downregulation in the PPAR-α transcriptional network, including expression of genes regulating fatty acid oxidation (FAO). In silico modeling of β-oxidation demonstrated that flux could be inhibited by both the accumulation of fatty acids as a substrate for mitochondria and the accumulation of medium-chain carnitines which induce competitive inhibition of the acyl-CoA dehydrogenases. We present a comprehensive analysis of changes in the metabolic pathways (transcriptome to metabolome) in severe AS, and its comparison to HCM. Our results demonstrate a progressive impairment of β-oxidation from HCM to AS, particularly for FAO of long-chain fatty acids, and that the PPAR-α signaling network may be a specific metabolic therapeutic target in AS.

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

Background

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

Patients and methods

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

Results

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

Conclusions

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

Prognostic Value of Left Ventricular Global Longitudinal Strain for Major Adverse Cardiovascular Events in Patients with Aortic Valve Disease: A Meta-Analysis

INTRODUCTION

Valvular heart disease is one of the most common heart diseases. It is characterized by abnormal function or structure of the heart valves. There may be no clinical symptoms in the early stages. Clinical symptoms of arrhythmia, heart failure, or thromboembolic events may occur in the late stages of the disease, such as palpitation after activities, breathing difficulties, fatigue, and so on. Aortic valve disease is a major part of valvular heart disease. The main treatment for aortic valve disease is valve replacement or repair surgery, but it is extremely risky. Therefore, a rigorous prognostic assessment is extremely important for patients with aortic valve disease. The global longitudinal strain is an index that describes the deformation capacity of myocardium. There is evidence that it provides a test for systolic dysfunction other than LVEF (left ventricular ejection fraction) and provides additional prognostic information.

METHOD

Search literature published between 2010 and 2023 on relevant platforms and contain the following keywords: "Aortic valve disease," "Aortic stenosis," "Aortic regurgitation," and "longitudinal strain" or "strain." The data is then extracted and collated for analysis.

RESULTS

A total of 15 articles were included. The total population involved in this study was 3,678 individuals. The absolute value of LVGLS was higher in the no-MACE group than in the MACE group in patients with aortic stenosis (Z = 8.10, p < 0.00001), and impaired LVGLS was a risk factor for MACE in patients with aortic stenosis (HR = 1.14, p < 0.00001, 95% CI: 1.08-1.20). There was also a correlation between impaired LVGLS and aortic valve surgery in patients with aortic valve disease (HR = 1.16, p < 0.0001, 95% CI: 1.08-1.25) or patients with aortic valve regurgitation (HR = 1.21, p = 0.0004, 95% CI: 1.09-1.34). We also found that impaired LVGLS had no significant association between LVGLS and mortality during the period of follow-up in patients with aortic valve stenosis (HR = 1.08, 95% CI: 0.94-1.25, p = 0.28), but it was associated with mortality in studies of prospective analyses (HR = 1.34, 95% CI: 1.02-1.75, p = 0.04).

CONCLUSIONS

Impaired LVGLS correlates with major adverse cardiovascular events in patients with aortic valve disease, and it has predictive value for the prognosis of patients with aortic valve disease.

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.

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.

Echocardiographic Evaluation of Aortic Stenosis: A Comprehensive Review

Echocardiography represents the most important diagnostic tool in the evaluation of aortic stenosis. The echocardiographic assessment of its severity should always be performed through a standardized and stepwise approach in order to achieve a comprehensive evaluation. The latest technical innovations in the field of echocardiography have improved diagnostic accuracy, guaranteeing a better and more detailed evaluation of aortic valve anatomy. An early diagnosis is of utmost importance since it shortens treatment delays and improves patient outcomes. Echocardiography plays a key role also in the evaluation of all the structural changes related to aortic stenosis. Detailed evaluation of subtle and subclinical changes in left ventricle function has a prognostic significance: scientific efforts have been addressed to identify the most accurate global longitudinal strain cut-off value able to predict adverse outcomes. Moreover, in recent years the role of artificial intelligence is increasingly emerging as a promising tool able to assist cardiologists in aortic stenosis screening and diagnosis, especially by reducing the rate of aortic stenosis misdiagnosis.

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.

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.

The influence of pectus excavatum on cardiac kinetics and function in otherwise healthy individuals: A systematic review

BACKGROUND

A number of anterior chest wall deformities, most notably pectus excavatum (PE), may have a detrimental effect on cardiac motion and function. Interpretation of transthoracic echocardiography (TTE) and speckle-tracking echocardiography (STE) results may be hampered by the possible influence of PE on cardiac kinetics.

METHODS

A comprehensive search of all articles assessing cardiac function in PE individuals was carried out. Inclusion criteria were: 1) individuals aged >10 years; 2) studies providing objective assessment of chest deformity (Haller index). Studies that measured myocardial strain parameters in PE patients were also included.

RESULTS

The search (EMBASE and Medline) yielded a total of 392 studies, 36 (9.2%) of which removed as duplicates; a further 339 did not meet inclusion criteria. The full-texts of 17 studies were then analyzed. All studies concordantly reported impaired right ventricular volumes and function. With respect to left ventricle (LV), TTE studies uniformly demonstrated a significant impairment in conventional echoDoppler indices in PE individuals, whereas STE studies provided conflicting results. Importantly, LV functional alterations promptly reverted upon surgical correction of chest defect. In subjects with PE of mild-to-moderate severity, we observed that degree of anterior chest wall deformity, as noninvasively assessed by modified Haller index (MHI), was strongly associated with myocardial strain magnitude, in heterogenous cohorts of otherwise healthy PE individuals.

