Left atrial dysfunction as marker of poor outcome in patients with hypertrophic cardiomyopathy

Assessment of left atrial function using two-dimensional speckle tracking echocardiography in cryptogenic stroke patients

BACKGROUND

Cryptogenic cerebrovascular stroke can be defined as an ischemic stroke that lacks a clear cause, even after a thorough evaluation. It should be distinguished from the embolic stroke of undetermined source (ESUS), a subgroup that includes cardio-embolic sources. This study aims to assess left atrial function through two-dimensional speckle tracking echocardiography (2D-STE) to determine its potential association with cryptogenic stroke and its predictive value for subclinical atrial fibrillation (AF). Our prospective cohort study involved 62 patients with unexplained cerebrovascular stroke or TIA, regardless of gender. Following TEE assessments, 22 patients were excluded due to identified sources of cardio-embolism. The remaining 40 participants were clustered into Group I. Group II, consisted of 40 healthy individuals without significant medical history, served as a control group. Both groups underwent two-dimensional trans-thoracic echocardiography and speckle tracking echocardiography.

RESULTS

LA dysfunction parameters exhibited significant differences between Group I and Group II. LV diastolic dysfunction, LAVI, LAEF, and LASr were notably affected in Group I. At the same time, LA diameter in the parasternal long-axis view (PLAX) displayed a significant difference with a p value of 0.001. Within Group I, 14 patients experienced AF episodes (Group Ia, 35%); while, the remaining 26 were categorized as Group Ib (65%). LV diastolic dysfunction displayed a p value < 0.011; while, LAVI, LAEF, and LASr exhibited considerable differences with p values < 0.0001. However, the LA diameter showed no significant variation between the two groups. LASr emerged as the most sensitive and specific parameter for predicting AF, with a cutoff point of ≤ 24.5% and a p value < 0.0001. LAEF showed a cutoff point of ≤ 40.5% and a p value of 0.011. Meanwhile, LAVI demonstrated the lowest sensitivity and specificity, with a mean cutoff point of ≥ 38.5 ml/m2 and a p value of 0.003.

CONCLUSIONS

2D-STE is crucial for assessing LA dysfunction as a potential cryptogenic stroke cause after TEE and ruling out cardio-embolism sources. LASr serves as a key LA cardiopathy indicator, even preceding AF. LASr independently poses an AF risk. While LAEF and LAVI are significant LA dysfunction parameters and AF predictors, they exhibit lower sensitivity and specificity than LASr.

Risk profiles for ventricular arrhythmias in hypertrophic cardiomyopathy through clustering analysis including left ventricular strain

AIMS

The prediction of ventricular arrhythmia (VA) in hypertrophic cardiomyopathy (HCM) remains challenging. We sought to characterize the VA risk profile in HCM patients through clustering analysis combining clinical and conventional imaging parameters with information derived from left ventricular longitudinal strain analysis (LV-LS).

METHODS

A total of 434 HCM patients (65% men, mean age 56 years) were included from two referral centers and followed longitudinally (mean duration 6 years). Mechanical and temporal parameters were automatically extracted from the LV-LS segmental curves of each patient in addition to conventional clinical and imaging data. A total of 287 features were analyzed using a clustering approach (k-means). The principal endpoint was VA.

RESULTS

4 clusters were identified with a higher rhythmic risk for clusters 1 and 4 (VA rates of 26%(28/108), 13%(13/97), 12%(14/120), and 31%(34/109) for cluster 1,2,3 and 4 respectively). These 4 clusters differed mainly by LV-mechanics with a severe and homogeneous decrease of myocardial deformation for cluster 4, a small decrease for clusters 2 and 3 and a marked deformation delay and temporal dispersion for cluster 1 associated with a moderate decrease of the GLS (p < 0.0001 for GLS comparison between clusters). Patients from cluster 4 had the most severe phenotype (mean LV mass index 123 vs. 112 g/m2; p = 0.0003) with LV and left atrium (LA) remodeling (LA-volume index (LAVI) 46.6 vs. 41.5 ml/m2, p = 0.04 and LVEF 59.7 vs. 66.3%, p < 0.001) and impaired exercise capacity (% predicted peak VO2 58.6 vs. 69.5%; p = 0.025).

CONCLUSION

Processing LV-LS parameters in HCM patients 4 clusters with specific LV-strain patterns and different rhythmic risk levels are identified. Automatic extraction and analysis of LV strain parameters improves the risk stratification for VA in HCM patients.

