Left Atrial Sphericity Index Research Articles

Possible predictors of stroke in patients with atrial microfibrillation

Background Very short-lasting episodes of AF-like activity (micro-AF) may be precursors of undiagnosed silent episodes of atrial fibrillation. In this study, we examined the relationship between increased left atrial sphericity index (LASI) and stroke in patients with micro-AF.Material and Methods A total of 100 consecutive patients with micro-AF enrolled in this study. The histories, cranial magnetic resonance, and computed tomography images of these patients were scanned from the hospital database. The patients were divided into two groups according to whether or not they had a stroke. LASI was calculated as a fraction of the left atrial maximum volume to the left atrial volume of the sphere in a 4‑chamber view. Atrial electromechanical delay (AEMD) intervals were calculated from the atrial wall and atrioventricular valve annulus levels by using tissue Doppler imaging (TDI). These two groups were compared in terms of stroke predictors.Results A history of stroke was present in 25 (25 %) patients diagnosed with micro-AF (Group 1). 75 patients did not have stroke (Group 2). There was a significant difference between the two groups in terms of left atrial lateral wall electromechanical delay (LA lateral AEMD) times, left atrial volume index (LAVI), and left atrial sphericity index (LASI). Findings: LAVI, 40.9±3.72 vs. 29.9±3.84, p<0.001; LASI, 0.84±0.07 vs. 0.66±0.07, p<0.001; LA lateral AEMD, 77.2±4.85 vs. 66.5±3.66, p<0.001.Conclusions Stroke precautions should be taken in patients with micro-AF. New predictive indexes should be given importance. Changes in LASI, LAVI and LA lateral AEMD values may be a predictor of stroke in patients with micro AF.

Could the echocardiographic parameters be a predictor to estimate cerebrovascular events in patients with micro-atrial fibrillation?

Objectives: This study examined possible predictors of stroke [left atrial sphericity index (LASI), left atrial kinetic energy (LAKE), left atrial volume index (LAVI) atrial electromechanical delay (AEMD)] intervals in patients with micro-atrial fibrillation (micro-AF). Patients and methods: A total of 102 consecutive patients (40 males, 62 females; mean age: 61.5±9.2 years; range, 18 to 75 years) diagnosed with micro-AF on rhythm Holter were included in this retrospective study between June 2021 and October 2021. Cranial magnetic resonance and computed tomography images of these patients were scanned from the hospital database. The patients were divided into two groups according to their stroke status (Group 1, the stroke group [n=25]; Group 2, the nonstroke group [n=77]). The LASI was calculated as a fraction of the left atrial maximum volume to the left atrial volume of the sphere in a four-chamber view. The biplane method of disks was used to calculate left atrium volume. The LAVI was calculated by dividing left atrium (LA) volume by the body surface area of patients. Atrial electromechanical delay intervals were calculated from the atrial walls by tissue Doppler imaging. These two groups were compared to assess whether echocardiographic parameters could be a predictor of cerebrovascular events. Results: There was a statistically significant difference between Groups 1 and 2 in terms of left (75.7±4.5 vs. 68.4±3.5, p<0.001) and right (69.5±7.1 vs. 57±3.2, p<0.001) atrial lateral wall and LA medial wall (72±4 vs. 66.2±3.5, p<0.001) electromechanical delay times, LAVI (38.9±3.3 vs. 30.9±3.8, p<0.001), LASI (0.78±0.05 vs. 0.67±0.4, p<0.001), and LAKE (3.7±0.9 vs. 7.9±1.9, p<0.001), left atrial diameter (40±5 vs. 38±2, p<0.001). Conclusion: Changes in LASI, LAVI, LAKE, left atrial diameter, and atrial AEMD times may be a predictor of stroke in patients with micro-AF.

