Speckle tracking assessment of the atrial function in patients with systemic sclerosis

Background Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by small vessel vasculopathy, autoantibodies production and exaggerated extracellular matrix deposition, leading to extensive tissue fibrosis. Cardiac involvement in SSc, albeit often asymptomatic, is frequent and represents a negative prognostic factor. Speckle tracking global longitudinal strain (GLS) has proved itself to be an effective tool to identify the presence and the progression of subclinical SSc-related cardiomyopathy. The aim of our study was to assess whether SSc-related cardiomyopathy affects not only the ventricles but also the right (RA) and left atria (LA) in patients with SSc and no overt cardiac disease nor pulmonary hypertension. Materials and methods Observational prospective study enrolling all consecutive patients with SSc age- and gender-matched 1:1 to healthy controls. Patients with structural heart disease, heart failure, atrial fibrillation and pulmonary hypertension were excluded. For every patient, standard echocardiographic parameters and speckle-tracking derived variables were registered. The reservoir function (from the end of ventricular contraction to mitral valve opening), conduit function (from mitral valve opening through the onset of atrium contraction) and contraction function (from the onset of atrium contraction to the end of ventricular diastole) were assessed via GLS. Zero strain reference was set at left ventricular end diastole. Results Fifty-two SSc patients and 52 matched controls were consecutively enrolled. Left ventricular ejection fraction (66.5%±7.4% vs. 66.1%±5.9%; p=ns) right fractional area change (49.4%±9.6% vs. 49.2%±9.2%; p=ns) and mean sPAP (29.0%±5.3% vs. 24.4%±4.1%; p=ns) were well within the normal range and similar between SSc patients and controls. Right atrial reservoir function (35.0%±7.3% vs. 42.3%±8.5%; p=.024) and contraction function (14.8%±4.3% vs. 18.5%±4.1%; p=.034) were significantly lower in SSc patients when compared to matched controls. No difference was seen in right atrial conduit function or left atrial strain. In patients with SSc, RA reservoir (r=.194; p=.033) and conduit function (r=.174; p=.036) were directly associated to right ventricular GLS. LA reservoir (r=.260; p=.008) and conduit function (r=.271; p=.006) were directly associated with left ventricular GLS. No association was observed between contraction function and GLS in both left and right chambers. Moreover, RA and LA reservoir (r=.358; p=.02), conduit (r=.525; p=.004) and contraction functions (r=.30; p=.0.18) were directly correlated. Conclusions While no significant difference was seen between cases and controls in terms of common echocardiographic parameters, RA reservoir and contraction function assessed through GLS were significantly impaired in patients with SSc. The correlation between impaired atrial and ventricular GLS in SSc may represent another indirect evidence of SSc-related heart global involvement. FUNDunding Acknowledgement Type of funding sources: None.

Left atrial strain analysis in hypertensive heart disease and hypertrophic cardiomyopathy by cardiovascular magnetic resonance feature tracking

Funding Acknowledgements Type of funding sources: None. Background Increasing evidence suggests that left atrial (LA) deformation is a sensitive marker of diastolic dysfunction in hypertrophic phenotypes. However, there is little data about the impact of hypertension on LA function; furthermore, LA deformation in hypertensive heart disease (HHD) and hypertrophic cardiomyopathy (HCM) has not been compared yet. Purpose The aim of this study is to compare atrial dimensions and function, evaluated by cardiovascular magnetic resonance feature tracking (CMR-FT) in patients with HHD, HCM and healthy subjects (HS). Methods 67 patients (20 HHD, 27 HCM, 20 HS) underwent CMR and were included in the study. Patients were matched for age, sex and BSA; HHD and HCM were also comparable for LV mass index and ejection fraction (EF). CMR-FT atrial strain analysis was performed using Qstrain, Medis software to obtain i) LA conduit function, ii) LA booster pump function), iii) LA reservoir function, iv) LA volumes and EF. Tissue Doppler echocardiography was used to assess diastolic function, including E/e’. LA stiffness was calculated as the ratio between E/e’ and LA reservoir. Both focal and interstitial myocardial fibrosis were assessed with LGE and extracellular volume (ECV) quantification. Results HHD and HCM showed impaired LA reservoir, conduit function and higher LA volumes vs HS (reservoir: 28 ± 11% and 28 ± 13% vs 41 ± 17%; conduit: 13 ± 7% and 13 ± 7% vs 22 ± 11%; LAESV: 76 ± 21 and 87 ± 22 vs 57 ± 19 ml respectively; all p ≤ 0.03). HHD and HCM were comparable for bi-ventricular morpho-functional parameters and ECV. HHD showed lower E/e’ values (8 ± 2 vs 16 ± 7, p = 0.002) and LA stiffness (0.23 ± 0.3 vs 0.74 ± 0.6, p 0.03), LA dimensions (LA area 13 ± 3 vs 16 ± 3 cm2/m2, p = 0.02 , LAESVi 41 ± 12 vs 48 ± 11 ml/m2, p = 0.05) and LGE extent (1 ± 2% vs 5 ± 5%, p = 0.001) as compared to HCM. Interestingly, HHD revealed a comparable reduced LA reservoir and conduit function (all p = 0.9) vs HCM. In HHD patients LA reservoir function was correlated with E/e’ (r -0.8, p = 0.02), but not in HCM. Conversely, LA reservoir function was correlated with LV mass index in HCM (r -0.5, p < 0.01). Conclusions HHD patients showed a similar and significant impairment of LA function, with lower LA dimensions and E/e’ compared to HCM with similar LV mass index and preserved function. CMR-FT atrial strain analysis could represent a useful tool for HHD management, able to detect diastolic dysfunction (and/or atrial dysfunction) earlier than traditional markers. Further studies are needed to explore the relationship of LA deformation to heart failure symptoms and atrial fibrillation occurrence and potential changes related to response to therapy.