Current and Clinically Relevant Echocardiographic Parameters to Analyze Left Atrial Function

The evaluation of the left atrial (LA) size using the LA volume index (LAVI) is clinically relevant due to its prognostic significance in various conditions. Nonetheless, adding a LA function assessment to the LAVI provides further clinical and prognostic information in different cardiovascular (CV) diseases. The assessment of LA function by echocardiography primarily includes volumetric measurements (LA ejection fraction [LAEF]), tissue Doppler imaging (TDI) (mitral annular late diastolic velocity [a']), and speckle-tracking methods, such as LA longitudinal reservoir strain (LA strain). This review analyzes and discusses the current medical evidence and potential clinical usefulness of these different methods to analyze LA function.

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.

From Atrial Fibrillation Management to Atrial Myopathy Assessment: The Evolving Concept of Left Atrium Disease in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetically inherited cardiovascular disorder in adults and a significant cause of heart failure and sudden cardiac death. Historically, atrial fibrillation (AF) has been considered as a critical aspect in HCM patients as it is considered to be a marker of disease progression, escalates the frequency of heart failure hospitalisations, increases the risk of thromboembolic events, and worsens quality of life and outcome. Increasing evidence suggests that AF is the result of a subtle long-standing process that starts early in the history of HCM. The process of left atrial dilation accompanied by morphologic and functional remodelling is the quintessential prerequisite for the onset of AF. This review aims to describe the current understanding of AF pathophysiology in HCM, emphasising the role of left atrial myopathy in its development. In addition, we discuss risk factors and management strategies specific to AF in the context of HCM, providing insights into the complexities and challenges of treating this specific patient population.

Clinical and biochemical predictors of longitudinal changes in left atrial structure and function: A general population study

PURPOSE

There is a need for better understanding the factors that modulate left atrial (LA) dysfunction. Therefore, we determined associations of clinical and biochemical biomarkers with serial changes in echocardiographic indexes of LA function in the general population.

METHODS

We measured LA maximal and minimal volume indexes (LAVImax and LAVImin) by echocardiography and LA reservoir strain (LARS) by two-dimensional speckle-tracking in 627 participants (mean age 50.8 years, 51.2% women) at baseline and after 4.8 years.

RESULTS

During follow-up, LARS decreased significantly in men (-.90%, P = .033) but not in women (-.23%, P = .60). In stepwise regression analysis, stronger decrease in LARS over time was associated with male sex, a higher age, body mass index (BMI), mean arterial pressure (MAP) and serum insulin at baseline and with a greater increase in BMI and MAP over time (P ≤ .018). Similarly, an increased risk of developing or retaining abnormal LARS was observed in older participants, in subjects with a higher baseline BMI, MAP, heart rate (HR), troponin T and ΔMAP, and in those who used β-blockers at baseline. Both LAVImax and LAVImin increased significantly over time (P ≤ .0007). This increase was associated with a higher baseline age, pulse pressure and a lower HR at baseline and a greater increase in pulse pressure over time (P ≤ .029). Higher serum insulin and D-dimer were independently associated with a stronger increase in LAVImin (P ≤ .0034).

CONCLUSION

Subclinical worsening in LA dysfunction was associated with older age, hypertension, obesity, insulin resistance and troponin T levels. Cardiovascular risk management strategies may delay LA deterioration.

Association between left atrial myopathy and sarcomere mutation in patients with hypertrophic cardiomyopathy: insights into left atrial strain by MRI feature tracking

OBJECTIVES

Left atrial (LA) myopathy, characterized by LA enlargement and mechanical dysfunction, is associated with worse prognosis in hypertrophic cardiomyopathy (HCM) while the impact of sarcomere mutation on LA myopathy remains unclear. We aimed to assess the association between LA myopathy and sarcomere mutation and to explore the incremental utility of LA strain in mutation prediction.

METHODS

A total of 105 consecutive HCM patients (mean age 47.8 ± 11.9 years, 71% male) who underwent HCM-related gene screening and cardiac MRI were retrospectively enrolled. LA volume, ejection fraction and strain indices in reservoir, conduit, and booster-pump phases were investigated respectively.