CONCLUSIONS

Clinicians should be aware that in PE individuals, TTE and STE results may not always be indicative of intrinsic myocardial dysfunction, but may be, at least in part, influenced by artifactual and/or external chest shape determinants.

Cardiac Magnetic Resonance Imaging in Appraising Myocardial Strain and Biomechanics: A Current Overview

Subclinical alterations in myocardial structure and function occur early during the natural disease course. In contrast, clinically overt signs and symptoms occur during late phases, being associated with worse outcomes. Identification of such subclinical changes is critical for timely diagnosis and accurate management. Hence, implementing cost-effective imaging techniques with accuracy and reproducibility may improve long-term prognosis. A growing body of evidence supports using cardiac magnetic resonance (CMR) to quantify deformation parameters. Tissue-tagging (TT-CMR) and feature-tracking CMR (FT-CMR) can measure longitudinal, circumferential, and radial strains and recent research emphasize their diagnostic and prognostic roles in ischemic heart disease and primary myocardial illnesses. Additionally, these methods can accurately determine LV wringing and functional dynamic geometry parameters, such as LV torsion, twist/untwist, LV sphericity index, and long-axis strain, and several studies have proved their utility in prognostic prediction in various cardiovascular patients. More recently, few yet important studies have suggested the superiority of fast strain-encoded imaging CMR-derived myocardial strain in terms of accuracy and significantly reduced acquisition time, however, more studies need to be carried out to establish its clinical impact. Herein, the current review aims to provide an overview of currently available data regarding the role of CMR in evaluating myocardial strain and biomechanics.

Peak systolic myocardial velocity in patients undergoing surgical aortic valve replacement for severe aortic stenosis: prognostic value and natural course

Myocardial systolic longitudinal function has been known to decrease in patients with severe aortic stenosis (AS). Preoperative peak systolic myocardial velocity at the septal mitral valve annulus (S'), measured using Doppler tissue imaging, was used as an indicator for myocardial systolic longitudinal function. The prognostic value and natural course of S' after surgical aortic valve replacement for severe AS have not been elucidated. This retrospective observational study included patients from January 2006 to December 2018. The patients were divided to 2 groups (pre-S'_HIGH vs. pre-S'_LOW) with a cut-off 5.4 cm/s of preoperative S' (pre-S') that was identified by restricted cubic spline curve. The primary outcome was postoperative long-term all-cause mortality. Nine hundred and five patients were analyzed. All-cause mortality rate at the median follow-up period of 5.2 years was 12% in pre-S'_LOW and 8% in pre-S'_HIGH. Multivariate analysis showed that pre-S'_LOW was associated with an increased all-cause mortality (hazard ratio, 1.60; 95% confidence interval, 1.04-2.48; P = 0.032). Significantly different trajectories of postoperative S' (post-S') were found between two groups (P < 0.001 for difference): In pre-S'_LOW, post-S' increased within 6 months after surgery, and gradually decreased over time, whereas it slowly decreased up to 5 years after surgery and then reached a plateau in pre-S'_HIGH. The difference in pre-S' level maintained over time, and remained consistent in the adjusted analysis. Pre-S' < 5.4 cm/s was found to be associated with an increased long-term all-cause mortality. In addition, the trajectories for post-S' were different according to pre-S', which remained after adjustment.

The influence of chest wall conformation on myocardial strain parameters in a cohort of mitral valve prolapse patients with and without mitral annular disjunction

PURPOSE

To evaluate the possible influence of chest wall conformation on myocardial strain parameters in a cohort of mitral valve prolapse (MVP) patients with and without mitral annular disjunction (MAD).

METHODS

All consecutive middle-aged patients with MVP referred to our Outpatient Cardiology Clinic for performing two-dimensional (2D) transthoracic echocardiography (TTE) as part of work up for primary cardiovascular prevention between March 2018 and May 2022, were included into the study. All patients underwent clinic visit, physical examination, modified Haller index (MHI) assessment (the ratio of chest transverse diameter over the distance between sternum and spine) and conventional 2D-TTE implemented with speckle tracking analysis of left ventricular (LV) global longitudinal strain (GLS) and global circumferential strain (GCS). Independent predictors of MAD presence on 2D-TTE were assessed.

RESULTS

A total of 93 MVP patients (54.2 ± 16.4 yrs, 50.5% females) were prospectively analyzed. On 2D-TTE, 34.4% of MVP patients had MAD (7.3 ± 2.0 mm), whereas 65.6% did not. Compared to patients without MAD, those with MAD had: 1) significantly shorter antero-posterior (A-P) thoracic diameter (13.5 ± 1.2 vs 14.8 ± 1.3 cm, p < 0.001); 2) significantly smaller cardiac chambers dimensions; 3) significantly increased prevalence of classic MVP (84.3 vs 44.3%, p < 0.001); 4) significantly impaired LV-GLS (-17.2 ± 1.4 vs -19.4 ± 3.0%, p < 0.001) and LV-GCS (-16.3 ± 4.1 vs -20.4 ± 4.9, p < 0.001), despite similar LV ejection fraction (63.7 ± 4.2 vs 63.0 ± 3.9%, p = 0.42). A-P thoracic diameter (OR 0.25, 95%CI 0.10-0.82), classic MVP (OR 3.90, 95%CI 1.32-11.5) and mitral annular end-systolic A-P diameter (OR 2.76, 95%CI 1.54-4.92) were the main independent predictors of MAD. An A-P thoracic diameter ≤ 13.5 cm had 59% sensitivity and 84% specificity for predicting MAD presence (AUC = 0.81). In addition, MAD distance was strongly influenced by A-P thoracic diameter (r = - 0.96) and MHI (r = 0.87), but not by L-L thoracic diameter (r = 0.23). Finally, a strong inverse correlation between MHI and both LV-GLS and LV-GCS was demonstrated in MAD patients (r = - 0.94 and - 0.92, respectively), but not in those without (r = - 0.51 and - 0.50, respectively).

