Left Remodeling Research Articles

792 FULL EVALUATION OF LEFT ATRIAL FUNCTION AFTER MITRACLIP IMPLANTATION

Abstract Objective interventional edge-to-edge repair by MitraClip ™ is widely demonstrated to be able to reduce the degree of MR in patients with high surgical risk. The left atrial (LA) dysfunction in patients with severe MR is associated with poor prognosis and its changes after MV repair is reported in several studies. While, little is known about the full evaluation of the LA function by Two-dimensional speckle echocardiography tracking (2D STE) Materials and methods from March 2015 to December 2021, clinical and echocardiographic data of 67 patients with MR who underwent Mitraclip™ implantation in our division were evaluated for LA function. Strain Reservoir (S_R), Conduit Strain (S_Cd), Contractile Strain (S_Ct), LA emptying Fraction (LAEF_4CH), LAESV (Left atrial end-systolic volume), LAEDV (Left atrial end-diastolic volume) at baseline, at 1 month, at 6 months and 1 year of follow up were assessed. The variation of continuous variables was evaluated using a student T test for paired data. The categorical variables between baseline, at 1 month, at 6 months and 1 year of follow up were evaluated using the ANOVA test. The Multiple Bonferroni test comparison was conducted as a post hoc analysis P values <0.05 were considered significant. Results the etiology of the MR was primary in 29,2% and secondary in 70,8% of the included patients. The MR degree was 3+ in 16,9% of patients and 4+ in 81,5%. When compared to baseline at 6 months and 1 year a statistically significant improvement was observed for LAEF_4CH (p 0.006 and <0.001) and at 1 year for S_R (p 0.013) and S_Cd (p 0.033). When compared at 1 month the S-R improvement was observed at 6 months and 1 year (shown in Table 1). Finally, no significant changes were observed in S_Ct at different time point analyzed. Conclusions the MR improvement after MitraClip™ procedure allows hemodynamic changes with LA remodeling which can be detected by 2D STE through an improvement in LA function. These data emphasize the hypothesis that these echocardiographic parameters represent an advanced method to evaluate the response to device implantation.

6 EVALUATION OF ECHOCARDIOGRAPHIC PARAMETERS IN PATIENTS WITH MICROVASCULAR DYSFUNCTION: A PROSPECTIVE STUDY.

Abstract Background The prevalence of microvascular angina is underestimated in the general population because it is often difficult to detect. Microvascular dysfunction is defined by parameters of reduced coronary flow reserve (CFR <2) without epicardial stenosis and/or increased index of microvascular resistance (IMR> 25). Purpose The aim of this study was to evaluate the echocardiographic parameters in patients with symptoms of myocardial ischemia without evident coronary epicardial obstruction. Primary endpoint was to analyze the global longitudinal strain of the left ventricle and the left atria strain in patients with microvascular angina. Secondary endpoint was to analyze echocardiographic parameters to evaluate the diastolic function of the left ventricle, the prevalence of cardiovascular risk factors and the blood tests values. Methods Between 1st February 2019 and 1st May 2022, subjects with angina and not functionally significant epicardial stenosis (Resting Full-cycle Ratio > 0.91, Fractional flow reserve >0.80), underwent assessment of microvascular function and were divided into 2 cohorts. All patients had sinus rhythm, preserved left ventricular ejection fraction (LVEF> 55%), no severe left ventricular hypertrophy (interventricular septum <13 mm) or structural heart disease. For each patient we analyzed the left ventricular global longitudinal strain in the three apical views (4 chamber, 2 chamber and 3 chamber) and the left atria strain, PALS (peak atrial longitudinal strain) and PACS (peak atrial contraction strain), in two apical views (4 chamber and 2 chamber). We also measured the diastolic function indices (E/e’, isovolumic relaxation time, deceleration time), the left atrial area and pulmonary artery systolic pressure (PASP) evaluated on echocardiography. Results A total of 132 patients were enrolled. Of those, 47 had evidence of microvascular dysfunction and 85 had normal CFR/IMR. Primary Endpoint: patients with microvascular dysfunction had reduced values of left ventricular global longitudinal strain and reduced values of left atrial strain compared to controls (p<0,001). Secondary Endpoint: a higher prevalence of diabetic and obese women was associated with microvascular dysfunction. However, there were no significant differences in age, prevalence of hypertension, dyslipidemia, smoking and dysthyroidism. Numerically higher values of NTproB-type Natriuretic Peptide (NTproBNP) and C-reactive protein were seen in patients with microvascular dysfunction, while there were no significant differences in hemoglobin, white bold cells, platelets, cholesterol, creatinine and troponin values. Left ventricular isovolumic relaxation time, left atrium area, and pulmonary artery systolic pressure as well as E/e' values were significantly increased in patients with microvascular dysfunction. Furthermore, there was a significant reduction in deceleration time values. Conclusion Patient with microvascular dysfunction are frequently diabetic and obese women. Echocardiographic parameters show left ventricular diastolic dysfunction and possibly subsequent left atrial remodeling. Furthermore, the analysis of the global longitudinal strain of the left ventricle could reveal alterations in cardiac contractile mechanics that are difficult to identify with conventional echocardiography. NTproBNP values were not significantly higher, demonstrating that patients with microvascular dysfunction have an early diastolic dysfunction that is not clinically evident.

