Atrial Sphericity Research Articles

Left Atrial Sphericity: A New Marker for Cardioembolic Stroke

Left Atrial Sphericity: A New Marker for Cardioembolic Stroke

Cardiac imaging correlates and predictors of stroke in patients with atrial fibrillation: a meta-analysis.

New nonclinical parameters are needed to improve the current stroke risk stratification schemes for patients with atrial fibrillation. This study aimed to summarize data on potential cardiac imaging correlates and predictors of stroke or systemic embolism in patients with atrial fibrillation. MEDLINE, EMBASE, and Web of Science were searched to identify all published studies providing relevant data through 16 November 2022. Random effects meta-analysis method was used to pool estimates. We included 64 studies reporting data from a pooled population of 56 639 patients. Left atrial spontaneous echo-contrast [adjusted odds ratio (aOR) 3.32, 95% confidence interval (CI) 1.98-5.49], nonchicken wing left atrial appendage (LAA) morphology (aOR 2.15, 95% CI 1.11-4.18), left atrial enlargement (aOR 2.12, 95% CI 1.45-3.08), and higher LAA orifice diameter (aOR 1.56, 95% CI 1.18-2.05) were highly associated with stroke. Other parameters associated with stroke included higher left atrial sphericity (aOR 1.14, 95% CI 1.01-1.29), higher left atrial volume (aOR 1.03, 95% CI 1.01-1.04), higher left atrial volume index (aOR 1.014, 95% CI 1.004-1.023), lower left atrial reservoir strain [adjusted hazard ratio (aHR) 0.86, 95% CI 0.76-0.98], higher left ventricular mass index (aOR 1.010, 95% CI 1.005-1.015) and E / e' ratio (aOR 1.12, 95% CI 1.07-1.16). There was no association between LAA volume (aOR 1.37, 95% CI 0.85-2.21) and stroke. These cardiac imaging parameters identified as potential predictors of thromboembolism may improve the accuracy of stroke risk stratification schemes in patients with atrial fibrillation. Further studies should evaluate the performance of holistic risk scores including clinical factors, biomarkers, and cardiac imaging.

Right and left atrial echocardiographic parameters and outcome in patients with atrial fibrillation

Abstract Background Atrial remodeling in atrial fibrillation (AF) can be evaluated by measuring atrial dimensions, volumes, or function, in the left atrium (LA) but right atrial (RA) changes are often neglected. Purpose The aim of the analysis was to evaluate the power of LA and RA parameters in predicting a composite endpoint (CEP) of all-cause death, any thromboembolism, any acute coronary syndrome, and hospitalization for new or worsening heart failure. Methods From March 2016 to December 2021, patients with ECG-documented AF within 1 year were prospectively enrolled. We retrieved echo data by reviewing clips and collected clinical and laboratory data. Patients were followed up after 1 month and every 6 months thereafter unless clinically relevant events occurred. We considered left and right atrial antero-posterior diameter (iLAAPD, iRAAPD), left and right atrial volume (LAVI, RAVI), left and right atrial sphericity index (LASI, RASI), right and left atrial emptying fraction (RAEF, LAEF). Volumes and diameters were indexed by body surface area. Echo parameters were collected according to the 2015 recommendations of the American Society of Echocardiography. Results We enrolled 489 patients, 300 males (61.3%), median age 75 (IQR 66-80) years, median CHA2DS2VASc 3 (2-5), median HAS-BLED 1 (1-2). Four-hundred fifty-one (92.2%) patients were anticoagulated. Eighty-seven patients (17.8%) had a paroxysmal AF, 141 (28.8%) a persistent AF, 198 (40.5%) a permanent AF, and 63 (12.9%) a first-detected AF. After a median follow-up of 1114 (392-1384) days, 129 (26.3%) achieved the CEP. LAEF < 28% and iRAAPD ≥ 44 mm/m2 showed better sensitivity (respectively 72% and 73%) while iLAAPD and LAVI showed better negative predictive values (both 81%). At multivariable Cox regression analysis (adjusted for CHA2DS2VASc, AF type, and pattern of anticoagulation), building one model for every echocardiographic parameter, LA dimension, volume and function were associated with a higher risk of worse outcome (LAAPD > 22 mm/m2 HR 1.78; 95%CI 1.24-2.57; LAVI ≥ 42 ml/m2 HR 1.50 95%CI 1.03-2.19; LAEF < 28% HR 1.74 95%CI 1.21-2.48) while RASI, LASI, and RA parameters (except for iRAAPD ≥ 44 mm/m2: HR 1.65; 95%CI 1.10-2.47) were not. Comparing those models with a null one (i.e. variables used for adjustments) using the likelihood ratio test, the above-mentioned models demonstrated a significant improvement in predicting the risk of CEP (iLAAPD p=0.0018; LAVI p=0.0347; LAEF p=0.0028; iRAAPD p=0.0148). Visual analysis of multivariable restricted cubic splines regression graphs confirmed iLAAPD and LAVI as the only atrial parameters that refined risk prediction, with their lower limits of CI exceeding the 1 HR line at reference points (Figure). Conclusions In patients with AF, LAVI and iLAAPD allow better discrimination and risk prediction for the composite outcome, while sphericity indexes and most of the RA parameters do not provide adequate predictionFigure