CONCLUSIONS

A narrow A-P thoracic diameter is strongly associated with MAD presence and is a major determinant of the impairment in myocardial strain parameters in MAD patients, in both longitudinal and circumferential directions.

Recommendations for the Use of Echocardiography in the Evaluation of Rheumatic Heart Disease: A Report from the American Society of Echocardiography

Acute rheumatic fever and its chronic sequela, rheumatic heart disease (RHD), pose major health problems globally, and remain the most common cardiovascular disease in children and young people worldwide. Echocardiography is the most important diagnostic tool in recognizing this preventable and treatable disease and plays an invaluable role in detecting the presence of subclinical disease needing prompt therapy or follow-up assessment. This document provides recommendations for the comprehensive use of echocardiography in the diagnosis and therapeutic intervention of RHD. Echocardiographic diagnosis of RHD is made when typical findings of valvular and subvalvular abnormalities are seen, including commissural fusion, leaflet thickening, and restricted leaflet mobility, with varying degrees of calcification. The mitral valve is predominantly affected, most often leading to mitral stenosis. Mixed valve disease and associated cardiopulmonary pathology are common. The severity of valvular lesions and hemodynamic effects on the cardiac chambers and pulmonary artery pressures should be rigorously examined. It is essential to take advantage of all available modalities of echocardiography to obtain accurate anatomic and hemodynamic details of the affected valve lesion(s) for diagnostic and strategic pre-treatment planning. Intraprocedural echocardiographic guidance is critical during catheter-based or surgical treatment of RHD, as is echocardiographic surveillance for post-intervention complications or disease progression. The role of echocardiography is indispensable in the entire spectrum of RHD management.

Incremental Prognostic Value of Left Ventricular Longitudinal Strain Over Ejection Fraction in Coronary Artery Bypass Grafting

OBJECTIVES

To evaluate the incremental prognostic value of longitudinal strain over left ventricular ejection fraction (LVEF) after coronary artery bypass grafting (CABG).

DESIGN

Retrospective cohort study.

SETTING

Single tertiary-care center.

PARTICIPANTS

Patients underwent isolated CABG between January 2014 and December 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 999 patients (median age, 65 years, 23.5% female) categorized into 3 groups according to their left ventricular (LV) systolic function status: pEF/pS (preserved LVEF and preserved longitudinal strain, n = 490), pEF/iS (preserved LVEF and impaired longitudinal strain, n = 186), and rEF (reduced LVEF, n = 323). During a median follow-up of 2.7 years, 86 (8.6%) patients had died. The 5-year survival significantly differed in patients with preserved LVEF according to the strain status (pEF/pS v pEF/iS, 90.0% v 84.6%; p = 0.002). After adjusting for potential confounders, the pEF/iS group (adjusted hazard ratio [HR], 2.17; 95% CI, 1.10-4.28; p = 0.03) and the rEF group (adjusted HR, 2.96; 95% CI, 1.46-6.00; p = 0.003) had significantly higher risks for all-cause death compared with the pEF/pS group. The addition of longitudinal strain to LVEF in the prediction model significantly improved its performance (global chi-squared, 105.2 v 110.2; p = 0.03).

CONCLUSIONS

Left ventricular longitudinal strain could differentiate the prognosis after CABG in patients with preserved LVEF and provide significant incremental prognostic value to LVEF.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The basic heart anatomy and physiology from the cardiologist's perspective: Toward a better understanding of left ventricular mechanics, systolic, and diastolic function

A comprehensive understanding of the cardiac structure-function relationship is essential for proper clinical cardiac imaging. This review summarizes the basic heart anatomy and physiology from the perspective of a heart imager focused on myocardial mechanics. The main issues analyzed are the left ventricular (LV) architecture, the LV myocardial deformation through the cardiac cycle, the LV diastolic function basic parameters and the basic parameters of the LV deformation used in clinical practice for the LV function assessment.

Aortic Stenosis: New Insights in Diagnosis, Treatment, and Prevention

Aortic stenosis (AS) is one of the most common valvular heart diseases and the number of patients with AS is expected to increase globally as the older population is growing fast. Since the majority of patients are elderly, AS is no longer a simple valvular heart disease of left ventricular outflow obstruction but is accompanied by other cardiac and comorbid conditions. Because of the significant variations of the disease, identifying patients at high risk and even earlier detection of patients with AS before developing symptomatic severe AS is becoming increasingly important. With the proven of efficacy and safety of transcatheter aortic valve replacement (TAVR) in the severe AS population, there is a growing interest in applying TAVR in those with less than severe AS. A medical therapy to reduce or prevent the progression in AS is actively investigated by several randomized control trials. In this review, we will summarize the most recent findings in AS and discuss potential future management strategies of patients with AS.

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.

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.

Regional longitudinal strain patterns according to left ventricular hypertrophy in the general population

AIMS

A pattern of reduced basal longitudinal strain (BLS) is often observed with left ventricular (LV) hypertrophy (LVH). Whether this pattern is associated with poor outcome is unclear. We aimed to evaluate the prognostic value of regional longitudinal strain according to LV geometry.

