Prognostic Implications of Left Atrial Stiffness Index in Heart Failure Patients With Preserved Ejection Fraction

Early left atrial reverse remodelling in patients with hypertrophic obstructive cardiomyopathy receiving transapical beating-heart septal myectomy

OBJECTIVES

This study aims to investigate the short-term effects of transapical beating-heart septal myectomy (TA-BSM) on left atrial (LA) anatomy and function and its association with clinical indicators in patients with hypertrophic obstructive cardiomyopathy (HOCM).

METHODS

A total of 105 HOCM patients who received TA-BSM were included. Clinical and comprehensive echocardiographic data were obtained before surgery, at discharge, and 3 months after myectomy. LA reverse remodelling was defined as LA maximum volume index (LAVI) ≤34 ml/m2 and a change of ≥10%.

RESULTS

At 3 months after TA-BSM, New York Heart Association (NYHA) functional class and 6-min walking test were significantly improved, N-terminal pro-B-type natriuretic peptide (NT-proBNP) decreased, left ventricular outflow tract (LVOT) peak gradient and mitral regurgitation were significantly reduced. LAVI decreased in 76%, with a median change of 20%, and the criteria for LA reverse remodelling were met in 48%. LA strain parameters were improved at 3 months after TA-BSM. Moreover, left ventricular (LV) diastolic function was significantly improved, but LV global longitudinal strain was not significantly changed at 3 months after operation. Improvement in LVOT peak gradient, LAVI, LA reservoir strain (LASr) and conduit strain (LAScd) were associated with reduction in NT-proBNP.

CONCLUSIONS

Along with effectively relieving the obstruction of the LVOT and mitral regurgitation, TA-BSM could significantly improve LA size and function during the short-term follow-up for HOCM patients. The indicators of LA reverse remodelling were associated with reduction in a biomarker of myocardial wall stress, indicating the early recovery of LV relaxation and clinical status for patients.

Echocardiographic predictors of cardiovascular outcome in heart failure with preserved ejection fraction

AIMS

The optimal echocardiographic predictors of cardiovascular outcome in heart failure (HF) with preserved ejection fraction (HFpEF) are unknown. We aimed to identify independent echocardiographic predictors of cardiovascular outcome in patients with HFpEF.

METHODS AND RESULTS

Systematic literature search of three electronic databases was conducted from date of inception until November 2022. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for echocardiographic variables from multivariate prediction models for the composite primary endpoint of cardiovascular death and HF hospitalization were pooled using a random effects meta-analysis. Specific subgroup analyses were conducted for studies that enrolled patients with acute versus chronic HF, and for those studies that included E/e', pulmonary artery systolic pressure (PASP), renal function, natriuretic peptides and diuretic use in multivariate models. Forty-six studies totalling 20 056 patients with HFpEF were included. Three echocardiographic parameters emerged as independent predictors in all subgroup analyses: decreased left ventricular (LV) global longitudinal strain (HR 1.24, 95% CI 1.10-1.39 per 5% decrease), decreased left atrial (LA) reservoir strain (HR 1.30, 95% CI 1.13-1.1.50 per 5% decrease) and lower tricuspid annular plane systolic excursion (TAPSE) to PASP ratio (HR 1.17, 95% CI 1.07-1.25 per 0.1 unit decrease). Other independent echocardiographic predictors of the primary endpoint were a higher E/e', moderate to severe tricuspid regurgitation, LV mass index and LA ejection fraction, although these variables were less robust.

CONCLUSIONS

Impaired LV global longitudinal strain, lower LA reservoir strain and lower TAPSE/PASP ratio predict cardiovascular death and HF hospitalization in HFpEF and are independent of filling pressures, clinical characteristics and natriuretic peptides. These echocardiographic parameters reflect key functional changes in HFpEF, and should be incorporated in future prospective risk prediction models.