Plasma FGF23 is associated with left atrial remodeling in children on hemodialysis.

FGF23 mediates cardiac fibrosis through the activation of pro-fibrotic factors in in vitro models and is markedly elevated in kidney disease. Left atrial global longitudinal strain (LA GLS) derived by echocardiographic speckle-tracking measures longitudinal shortening of the LA walls, quantifies atrial performance and may enable detection of early LA remodeling in the setting of normal ventricular function. We hypothesized that LA GLS is abnormal in children on hemodialysis (HD) compared to healthy controls of comparable age/sex distribution and that, among HD patients, greater FGF23 levels are associated with abnormal LA GLS. Clinical and echocardiographic data from 29 children receiving HD and 13 healthy controls were collected in a cross-sectional single-center study. Plasma FGF23 concentrations were measured using ELISA. The primary outcome was LA GLS measured using 2D speckle-tracking strain analysis. Linear regression analysis was used to investigate predictors of LA GLS in HD. Median dialysis vintage was 1.5 (IQR 0.5-4.3) years. Median intact FGF23 levels were substantially higher in the HD vs. control group (1206 [215, 4707] vs. 51 [43, 66.5] pg/ml; P = 0.0001), and LA GLS was 39.9% SD 11.6 vs. 32.8% SD 5.7 (P = 0.04). Among HD patients, higher FGF23 was associated with lower LA GLS (β per unit Ln-FGF23: - 2.7; 95% CI slope - 5.4, - 0.1; P = 0.04 after adjustment for age, body size, and HD vintage. FGF23 was not associated with LA phasic reservoir, conduit, or contractile strain. In children on HD and preserved left ventricularejection fraction, greater FGF23 is associated with lower LA GLS (indicative of impaired atrial performance). A higher resolution version of the Graphical abstract is available as Supplementary information.

Left Atrial Remodeling in Response to Aortic Valve Replacement: Pathophysiology and Myocardial Strain Analysis.

Severe aortic stenosis (AS) is the most common valve disease in the elderly and is associated with poor prognosis if treated only medically. AS causes chronic pressure overload, concentric left ventricular (LV) hypertrophy, myocardial stiffness, and diastolic dysfunction. This adverse remodeling also affects the left atrium (LA), which dilates and develops myocardial fibrosis, with a reduction in intrinsic function and a consequent high risk of the development of atrial fibrillation. Speckle-tracking echocardiography is able to detect myocardial dysfunction before other conventional parameters, such as LV ejection fraction, and also predict clinical outcomes. This review aims at describing LV and LA remodeling in AS and before and after aortic valve replacement and the usefulness of myocardial strain analysis in this clinical setting.

Circulating fibroblast activation protein α is reduced in acute ischemic stroke.