Left atrial sphericity in relation to atrial strain and strain rate in atrial fibrillation patients

PurposeLeft atrial (LA) sphericity is a novel, geometry-based parameter that has been used to visualize and quantify LA geometrical remodeling in patients with atrial fibrillation (AF). This study examined the association between LA sphericity, and LA longitudinal strain and strain rate measured by feature-tracking in AF patients.Methods128 AF patients who underwent cardiovascular magnetic resonance (CMR) imaging in sinus rhythm prior to their pulmonary vein isolation (PVI) procedure were retrospectively analyzed. LA sphericity was calculated by segmenting the LA (excluding the pulmonary veins and the LA appendage) on a 3D contrast enhanced MR angiogram and comparing the resulting shape with a perfect sphere. LA global reservoir strain, conduit strain, contractile strain and corresponding strain rates were derived from cine images using feature-tracking. For statistical analysis, Pearson correlations, multivariable logistic regression analysis, and Student t-tests were used.ResultsPatients with a spherical LA (dichotomized by the median value) had a lower reservoir strain and conduit strain compared to patients with a non-spherical LA (-15.4 ± 4.2% vs. -17.1 ± 3.5%, P = 0.02 and − 8.2 ± 3.0% vs. -9.5 ± 2.6%, P = 0.01, respectively). LA strain rate during early ventricular diastole was also different between both groups (-0.7 ± 0.3s− 1 vs. -0.9 ± 0.3s− 1, P = 0.001). In contrast, no difference was found for LA contractile strain (-7.2 ± 2.6% vs. -7.6 ± 2.2%, P = 0.30).ConclusionsLA passive strain is significantly impaired in AF patients with a spherical LA, though this relation was not independent from LA volume.

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.

Progressive and Simultaneous Right and Left Atrial Remodeling Uncovered by a Comprehensive Magnetic Resonance Assessment in Atrial Fibrillation.

Background Left atrial structural remodeling contributes to the arrhythmogenic substrate of atrial fibrillation (AF), but the role of the right atrium (RA) remains unknown. Our aims were to comprehensively characterize right atrial structural remodeling in AF and identify right atrial parameters predicting recurrences after ablation. Methods and Results A 3.0 T late gadolinium enhanced-cardiac magnetic resonance was obtained in 109 individuals (9 healthy volunteers, 100 patients with AF undergoing ablation). Right and left atrial volume, surface, and sphericity were quantified. Right atrial global and regional fibrosis burden was assessed with validated thresholds. Patients with AF were systematically followed after ablation for recurrences. Progressive right atrial dilation and an increase in sphericity were observed from healthy volunteers to patients with paroxysmal and persistent AF; fibrosis was similar among the groups. The correlation between parameters recapitulating right atrial remodeling was mild. Subsequently, remodeling in both atria was compared. The RA was larger than the left atrium (LA) in all groups. Fibrosis burden was higher in the LA than in the RA of patients with AF, whereas sphericity was higher in the LA of patients with persistent AF only. Fibrosis, volume, and surface of the RA and LA, but not sphericity, were strongly correlated. Tricuspid regurgitation predicted right atrial volume and shape, whereas diabetes was associated with right atrial fibrosis burden; sex and persistent AF also predicted right atrial volume. Fibrosis in the RA was mostly located in the inferior vena cava-RA junction. Only right atrial sphericity is significantly associated with AF recurrences after ablation (hazard ratio, 1.12 [95% CI, 1.01-1.25]). Conclusions AF progression associates with right atrial remodeling in parallel with the LA. Right atrial sphericity yields prognostic significance after ablation.