Sex differences in left atrial volumes, mechanics, and stiffness in primary mitral regurgitation-a combined 2D and 3D echocardiographic study

AIMS

Mitral regurgitation (MR) causes left atrial (LA) enlargement and impaired reservoir function. We assessed whether changes in LA size, strain, and stiffness in significant (moderate or greater) primary MR are sex-specific.

METHODS AND RESULTS

In the 3D Echocardiography and Cardiovascular Prognosis in Mitral Regurgitation study, 111 patients with primary MR were prospectively investigated with 2D and 3D echocardiography. MR was severe if the 3D regurgitant fraction was ≥50%. LA size was assessed by maximum, minimum, and pre-A 3D volume (LAV), mechanics by peak reservoir (LASr) and contractile strain, and stiffness by the ratio: mitral peak E-wave divided by the annular e' velocity (E/e')/LASr. Women were older, had higher heart rate, and lower body mass index and MR regurgitant volumes (P < 0.05). 3D LAV indexed for body surface area and LA contractile strain did not differ by sex, while LASr was lower (22.2 vs. 25.0%) and LA stiffness higher in women (0.56 vs. 0.44) (P < 0.05). In linear regression analysis, female sex was associated with higher LA stiffness independent of age, minimum LAV, left ventricular global longitudinal strain, diabetes, and coronary artery disease (R2 = 0.56, all P < 0.05). In logistic regression analysis, women had a four-fold (95% CI 1.2-13.1, P = 0.02) higher adjusted risk of increased LA stiffness than men.

CONCLUSION

Women with significant primary MR have more impaired LA reservoir mechanics and increased LA stiffness compared with men despite lower MR regurgitant volumes and similar indexed LA size. The findings reveal sex-specific features of LA remodeling in MR.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04442828.

Structural, Functional, and Electrical Remodeling of the Atria With Reduced Cardiorespiratory Fitness: Implications for AF

BACKGROUND

Reduced cardiorespiratory fitness (CRF) is an independent risk factor for the progression of atrial fibrillation (AF). We hypothesized that reduced CRF is associated with structural, functional, and electrical remodeling of the left atrium.

OBJECTIVES

This study sought to correlate objectively assessed CRF with functional and electrical left atrial (LA) parameters using invasive and noninvasive assessments.

METHODS

Consecutive patients with symptomatic AF undergoing catheter ablation were recruited. CRF was objectively quantified pre-ablation by using cardiopulmonary exercise testing. Using peak oxygen consumption, participants were classified as preserved CRF (>20 mL/kg/min) or reduced CRF (<20 mL/kg/min). LA stiffness was assessed invasively with hemodynamic monitoring and imaging during high-volume LA saline infusion. LA stiffness was calculated as ΔLA diameter/ΔLA pressure over the course of the infusion. LA function was assessed with echocardiographic measures of LA emptying fraction and LA strain. Electrical remodeling was assessed by using high-density electroanatomical maps for LA voltage and conduction.

RESULTS

In total, 100 participants were recruited; 43 had reduced CRF and 57 had preserved CRF. Patients with reduced CRF displayed elevated LA stiffness (P = 0.004), reduced LA emptying fraction (P = 0.006), and reduced LA reservoir strain (P < 0.001). Reduced CRF was also associated with reduced LA voltage (P = 0.039) with greater heterogeneity (P = 0.027) and conduction slowing (P = 0.04) with greater conduction heterogeneity (P = 0.02). On multivariable analysis, peak oxygen consumption was independently associated with LA stiffness (P = 0.003) and LA conduction velocities (P = 0.04).

CONCLUSIONS

Reduced CRF in patients with AF is independently associated with worse LA disease involving functional and electrical changes. Improving CRF may be a target for restoring LA function in AF.

Left Atrial Mechanics Following Preeclamptic Pregnancy

BACKGROUND

Preterm preeclampsia is a pregnancy complication associated with myocardial dysfunction and premature cardiovascular disease morbidity and mortality. Left atrial (LA) strain is a noninvasive index of left ventricular end diastolic pressure and an early marker of heart failure risk. This study aimed to evaluate LA strain during the postpartum period in participants with and without preterm preeclampsia and to assess whether this varied in the presence of hypertension, cardiac dysfunction or both.