RESULTS

Fifty mutation-positive patients showed higher LA maximal volume index (59.4 ± 28.2 vs 43.8 ± 18.1 mL/m2, p = 0.001), lower reservoir (21.3 ± 7.9 vs 26.2 ± 6.6%, p < 0.001), and booster-pump strain (12.1 ± 5.4 vs 17.1 ± 5.0%, p < 0.001) but similar conduit strain (9.2 ± 4.5 vs 9.1 ± 4.5%, p = 0.909) compared with mutation-negative patients. In multivariate logistic regression, LA booster-pump strain was associated with sarcomere mutation (odds ratio = 0.86, 95% confidence interval: 0.77-0.96, p = 0.010) independent of maximal wall thickness, late gadolinium enhancement, and LA volume. Furthermore, LA booster-pump strain showed incremental value for mutation prediction added to Mayo II score (AUC 0.798 vs 0.709, p = 0.024).

CONCLUSIONS

In HCM, mutation-positive patients suffered worse LA enlargement and worse reservoir and booster-pump functions. LA booster-pump strain was a strong factor for sarcomere mutation prediction added to Mayo II score.

CLINICAL RELEVANCE STATEMENT

The independent association between sarcomere mutation and left atrial mechanical dysfunction provide new insights into the pathogenesis of atrial myopathy and is helpful to understand the adverse prognosis regarding atrial fibrillation and stroke in mutation-positive patients.

KEY POINTS

• In patients with hypertrophic cardiomyopathy, left atrial (LA) reservoir and booster-pump function, but not conduit function, were significantly impaired in mutation-positive patients compared with mutation-negative patients. • LA booster-pump strain measured by MRI-derived feature tracking is feasible to predict sarcomere mutation with high incremental value added to Mayo II score.

Coronary microvascular dysfunction as assessed by multimodal diagnostic imaging in patients with hypertrophic cardiomyopathy is related to the severity of cardiac dysfunction

INTRODUCTION

Coronary microvascular dysfunction (CMD) plays a major role in hypertrophic cardiomyopathy (HCM) physiopathology but its assessment in clinical practice remains a challenge. Nowadays, innovations in invasive and noninvasive coronary evaluation using multimodal imaging provide options for the diagnosis of CMD. The objective of the present study was to investigate if new multimodal imaging diagnosis of CMD could detect HCM patients with more impaired cardiac function by left atrioventricular coupling index (LACI).

METHODS AND RESULTS

A total of 32 consecutive patients with a confirmed diagnosis of HCM (62 ± 13 years, 62% men) were prospectively screened for CMD using a multimodal imaging method. LACI was assessed by cardiovascular magnetic resonance imaging. Fifteen (47%) patients had CMD by multimodal imaging method. Patients with CMD presented a significantly higher LACI (48.5 ± 25.4 vs. 32.5 ± 10.6, p = .03). A multivariate logistic regression analysis demonstrated that CMD was independently associated with LACI (OR = 1.069, 95% CI 1.00-1.135, p = .03).

CONCLUSION

Multimodal imaging diagnosis of CMD is applicable to HCM patients and is associated with more impaired cardiac function.

A systematic review and meta-analysis of left atrial strain in hypertrophic cardiomyopathy and its prognostic utility

Despite advances in noninvasive imaging modalities to identify atrial fibrillation (AF) risk in Hypertrophic Cardiomyopathy (HCM), there is a paucity of evidence concerning the impact of low Left Atrial strain (LAS) on AF and major adverse cardiac events (MACE) incidence in these patients. This study investigated the diagnostic and prognostic significance of LAS in predicting AF and MACE in HCM. Findings revealed lower LA reservoir (MD: -11.79, 95% CI -14.83, -8.74; p<0.00001), booster (MD: -4.10, 95% CI -6.29, -1.91; p=0.0002), and conduit (MD: -7.52, 95% CI -9.39, -5.65; p<0.00001) strains in HCM patients versus healthy controls, and also indicated a significant association between low LA reservoir/conduit/booster strain and the development of new AF as well as MACE prevalence in HCM patients. The results from this study suggest the valuable role of LA strain in HCM and its utility in predicting the development of new AF and cardiac events in HCM patients.

Impact of enzyme replacement therapy and migalastat on left atrial strain and cardiomyopathy in patients with Fabry disease

Aims

Cardiomyopathy in Fabry disease (FD) is a major determinant of morbidity and mortality. This study investigates the effects of FD-specific treatment using enzyme replacement therapy (ERT) and chaperone therapy on left atrial (LA) function using two-dimensional speckle tracking echocardiography (2DSTE).