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.

MIP-1α Level and Its Correlation with the Risk of Left Atrial Remodeling in Patients with Atrial Fibrillation.

The aim of this study is to investigate the expression level of macrophage inflammatory protein-1α (MIP-1α) in atrial fibrillation patients and its correlation with the risk of left atrial remodeling. A total of 64 atrial fibrillation patients admitted to our hospital from April 2020 to December 2021 were prospectively selected as the case group and 61 healthy subjects who received physical examination during the same period were selected as the control group. Serum MIP-1α level was determined by a double-antibody sandwich enzyme-linked immunosorbent assay. Serum MIP-1α expression levels were compared between the case and the control groups. The case group was divided into high-level and low-level groups according to the serum MIP-1α median. Simultaneously, the sociodemographic data, clinical data, and left atrial remodeling indexes of the patients were collected in the case group. The Pearson correlation analysis was applied to analyze the correlation between the serum MIP-1α level and the risk of left atrial remodeling in patients with atrial fibrillation. The serum MIP-1α level was significantly higher in the case group than that in the control group (P < 0.05), high-level group (≥2.14 pg/mL, 32 cases), and low-level group (<2.14 pg/mL, 32 cases). There were significant differences in the anteroposterior diameter, upper and lower diameter, left and right diameter of the left atrium, left atrial volume, volume index, left atrial global ejection fraction, and sphericity between the low-level and high-level groups (P < 0.05). The Pearson correlation analysis showed that serum MIP-1α level was positively correlated with the left atrial anteroposterior diameter (r = 0.745), left atrial left and right diameter (r = 0.759), left atrial upper and lower diameter (r = 0.810), left atrial volume (r = 0.837), left atrial volume index (r = 0.813), and left atrial sphericity (r = 0.785) but negatively correlated with the left atrial global ejection fraction (r = -0.731) (P < 0.05). The expression level of serum MIP-1α is high in atrial fibrillation patients and is associated with the risk of left atrial remodeling.

Association of Left Atrial Sphericity with Risk of Stroke in Patients with Atrial Fibrillation. Sub-Analysis of the ASSAM Study

PurposeThe study was designed to evaluate the value of left atrial (LA) sphericity (LASP) in the identification of patients with atrial fibrillation (AF) who had prior ischemic stroke. The secondary aim was to investigate the possibility of improving stroke risk assessment based on six geometrical variables of LA.MethodsThis prospective observational study involved 157 patients: 74 in the stroke group and 83 in the control. All patients had cardiac computed tomography (CT) performed to analyze LA volume and dimensions. LASP and the discriminant function of six geometrical measurements were calculated.ResultsMultivariate logistic regression analysis showed a significant association of stroke with and gender, diabetes, CHA2DS2-VASc score, LA anteroposterior diameter, and LA sphericity. Patients with prior stroke had lower LASP than those without (66.6 ± 10.3% vs. 70.5 ± 7%; p = 0.0062). The most accurate identification of patients with a history of ischemic stroke was achieved by using a function of six geometrical measurements, the sphericity and volume coefficient. The C-statistic was higher for the above discriminant function (0.7273) than for LASP (0.3974). The addition of the discriminant function to the CHA2DS2-VASc score increased the performance of the risk score alone.ConclusionLASP is associated with prior stroke in AF patients. The proposed new formula for identification of AF patients who are at risk of stroke, based on geometrical measurements of LA, is superior to the basic LASP in identification of AF patients with a history of stroke.