METHODS AND RESULTS

We investigated participants in the 4th Copenhagen City Heart Study who had an echocardiogram with speckle tracking performed. Participants were stratified according to the presence of LVH (LV mass index ≥116 g/m2 for men and ≥96 g/m2 for women). The outcome was major adverse cardiovascular events (MACE) defined as a composite of myocardial infarction, heart failure, and/or cardiovascular death. The study population consisted of 1090 participants. Mean LVEF was 60% and 160 (15%) had LVH. During a median follow-up of 14.7 years, there were 137 events. Both BLS and midventricular strain, but not apical strain, became incrementally impaired in the spectrum from normal to hypertensives subjects without LVH, and to participants with hypertension and LVH. After multivariable adjustment, BLS and midventricular strain were independently associated with MACE in participants with LVH (BLS: HR 1.08, 95% CI 1.00-1.17, P = 0.041; midventricular strain: HR 1.10, 95% CI 1.00-1.21, P = 0.041) but not in participants without LVH (BLS: HR 0.96, 95% CI 0.90-1.01, P = 0.13; midventricular strain: HR 0.97, 95% CI 0.91-1.03, P = 0.36).

CONCLUSION

BLS and midventricular strain, but not apical strain, become incrementally impaired in the spectrum from normal geometry to LVH, and are independently associated with MACE in participants with LVH.

Prognostic implications of impaired longitudinal left ventricular systolic function assessed by tissue Doppler imaging prior to transcatheter aortic valve implantation for severe aortic stenosis

Change in longitudinal left ventricular (LV) systolic function serves as an early marker of the deleterious effect of aortic stenosis (AS) and other cardiac comorbidities on cardiac function. We explored the prognostic value of tissue Doppler imaging (TDI)-derived longitudinal LV systolic function, defined by the peak systolic average of lateral and septal mitral annular velocities (average S') among symptomatic patients with severe AS undergoing transcatheter aortic valve implantation (TAVI). 297 consecutive patients with severe AS undergoing TAVI at three european centers with available average S' at preprocedural echocardiography were retrospectively included. The primary endpoint was the Kaplan Meier estimate of all-cause mortality. After a median 18 months (IQR 12-18) follow-up, 36 (12.1%) patients had died. Average S' was associated with all-cause mortality (per 1 cm/sec decrease: HR 1.29, 95%CI 1.03-1.60, p = 0.025), the cut-off of 6.5 cm/sec being the most accurate. Patients with average S' < 6.5 cm/sec (55.2%) presented characteristics of more advanced LV remodeling and functional impairment along with higher burden of cardiac comorbidities, and experienced higher all-cause mortality (17.6% vs. 7.5%, p = 0.007), also when adjusted for in-study outcome predictors (adj-HR: 2.69, 95%CI 1.22-5.93, p = 0.014). Results were consistent among patients with preserved ejection fraction, normal-flow AS, high-gradient AS and in those without LV hypertrophy. Longitudinal LV systolic function assessed by average S' is independently associated with long-term all-cause mortality among TAVI patients. An average S' below 6.5 cm/sec best defines clinically meaningful reduced longitudinal systolic function and may aid clinical risk stratification in these patients.

Prognostic Value of Global Longitudinal Strain in Asymptomatic Aortic Stenosis: A Systematic Review and Meta-Analysis

Backgrounds

The presence of impaired global longitudinal strain (GLS) may be a valuable bio-marker in the early diagnosis for left ventricle (LV) impairment, which would help scrutinize asymptomatic aortic stenosis (AS) patients with high risk of adverse outcomes, such as major adverse cardiovascular events (MACE).

Methods

The study was prospectively registered in PROPSERO (CRD 42021223472). Databases, such as Pubmed, Embase, Cochrane Library, Web of science, and Scopus were searched for studies evaluating the impact of impaired GLS on MACE, all-cause mortality, and aortic valve replacement (AVR) in asymptomatic AS. Hazard ratios (HRs) with 95% CIs were calculated with meta-analysis for binary variants. Meta-regression, subgroup analysis, and sensitivity analyses were applied as needed to explore the heterogeneity.

Results

Eventually, a total of nine studies reporting 1,512 patients were enrolled. Compared with the normal GLS group, impaired GLS significantly increased MACE (HR = 1.20, 95% CI: 1.10–1.30, I² = 79%) with evident heterogeneity, all-cause mortality (HR = 1.42, 95% CI: 1.24–1.63), and AVR (HR = 1.17, 95% CI: 1.07–1.28). Subgroup analyses stratified by left ventricular ejection fraction (LVEF) > 50% or LVEF without precise cut-off point found that compared with the normal GLS group, impaired GLS remarkably increased MACE both in two subgroups (LVEF > 50%: HR: 1.22, 95% CI: 1.05–1.50; LVEF without cutpoint: HR: 1.25, 95% CI: 1.05–1.50). The results stratified by AS severity (mild/moderate and severe) or follow-up time resembled those stratified by LVEF. In addition, when subgroup analysis was stratified by mean aortic valve pressure gradient (MG ≥ 40 mm Hg and MG <40 mm Hg), compared with normal GLS, impaired GLS significantly increased MACE both in two subgroups (MG ≥ 40 mm Hg: HR: 3.41, 95% CI: 1.64–7.09; MG below 40 mm Hg: HR: 3.17, 95% CI: 1.87–5.38). Moreover, the effect sizes here were substantially higher than those in the former two stratified factors.