Methods and results

In this prospective observational single-center study, 20 FD patients [10 (50%) females] treated with migalastat, 48 FD patients [24 (50%) females] treated with ERT (agalsidase-alfa and agalsidase-beta), and 30 untreated FD patients (all females) as controls were analyzed. The mean follow-up time ranged from 26 to 81 months. 2DSTE was performed for left ventricle strain, right ventricle strain, and LA strain (LAS). FD-specific treated patients presented with increased left ventricular mass index (LVMi) and higher frequency of left ventricular hypertrophy at baseline, whereas untreated control patients showed normal baseline values. FD-specific treated (including migalastat and ERT) patients showed stabilization of LAS over time (p > 0.05). LVMi was also stable in treated FD patients during observation (p > 0.05).

Conclusion

In patients with FD, treated with either ERT or chaperone therapy, LAS values measured by echocardiographic speckle tracking were stable over time, pointing toward disease stabilization.

Predictive value of left atrial strain analysis in adverse clinical events in patients with hypertrophic cardiomyopathy: a CMR study

BACKGROUND

A subset of patients with hypertrophic cardiomyopathy (HCM) will experience adverse clinical events such as heart failure (HF), cardiovascular death, and new-onset atrial fibrillation (AF). Current risk stratification methods are imperfect and limit the identification of patients at high risk for HCM. This study aimed to evaluate the role of cardiac magnetic resonance (CMR)-derived left atrial strain parameters in the occurrence of adverse clinical events in patients with HCM.

METHODS

Left atrial (LA) structural, functional, and strain parameters were evaluated in 99 patients with HCM and compared with 89 age-, sex-, and BMI-matched control subjects. LA strain parameters were derived from CMR two- and four-chamber cine images by a semiautomatic method. LA strain parameters include global longitudinal strain (GLS) and global circumferential strain (GCS). The LA GLS includes reservoir strain (GLS reservoir), conduit strain (GLS conduit), and booster strain (GLS booster). Three LA GLS strain rate (SR) parameters were derived: SR reservoir, SR conduit, and SR booster. The primary endpoint was set as a composite of adverse clinical events, including SCD, new-onset or worsening to hospitalized HF, new-onset AF, thromboembolic events, and fatal ventricular arrhythmias.

RESULTS

LA GLS, GLS SR and GCS were impaired in HCM patients compared to control subjects (all p < 0.001). After a mean follow-up of 37.94 ± 23.69 months, 18 HCM patients reached the primary endpoint. LA GLS, GLS SR, and GCS were significantly lower in HCM patients with adverse clinical events than in those without adverse clinical events (all p < 0.05). In stepwise multiple Cox regression analysis, LV SV, LA diameter, pre-contraction LAV (LAV pre-ac), passive LA ejection fraction (EF), and LA GLS booster were all independent determinants of adverse clinical events. LA GLS booster ≤ 8.9% was the strongest determinant (HR = 8.9 [95%CI (1.951, 40.933)], p = 0.005). Finally, LA GLS booster provided predictive adverse clinical events value (AUC = 0.86 [95%CI 0.77-0.98]) that exceeded traditional outcome predictors.

CONCLUSION

LA strain assessment, a measure of LA function, provides additional predictive information for established predictors of HCM patients. LA GLS booster was independently associated with adverse clinical events in patients with HCM.

Prognostic value of global longitudinal strain in hypertrophic cardiomyopathy: A systematic review and meta-analysis

BACKGROUND

As previously reported, impairment of left ventricular global longitudinal strain (LVGLS) is associated with myocardial fibrosis, arrhythmias, and heart failure in hypertrophic cardiomyopathy (HCM) patients.

HYPOTHESIS

This study aimed to estimate the association between LVGLS measured by echocardiography and major adverse cardiovascular events (MACE) in patients with HCM.

METHODS

Pubmed, Embase, Scopus, and Cochrane Library databases were systematically searched for evaluating the difference of LVGLS between MACE and non-MACE and the relevance of LVGLS and MACE in HCM patients, mean difference (MD), and pooled hazard ratios (HR) with 95% confidence interval (CI) were calculated. Publication bias was detected by funnel plots and Egger's test, and trim-and-fill analysis was employed when publication bias existed.