METHODS

In this longitudinal cohort study, 321 women from 28 hospitals with preterm preeclampsia (cases) underwent cardiovascular assessment 6 months postpartum. This is a secondary analysis of the PHOEBE study (ISRCTN01879376). An uncomplicated pregnancy control group (n=30) was recruited from a single center for comparison. A full cross-sectional transthoracic echocardiogram was performed, and from these images, the myocardial strain of the left atrium, including reservoir, conduit, and contractile strain, as well as LA stiffness, were calculated.

RESULTS

At 6 months postpartum, compared with controls, prior preeclampsia was associated with a significantly attenuated LA reservoir, conduit, and contractile strain, as well as increased LA stiffness (all P<0.001). LA strain was further reduced in preeclamptic women who had and had not developed hypertension, systolic, or diastolic dysfunction at 6 months postpartum (all P<0.05).

CONCLUSIONS

LA mechanics were significantly attenuated at 6 months postpartum in participants with preterm preeclampsia, whether or not they remained hypertensive or had evidence of ventricular dysfunction. Further studies are needed to determine whether postnatal LA strain may identify women at greater risk for future cardiovascular disease.

The assessment of left ventricular diastolic function: guidance and recommendations from the British Society of Echocardiography

Impairment of left ventricular (LV) diastolic function is common amongst those with left heart disease and is associated with significant morbidity. Given that, in simple terms, the ventricle can only eject the volume with which it fills and that approximately one half of hospitalisations for heart failure (HF) are in those with normal/'preserved' left ventricular ejection fraction (HFpEF) (Bianco et al. in JACC Cardiovasc Imaging. 13:258-271, 2020. 10.1016/j.jcmg.2018.12.035), where abnormalities of ventricular filling are the cause of symptoms, it is clear that the assessment of left ventricular diastolic function (LVDF) is crucial for understanding global cardiac function and for identifying the wider effects of disease processes. Invasive methods of measuring LV relaxation and filling pressures are considered the gold-standard for investigating diastolic function. However, the high temporal resolution of trans-thoracic echocardiography (TTE) with widely validated and reproducible measures available at the patient's bedside and without the need for invasive procedures involving ionising radiation have established echocardiography as the primary imaging modality. The comprehensive assessment of LVDF is therefore a fundamental element of the standard TTE (Robinson et al. in Echo Res Pract7:G59-G93, 2020. 10.1530/ERP-20-0026). However, the echocardiographic assessment of diastolic function is complex. In the broadest and most basic terms, ventricular diastole comprises an early filling phase when blood is drawn, by suction, into the ventricle as it rapidly recoils and lengthens following the preceding systolic contraction and shortening. This is followed in late diastole by distension of the compliant LV when atrial contraction actively contributes to ventricular filling. When LVDF is normal, ventricular filling is achieved at low pressure both at rest and during exertion. However, this basic description merely summarises the complex physiology that enables the diastolic process and defines it according to the mechanical method by which the ventricles fill, overlooking the myocardial function, properties of chamber compliance and pressure differentials that determine the capacity for LV filling. Unlike ventricular systolic function where single parameters are utilised to define myocardial performance (LV ejection fraction (LVEF) and Global Longitudinal Strain (GLS)), the assessment of diastolic function relies on the interpretation of multiple myocardial and blood-flow velocity parameters, along with left atrial (LA) size and function, in order to diagnose the presence and degree of impairment. The echocardiographic assessment of diastolic function is therefore multifaceted and complex, requiring an algorithmic approach that incorporates parameters of myocardial relaxation/recoil, chamber compliance and function under variable loading conditions and the intra-cavity pressures under which these processes occur. This guideline outlines a structured approach to the assessment of diastolic function and includes recommendations for the assessment of LV relaxation and filling pressures. Non-routine echocardiographic measures are described alongside guidance for application in specific circumstances. Provocative methods for revealing increased filling pressure on exertion are described and novel and emerging modalities considered. For rapid access to the core recommendations of the diastolic guideline, a quick-reference guide (additional file 1) accompanies the main guideline document. This describes in very brief detail the diastolic investigation in each patient group and includes all algorithms and core reference tables.