Impact of left atrial geometric remodeling on late atrial fibrillation recurrence after catheter ablation.

To quantitatively investigate the impact of left atrial geometric remodeling on atrial fibrillation recurrence after catheter ablation. A retrospective analysis of 105 patients with atrial fibrillation who underwent coronary computed tomographic angiography before catheter ablation. Risk factors for atrial fibrillation recurrence were identified by multivariable logistic regression analysis and used to create a nomogram. After at least 12 months of follow-up, 30 patients (29%) developed recurrent atrial fibrillation. Patients with recurrence had higher left atrial volume, left atrial sphericity, and lower left atrial ejection fraction (LAEF) (P < 0.05). There was no significant difference in asymmetry index between the two groups (P = 0.121). Multivariable regression analysis showed that left atrial minimal volume index (LAVImin) [odds ratio (OR): 1.026, 95% confidence interval (CI): 1.002-1.050, P = 0.034], left atrial sphericity (OR: 1.222, 95% CI: 1.040-1.435, P = 0.015) and CHADS2 score (OR: 1.511, 95% CI: 1.024-2.229, P = 0.038) were independent predictors of atrial fibrillation recurrence. The combined model of the left atrial sphericity to the LAVImin substantially increased the predictive power for atrial fibrillation recurrence [area under the curve (AUC) = 0.736, 95% CI: 0.627-0.844, P < 0.001], with a sensitivity of 80% and a specificity of 61%. A nomogram was generated based on the contribution weights of the risk factors; the AUC was 0.772 (95% CI: 0.670-0.875) and had good internal validity. The CHADS2 score, left atrial sphericity, and LAVImin were significant and independent predictors of atrial fibrillation recurrence after catheter ablation. Furthermore, the nomogram had a better predictive capacity for atrial fibrillation recurrence.

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.

P1015Left atrial sphericity as a marker of atrial remodeling: comparison of atrial fibrillation patients and controls

Abstract Background/Introduction Left atrial (LA) sphericity has been proposed as a more sensitive marker of atrial fibrillation (AF)-associated atrial remodeling compared to traditional markers such as LA size. However, mechanisms that underlie changes in LA sphericity are not fully understood and studies investigating the predictive value of LA sphericity for AF ablation outcome have yielded conflicting results. Purpose The present study aimed to assess correlates of LA sphericity and to compare LA sphericity in subjects with and without AF. Methods Measures of LA size (LA diameter, LA volume, LA volume index), LA sphericity and thoracic anteroposterior diameter (APd) at the level of the LA were determined in a total of 293 AF patients (62% paroxysmal AF) and 110 controls. Cardiac computed tomography (CT) images were analyzed offline by a reviewer blinded to clinical parameters. The AF cohort consisted of consecutive patients referred for cardiac CT imaging prior to first AF ablation procedure between January 2015 and January 2018. The control cohort consisted of subjects with no history of AF who underwent cardiac CT imaging between January 2012 and October 2014 to exclude coronary artery disease. Results LA diameter (40.1 ± 6.8 mm vs. 35.2 ± 5.1 mm; p &amp;lt; 0.001), LA volume (116.0 ± 33.0 ml vs. 80.3 ± 22.6 ml; p &amp;lt; 0.001) and LA volume index (56.1 ± 15.3 ml/m² vs. 41.6 ± 11.1 ml/m²; p &amp;lt; 0.001) were significantly larger in AF patients compared to controls (Figure), also after adjustment for age and sex. LA sphericity did not differ between AF patients and controls (83.7 ± 2.9 vs. 83.9 ± 2.4; p = 0.642). A moderate correlation was noted between thoracic APd and LA sphericity in both females (R = 0.521, p &amp;lt; 0.001) and males (R = 0.498, p &amp;lt; 0.001). Multivariable linear regression analysis demonstrated that LA diameter, LA volume, female sex, body length and thoracic APd were independently associated with LA sphericity. Conclusion The present study suggests that thoracic constraints rather than the presence of AF determine LA sphericity, implying LA sphericity to be unsuitable as a marker of AF-related atrial remodeling. Abstract Figure. Comparison of LA imaging characteristics