RESULTS

A total of 13 studies reporting 2441 HCM patients were included in this meta-analysis. Absolute value of LVGLS was lower in the group of HCM with MACE (MD = 2.74, 95% CI: 2.50-2.99, p < .001; I²  = 0, p = .48). In the pooled unadjusted model, LVGLS was related to MACE (HR = 1.14, 95% CI: 1.06-1.22, p < .05, I²  = 58.4%, p < .01) and there is a mild heterogeneity, and sensitivity analysis showed stable results. In the pooled adjusted model, LVGLS was related to MACE (HR = 1.12, 95% CI: 1.08-1.16, p < .05; I²  = 0%, p = .442). Egger's tests showed publication bias, and trim-and-fill analysis was applied, with final results similar to the previous and still statistically significant.

CONCLUSION

The meta-analysis suggested that impaired LVGLS was associated with poor prognosis in HCM patients.

The predictive value of fast semi-automated left atrial long-axis strain analysis for atrial fibrillation in hypertrophic cardiomyopathy

OBJECTIVES

Hypertrophic cardiomyopathy (HCM) patients are closely related to LA functional impairment. Left atrial (LA) strain provides more insight into LA function. The study aimed to investigate the left atrial dysfunction of HCM patients by rapid semi-automatic method and determine the predictive value of left atrial long-axis strain (LAS) for atrial fibrillation (AF).

METHODS

We enrolled 372 HCM patients and 100 healthy participants to assess the LA functional parameters. LAS was obtained by semi-automated tracking of the distance between the mid-posterior point of LA wall which is defined as the intersection of the LA long axis and the posterior wall, and the origins of the mitral valve. The inferior and anterior mitral valve annular insertion points on the 2-chamber view and the lateral and septal insertion points on the 4-chamber view were chosen as the origins of the mitral valve. The clinical outcome was defined as detecting the onset of AF.

RESULTS

The LA strain values were analyzed as 20.8 ± 7.48% for ε_s, 9.81 ± 5.09% for ε_e, and 10.91 ± 4.24% for ε_a in HCM patients, which decreased significantly compared with normal controls. Significant correlations were detected between LV functional parameters and LA strain. During a median follow-up of 61 months, 44 (11.8%) patients developed AF. In the Cox regression analysis, LA strain was identified as a significant predictor of the onset of AF.

CONCLUSIONS

HCM patients had impairment of LA strain before LA enlargement and reduced EF. LA-LAS can be used as a predictive value for predicting the occurrence of AF in HCM patients.

KEY POINTS

• Fast semi-automated long-axis strain analysis by CMR is feasible and effective for evaluating the LA longitudinal function. • Hypertrophic cardiomyopathy patients show significant impairment of left atrial strain before LA enlargement. • The left atrial long-axis strain was an independent predictor of atrial fibrillation in hypertrophic cardiomyopathy.

Could echocardiographic left atrial characterization have additive value for detecting risks of atrial arrhythmias and stroke in patients with hypertrophic cardiomyopathy?

AIMS

Atrial arrhythmia (AA) is considered a turning point for prognosis in patients with hypertrophic cardiomyopathy (HCM). We sought to assess whether the occurrence of AA and stroke could be estimated by an echocardiographic evaluation.

METHODS AND RESULTS

A total of 216 patients with HCM (52 ± 16 years old) were analysed. All patients underwent transthoracic echocardiography for the evaluation of left atrial volume (LAV), peak left atrial strain (PLAS), and peak atrial contraction strain. The patients were followed for 2.9 years for the occurrence of a composite endpoint including AA and/or stroke and peripheral embolism. Among the 216 patients, 78 (36%) met the composite endpoint. These patients were older (57.1 ± 14.4 vs. 50.3 ± 16.7 years; P = 0.0035), had a higher prevalence of arterial hypertension (62.3 vs. 42.3%; P = 0.005), and had higher NT-proBNP. The LAV (47 ± 20 vs. 37.2 ± 15.7 mL/m²; P = 0.0001) was significantly higher in patients who met the composite endpoint, whereas PLAS was significantly impaired (19.3 ± 9.54 vs. 26.6 ± 9.12%; P < 0.0001). After adjustment, PLAS was independently associated with events with an odds ratio of 0.42 (95% confidence interval 0.29-0.61; P < 0.0001). Stroke occurred in 67% of the patients without any clinical AA. The PLAS with a cut-off of under 15.5% provided event prediction with 91% specificity. Using a 15% cut-off, PLAS also demonstrated a predictive value for new-onset of AA.