Fibroblast activation protein α (FAP), a membrane glycoprotein with dipeptidyl-peptidase and collagenase properties, is expressed in atherosclerotic plaques and remodeling of the extracellular matrix based on fibrosis. Fibrosis is a main contributor of atrial cardiomyopathies. In acute MI, circulating FAP is associated with outcome. Here, we investigated the correlation of circulating FAP to echocardiographic parameters of atrial remodeling and neurological impairment in acute ischemic stroke. Circulating FAP plasma concentrations were determined by ELISA in 47 patients with acute stroke and 22 control patients without stroke. Echocardiography was performed in all participants. Laboratory analysis, National Institutes of Health Stroke Scale (NIHSS) scoring and prolonged Holter-ECG-monitoring were performed in all stroke patients. Patients with acute stroke had lower circulating FAP concentrations than the control cohort (92 ± 24 vs. 106 ± 22 ng/mL, P < 0.001). There was no difference between the circulating FAP concentration comparing stroke due to atrial fibrillation, embolic stroke of undetermined source (ESUS) or atherosclerotic origin. Septal atrial conduction time (sPA-TDI) and left atrial (LA) volume index to tissue Doppler velocity (LAVI/a') representing echocardiographic parameters of LA remodeling did not correlate with FAP concentrations (sPA-TDI: r = 0.123, p = 0.31; LAVI/a': r = 0.183, p = 0.132). Stroke severity as assessed by NIHSS inversely correlated with circulating FAP (r = -0.318, p = 0.04). FAP concentration had a fair accuracy for identifying stroke in the receiver operating characteristic (ROC) analysis (AUC = 0.710, 95% CI: 0.577-0.843). A FAP concentration of 101 ng/mL discriminated between presence and absence of stroke with a sensitivity of 72% and a specificity of 77%. Lower circulating FAP concentration was associated with cardio-cerebro-vascular events within 12 months after admission. Our study is the first to associate FAP with echocardiographic parameters of LA-remodeling and function. FAP did not correlate with sPA-TDI and LAVI/a'. However, FAP was associated with stroke, neurological impairment, and cardio-cerebral events within 12 months. Therefore, FAP might enable individualized risk stratification in ischemic stroke.

Sex differences in atrial remodeling and its relationship with myocardial fibrosis in hypertrophic obstructive cardiomyopathy.

This study aimed to explore the effect of sex on left atrial (LA) remodeling and its relationship with myocardial fibrosis in patients with hypertrophic obstructive cardiomyopathy (HOCM). A total of 85 patients with HOCM were enrolled. Myocardial fibrosis was quantified by the collagen volume fraction (CVF) in myocardial samples. The early atrial peak of emptying rate (PER-E) was assessed by LA volume/time (V/t) curves derived from cardiac magnetic resonance (CMR) imaging analysis. The PER-E index was PER-E normalized by left ventricular (LV) filling volume. Patients with HOCM showed a lower PER-E index than healthy controls (P = 0.027). Compared with men, the PER-E (P < 0.001) and the PER-E indexes (P = 0.012) in women were lower. In CVF-stratified subgroups, a sex difference in the PER-E index was eliminated (P > 0.05). The CVF was correlated with the PER-E and PER-E indexes in both sexes (all P-values were <0.05). In multivariate regression analysis, sex (P = 0.007) and CVF (P < 0.001) were independently correlated with PER-E (all P-values were <0.05). Patients with HOCM presented LA reverse remodeling. Impaired LA function was more common in female patients with HOCM due to their susceptibility to myocardial fibrosis.

Prevalence, Determinants, and Prognostic Value of Left Atrial Dysfunction in Patients With Chronic Coronary Syndrome and Normal Left Ventricular Ejection Fraction

Patients with chronic coronary syndrome (CCS), even when they have complete revascularization and normal left ventricular (LV) systolic function, experience subsequent cardiovascular disease (CVD), highlighting the importance of surrogate markers to prevent adverse consequences. Speckle-tracking echocardiography-derived left atrial (LA) reservoir strain has emerged as a sensitive marker for CVD in various clinical settings. The present study investigated the prevalence, determinants, and prognostic value of LA dysfunction in CCS. We included 278 consecutive patients with CCS with completed percutaneous coronary intervention and preserved LV ejection fraction who underwent follow-up echocardiography. Speckle-tracking analysis was performed to assess LA reservoir strain, and LA dysfunction was defined as LA reservoir strain ≤24%. The primary outcome comprised new-onset atrial fibrillation, heart failure hospitalization, acute coronary syndrome, stroke, or all-cause death. At baseline, 28 patients (10.1%) had LA dysfunction. Multivariable analysis identified age, hypertension, LV ejection fraction, and multivessel disease as independent determinants of LA reservoir strain (all p <0.05). During a median follow-up of 4.8 years, the primary outcome occurred in 60 patients (21.6%). LA dysfunction carried a significant risk for primary outcome independent of traditional risk factors, LV parameters, and LA size (adjusted hazard ratio 3.10, p=0.003); the risk increase remained significant even after excluding atrial fibrillation from the primary outcome (adjusted hazard ratio 2.27, p=0.043). In conclusion, approximately 10% of patients with CCS with normal LV ejection fraction had LA dysfunction associated with adverse cardiovascular outcomes. Further studies are needed to explore whether therapeutic interventions affecting LA remodeling may help prevent CVD events.