Left atrial sphericity as a marker of atrial remodeling: Comparison of atrial fibrillation patients and controls

BackgroundLeft atrial (LA) sphericity has been proposed as a more sensitive marker of atrial fibrillation (AF)-associated atrial remodeling compared to traditional markers such as LA size. However, mechanisms that underlie changes in LA sphericity are not fully understood and studies investigating the predictive value of LA sphericity for AF ablation outcome have yielded conflicting results. The present study aimed to assess correlates of LA sphericity and to compare LA sphericity in subjects with and without AF. MethodsMeasures of LA size (LA diameter, LA volume, LA volume index), LA sphericity and thoracic anteroposterior diameter (APd) at the level of the LA were determined using computed tomography (CT) imaging data in 293 AF patients (62% paroxysmal AF) and 110 controls. ResultsLA diameter (40.1 ± 6.8 mm vs. 35.2 ± 5.1 mm; p < 0.001), LA volume (116.0 ± 33.0 ml vs. 80.3 ± 22.6 ml; p < 0.001) and LA volume index (56.1 ± 15.3 ml/m2 vs. 41.6 ± 11.1 ml/m2; p < 0.001) were significantly larger in AF patients compared to controls, also after adjustment for covariates. LA sphericity did not differ between AF patients and controls (83.7 ± 2.9 vs. 83.9 ± 2.4; p = 0.642). Multivariable linear regression analysis demonstrated that LA diameter, LA volume, female sex, body length and thoracic APd were independently associated with LA sphericity. ConclusionsThe present study suggests that thoracic constraints rather than the presence of AF determine LA sphericity, implying LA sphericity to be unsuitable as a marker of AF-related atrial remodeling.

The correlation between left atrial sphericity and thromboembolic events in patients with atrial fibrillation

Objective: To study the correlation between left atrial sphericity (LASP) and thromboembolic events (TE) in patients with atrial fibrillation (AF). Methods: This study was conducted in patients with AF underwent radiofrequency ablation in the Department of Cardiology of First Affiliated Hospital of Zhengzhou University from January 2011 to October 2018. The AF patients with TE (study group, n=157) and the AF patients without TE (control group, n=157) were matched for age and gender. The differences of LASP and other related indexes between the two groups were compared, and the correlation between LASP and TE was analyzed by conditional logistic regression. The receiver operating characteristic (ROC) curve was drawn to analyze the diagnostic value of LASP for TE. Results: (1) The LASP in the study group was significantly higher than that in the control group [ (87.5±7.1) % vs. (82.8±6.1) %, P=0.001]. (2) Conditional logistic regression analyses showed that LASP (OR=1.10, 95%CI 1.05-1.16, P=0.001), left atrial volume index (OR=1.01, 95%CI 1.00-1.02, P=0.016) and CHA(2)D-VASc score (OR=1.77, 95%CI 1.30-2.41, P=0.001) were independently and positively correlated with TE. (3) The ROC curve analysis showed that the area under the curve (AUC) of left atrial sphericity (AUC=0.712, 95%CI 0.656-0.768, P=0.001) was larger than the AUC of either left atrial volume index (AUC=0.650, 95%CI 0.589-0.710, P=0.001) or CHA(2)D-VASc score (AUC=0.612, 95%CI 0.550-0.674, P=0.001). (4) CHA(2)D-VASc-LASP(2) score was positively correlated with TE (OR=1.95, 95%CI 1.55-2.42, P=0.001). Conclusion: LASP is independently and positively correlated with TE in patients with AF.

Prediction and Management of Recurrences after Catheter Ablation in Atrial Fibrillation and Heart Failure.

Catheter ablation is recommended in patients with symptomatic atrial fibrillation (AF) refractory to pharmacologic therapy. AF recurrence is common postablation, particularly in patients with heart failure, because of multiple structural and functional changes that can occur. Determining predictors of AF recurrence has become increasingly important. These include increased left atrial volume, termination of AF during the index ablation, electrocardiogram parameters, and serum biomarkers. Cardiac MRI can also determine the degree of scarring and left atrial sphericity, which is used in risk prediction scores. In patients with recurrence, further treatment options include pharmacologic therapy and atrioventricular nodal ablation with pacing.