CONCLUSION

The decrease in PLAS was strongly associated with the risk of stroke, even in patients without any documented AA. Its value for guiding the management of patients with HCM requires further investigation.

The Impact of Left Atrial Mechanics on Adverse Events and Clinical Outcome After Cardiac Surgery

OBJECTIVES

Post-operative atrial fibrillation (POAF) represents a common complication after cardiac surgery that is associated with unfavorable clinical outcome. Identifying patients at risk for POAF is crucial but challenging. This study aimed to investigate the prognostic potential of speckle tracking echocardiography (STE) on POAF and fatal adverse events from a long-term perspective.

METHODS

A total of 124 patients undergoing elective cardiac surgery were prospectively enrolled and underwent pre-operative STE. Patients were followed prospectively for the occurrence of POAF within the entire hospitalization and reaching the secondary end-points cardiovascular (CV) and all-cause mortality.

RESULTS

Within the study population 43.5% (n = 53) of enrolled individuals developed POAF. After a median follow-up of 3.9 years, 25 (20.2%) patients died. We observed that patients presenting with POAF had lower global peak atrial longitudinal strain (PALS) values compared to the non-POAF arm (POAF: 14.8% [95% CI : 10.9-17.8] vs non-POAF: 19.4% [95% CI : 14.8-23.5], p < 0.001). Moreover, global PALS was a strong and independent predictor for POAF (adjusted Odds Ratio per 1-SD: 0.37 [95% CI : 0.22-0.65], p < 0.001), and independently associated with mortality (adjusted Hazard Ratio per 1-SD: 0.63 [95% CI : 0.40-0.99], p = 0.048). CART analysis revealed a cut-off value of < 17% global PALS as high-risk for both POAF and mortality.

CONCLUSION

Global PALS is associated with the development of POAF following surgery in an unselected patient population undergoing CABG and/or valve surgery. Since patients with global PALS <17% face a poor long-term prognosis, routine assessment of global PALS needs to be considered in terms of proper secondary prevention in the era of personalized medicine.

Left Atrial Reservoir Strain-Based Left Ventricular Diastolic Function Grading and Incident Heart Failure in Hypertrophic Cardiomyopathy

BACKGROUND

The echocardiographic assessment of left ventricular (LV) diastolic dysfunction (LVDD) in patients with hypertrophic cardiomyopathy is complex and not well-established. We investigated whether the left atrial reservoir strain (LARS) could be used to categorize LVDD and whether this grading is predictive of heart failure (HF) events in hypertrophic cardiomyopathy.

METHODS

A total of 414 patients with hypertrophic cardiomyopathy (aged 58.3±12.8 years; 65.7% male) were categorized using LARS-defined LVDD (LARS-DD) grades: ≥35% (grade 0), ≥24% to <35%, ≥19% to <24%, and <19% (grade 3). Patients were followed for a median of 6.9 years to assess hospitalization for HF or HF-related death.

RESULTS

An increase in LARS-DD grade was associated with worse conventional echocardiographic parameters of LVDD, such as lower e', higher E/e' ratio, greater maximum tricuspid regurgitation velocity, and restrictive mitral inflow pattern. Higher LARS-DD grade was also associated with parameters reflecting increased LV filling pressure, such as greater LV wall thickness, greater extent of fibrosis, obstructive physiology, and decreased LV longitudinal strain. Furthermore, higher LARS-DD grade was associated with worse HF-free survival (log-rank P<0.001). Patients with LARS-DD grades 0, 1, 2, and 3 showed 10-year HF-free survival of 100%, 91.6%, 84.1%, and 67.5%, respectively. LARS-DD grade was an independent predictor of HF events after adjusting for clinical and echocardiographic variables (hazard ratio, 1.53 [95% CI, 1.03-2.28], per 1-grade increase). The LARS-DD grade also had incremental prognostic value for incident HF events over the traditional echocardiographic LVDD parameters and grading system. The prognostic value of advanced LARS-DD grade was consistent in sensitivity analyses and various patient subgroups.

CONCLUSIONS

LARS can be used as a simple single or supplemental index to categorize LV diastolic function and predict HF events in hypertrophic cardiomyopathy.