Abstract P670: Association of Left Atrial and Left Ventricular Sphericity With Left Ventricular Structure and Function

Introduction: Spherical remodeling of atria and ventricles is associated with cardiovascular disease (CVD) and mortality. We hypothesized that volumetric left atrial (LA) and left ventricular (LV) sphericity index (SI) are associated with adverse measures of LV structure and function in older adults free of CVD. Methods: Framingham Heart Study 2nd generation participants without prevalent CVD with echocardiography at exam 8 were studied (n=1701). Volumetric LA SI was calculated as the ratio of biplane LA volume to the volume of a sphere [4/3*pi*(r^3)] calculated using the radius of LA length (r=½ average length of the atria in 4- and 2-chamber views in diastole). Volumetric LV SI was calculated as the ratio of LV end-diastolic volume (LVEDV) to the volume of a sphere calculated using the radius of LV length (r= ½ length of LV in 4-chamber view in diastole). LVEDV was measured by biplane area-length method. In multivariable models adjusting for CV risk factors including age, sex, BMI, hypertension, dyslipidemia, diabetes, and smoking, we evaluated the relations of LA and LV SI with echocardiographic LV structure and function: wall thickness (septal and posterior wall average), mass, global longitudinal strain, ejection fraction (EF), and log-transformed mitral Doppler E/A. β coefficients are presented as standard deviation (SD) change in outcome per SD change in predictor variable. Results: Descriptives are presented in the Table . There was no association of LA or LV SI with sex (p=0.48, p=0.61, respectively). LA SI was associated with worse (positive) LV global longitudinal strain (std β±SE: 0.08±0.03, p=0.016). LV SI was associated with LV wall thickness (std β±SE: 0.24±0.03, p<0.0001), mass (0.45±0.03, p<0.0001) and log-Doppler E/A (0.07±0.03, p=0.015) and was inversely associated with LV EF (-0.12±0.03, p<0.0001). Conclusions: In a large community sample without prevalent CVD, spherical remodeling of the heart was associated with unfavorable LV structure and both systolic and diastolic dysfunction.

Reverse Atrial Remodeling in Heart Failure With Recovered Ejection Fraction.

Background Heart failure with recovered ejection fraction (HFrecEF) has been a newly recognized entity since 2020. However, the concept has primarily focused on left ventricular ejection fraction improvement, with less focus on the recovery of the left atrium. In this study, we investigated changes in left atrial (LA) echocardiographic indices in HFrecEF. Methods and Results An inpatient cohort with heart failure with reduced ejection fraction (HFrEF) was identified retrospectively and followed up prospectively in a single tertiary hospital. The enrolled patients were classified into HFrecEF and persistent HFrEF groups. Alternations in LA parameters by echocardiography were calculated. The primary outcome was a composite of cardiovascular death or heart failure rehospitalization. A total of 699 patients were included (HFrecEF: n=228; persistent HFrEF: n=471). Compared with persistent HFrEF, the HFrecEF group had greater reductions in LA diameter, LA transverse diameter, LA superior-inferior diameter, LA volume, and LA volume index but not in LA sphericity index. Cox regression analysis showed that the HFrecEF group experienced lower risks of prespecified end points than the persistent HFrEF group after adjusting for confounders. Additionally, 136 (59.6%) and 62 (13.0%) patients showed LA reverse remodeling (LARR) for the HFrecEF and persistent HFrEF groups, respectively. Among the HFrecEF subgroup, patients with LARR had better prognosis compared with those without LARR. Multivariate logistic analysis demonstrated that age and coronary heart disease were 2 independent negative predictors for LARR. Conclusions In HFrecEF, both left ventricular systolic function and LA structure remodeling were improved. Patients with HFrecEF with LARR had improved clinical outcomes, indicating that the evaluation of LA size provides a useful biomarker for risk stratification of heart failure.

629 RELATIONSHIP BETWEEN RIGHT/LEFT ATRIAL ECHOCARDIOGRAPHIC PARAMETERS (INCLUDING ATRIAL SPHERICITY) AND OUTCOME IN PATIENTS WITH ATRIAL FIBRILLATION