Conclusions

The presence of impaired GLS substantially worsens the outcomes for adverse cardiovascular events in asymptomatic patients with AS regardless of LVEF or AS severity or follow-up time or mean aortic valve pressure gradient, which highlights the importance of incorporating impaired GLS into risk algorithms in asymptomatic AS.

Systematic Review Registration

PROSPERO (registration number: CRD42021223472).

Assessment of diastolic function in aortic stenosis: A comparison between 2009 and 2016 guidelines

AIMS

New diastolic dysfunction (DD) guidelines were introduced in 2016 to replace the 2009 guidelines, but have not yet been evaluated in aortic stenosis (AS). We aimed to compare the 2009 and 2016 DD guidelines in severe AS patients in terms of association with left ventricular (LV) and left atrial (LA) remodeling, with pulmonary capillary wedge pressure (PCWP) at rest and exercise, and with prognosis.

METHODS AND RESULTS

We included 212 patients with severe AS (112 undergoing AVR, 100 asymptomatic). Echocardiography, magnetic resonance imaging, and brain natriuretic peptides (BNP) were performed/measured. Thirty-nine asymptomatic patients had PCWP measured during rest and maximal exertion. Asymptomatic patients were followed for 3.1 years for the combined endpoint of death, AVR or admission with heart failure. The 2009 and 2016 DD guidelines agreed poorly with each other (Cohens' κ = .15). 2009 guidelines showed many ambiguous DD findings. With the 2016 guidelines, 20% of patients had indeterminate DD. DD grade 2 according to 2016 guidelines showed stronger association with symptom status, BNP, global longitudinal strain (GLS) and peak exercise PCWP than 2009 guidelines. For indeterminate DD patients according to 2009 guidelines, GLS above the median was associated with event-free survival (HR .11 (95% CI .02-.53)). For neither guideline was DD associated with the combined endpoint in asymptomatic patients.

CONCLUSION

The 2016 guidelines show a stronger association with BNP, GLS, and exercise PCWP than the 2009 guidelines. The 2016 guidelines result in 20% of patients with indeterminate DD; however, these patients may possibly be stratified according to GLS.

Does chest wall conformation influence myocardial strain parameters in infants with pectus excavatum?

PURPOSE

To investigate the possible influence of chest wall conformation on myocardial strain parameters in a consecutive population of infants with pectus excavatum (PE), noninvasively assessed by modified Haller index (MHI).

METHODS

Sixteen consecutive PE infants (MHI >2.5) and 44 infants with normal chest shape (MHI ≤2.5) entered in this prospective case-control study. All infants underwent evaluation by neonatologist, transthoracic echocardiography implemented with two-dimensional speckle tracking echocardiography (2D-STE) analysis of both ventricles and MHI assessment (ratio of chest transverse diameter over the distance between sternum and spine), at two time points: within 3 days and at about 40 days of life.

RESULTS

At 2.1 ± 1 days of life, compared to controls (MHI = 2.01 ± 0.2), PE infants (MHI = 2.76 ± 0.2) were diagnosed with significantly smaller cardiac chambers dimensions. Biventricular contractile function and hemodynamics were similar in both groups of infants. Left ventricular (LV) global longitudinal strain (GLS) (-16.0 ± 2.8 vs. -21.7 ± 2.2%), LV-global circumferential strain (GCS) (-16.3 ± 2.7 vs. -24.0 ± 5.2%), LV-global radial strain (GRS) (24.2 ± 3.0 vs. 31.5 ± 6.3%), and right ventricular free wall longitudinal strain (RVFWLS) (-16.0 ± 3.2 vs. -22.3 ± 4.4%) were significantly reduced in PE infants versus controls (all p < 0.001). A strong inverse correlation between MHI and the following parameters: LV-GLS (r = -0.92), LV-GCS (r = -0.88), LV-GRS (r = -0.87), and RVFWLS (r = -0.88), was demonstrated in PE infants, but not in controls, in perinatal period (all p < 0.001). Analogous results were obtained at 36.8 ± 5.2 days after birth.

CONCLUSIONS

Abnormal chest anatomy progressively impairs myocardial strain parameters in PE infants. This impairment might reflect intraventricular dyssynchrony due to compressive phenomena rather than intrinsic myocardial dysfunction.

Chest conformation spuriously influences strain parameters of myocardial contractile function in healthy pregnant women

AIMS

Left ventricular (LV) contractility during noncomplicated pregnancy has been previously investigated by two-dimensional speckle-tracking echocardiography (2D-STE), with conflicting results. Chest abnormalities might affect myocardial strain parameters, yet this issue has not been previously investigated during pregnancy. We evaluated the influence of chest conformation on myocardial strain parameters in healthy pregnant women.

METHODS

Between October 2019 and February 2020, 50 healthy pregnant women (32.3 ± 4.0 years old) were consecutively studied. They underwent obstetric visit, assessment of chest shape by modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) and transthoracic echocardiography implemented with 2D-STE analysis of all myocardial strain parameters in the first trimester (12-14 weeks), third trimester (36-38 weeks) and 6-9 weeks after delivery.

RESULTS

LV ejection fraction remained substantially unchanged (P = 0.13), while on the average all myocardial strain parameters showed a small but significant decrease during pregnancy, and recovered postpartum (all P < 0.001). Women with concave-shaped chest wall (MHI > 2.5, n = 29), and those with normal chest conformation (MHI ≤ 2.5, n = 21) were then separately analyzed. Pregnant women with MHI above 2.5, but not those with MHI 2.5 or less, showed a progressive but reversible decrease in all myocardial strain parameters (all P < 0.001). MHI was strongly correlated with LV global longitudinal strain (r = -0.87) and LV global circumferential strain (r = -0.83) in the third trimester of pregnancy.