Atrial Mechanics in Hypertrophic Cardiomyopathy: Discriminating between Ventricular Hypertrophy and Fibrosis

BACKGROUND

Hypertrophic cardiomyopathy (HCM) and left ventricular hypertrophy (LVH) secondary to systemic hypertension (HTN) may be associated with left atrial (LA) functional abnormalities.

OBJECTIVES

We aimed to characterize LA mechanics in HCM and HTN and determine any correlation with the extent of left ventricular (LV) fibrosis measured by cardiac magnetic resonance (CMR) in HCM patients.

METHODS

Two-dimensional speckle tracking-derived longitudinal LA function was acquired from apical views in 60 HCM patients, 60 HTN patients, and 34 age-matched controls. HCM patients also underwent CMR, with measurement of late gadolinium enhancement (LGE) extension. Association with LA strain parameters was analyzed. Statistical significance was set at p<0.05.

RESULTS

Mean LV ejection fraction was not different between the groups. The E/e' ratio was impaired in the HCM group and preserved in the control group. LA mechanics was significantly reduced in HCM, compared to the HTN group. LA strain rate in reservoir (LASRr) and in contractile (LASRct) phases were the best discriminators of HCM, with an area under the curve (AUC) of 0.8, followed by LA strain in reservoir phase (LASr) (AUC 0.76). LASRr and LASR-ct had high specificity (89% and 91%, respectively) and LASr had sensitivity of 80%. A decrease in 2.79% of LA strain rate in conduit phase (LASRcd) predicted an increase of 1cm in LGE extension (r2=0.42, β 2.79, p=0.027).

CONCLUSIONS

LASRr and LASRct were the best discriminators for LVH secondary to HCM. LASRcd predicted the degree of LV fibrosis assessed by CMR. These findings suggest that LA mechanics is a potential predictor of disease severity in HCM.

A preliminary study on the evaluation of left atrial function of rheumatoid arthritis by two dimensional speckle tracking imaging

To evaluate the changes of left atrial (LA) geometry and function in patients with rheumatoid arthritis (RA) by conventional echocardiography and two-dimensional speckle tracking imaging (2D-STI). We enrolled 46 RA patients with a duration of < 5 years as Group I, 40 RA patients with a duration of ≥ 5 years as Group II, and 40 normal subjects as the control group. Conventional echocardiography was conducted to measure traditional parameters. The LA strain during reservoir phase (LASr), LA strain during conduit phase (LAScd), LA strain during contraction phase (LASct), and LA global longitudinal strain (LAGLS) were obtained from 2D-STI. Related ultrasound results were compared. The LASct was significantly higher in Group I than in control group (P < 0.05). The LASr, LAScd, and LAGLS were significantly lower in Group I than in control group (all P < 0.05). The LASr, LAScd, LASct, and LAGLS were significantly lower in Group II than in control group and Group I (all P < 0.05). The function of LA impaired in RA patients, and the impairment aggravated with the clinical course of RA patients. 2D-STI technology can early and accurately evaluate the LA function of RA patients by evaluating LASr, LAScd, LASct, and LAGLS.

Cost-Effectiveness Analysis of Evolocumab Therapy in Patients at High Risk of Cardiovascular Events in the Context of the Brazilian Unified Health System

BACKGROUND

Hypertrophic cardiomyopathy (HCM) and left ventricular hypertrophy (LVH) secondary to systemic hypertension (HTN) may be associated with left atrial (LA) functional abnormalities.

OBJECTIVES

We aimed to characterize LA mechanics in HCM and HTN and determine any correlation with the extent of left ventricular (LV) fibrosis measured by cardiac magnetic resonance (CMR) in HCM patients.

METHODS

Two-dimensional speckle tracking-derived longitudinal LA function was acquired from apical views in 60 HCM patients, 60 HTN patients, and 34 age-matched controls. HCM patients also underwent CMR, with measurement of late gadolinium enhancement (LGE) extension. Association with LA strain parameters was analyzed. Statistical significance was set at p<0.05.