Abstract Background Atrial fibrillation (AF) is the most common arrhythmia seen in the daily practice. AF and atrial remodeling share a biunivocal link, been one cause and effect of the other. Usually we evaluate the remodeling by measuring atrial dimensions. Aim Aim of the analysis was to evaluate the power of left atrial (LA) antero-posterior diameter (LAAPD), LA volume indexed for body surface area (LAVI), LA sphericity index (LASI), right atrial (RA) antero-posterior diameter (RAAPD), RA volume indexed for body surface area (RAVI), RA sphericity index (RASI) in predicting a primary endpoint (CEP2) (a composite of all-cause death, any thromboembolism, any acute coronary syndrome or unplanned revascularization). A secondary endpoint (CEP 3) was also evaluated adding to the primary endpoint unplanned admissions for acute heart failure or major or clinically relevant non-major bleeding. Methods Starting from 2016 to 2021, patients with ECG-documented AF within 1 year were enrolled in a prospective registry. Patients were not required to be in AF at the time of enrollment, nor AF to be the reason for admission/consultation. We retrieved echocardiographic (echo) data by reviewing clips, when available; we prospectively collected clinical and laboratory data. Patients were followed up after 1 month and usually every 6 months unless complications occurred. Results From the original dataset, we analyzed 489 (51.8%) patients with a complete echo evaluation. They were 300 males (61.3%), median age 75 (IQR 66-80) years, median CHA2DS2VASc 3 (2-5), median HAS-BLED 1 (1-2). Four-hundred fifthy-one (92.2%) were anticoagulated. After a median follow-up of 1114 (392-1384) days, 84 (17.2%) patients died, 115 (23.5%) achieved the CEP2, and 189 (38.7%) the CEP3. At Cox regression analysis for the CEP2, adjusted for CHA2DS2VASc, AF type and OAC pattern, LA parameters only were predictive of a worse outcome (LAAPD HR 1.04; 95%CI 1.02-1.05; LAVI HR 1.01 95%CI 1.005-1.05; LASI HR 5.29 95%CI 1.02-27.71); RA parameters were not significantly associated with the outcome. The same results were obtained with CEP3, adjusting the Cox regression for CHA2DS2VASc, AF type, OAC pattern and renal function (LAAPD HR 1.03 95%CI 1.02-1.05; LAVI HR 1.00 95%CI 1.00-1.01; LASI HR 6.00 95%CI 1.62-22.21) (Table.). At ROC curves analysis the AUC were moderately significant, all beeing lower than 0.7; either for CEP2 and CEP3 the better predictive value was seen for LAAPD and LAVI. Taking LAAPD as reference and comparing it with other atrial parameters, LAAPD was not statistically different only for LAVI Table. Conclusions In “real world” patients with AF, LA sphericity and other LA parameters are significantly associated with outcome, while this association is lacking for RA parameters. This finding reinforces the need of comprehensive clinical and echo evaluation of AF in clinical practice.

Abstract 11287: Structural Remodeling Impairs Left Atrial Function in Patients With Atrial Fibrillation: A Cardiac MRI Study

Introduction: Left atrial (LA) fibrosis and enlargement are hallmarks of structural remodeling that contribute to atrial fibrillation (AF) pathophysiology. Cardiac magnetic resonance (CMR) feature tracking has higher spatial resolution and better ability to define the endocardial border, overcoming the challenges related to speckle tracking echocardiography particularly the anatomic location of LA and thinness of the atrial wall. We aimed to assess the association of LA fibrosis and volume with LA function and compliance using CMR imaging. Methods: We analyzed CMR images of AF patients prior to their first catheter ablation. LA fibrosis was assessed using Late Gadolinium Enhancement CMR (Panel A). Feature tracking was applied to assess global longitudinal reservoir strain (GLRS) (Panel B). LA emptying fraction, LA volume index and LA sphericity index were measured using the Cine sequences. All CMR images were acquired in sinus rhythm. Results: 101 patients were included in the study (61% male, mean age 62 years). Median LA volume index was 45.16 mL/m 2 [36.64, 56.5], LA fibrosis percentage was 15.5% [9.6, 19], LA sphericity index was 54.09% [46.44, 64.58] and GLRS was 17.4 [14.95, 20.1]. A Pearson correlation analysis showed that increased LA fibrosis was negatively associated with both GLRS and LA emptying fraction (R=-0.35, p<0.001 and R=-0.27, p=0.007 respectively). LA volume index was also negatively correlated with GLRS and LA emptying fraction (R=-0.37, p<0.001 and R=-0.54, p<0.001, respectively) (Panel C). Neither LA fibrosis nor LA volume index was associated with LA sphericity index (p=0.55 and p=0.4 respectively). Conclusion: LA structural remodeling including increased fibrosis and LA volume is associated with a worsening LA function by strain imaging on CMR. Fibrotic remodeling may lead to blood stasis and play a role in the pathophysiology of thromboembolic stroke associated with AF.