P373Left atrial pressure correlates with atrial sphericity but not with the degree of atrial dilatation and scar burden, in patients who underwent pulmonary vein isolation

P373Left atrial pressure correlates with atrial sphericity but not with the degree of atrial dilatation and scar burden, in patients who underwent pulmonary vein isolation

Prognostic implication of left atrial sphericity in atrial fibrillation patients undergoing radiofrequency catheter ablation.

Left atrial (LA) sphericity can predict recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). We sought to reconfirm the prognostic role of atrial sphericity after RFCA of atrial fibrillation (AF), assess any relationship between the atrial pressure and sphericity, and determine the characteristics of the patients for whom atrial sphericity was most highly predictive. All 148 nonvalvular AF patients (57 ± 11 years, 121 men, 95 paroxysmal AF [PaAF]) who underwent RFCA were enrolled. The LA volume (LAV) was determined and LA sphericity assessed from three-dimensional computed tomographic images. The preprocedural mean LA pressure (mLAP) was measured. After a 3-month blanking period, AF/atrial tachycardia (AT) recurrences within 1 year were documented in 38 patients (26%). Patients with recurrence had a greater LAV (124 ± 35 mL vs 151 ± 45 mL, P < 0.001) and LA sphericity (0.669 ± 0.040 vs 0.684 ± 0.038, P = 0.041). In patients with smaller LAs (LAV < 125 mL), LA sphericity predicted AF/AT recurrences (odds ratio [OR]: 1.030 [for each 0.001 increase], 95% confidence interval [CI]: 1.008-1.053, P = 0.007), whereas the LAV did not. In patients with larger LAs (LAV ≥ 125 mL), the LAV could predict recurrence (OR: 1.021, 95% CI: 1.001-1.041, P = 0.036), while the LA sphericity could not. The LA sphericity and mLAP are linearly correlated (r = 0.345, P < 0.022) in persistent AF, but not PaAF. LA spherical change precedes severe LA enlargement in AF. It predicts 1-year AF/AT recurrence after RFCA and is more important than the LA size in patients with less severe LA enlargement.

Left Atrial Geometry Improves Risk Prediction of Thromboembolic Events in Patients With Atrial Fibrillation.

Left atrial (LA) sphericity (LASP) is a new remodeling parameter based on LA shape analysis, with independent predictive value for recurrence after atrial fibrillation (AF) ablation. To evaluate the association between LASP and thromboembolic events (TE) in patients with AF. Twenty-nine AF patients and prior TE and 29 age- and gender-matched controls were included. LASP was calculated using a 3D-LA reconstruction. The LA appendage (LAA) volume and morphology were assessed. ROC curve analysis was performed for LASP, LA volume, LAA volume, and CHAD/CHA2 D-VASc scores (Stroke2 -the grouping variable-was excluded). Mean age of the study population was 61 ± 11 years (79.3% males, 53.4% hypertension, 8.6% diabetes). Patients with prior TE had higher LASP than those without (82.5 ± 3.3% vs. 80.2 ± 3.1%, P = 0.008); there were no differences in CHAD or CHA2 D-VASc scores, LA volume, LAA volume, or LAA morphology. The C-statistic was higher for LASP (0.71) than for other tested variables (CHAD score = 0.58, CHA2 D-VASc score = 0.59, LA volume = 0.50, LAA volume = 0.46; P < 0.01 for all vs. LASP). The best cutoff value for LASP was 83.6% (sensitivity 0.52, specificity 0.90). Logistic regression analysis showed predictive value for LASP (OR 1.26 per each 1% increase [1.85-52.20], P = 0.013), but not for clinical risk scores. The addition of LASP to the CHAD and CHA2 D-VASc scores increased the predictive value over the risk scores alone (P = 0.004), and reclassified 45.5% of patients with CHAD = 0 (no anticoagulation indicated) to moderate-risk (anticoagulation indicated). LA sphericity is associated with prior TE in AF patients and improves the performance of the CHAD and CHA2 D-VASc scores alone.

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.