CONCLUSION

Myocardial strain impairment during healthy pregnancy may not reflect intrinsic myocardial dysfunction but rather intraventricular dyssynchrony related to a narrow antero-posterior chest diameter and rise in the diaphragm, with consequent extrinsic myocardial compression.

Global longitudinal strain in heart transplantation recipients using different vendors: reliability and validity in a tertiary hospital in Colombia

Global Longitudinal Strain (GLS) is a useful tool to follow-up heart transplant (HT) recipients. Important inter-vendor variability of GLS measurements has been reported in healthy subjects and different conditions, but there is still limited evidence among HT patients. We assessed the reliability and validity of GLS using two vendors (General Electric and Philips) in a group of consecutive and stable adult HT recipients. Patients underwent two concurrent GLS analyses during their echocardiographic follow-up. We evaluated GLS inter-vendor reliability using Bland-Altman's limits of agreement (LOA) plots, computing its coverage probability (CP) and the intraclass correlation coefficient (ICC). Validity was assessed though receiver operating characteristics (ROC) curves, predictive values, sensitivity and specificity of GLS for each vendor to detect a normal left ventricle function. 78 pairs of GLS studies in 53 stable HT patients were analyzed. We observed a modest inter-vendor reliability with a broad LOA (less than 50% of values falling out our CP of 2% and an ICC of 0.49). ROC analyses (areas under the curve of 0.824 Vs. 0.631, p < 0.05) and diagnosis test indices (Sensitivity of 0.73 Vs. 0.64; and Specificity of 0.79 Vs. 0.50) favored GE over Philips. Inter-vendor variability for GLS analysis exceeded clinically acceptable limits in HT recipients. GLS from GE software seemed to show higher validity as compared to Philips'. The present study provides evidence to consider caution for the interpretation of GLS for clinical management in the follow-up of HT patients, especially when GLS is measured by different vendors.

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.

Left ventricular twist predicts mortality in severe aortic stenosis

OBJECTIVE

Left ventricular (LV) twist is a major component of ventricular mechanics reflecting the helical orientation of cardiac fibres and compensating for afterload mismatch. However, it is not known whether it determines outcome after transcatheter aortic valve implantation (TAVI). This study sought to investigate TAVI-induced short-term changes of LV twist and to define its role in outcome prediction.

METHODS

A total of 146 patients (median age 81.78 years, 50.7% male) undergoing TAVI for severe aortic stenosis were included. LV rotation and twist were determined by speckle tracking echocardiography within 3 months before and 2 weeks after TAVI. All-cause mortality at 2 years was defined as primary end point.

RESULTS

Patients who survived exhibited a higher apical peak systolic rotation (APSR) (p<0.001), twist (p=0.003) and torsion (p=0.019) pre-TAVI compared with those who died (n=22). Within 2 weeks after TAVI, APSR, twist and torsion decreased in patients who survived (all p<0.001), while no change occurred in those who died. Cox regression analysis showed an association of pre-TAVI APSR (HR 0.92, p=0.010), twist (HR 0.93, p=0.018) and torsion (HR 0.68, p=0.040) with all-cause mortality and an even stronger association of the respective changes after TAVI (∆APSR: HR 1.15, p<0.001; ∆twist: HR 1.14, p<0.001; ∆torsion: HR 2.53, p<0.001). All the parameters determined outcome independently of global longitudinal strain (GLS) and LV ejection fraction (LVEF).

CONCLUSION

APSR, twist and torsion pre-TAVI as well as their change within 2 weeks after TAVI predict 2-year all-cause mortality after TAVI, adding incremental prognostic value to LVEF and GLS.

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.

The Prognostic Value of Left Atrial Global Longitudinal Strain and Left Atrial Phasic Volumes in Patients Undergoing Transcatheter Valve Implantation for Severe Aortic Stenosis

INTRODUCTION

The changes and the prognostic implications of left atrial (LA) volumes (LAV), LA function, and vascular load in patients undergoing transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS) are less known.

METHODS

We enrolled 150 symptomatic patients (mean age 82 ± 8 years, 58% female, and pre-TAVI aortic valve area 0.40 ± 0.19 cm/m2) with severe AS who underwent 2D transthoracic echocardiography and 2D speckle tracking echocardiography at average 21 ± 35 days before and 171 ± 217 days after TAVI. The end point was a composite of new onset of atrial fibrillation, hospitalization for heart failure and all-cause death (major adverse cardiac events [MACE]).

RESULTS

After TAVI, indexed maximal LA volume and minimum volume of the LA decreased by 2.1 ± 10 mL/m2 and 1.6 ± 7 mL/m2 (p = 0.032 and p = 0.011, respectively), LA function index increased by 6.8 ± 11 units (p < 0.001), and LA stiffness decreased by 0.38 ± 2.0 (p = 0.05). No other changes in the LA phasic volumes, emptying fractions, and vascular load were noted. Post-TAVI, both left atrial and ventricular global peak longitudinal strain improved by about 6% (p = 0.01 and 0.02, respectively). MACE was reached by 37 (25%) patients after a median follow-up period of 172 days (interquartile range, 20-727). In multivariable models, MACE was associated with both pre- and post-TAVI LA global peak longitudinal strain (hazard ratio [HR] 0.75, CI 0.59-0.97; and HR 0.77, CI 0.60-1.00, per 5 percentage point units, respectively), pre-TAVI LV global endocardial longitudinal strain (HR 1.37, CI 1.02-1.83 per 5 percentage point units), and with most of the LA phasic volumes.