Abstract 15312: Automatic Left Atrial Volume and Sphericity Index Calculation From Cardiac CT Using Computer Graphics Imaging and Deep Learning

Introduction: Left atrial (LA) volume and sphericity index are important for atrial fibrillation (AF) recurrence prediction after ablation and AF-associated atrial remodeling analysis. However, calculating these indexes from computed tomography (CT) requires manual outlining, which is subjective and difficult to scale. Hypothesis: We hypothesized LA body can be "virtually" dissected from electroanatomic shells using computer graphics imaging (CGI). We further hypothesized that the results of virtual dissection can be used to train a deep learning (DL) model for automatic LA volume and sphericity index calculation. Methods: First, by encoding the anatomic knowledge with geometric modeling, we developed a mathematical method (termed "virtual dissection") based on CGI techniques to isolate the LA body from electroanatomic shells (Fig A). Second, we used virtual dissection to train a DL model to segment CTs in N=20 patient atria (Fig B-C). Finally, we used this pipeline to segment raw CTs in a test cohort of N=100 patients (30.0% women, 66.0±10.3Y; Fig D). Results: In the independent test cohort (N=100), the LA volume and sphericity index were automatically calculated from DL-based segmentation, with the agreement within 4.04 ml (95% CI: -11.48 to 19.55; r=0.98; p < 0.0001; Fig E-F) and 2.75% (95% CI: -5.71 to 11.22; r=0.88; p < 0.0001; Fig G-H), compared to expert annotation. Conclusions: Encoded anatomical knowledge combined with deep learning in small datasets can accurately extract 3D cardiac models from raw CT scans in large populations, yielding automatic calculation of indexes such as volume and sphericity. This computational pipeline may simplify the outcome analysis and prediction using geometric indexes as predictors.

Abstract 12090: Catheter Ablation Impairs Left Atrial Function in Patients With Atrial Fibrillation: A Magnetic Resonance Imaging Study

Introduction: Atrial fibrillation (AF) is associated with left atrial (LA) fibrosis and morphological remodeling. Catheter ablation (CA) is a well-established method of treatment for AF which results in additional LA scarring. Cardiac magnetic resonance (CMR) imaging is the gold standard for evaluating LA volumes and function, and feature tracking in CMR has been increasingly confirmed as a feasible and reproducible technique for assessing LA function through strain. We used CMR to assess baseline fibrosis, ablation-induced scarring and the impact of CA on LA volume, shape and function in patients with AF undergoing their first catheter ablation. Methods: AF patients underwent late gadolinium enhancement CMR prior to, then at least 3 months after CA for quantification of LA volumes, fibrosis and ablation-induced scarring, respectively (Panel A). Global longitudinal reservoir strain (GLRS) was assessed by feature tracking (Panel B). Cine-images were used to assess sphericity and emptying fraction. All CMR images were obtained in sinus rhythm. Wilcoxon signed rank analysis was used to assess the effect of CA on LA volume and sphericity index, emptying fraction and GLRS. Results: 40 patients (57% male, average age 61.9 years, 72.5% paroxysmal AF) were included. Pre-ablation LA fibrosis was 16.6% [9.1, 20.7] whereas ablation-induced LA scar was 8.0% [6.5, 12.1]. GLRS and LA emptying fraction decreased after CA (17.8 [15.3, 20.5] vs 16.0 [13.5, 19.0] p=0.006, and 60.2% [51.3, 66.4] vs 51.6% [46.3, 61.1], p<0.001, respectively). However, LA volume index and sphericity index were unchanged after CA in our study cohort (48.0 mL/m 2 [37.1, 61.1] vs 47.0 mL/m 2 [36.2, 52.7] p=0.91 and 54.6% [47.2, 65.4] vs 53.2% [46.5, 64.5] p=0.8, respectively) (Panel C). Conclusion: LA function is negatively impacted by catheter ablation for AF. The competing impact of ablation on rhythm control and atrial function with respect to stroke and heart failure need to be further evaluated.