Sudden Cardiac Death Risk Stratification in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) poses a significant clinical challenge, with sudden cardiac death (SCD) emerging as one of the leading causes of mortality. Despite advancements in cardiovascular medicine, predicting and preventing SCD in HFpEF remains complex due to multifactorial pathophysiological mechanisms and patient heterogeneity. Unlike heart failure with reduced ejection fraction, where impaired contractility and ventricular remodeling predominate, HFpEF pathophysiology involves heavy burden of comorbidities such as hypertension, obesity, and diabetes. Diverse mechanisms, including diastolic dysfunction, microvascular abnormalities, and inflammation, also contribute to distinct disease and SCD risk profiles. Various parameters such as clinical factors and electrocardiogram features have been proposed in SCD risk assessment. Advanced imaging modalities and biomarkers offer promise in risk prediction, yet comprehensive risk stratification models specific to HFpEF ar0e lacking. This review offers recent evidence on SCD risk factors and discusses current therapeutic strategies aimed at reducing SCD risk in HFpEF.

Left atrial stiffness is in correlation with left atrial reservoir strain in pediatric patients with mitral regurgitation

BACKGROUND

Left atrial stiffness index (LASI), defined as the ratio of early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e') to peak atrial strain, reflects reduced left atrial (LA) compliance and represents an emerging marker that can be used for noninvasive measurement of fibrosis of LA in patients with mitral regurgitation (MR).

OBJECTIVE

To investigate the impact of chronic MR in children and adolescents on the remodeling and function of the LA, quantified through strain parameters and diastolic function.

METHODS

The study included fifty patients (n= 50) diagnosed with primary and secondary chronic MR lasting at least 5 years. The echocardiographic recordings were performed by a third party, two cardiologists actively engaged in echocardiography on a daily basis.

RESULTS

Older participants had higher values of the LASI (r= 0.467, p= 0.001). Participants with higher LASI values had a smaller LA reservoir (r= 0.784, p= 0.0001) and smaller LA conduit values (r=-0.374, p= 0.00). Participants with higher LASI values had a larger LA diameter (r= 0.444, p-value= 0.001) and higher average E/e' ratio (r= 0.718, p= 0.0001). There was a significant difference (p= 0.04) in the LASI among participants based on the MR jet area (< 20.85% ⩾ 20.85%), LASI was higher in participants with an area greater than 20.85%. Differences in other parameters such as LA reservoir, LA conduit, LA contractile were not statistically significant.

CONCLUSION

Increased LA stiffness is associated with diminished atrial compliance and reservoir capacity, and LASI has a potential to as an early marker for assessing disease severity and progression in pediatric MR.

Incremental diagnostic and prognostic utility of left atrial deformation in heart failure using speckle tracking echocardiography

Left atrium (LA) is a very important component of cardiovascular performance. The assessment of LA function has gathered the interest with expanding research supporting the utility as a biomarker for outcomes in heart failure (HF). Echocardiography is the main imaging modality which helps in a qualitative and quantitative assessment of the LA size and function. Recent advances in probe technology and software analysis have provided a better understanding of LA anatomy, physiology, pathology, and function. A variety of parameters have been defined as markers of LA function but there is no single parameter that best defines LA function. Speckle tracking echocardiography-derived analysis of LA deformation provides a window on all phases of LA function (reservoir, conduit, and booster pump). There is accumulative published data that supported the diagnostic and prognostic values of LA deformation integration during echo assessment of LA in HF. This review article summarized the clinical utility of LA deformation that may help in prediction, diagnosis, categorization, risk stratification, and guiding the proper selection of therapy in HF patients in daily practice.