Left Atrial Wall Motion Velocity Assessed during Atrial Fibrillation Predicts Sinus Rhythm Maintenance after Electrical Cardioversion in Patients with Persistent Atrial Fibrillation.

Reduced left atrial wall motion velocity measured during AF (LAWMV) indicates left atrial remodeling. The aim of this study was to investigate whether LAWMV assessed with tissue Doppler imaging during atrial fibrillation (AF) predicts sinus rhythm (SR) maintenance after direct current cardioversion (DCCV) for persistent AF. The study included 126 patients who underwent DCCV and were followed for 12 months. At 12 months, maintained SR was reported in 55 patients (43.7%). We noted that LAWMV was higher in patients with maintained SR at 12 months than in those with recurrent AF (3.69 ± 0.84 vs. 2.86 ± 1.09; p < 0.001). In the multivariable regression model containing echocardiographic variables, LAWMV was an independent predictor of SR maintenance at 12 months (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.1-2.69; p = 0.017). Similarly, LAWMW was an independent predictor of SR maintenance at 12 months (OR 1.81, 95% CI 1.19-2.77; p = 0.006) in the multivariate regression model containing both echocardiographic and clinical variables. LAWMV predicts SR maintenance after DCCV for persistent AF. Echocardiographic markers of left atrial mechanical remodeling are better at predicting SR maintenance than markers of structural remodeling.

Reverse structural left atrial remodeling and atrial tachycardia in patients with repeat ablation for atrial fibrillation.

Catheter ablation has been evolved to a cornerstone in the therapy of atrial fibrillation (AF); however, atrial tachycardias (AT) after AF ablation are still an important issue. Besides the electrical recurrence of atrial tachyarrhythmia after ablation, left atrial (LA) remodeling has received attention as a consequence of AF. The aim of this study is to evaluate predictors for AT recurrence and LA remodeling in patients with repeat AF ablation procedures. One hundred thirteen patients who underwent repeat AF ablation with 3D electro-anatomical mapping system were evaluated. Mean age was 63.1 ± 9.3 years, and 2.3 ± 0.5 ablation procedures were performed during a time period of 22 [IQR 7;48] months. Reverse structural LA remodeling (LA volume decreased more than 15%) was observed in 25 (22.1%) patients. LA volume index (LAVI) during first procedure was the only predictor for positive reverse structural LA remodeling (hazard ratio (HR): 1.03, 95% CI: 1.00-1.07, p = .036) in multivariate analysis. Fifty-nine (52.2%) patients experienced only AF and 54 (47.8%) patients AT after first procedure. Female gender (HR: 5.21, 95% CI: 1.66-18.08, p = .006), LAVI (HR: 1.06, 95% CI: 1.02-1.11, p = .008) and LA scar percentage (HR: 1.08, 95% CI: 1.02-1.17, p = .019) were independent significant predictors for AT recurrence in multivariate analysis. Reverse structural LA remodeling occurred in a quarter of patients with repeat ablation procedures for AF. Only larger LAVI during first procedure predicted reverse structural LA remodeling. Half of the patients experienced AT between first and last ablation procedure. Female gender, larger LAVI and larger scar area were significant predictors for AT after catheter ablation for AF.

Association between heart and dementia… keep an eye on the left atrium.

Atrial fibrillation is associated with an increased risk of cognitive impairment and dementia. The mechanisms are not well known, but they are probably multifactorial and involve atrial myopathy, cardio-embolism, cerebral hypoperfusion, and comorbidities (systemic vascular sclerosis, disease of the small cerebral vessels, inflammation, etc.). Atrial fibrillation therapy could have a protective effect on dementia through diversified actions: (i) prevention of left atrial remodelling; (ii) prevention of cardio-embolism and silent (and not) cerebral infarcts; (iii) improvement of cardiac output and cerebral perfusion. Randomized trials will be needed to clarify the links between left atrium and dementia and to identify the most appropriate therapeutic strategies.