Evaluation of left atrial reservoir function and sphericity index in patients with mitral valve disease: a cardiac magnetic resonance imaging study

To assess the performance of biplane area-length method in measuring left atrial (LA) volume and sphericity index and to investigate the correlation of LA reservoir function and sphericity index with atrial fibrosis on cardiac magnetic resonance imaging (MRI) in patients with mitral valve disease (MVD). Forty-eight patients with MVD undergoing cardiac MRI scan were enrolled in this retrospective study. LA reservoir function, measured as maximum volume (LAVmax), minimum volume (LAVmin) and ejection fraction (LAEF), and sphericity index were quantified using the biplane area-length method and standard short-axis approach, respectively. Comparisons of LA reservoir function and sphericity index between the two different methods were performed, as well as between positive (n = 17, 35%) and negative atrial wall fibrosis groups (n = 31, 65%). There was no difference in the values of LAVmax index and sphericity index between the two different methods. The biplane area-length method had poor performance in assessing LAVmin index and LAEF compared to standard short-axis approach, with an underestimation of 13.5% for LAVmin index and an overestimation of 27% for LAEF. Patients with positive atrial fibrosis had larger LAVmax index, LAVmin index and sphericity index, and lower LAEF levels in comparison to the negative atrial fibrosis group. The biplane area-length method has good performance in assessing LA sphericity index for patients with MVD, not in LA reservoir function. Patients with positive atrial fibrosis tend to suffer from more adverse LA remodelling.

Characterization of left atrial geometry and function in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance imaging study.

Left atrial (LA) remodelling is an interesting pathological aspect in hypertrophic cardiomyopathy (HCM) which has not been yet fully understood. Also, a comprehensive evaluation of LA alterations in HCM is still lacking. Cardiac magnetic resonance imaging (cMRI) can precisely characterize LA function and structure. We sought to thoroughly assess LA remodelling using cMRI in patients with HCM. We enrolled 105 patients with HCM and 105 healthy controls. LA parameters determined by cMRI comprise LA volume (LAV), total ejection fraction (LATF), total strain LA- εt, passive ejection fraction (LAPF), passive strain LA-εe, active ejection fraction (LAAF), active strain LA-εa. LA sphericity index (LASI) and LA strain were also determined. Parameters of LV systolic and diastolic functions were also assessed. LAV and LASI were significantly increased, while LA phasic functions were decreased in patients with HCM (p<.001). LATF was inversely correlated with LV long-axis strain (r= -0.466, p<.0001) and mass (r= -0.515, p<.0001), and as well with filling pressures, described by E/E' (r= -0.424, p<.0001). LA volumes, phasic functions and geometry were negatively associated with LV measurements, whereas a positive correlation between the LATF and LA strain (r = 0.496, p<.0001) was found. In addition, LAV was closely related to diastolic dysfunction severity (p<.0001). In patients with HCM, all three LA phasic functions were impaired, being directly related to LA enlargement. LASI and LA strain predicted LA reservoir function impairment.

Left atrial remodeling in heart failure: the role of sphericity index (the SPHERICAT-HF study).

Left atrial sphericity index (LASI) is an echocardiographic index easily obtained; its use in patients with heart failure (HF) has never been investigated so far. This single-centre study aimed to investigate the usefulness of LASI in an unselected cohort of patients hospitalized for acute HF, and its potential correlation with the amino-terminal portion of pro-B-type natriuretic peptide (NT-proBNP) levels and with New York Heart Association (NYHA) functional class. Ninety-four consecutive HF patients underwent a transthoracic echocardiogram with a detailed study of the left atrium (LA) including LASI (calculated from the apical four-chamber view as the ratio between the transverse and longitudinal diameters), and blood tests (including NT-proBNP) on the same day. Median age was 75.5 (interquartile range-IQR 62-82) years and 55% were males, 58.5% had a NYHA class III-IV, and median NT-proBNP was 3284 (IQR 1215-7055) pg/ml. The LA was dilated in 94%, and median biplane LA volume index was 62ml/m2. Patients with advanced NYHA class showed more advanced LA remodeling. Mean LASI was 0.78 ± 0.09 and did not correlate with NT-proBNP levels (r 0.03; p 0.75) or with patient NYHA class (R2 0.011; p 0.287). None of the echocardiographic indices of LA structural and functional remodeling proved to be independently associated with a high NYHA class on multivariate regression analysis. In conclusion, LA remodeling is almost invariably present in patients with HF. LASI does not correlate with NT-proBNP levels or with NYHA functional class. Further studies are needed to describe the complex patterns of atrial remodeling in HF.