RESULTS

Mean LV ejection fraction was not different between the groups. The E/e' ratio was impaired in the HCM group and preserved in the control group. LA mechanics was significantly reduced in HCM, compared to the HTN group. LA strain rate in reservoir (LASRr) and in contractile (LASRct) phases were the best discriminators of HCM, with an area under the curve (AUC) of 0.8, followed by LA strain in reservoir phase (LASr) (AUC 0.76). LASRr and LASR-ct had high specificity (89% and 91%, respectively) and LASr had sensitivity of 80%. A decrease in 2.79% of LA strain rate in conduit phase (LASRcd) predicted an increase of 1cm in LGE extension (r2=0.42, β 2.79, p=0.027).

CONCLUSIONS

LASRr and LASRct were the best discriminators for LVH secondary to HCM. LASRcd predicted the degree of LV fibrosis assessed by CMR. These findings suggest that LA mechanics is a potential predictor of disease severity in HCM.

Incremental value of left atrial booster and reservoir strain in predicting atrial fibrillation in patients with hypertrophic cardiomyopathy: a cardiovascular magnetic resonance study

BACKGROUND

Left atrial (LA) size and function are known predictors of new onset atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients. Components of LA deformation including reservoir, conduit, and booster function provide additional information on atrial mechanics. Whether or not LA deformation can augment our ability to predict the risk of new onset AF in HCM patients beyond standard measurements is unknown.

METHODS

We assessed LA size, function, and deformation on cardiovascular magnetic resonance (CMR) in 238 genotyped HCM patients and compared this with twenty age, sex, blood pressure and body mass index matched control subjects. We further evaluated the determinants of new onset AF in HCM patients.

RESULTS

Compared to control subjects, HCM patients had higher LA antero-posterior diameter, lower LA ejection fraction and lower LA reservoir (19.9 [17.1, 22.2], 21.6 [19.9, 22.9], P = 0.047) and conduit strain (10.6 ± 4.4, 13.7 ± 3.3, P = 0.002). LA booster strain did not differ between healthy controls and HCM patients, but HCM patients who developed new onset AF (n = 33) had lower booster strain (7.6 ± 3.3, 9.5 ± 3.0, P = 0.001) than those that did not (n = 205). In separate multivariate models, age, LA ejection fraction, and LA booster and reservoir strain were each independent determinants of AF. Age ≥ 55 years was the strongest determinant (HR 6.62, 95% CI 2.79-15.70), followed by LA booster strain ≤ 8% (HR 3.69, 95% CI 1.81-7.52) and LA reservoir strain ≤ 18% (HR 2.56, 95% CI 1.24-5.27). Conventional markers of HCM phenotypic severity, age and sudden death risk factors were associated with LA strain components.

CONCLUSIONS

LA strain components are impaired in HCM and, together with age, independently predicted the risk of new onset AF. Increasing age and phenotypic severity were associated with LA strain abnormalities. Our findings suggest that the routine assessment of LA strain components and consideration of age could augment LA size in predicting risk of AF, and potentially guide prophylactic anticoagulation use in HCM.

Left Atrium Assessment by Speckle Tracking Echocardiography in Cryptogenic Stroke: Seeking Silent Atrial Fibrillation

Silent atrial fibrillation (AF) may be the cause of some cryptogenic strokes (CrS). The aim of the study was to analyse atrial size and function by speckle tracking echocardiography in CrS patients to detect atrial disease. Patients admitted to the hospital due to CrS were included prospectively. Echocardiogram analysis included left atrial ejection fraction (LAEF) and atrial strain. Insertable cardiac monitor was implanted, and AF was defined as an episode of ≥1 min in the first year after stroke. Left atrial enlargement was defined as indexed volume > 34 mL/m². Seventy-five consecutive patients were included, aged 76 ± 9 years (arterial hypertension 75%). AF was diagnosed in 49% of cases. The AF group had higher atrial volume and worse atrial function: peak atrial longitudinal strain (PALs) 19.6 ± 5.7% vs. 29.5 ± 7.2%, peak atrial contraction strain (PACs) 8.9 ± 3.9% vs. 16.5 ± 6%, LAEF 46.8 ± 11.5% vs. 60.6 ± 5.2%; p < 0.001. AF was diagnosed in 20 of 53 patients with non-enlarged atrium, and in 18 of them, atrial dysfunction was present. The multivariate logistic regression analysis demonstrated an independent association between detection of AF and atrial volume, LAEF, and strain. Cut-off values were obtained: LAEF < 55%, PALs < 21.4%, and PACs < 12.9%. In conclusion, speckle tracking echocardiography in CrS patients improves silent atrial disease diagnosis, with or without atrial enlargement.