CONCLUSION

Within 6 months after TAVI, there is reverse LA remodeling and an improvement in LA reservoir function. Pre- and post-TAVI indices of LA function and volume remain independently associated with MACE. Larger studies enrolling a greater diversity of patients may provide sufficient evidence for the utilization of these imaging biomarkers in clinical practice.

Left Ventricular Longitudinal Strain in Characterization and Outcome Assessment of Mixed Aortic Valve Disease Phenotypes

OBJECTIVES

The aims of this study were to characterize the interplay between mixed aortic valve disease (MAVD) phenotypes (defined by concomitant severities of aortic stenosis and aortic regurgitation) and left ventricular global longitudinal strain (LV-GLS), and to assess the prognostic utility of LV-GLS in MAVD.

BACKGROUND

Little is known about the way LV-GLS separates MAVD phenotypes and if it is associated with their outcomes.

METHODS

This observational cohort study evaluated 783 consecutive adult patients with left ventricular ejection fraction ≥50% and MAVD, which was defined as coexisting with at least moderate aortic stenosis and at least moderate aortic regurgitation. We measured the conventional echocardiographic variables and average LV-GLS from apical long, 2- and 4-chamber views. The primary endpoint was all-cause mortality.

RESULTS

Mean age of patients was 69 ± 15 years, and 58% were male. Mean LV-GLS was -14.7 ± 2.9%. In total, 458 patients (59%) underwent aortic valve replacement at a median period of 50 days (25th to 75th percentile range: 6 to 560 days). During a median follow-up period of 5.6 years (25th to 75th percentile range: 1.8 to 9.4 years), 391 patients (50%) died. When stratified patients into tertiles according to LV-GLS values, patients with worse LV-GLS had worse outcomes (p < 0.001). LV-GLS was independently associated with mortality (hazard ratio: 1.09; 95% confidential intervals: 1.04 to 1.14; p < 0.001), with the relationship between LV-GLS and mortality being linear.

CONCLUSIONS

LV-GLS is associated with all-cause mortality. LV-GLS may be useful for risk stratification in patients with MAVD.

Left ventricular reverse remodeling and function by strain analysis in aortic stenosis: A CMR analysis of the EPICHEART study

INTRODUCTION AND OBJECTIVES

In severe aortic stenosis (AS), the impact of aortic valve replacement (AVR) on left ventricular (LV) systolic function assessed by strain and measured by echocardiography or cardiac magnetic resonance (CMR) has been controversial. We aimed to investigate LV systolic myocardial function changes six months after AVR using global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain derived from CMR imaging.

METHODS

We included 39 severe AS patients (69.3±7.8 years; 61.5% male) with preserved LV ejection fraction (LVEF) who were recruited as part of the EPICHEART study and underwent successful AVR (aortic valvular area: 0.8 cm² (IQR: 0.2) pre- to 1.8 cm² (IQR:0.5) post-AVR). Structural and functional parameters were assessed at baseline and six months after AVR, including LV GRS, GCS and GLS analysis by CMR, using cine short-axial and two-, three-, and four-chamber long-axial view. Comparison between baseline and postoperative LV remodeling was performed using Student t-test and Wilcoxon test.

RESULTS

At six-month follow-up, LV mass, end-diastolic and end-systolic volumes, stroke volume, cardiac output, lateral E/e', tricuspid annular plane systolic excursion, right ventricular (RV) S wave velocity, GLS [-15.6% (IQR: 4.39) to -13.7% (IQR: 4.62)] and GCS [-17.8±3.58% to -16.1±2.94%] reduced significantly, while LVEF and GRS remained unchanged and lateral e' velocity increased.

CONCLUSIONS

Despite favorable reverse LV structural and diastolic functional remodeling six months following AVR, GLS and GCS assessed by CMR reduced compared to baseline, LVEF remained unchanged. The clinical utility and timing of assessment of postoperative strain changes as a marker of systolic function progression needs further research.

Circulatory efficiency in patients with severe aortic valve stenosis before and after aortic valve replacement

BACKGROUND

Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quantify left ventricular (LV) efficiency in patients with severe AS before and after surgical AVR.

METHODS

Circulatory efficiency was computed from cardiovascular magnetic resonance (CMR) imaging derived volumetric data, echocardiographic and clinical data in patients with severe AS (n = 41) before and 4 months after AVR and in age and sex-matched healthy subjects (n = 10).

RESULTS

In patients with AS circulatory efficiency was significantly decreased compared to healthy subjects (9 ± 3% vs 12 ± 2%; p = 0.004). There were significant negative correlations between circulatory efficiency and LV myocardial mass (r = - 0.591, p < 0.001), myocardial fibrosis volume (r = - 0.427, p = 0.015), end systolic volume (r = - 0.609, p < 0.001) and NT-proBNP (r = - 0.444, p = 0.009) and significant positive correlation between circulatory efficiency and LV ejection fraction (r = 0.704, p < 0.001). After AVR, circulatory efficiency increased significantly in the total cohort (9 ± 3 vs 13 ± 5%; p < 0.001). However, in 10/41 (24%) patients, circulatory efficiency remained below 10% after AVR and, thus, did not restore to normal values. These patients also showed less reduction in myocardial fibrosis volume compared to patients with restored circulatory efficiency after AVR.

CONCLUSION

In our cohort, circulatory efficiency is reduced in patients with severe AS. In 76% of cases, AVR leads to normalization of circulatory efficiency. However, in 24% of patients, circulatory efficiency remained below normal values even after successful AVR. In these patients also less regression of myocardial fibrosis volume was seen. Trial Registration clinicaltrials.gov NCT03172338, June 1, 2017, retrospectively registered.