Atrial function and geometry differences in transthyretin versus immunoglobulin light chain amyloidosis: a cardiac magnetic resonance study

To determine the differences in left atrial (LA) function and geometry assessed by cardiac magnetic resonance (CMR) between transthyretin (ATTR) and immunoglobulin light chain (AL) cardiac amyloidosis (CA). We performed a retrospective analysis of 54 consecutive patients (68.5% male, mean age 67 ± 11 years) with confirmed CA (24 ATTR, 30 AL) who underwent comprehensive CMR examinations. LA structural and functional assessment including LA volume, LA sphericity index, and LA strain parameters were compared between both subtypes. In addition, 15 age-matched controls were compared to all groups. Patients with ATTR-CA were older (73 ± 9 vs. 62 ± 10 years, p < 0.001) and more likely to be male (83.3% vs. 56.7%, p = 0.036) when compared to AL-CA. No significant difference existed in LA maximum volume and LA sphericity index between ATTR-CA and AL-CA. LA minimum volumes were larger in ATTR-CA when compared with AL-CA. There was a significant difference in LA function with worse strain values in ATTR vs AL: left atrial reservoir [7.4 (6.3–12.8) in ATTR vs. 13.8 (6.90–24.8) in AL, p = 0.017] and booster strains [3.6 (2.6–5.5) in ATTR vs. 5.2 (3.6–12.1) in AL, p = 0.039]. After adjusting for age, LA reservoir remained significantly lower in ATTR-CA compared to AL-CA (p = 0.03), but not LA booster (p = 0.16). We demonstrate novel differences in LA function between ATTR-CA and AL-CA despite similar LA geometry. Our findings of more impaired LA function in ATTR may offer insight into higher AF burden in these patients.

Effect of angiotensin receptor neprilysin inhibitors on left atrial remodeling and prognosis in heart failure.

AimsThe angiotensin receptor–neprilysin inhibitor (ARNI), sacubitril/valsartan, confers additional protective effects compared with angiotensin‐converting enzyme inhibitors/angiotensin II receptor blockers (ACEIs/ARBs) in terms of reversed left ventricular (LV) remodelling and improves the prognosis of patients with heart failure (HF). However, few studies have examined the effects of ARNI on the left atrium. Accordingly, this study compared the effects of ARNI and ACEI/ARB on left atrial (LA) remodelling in heart failure with reduced ejection fraction (HFrEF).Methods and resultsThis was a single‐centre retrospective study of patients with HFrEF hospitalized at the First Affiliated Hospital of Dalian Medical University between 26 February 2016 and 8 July 2020. Patients were classified into ARNI and ACEI/ARB groups and further subgroups based on the left atrial volume index (LAVI): mildly abnormal (29 mL/m2 ≤ LAVI < 34 mL/m2), moderately abnormal (34 mL/m2 ≤ LAVI < 40 mL/m2), and severely abnormal (LAVI ≥ 40 mL/m2). The primary endpoint was changes in LA parameters by echocardiography. The secondary endpoint was all‐cause mortality. A total of 336 patients (mean age: 64.11 ± 12.86, 30.06% female) were included. Except those lost to follow‐up, 274 HFrEF patients remained, with 144 cases in the ARNI group and 130 cases in the ACEI/ARB group. Greater reductions from baseline were seen with ARNI in LA diameter (LAD) (P = 0.013, t‐test), superior and LA superior–inferior diameter (LASID) (P < 0.0001), LA transverse diameter (LATD) (P < 0.0001), LA volume (LAV) (P < 0.0001), LAVI (P < 0.0001), and LA sphericity index (LASI) (P < 0.0001). Over a mean follow‐up of 19.40 months, 97 patients (67.3%) in the ARNI group and 29 patients (22.3%) in the ACEI/ARB group showed LA reverse remodelling (LARR). Kaplan–Meier analysis showed significantly lower overall mortality in the ARNI group compared with the ACEI/ARB group (P = 0.048, log‐rank test). The mildly abnormal LAVI group of ARNI patients showed a reduction in mortality compared with ACEI/ARB patients (P = 0.044). However, no significant difference was observed for the moderately abnormal (P = 0.571) or severely abnormal LAVI groups (P = 0.609), suggesting that early initiation of ARNI was associated with a better prognosis.ConclusionsIn this proof‐of‐concept study, ARNI use showed greater effects on LARR and was associated with a better prognosis compared with ACEI/ARB use in HFrEF. Early initiation of ARNI in the HF disease process may produce greater benefit, but this needs to be confirmed in future studies.