Abstract P150: Association Of Leisure Time Physical Activity (LTPA) With Left Atrial Function In Older Adults: The Atherosclerosis Risk In Communities (ARIC) Study

Introduction: Prior research indicates that higher LTPA is associated with better left ventricular (LV) diastolic function, but not with left atrial volume index (LAVI). Left atrial (LA) strain is a more sensitive marker of LA pathology. Hence, we evaluated association of LTPA with LA strain in the ARIC study, a community-based cohort study. Hypothesis: Higher LTPA is associated with better LA reservoir, conduit and contractile function. Methods: We included 4005 participants (mean age 75 years, 63% female, 21% black) with 2D echocardiographic (2DE) LA % strain data, LTPA data, and without prevalent coronary heart disease, valvular heart disease, heart failure, atrial fibrillation, and stroke at Visit 5 (V5, 2011-13). We estimated LTPA as metabolic equivalent-minutes per week from validated Baecke questionnaire and categorized it as poor, intermediate, or ideal as per AHA recommendation. We categorized change in LTPA from V3 (1993-95) to V5 as persistently poor (referent), decreasing, increasing, or persistently active. LA reservoir, conduit, and contractile % strain were measured from speckle-tracking 2DE. Linear regression was used to evaluate association of LTPA with LA function. We modeled LTPA (1) cross-sectionally at V5 as a continuous variable and (2) change from V3 to V5, as continuous and categorical variables (referent- persistently poor). Results: Higher LTPA at V5 (Table) and persistently high (vs poor) LTPA from V3 to 5 (β estimate -0.89, 95% CI -1.40, -0.38) were significantly associated with better LA conduit function after adjusting for CV risk factors, LV function, and LAVI. The same associations with LA reservoir function were no longer significant after adjusting for CV risk factors. LTPA was not associated with LA contractile function (Table). Conclusions: Consistent with LTPA’s salutary effect on LV diastolic function, higher LTPA is associated with better LA conduit function. Maintaining high LTPA from midlife to late-life may be beneficial in mitigating age-related changes in cardiac function.

Comprehensive assessment of left atrial and ventricular remodeling in paroxysmal atrial fibrillation by the cardiovascular magnetic resonance myocardial extracellular volume fraction and feature tracking strain

Atrial fibrillation (AF) is a progressive disease that starts with structural or functional changes in the left atrium and left ventricle, and evolves from paroxysmal toward sustained forms. Early detection of structural or functional changes in the left atrium and left ventricle in the paroxysmal stage could be useful for identifying a higher risk of progression to persistent AF and future cardio-cerebrovascular events. The aim of this study was to test the hypothesis that the feature tracking (FT) left atrial (LA) strain and left ventricular (LV) extracellular volume fraction (ECV) derived from cardiovascular magnetic resonance (CMR) could detect early changes in remodeling of the left atrium and ventricle in the paroxysmal AF (PAF) stage. The participants were comprised of 106 PAF patients (age, 66.1 ± 10.7 years; 66% male) who underwent clinical CMR before pulmonary vein isolation and 20 control subjects (age, 68.3 ± 8.6 years; 55% male). The CMR-FT LA strain/phasic function and LV-ECV were compared between the PAF and control groups. The total and passive LA empty fraction (LAEF) and LA strain (corresponding to LA reservoir and conduit function) were decreased in the PAF group as compared to the control group. However, active LAEF (corresponding to the LA booster pump function) did not differ significantly between the PAF group (33.9 ± 10.9%) and control group (37.9 ± 13.3%, p = 0.15), while the active LA strain (corresponding to the LA booster pump function) was significantly decreased in the PAF group (11.4 ± 4.3 vs. 15.2 ± 5.6%, p = 0.002). The LV-ECV was significantly greater in the PAF group (28.7 ± 2.8%) than control group (26.6 ± 2.0%, p = 0.002). In the PAF group, the LV-ECV correlated significantly with the E/e′ and LA volume index. Regarding the LA strain, correlations were seen between the LV-ECV and both the reservoir function and conduit function. CMR-FT LA strain in combination with the LV-ECV in a single clinical study offers a potential imaging marker that identifies LA/LV remodeling including subtle LA booster pump dysfunction undetectable by the conventional booster pump LAEF in the PAF stage.