Impact of surgical aortic valve replacement on global and regional longitudinal strain across four flow gradient patterns of severe aortic stenosis

To evaluate the impact of surgical aortic valve replacement (SAVR) on global (GLS) and regional longitudinal strain (RLS) across four flow-gradient patterns of severe aortic stenosis (AS) 3 months after surgery. A total of 103 patients with severe AS (aortic valve area < 1.0 cm²) were examined by speckle tracking echocardiography the day before SAVR and at 3-months follow-up. Patients were stratified into four flow-gradient patterns by stroke volume index (>35 mL/m² vs. ≤35 mL/m²) and mean transaortic gradients (>40 mmhg vs. ≤40 mmhg): normal-flow, high gradient (NF/HG); low-flow, high gradient (LF/HG); normal-flow, low gradient (NF/LG); low-flow, low gradient (LF/LG). Strain analysis comprised GLS and RLS at a basal (BLS), mid-ventricular (MLS) and apical level (ALS). Patients with high gradients improved GLS (NF/HG: 16.1 ± 3.5 % vs. 17.3 ± 3.4 %, p = 0.03 and LF/HG: 15.4 ± 3.6 % vs. 16.9 ± 3.1 %, p = 0.03), BLS (NF/HG: 12.7 ± 3.1 % vs. 14.2 ± 3.1 %, p = 0.003 and LF/HG: 11.4 ± 3.2 % vs. 13.8 ± 2.7 %, p = 0.005) and MLS (NF/HG: 15.4 ± 3.3 % vs. 16.5 ± 3.3 %, p = 0.04 and LF/HG: 14.5 ± 3.1 % vs. 16.2 ± 2.7 %, p = 0.01) whereas patients with low gradients showed no improvements three months after SAVR. ALS did not change significantly in any group. Patients with high gradients demonstrated a reduction in left ventricular (LV) mass index (p < 0.001) and N-terminal pro-Brain Natriuretic Peptide levels (p < 0.001) following SAVR in contrast to patients with low gradients. Patients with high gradient severe AS improve GLS and RLS three months after SAVR with concomitant reduction of LV mass and neurohormonal activation whereas patients with low gradients do not improve longitudinal strain, LV mass or neurohormonal activation.

Asymptomatic Left Ventricular Dysfunction: Is There a Role for Screening in General Population?

Stage A and B heart failure (HF) include asymptomatic patients without and with structural cardiac disorder, respectively. Asymptomatic left ventricular (LV) dysfunction represents an early stage of HF that should be recognized to prevent overt HF development. Echocardiography plays a pivotal role in assessment of cardiac structure and function and represents the ideal imaging technique for screening in the general population, thanks to its availability, feasibility, and low cost. Traditional echocardiography, with LV systolic and diastolic function and cardiac remodeling assessment, is usually performed. Development of new technologies may offer additional information and insights in detection of early LV dysfunction.

Right Ventricular Longitudinal Strain Predicts Low-Cardiac- Output Syndrome After Surgical Aortic Valve Replacement in Patients With Preserved and Mid-range Ejection Fraction

OBJECTIVES

The aim of this study was to analyze whether right ventricular free wall longitudinal strain (RVFWSL) could be a predictor of low-cardiac-output syndrome (LCOS) after surgical aortic valve replacement (SAVR) in patients with left ventricular ejection fraction ≥40%.

DESIGN

Prospective, observational study.

SETTING

The study was conducted at a third level university hospital.

PARTICIPANTS

The study comprised 75 patients with severe aortic stenosis and LVEF ≥40% who underwent SAVR. The primary outcome was the occurrence of LCOS, and secondary outcomes were in-hospital mortality, hospital stay, or vasoplegic syndrome.

INTERVENTIONS

Patients were divided into two groups (LCOS and no LCOS), and RVFWSL was analyzed to determine whether it is a predictor for LCOS. In addition, a receiver operating characteristic curve also was constructed, and the best cutoff value to predict LCOS was found. Furthermore, the reproducibility of RVFWSL measurements was evaluated.

MEASUREMENT AND MAIN RESULTS

The incidence of LCOS was 20% in the present study's cohort. After multivariate analysis, cross-clamp time (odds ratio 1.06, 95% confidence interval 1.02-1.11; p = 0.002) and RVFWSL (odds ratio 1.41, 95% confidence interval 1.07-1.87; p = 0.015) were the only predictors of LCOS. However, RVFWSL did not show association with secondary outcomes (p > 0.05 for all). The area under the curve of RVFWSL to predict LCOS was 0.75, and the best cutoff value was -17.3%, with a sensitivity of 86.7% and specificity of 61.7%.

CONCLUSIONS

RVFWSL seems to be a predictor of LCOS in patients with severe aortic stenosis and LVEF ≥40% undergoing SAVR. RVFWSL less than -17.3% may identify patients at increased risk for LCOS.

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.

False-positive electrocardiographic changes during exercise test in a patient with pectus excavatum

Exercise-induced ST-segment changes simulating myocardial ischemia have been described in otherwise normal subjects during hyperventilation. We present the case of a 60-year-old man with pectus excavatum showing significant exercise-induced "pseudo-ischaemic" ST-segment changes with neither coronary artery disease nor anxiety-induced hyperventilation. We found no report of the possible causative role of a narrow antero-posterior chest diameter in inducing "pseudo-ischaemic" ST-segment changes during exercise stress test in the literature.