Impact of Left Atrial Sphericity Index on the Outcome of Catheter Ablation for Atrial Fibrillation.

Left atrial sphericity index (LASI) is one significant geometric remodeling parameter to evaluate the prognosis of atrial fibrillation (AF). We aimed to determine whether transthoracic echocardiography (TTE)-derived LASI may help predict the outcomes following AF radiofrequency catheter ablation (RFCA). This prospective study enrolled 190 consecutive AF patients who underwent TTE 24h before RFCA. LASI was calculated as the ratio of left atrial maximum volume to spherical volume. After 1-year follow-up, 56 patients (29.5%) relapsed. Multivariate Cox regression showed that LASI (hazard ratio = 1.48, 95% Cl 1.15-1.92, P= 0.003) was an independent predictor of AF recurrence. Stratifying patients into four subgroups with different LAVI showed that high LASI value indicated a high risk of recurrence, especially in patients with mildly and moderately enlarged atria (the recurrence rate was 0% vs. 26.3%, P= 0.049; 9.5% vs. 40.9%, P= 0.018, respectively). In conclusion, TTE-derived LASI may be useful to predict AF recurrence after RFCA.

Clinical significance of left atrial geometry in dilated cardiomyopathy patients: A cardiovascular magnetic resonance study.

BackgroundClinical significance of left atrial (LA) function and geometry in patients with dilated cardiomyopathy (DCM) remains uncertain.HypothesisLA geometric parameters assessed by cardiac magnetic resonance (CMR) predict the prognosis in patients with DCM.MethodsThe present study included patients with DCM and sinus rhythm who underwent CMR between December 2007 and April 2018. LA volume was measured using CMR. LA sphericity index was computed as the ratio of the measured maximum LA volume by the volume of a sphere with maximum LA length diameter.ResultsWe included 255 patients in this study. During the mean follow‐up of 3.92 years, hospitalization for HF occurred in 37 patients. The LA sphericity index was significantly higher in patients with hospitalization for HF than in those without (0.78 ± 0.35 vs. 0.58 ± 0.18, p < .001). Multivariable Cox regression analysis identified a higher LA sphericity index as an independent predictor of hospitalization for HF. Patients were categorized based on the median of LA sphericity index. The Kaplan–Meier curve showed that patients with a high LA sphericity index (≥0.57) had a significantly higher risk of hospitalization for HF than those with a low LA sphericity index (<0.57).ConclusionLA sphericity index was an independent predictor of hospitalization for HF. Assessment of LA geometric parameters might be useful for risk stratification in patients with DCM.

Normal left atrial strain and strain rate using cardiac magnetic resonance feature tracking in healthy volunteers.

The aim of our study was to establish normal ranges for left atrial (LA) strain and strain rate using cardiac magnetic resonance feature tracking (CMR-FT), LA sphericity index, and to compare LA strain using CMR-FT with 2D-speckle tracking echocardiography (STE) in a healthy population. A total of 112 volunteers (45 male, 67 female) had adequate tracking for analysis on CMR-FT (Circle Cardiovascular Imaging, Calgary, Canada). The median age was 42 years (range 19-79 years, interquartile range 30-53 years). LA reservoir, conduit, booster strain, strain rate using CMR-FT, and sphericity index were evaluated. Of the 112 volunteers, 91 patients had adequate tracking on 2D-STE using three commonly applied zero-baseline time reference methods: R-R gating, P-P gating, and volume gating (defining end-systole at the LA maximum and end-diastole at the LA minimum). The LA strain, strain rate using CMR-FT, and sphericity index were reported and comparable between both genders (P > 0.05 for all). The LA booster function including strain and strain rate increased significantly with age (P < 0.001 for all), while the LA conduit function gradually decreased. In comparison with STE, the LA reservoir strain was comparable between CMR and volume-gating methods (38.48 ± 9.31 vs. 36.77 ± 6.46; P = 0.13) but not with R-R and P-P gating methods (P < 0.001 for all). LA strain, strain rate, and sphericity index using CMR-FT had good intraobserver and interobserver reproducibility. LA strain, strain rate using CMR-FT, and sphericity index can be quickly assessed with good intraobserver and interobserver reproducibility.