Effect of Weight Loss on Early Left Atrial Myopathy in People With Obesity But No Established Cardiovascular Disease.

Background Obesity is associated with left atrial (LA) remodeling (ie, dilatation and dysfunction) which is an independent determinant of future cardiovascular events. We aimed to assess whether LA remodeling is present in obesity even in individuals without established cardiovascular disease and whether it can be improved by intentional weight loss. Methods and Results Forty-five individuals with severe obesity without established cardiovascular disease (age, 45±11 years; body mass index; 39.1±6.7 kg/m2; excess body weight, 51±18 kg) underwent cardiac magnetic resonance for quantification of LA and left ventricular size and function before and at a median of 373 days following either a low glycemic index diet (n=28) or bariatric surgery (n=17). Results were compared with those obtained in 27 normal-weight controls with similar age and sex. At baseline, individuals with obesity displayed reduced LA reservoir function (a marker of atrial distensibility), and a higher mass and LA maximum volume (all P<0.05 controls) but normal LA emptying fraction. On average, weight loss led to a significant reduction of LA maximum volume and left ventricular mass (both P<0.01); however, significant improvement of the LA reservoir function was only observed in those at the upper tertile of weight loss (≥47% excess body weight loss). Following weight loss, we found an average residual increase in left ventricular mass compared with controls but no residual significant differences in LA maximum volume and strain function (all P>0.05). Conclusions Obesity is linked to subtle LA myopathy in the absence of overt cardiovascular disease. Only larger volumes of weight loss can completely reverse the LA myopathic phenotype.

Abstract 12425: The Interplay Between Left Atrial and Mitral Valvular Remodeling in Subtypes of Mitral Regurgitation

Background: The interaction between left atrial (LA) mechanics and mitral valve remodeling patterns in patients with mitral regurgitation (MR) is poorly described. Objectives: To assess three-dimensional (3D) LA volumes and strain in relation to 3D mitral valve morphology in patients with degenerative vs. functional MR. Methods: Patients included in the 3D-PRIME (3D Echocardiography and Cardiovascular Prognosis in Mitral Regurgitation) study at our heart valve clinic between 2020-2022 and with moderate or severe MR by combined transthoracic/transesophageal assessment were examined. LA remodeling was assessed by 3D maximum and minimum LA volume, reservoir strain (LASr) and contraction strain (LASct). Mitral valve annulus area, anterior and posterior leaflet length and area, tenting volumes and non-planar angle were measured using dedicated 3D mitral valve software. Results: 100 patients with moderate or severe MR were included. Patients with atrial functional MR (n=26) were older, more often women and had higher heart rate compared to degenerative MR (n=54) and ventricular functional MR (n=20) (p &lt;0.05). They also had larger LA volumes and severely impaired LASr and LASct despite smaller MR regurgitation volumes compared to MR by other mechanisms (Figure). Mitral annulus area was comparable between groups, but anterior mitral leaflet was higher, with larger area and the non-planar angle wider in functional MRs (p &lt;0.05). In multivariable analysis, low LASr (below median) was associated with larger LA volume, and higher anterior mitral leaflet height independent of age, sex, heart rate, left ventricular global longitudinal strain, and right ventricular stroke volume (Nagelkerke R 2 0.67, p &lt;0.01). In a similar model, low LASct was only associated with larger LA volumes. Conclusions: Patients with atrial functional MR have large LAs with severely impaired LA function and a specific mitral valve remodeling pattern at lower MR regurgitation volumes.

Abstract 10362: Prognostic Value of Assessing Left Atrial Remodeling in Predicting Cardiac Events Following Transcatheter Aortic Valve Replacement