The Role of Left-Atrial Mechanics Assessed by Two-Dimensional Speckle-Tracking Echocardiography to Differentiate Hypertrophic Cardiomyopathy from Hypertensive Left-Ventricular Hypertrophy

Hypertrophic cardiomyopathy (HCM) and arterial hypertension (HTN) are conditions with different pathophysiology, but both can result in left-ventricular hypertrophy (LVH). The role of left-atrial (LA) functional changes detected by two-dimensional speckle-tracking echocardiography (STE) in indicating LVH etiology is unknown. Methods: We aimed to characterize LA mechanics using STE in LVH patients with HCM and HTN. LA 2D volumetric and STE parameters were analyzed in 86 LVH patients (43 HCM and 43 isolated HTN subjects) and 33 age- and sex-matched controls. Results: The volumetric study showed that LA reservoir and conduit function were impaired in the HCM group compared to controls, while, in the HTN group, only LA conduit function was deteriorated. The HCM group had all three STE-derived LA functions impaired compared to controls. The HTN group, consistently with volumetric analysis, had solely LA conduit function reduced compared to controls. Ratios of LA booster-pump strain (S) and strain rate (SR) to interventricular septum (IVS) thickness were the most accurate parameters to discriminate between HCM and HTN. The subgroup harboring sarcomeric pathogenic (P)/likely pathogenic (LP) variants had reduced LA booster-pump S and SR compared with the genotype-negative subgroup. Conclusions: LA reservoir, conduit, and pump functions are decreased in HCM compared to HTN patients with similar LVH. We report the ratios between LA contraction S/SR and IVS thickness as novel parameters with high accuracy in discriminating LVH due to HCM. The presence of P/LP variants in sarcomeric or sarcomeric-associated genes could be associated with more severe LA dysfunction.

Effect of Left Atrial Appendage Closure in Combination With Catheter Ablation on Left Atrial Function for Persistent Atrial Fibrillation

Background: A single procedure combining left atrial appendage closure (LAAC) plus catheter ablation (CA) has been proven to be safe and feasible for treating atrial fibrillation (AF). However, the influence of treatment modality on left atrial (LA) function is not thoroughly explained.Objective: We aimed to investigate the changes of LA function in persistent AF patients undergoing concomitant LAAC and CA.Methods: The study population comprised 65 patients who underwent combined AF ablation and Watchman LAAC (combined therapy group) in our center, and 65 participants of the AF simple ablation group who were matched based on sex, age, CHA2DS2-VASc score and HAS-BLED score using propensity score matching. During the 1-year follow-up period, two-dimensional echocardiography and speckle tracking echocardiography were performed to assess LA reservoir, conduit, and contractile function.Results: The combined therapy was associated with a significant improvement in the LA reservoir function with increased expansion index and strain indices, including strain and strain rate (SR) during ventricular systole. Conduit function with SR during early ventricular diastole was also improved, as was contractile function with active atrial emptying fraction and SR during atrial systole. Similarly, LA reservoir and contractile function indices all improved continuously during follow-up after catheter ablation alone. At 3 months follow-up LA reservoir and conduit function with strain indices had a tendency to improve only in the simple procedure group. At 1-year follow-up there was no significant difference in either LA volumes or strain indices between the two groups.Conclusion: Both the combined therapy group and the simple ablation group demonstrated significant improvement in LA function. Based upon the fact that LA function was improved in both groups it might be concluded that most of the effects appeared to result from ablation, not LAAC; furthermore the additional LAAC procedure did not affect the improvement of LA function after CA.

The Indices of Cardiovascular Magnetic Resonance Derived Atrial Dynamics May Improve the Contemporary Risk Stratification Algorithms in Children with Hypertrophic Cardiomyopathy

Introduction: The most efficient risk stratification algorithms are expected to deliver robust and indefectible identification of high-risk children with hypertrophic cardiomyopathy (HCM). Here we compare algorithms for risk stratification in primary prevention in HCM children and investigate whether novel indices of biatrial performance improve these algorithms. Methods and Results: The endpoints were defined as sudden cardiac death, resuscitated cardiac arrest, or appropriate implantable cardioverter-defibrillator discharge. We examined the prognostic utility of classic American College of Cardiology/American Heart Association (ACC/AHA) risk factors, the novel HCM Risk-Kids score and the combination of these with indices of biatrial dynamics. The study consisted of 55 HCM children (mean age 12.5 ± 4.6 years, 69.1% males); seven had endpoints (four deaths, three appropriate ICD discharges). A strong trend (DeLong p = 0.08) was observed towards better endpoint identification performance of the HCM Risk-Kids Model compared to the ACC/AHA strategy. Adding the atrial conduit function component significantly improved the prediction capabilities of the AHA/ACC Model (DeLong p = 0.01) and HCM Risk-Kids algorithm (DeLong p = 0.04). Conclusions: The new HCM Risk-Kids individualised algorithm and score was capable of identifying high-risk children with very good accuracy. The inclusion of one of the atrial dynamic indices improved both risk stratification strategies.