Reproducibility and accuracy of late gadolinium enhancement cardiac magnetic resonance measurements for the detection of left atrial fibrosis in patients undergoing atrial fibrillation ablation procedures.

Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) may define left atrial (LA) anatomy and structural remodelling, and facilitate atrial fibrillation (AF) ablation. We aimed to assess the intra- and inter-observer reproducibility and agreement of LGE-CMR parameters with direct application to AF ablation techniques. One experienced and one non-experienced observer performed complete LGE-CMR data analysis twice, on different days, in 40 randomly selected LGE-CMR examinations [20 performed before ablation (pre-ablation) and 20 performed 3 months after ablation (post-ablation)]. Four additional observers (two experienced and two non-experienced) performed complete LGE-CMR data analysis in a subgroup of 30 patients (15 pre-ablation and 15 post-ablation). All LGE-CMR were performed in sinus rhythm. Intra- and inter-observer reproducibility of LA volume, LA area, and sphericity index (SI) was high: coefficient of variation <10% and intraclass correlation coefficient >0.71. Geometric congruency of repeated reconstruction of LA shape was high: maximal error <5 mm for intra-observer and <8 mm for inter-observer. The precision of scar location increased with extent of scar, and was high (Dice coefficient >0.75) when the scar area was >5 cm2 for a single observer and >15 cm2 for multiple observers. Non-experienced observers performed equally well to experienced observers. Late gadolinium enhancement cardiac magnetic resonance measurements of LA area, volume, and SI were reproducible, and geometric congruency of LA shape was high. Location of scar was precise for scar areas >5 cm2 for single observers and >15 cm2 for multiple observers, regardless of the observers' experience. These results may serve as a reference for future studies on the role for substrate-based AF ablation procedures.

Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct-Current Cardioversion: An Echocardiographic Study.

Attempts to achieve rhythm control using direct-current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atrial sphericity index (LASI) acquired by 2-dimensional transthoracic echocardiography (TTE) could be used as a predictor of AF recurrence after successful DCC. A baselline LASI assessed by 2D TTE can predict AF recurrence after successful DCC in patients with persistent AF. A total of 124 consecutive patients with persistent AF lasting <120 days underwent successful DCC. Other than β-blockers, no other antiarrhythmic treatment was administered. Prior to DCC, all patients underwent thorough TTE, and LASI was calculated as the fraction of the left atrial width/length of the largest possible left atrial volume in a 4-chamber view. The primary outcome was a TTE-estimated baseline LASI as a predictor of AF recurrence after successful DCC for persistent AF. Anatomically, a more spherical shape of the left atrium (LASI >0.9) proved to be a strong and independent predictor of AF recurrence, with an odds ratio between 4.1 (95% confidence interval: 1.6-11.9, P = 0.005) and 7.6 (95% confidence interval: 3.3-19.7; P = 7.2 × 10(-6) ). The receiver operating characteristic curve indicated good power for distinguishing between recurring and nonrecurring AF, and we chose a cutoff of 0.9 because high specificity was a priority for clinical reasons. In conclusion, baseline LASI >0.9 was associated with significantly greater AF recurrence throughout the 12-month follow-up period.

E0617 Research of relation between the type of left ventricular remodelling and atrial fibrillation in patients with essential hypertension

BackgroundEssential hypertension (EH) is the common cause of left ventricular (LV) geometric remodelling which includes shape remodelling, volume remodelling and mass remodelling. The relation between the type of LV geometric...