Evaluation of the relationship between left atrial stiffness, left ventricular stiffness, and left atrioventricular coupling index in type 2 diabetes patients: a speckle tracking echocardiography study

Background

Cardiovascular complications are a leading cause of mortality and disability in individuals with diabetes mellitus (DM). Moreover, DM can directly impact the structure and function of cardiac muscle. We conducted a study to evaluate cardiac stiffness in DM patients in both the left atrium (LA) and left ventricle (LV), as well as to assess the impact of DM on the synchronization of the LA and LV, particularly within the Vietnamese population, utilizing speckle tracking echocardiography (STE).

Methods

We studied 111 research subjects divided into two groups comprising 52 patients with DM and 59 healthy individuals. All the subjects provided relevant clinical information, and echocardiography was performed to assess the indices of LA stiffness, LV stiffness, and left atrioventricular coupling index (LACI).

Results

Our study indicated that DM patients exhibited greater LA and LV stiffness than control patients. The LACI (%) in the DM group was also greater than that in the control group (17.12% ± 6.72% vs. 12.28% ± 3.96%, respectively; p < 0.001). The LACI was positively correlated with the LA and LV stiffness indices. Decreased levels of LV GLS, adjusted for age, sex, blood pressure, and BMI, have emerged as identified risk factors for DM.

Conclusions

LA stiffness, LV stiffness, and the LACI are greater in DM patients than in normal individuals.

Left Atrial Stiffness Increases after Trans-Catheter Atrial Septal Closure

BACKGROUND

Transcatheter atrial septal closures for secundum atrial septal defects (ASD) have demonstrated favorable clinical outcomes. However, the impact of device implantation on the stiffness of the left atrium remains unclear.

METHOD

Patients with secundum ASD undergoing transcatheter closure and follow-up right heart catheterization at six months were included. We investigated the relationship between post-procedural (E/e' ratio)/(LAs strain) ratio, an index of left atrial stiffness, and baseline characteristics, including echocardiographic and hemodynamic parameters.

RESULTS

Forty patients were included (median 69 (56, 75) years, 12 men, and pulmonary systemic flow ratio 2.27 (1.96, 2.86)). Trans-catheter ASD closure was successfully performed without any major complications, accompanying a significant reduction in right ventricular to left ventricular size ratio from 1.04 (0.87, 1.13) to 0.74 (0.66, 0.86) (p < 0.01). The (E/e' ratio)/(LAs strain) ratio was markedly elevated the day after the procedure and was further increased 6 months later (before: 0.25 (0.17, 0.34), 1 day later: 0.34 (0.27, 0.50), 6 months later: 0.43 (0.27, 0.76), p < 0.01). The groups with higher (E/e' ratio)/(LAs strain) ratios at 6 months had significantly more severe heart failure conditions including lower cardiac output and higher plasma B-type natriuretic peptides.

CONCLUSIONS

Patients undergoing transcatheter ASD closure experienced improvement in hemodynamics and clinical symptoms but an elevation in left atrial stiffness post-procedure. The clinical ramifications of this finding, particularly during the longer-term observation period subsequent to ASD closure, warrant further investigation.

Left Atrial Stiffness Index as a Predictor of Effort Intolerance and Hemodynamics Evaluated by Invasive Exercise Stress Testing in Degenerative Mitral Regurgitation

In patients with degenerative mitral regurgitation (DMR), peak oxygen consumption is the significant prognostic factor, and exercise intolerance has been considered a trigger for surgical intervention. The significant mitral regurgitation (MR) induces left atrial (LA) remodeling, but the significance of LA stiffness calculated by the ratio of E/e' to LA reservoir strain in degenerative MR has not been elucidated. A total of 30 patients with asymptomatic or minimally symptomatic grade ≥III + DMR underwent the cardiopulmonary exercising test simultaneously with invasive hemodynamic assessment. LA stiffness index significantly correlated with exercise hemodynamic deterioration, including pulmonary arterial wedge pressure (r = 0.71, p <0.01), systolic pulmonary arterial pressure at peak exercise (r = 0.73, p <0.01), and pulmonary circulatory reserve (mean pulmonary arterial pressure/cardiac output slope, r = 0.45, p = 0.012). Multiple linear regression analysis revealed that the higher LA stiffness index was significantly associated with decreased percent predicted peak oxygen consumption (per 0.1 increase, β -4.0, 95% confidence interval -6.9 to -1.3, p <0.01) independently of MR deterioration during exercise. In conclusion, increased LA stiffness was associated with exercise intolerance through hemodynamic deterioration during exercise in patients with asymptomatic or minimally symptomatic severe DMR.

Atrial Myopathy Quantified by Speckle-tracking Echocardiography in Mice

BACKGROUND

Emerging evidence suggests that atrial myopathy may be the underlying pathophysiology that explains adverse cardiovascular outcomes in heart failure (HF) and atrial fibrillation. Lower left atrial (LA) function (strain) is a key biomarker of atrial myopathy, but murine LA strain has not been described, thus limiting translational investigation. Therefore, the objective of this study was to characterize LA function by speckle-tracking echocardiography in mouse models of atrial myopathy.

METHODS

We used 3 models of atrial myopathy in wild-type male and female C57Bl6/J mice: (1) aged 16 to 17 months, (2) Ang II (angiotensin II) infusion, and (3) high-fat diet+Nω-nitro-L-arginine methyl ester (HF with preserved ejection fraction, HFpEF). LA reservoir, conduit, and contractile strain were measured using speckle-tracking echocardiography from a modified parasternal long-axis window. Left ventricular systolic and diastolic function, and global longitudinal strain were also measured. Transesophageal rapid atrial pacing was used to induce atrial fibrillation.

RESULTS

LA reservoir, conduit, and contractile strain were significantly reduced in aged, Ang II and HFpEF mice compared with young controls. There were no sex-based interactions. Left ventricular diastolic function and global longitudinal strain were lower in aged, Ang II and HFpEF, but left ventricular ejection fraction was unchanged. Atrial fibrillation inducibility was low in young mice (5%), moderately higher in aged mice (20%), and high in Ang II (75%) and HFpEF (83%) mice.

CONCLUSIONS

Using speckle-tracking echocardiography, we observed reduced LA function in established mouse models of atrial myopathy with concurrent atrial fibrillation inducibility, thus providing the field with a timely and clinically relevant platform for understanding the pathophysiology and discovery of novel treatment targets for atrial myopathy.

Echocardiography algorithms to assess high left atrial pressure and grade diastolic function in preterm infants

BACKGROUND

Relaxation, restoring forces, myocardial stiffness and atrial function determine left ventricular (LV) diastolic function. This study aims to provide a comprehensive assessment of diastolic function in preterm infants using conventional echocardiography and speckle tracking imaging and determine the diagnostic accuracy of various algorithms to detect high left atrial pressure (LAP).

METHODS

Preterm infants received an echocardiogram 1 week after birth and diastolic reference values were derived from the outer percentiles of stable preterm infants. Impaired relaxation, LV stiffness and high LAP were defined by using algorithms where at least half of the parameters were outside the normal range. Diastolic function was graded using the 2016 American Society of Echocardiography algorithm and expanded with the EA ratio and left atrial strain. The diagnostic accuracy of various algorithms to detect high LAP was determined with sensitivity analysis.

RESULTS

We studied 146 infants (59 stable) with a mean of 27(1) weeks gestation. Impaired relaxation, LV stiffness and high LAP were found in 8%, 7%, and 14% of infants. The patent ductus arteriosus was a contributing factor to high LAP and LV stiffness, not impaired relaxation. Diagnostic accuracy improved from 90% to 96% and sensitivity from 40% to 90% by adding left atrial strain to the 2016 algorithm.

CONCLUSION

Various grades of diastolic dysfunction could be appreciated in preterm infants using a multi-parameter approach. Adding left atrial strain improved sensitivity to detect infants with high LAP.