Introduction: Left atrial (LA) volume indexed to body surface area (LAVi) is an established predictor of cardiovascular risk. The ratio of LAVi to mitral annular velocity during atrial contraction (LAVi/a') has emerged as a superior indicator to LAVi in assessing LA remodeling. However, the significance of calculating LAVi/a' in patients undergoing transcatheter aortic valve replacement (TAVR) has not been fully investigated. Hypothesis: The assessment of LA remodeling using LAVi/a' in patients with severe aortic stenosis (AS) provides crucial prognostic information after TAVR. Methods and Results: This study was composed of 486 patients with sinus rhythm (aged 83 ± 5 years; 175 men, 311 women) who underwent TAVR. Transthoracic echocardiography, including tissue Doppler, was performed before TAVR. Patients were divided into two groups according to the median LAVi/a'. The Kaplan-Meier method showed more adverse cardiac events (cardiac death and heart failure hospitalization) in the group with LAVi/a' above the median (log-rank test, P = 0.030). Multivariate Cox regression analysis adjusted for age and sex revealed that LAVi/a' was an independent prognostic parameter (hazard ratio, 1.058; P = 0.001). Conclusions: Patients with AS who have advanced LA remodeling are more likely to develop the adverse cardiac events even after successful TAVR. LAVi/a' is useful for predicting the cardiac events following TAVR and may be superior to LAVi.

Abstract 10242: Right Atrial Function and Fibrosis in Relation to Successful Atrial Fibrillation Ablation

Introduction: Atrial remodeling, characterized by changes in atrial structure and function, is central to the development and maintenance of atrial fibrillation (AF). Besides left atrial (LA) remodeling, right atrial (RA) remodeling may also contribute to AF perpetuation, and its presence may affect clinical outcome of AF ablation. Bi-atrial remodeling in patients with AF is rarely assessed and data on the presence of RA fibrosis, the relationship between RA and LA fibrosis, and possible association of RA remodeling with AF recurrence after ablation is limited. Methods: 110 AF patients undergoing initial pulmonary vein isolation (PVI) were included in the present study. Patients were in sinus rhythm during cardiac magnetic resonance (CMR) imaging performed prior to ablation. LA and RA volumes and function (volumetric and strain) were derived from cine CMR images. The extent of LA and RA fibrosis was assessed from 3D late gadolinium enhancement images. AF recurrence was followed-up for 12 months after PVI using either 12 lead ECGs or Holter monitoring. Results: Arrhythmia recurrence was observed in 39 patients (36%) after the 90-day blanking period, occurring at a median of 181 (IQR: 122-286) days. RA remodeling parameters were not significantly different between patients with AF recurrence as compared to patients without AF recurrence after ablation, whereas LA remodeling parameters were (volume, emptying fraction and strain). LA fibrosis had a strong correlation with RA fibrosis (r=0.88, P &lt;0.001). Both, LA and RA fibrosis was not different between patients with and without AF recurrence. Conclusions: RA remodeling parameters were not predictive of AF recurrence after AF ablation. Bi-atrial fibrotic remodeling is present in AF patients and the amount of LA fibrosis had a strong correlation with the amount of RA fibrosis. The presence of bi-atrial fibrotic tissue may be an expression of disease state although no relation with AF recurrence after AF ablation was found.

Abstract 10950: Prognostic Utility of Left Atrio-Ventricular Deformation Analysis in Heart Failure Patients Underwent Cardiac Resynchronization Therapy

Introduction: Left atrial (LA) adverse remodeling is a prognostic marker in patients with heart failure. Although left ventricular (LV) deformation analysis by speckle tracking method has been shown as a useful predictive marker after cardiac resynchronization therapy (CRT), the prognostic impact of baseline left atrio-ventricular functional deterioration on the outcome of patients underwent CRT implantation. Hypothesis: We hypothesized that a combination of LV and LA deformation assessments by speckle-tracking strain is of additive prognostic value in patients with CRT. Methods: We retrospectively analyzed 71 participants who received CRT implantation in the clinical guidelines. Global longitudinal strain (GLS) was defined as averaged strain from 3 apical views. LA strain (LAS) was calculated as the average strain using apical two- and four-chamber views. The endpoint was composite outcome of death, hospitalization due to worsening HF for 5 years after CRT implantation. Results: Out of 71 patients aged 68 ± 11 years with 162±24ms of QRS duration and 30±8% of LV ejection fraction, 40 patients (56%) met the endpoint. The patients were stratified using median value of LAS (-15%) and GLS (-8%). LAS and GCS remained significantly associated with poor outcome after adjusting for LVEF (LAS hazard ratio, 0.92; p&lt;0.001; GLS hazard ratio, 1.15; p = 0.01). Kaplan-Meier analysis showed that the subgroup of patients with both lower median values of LAS and GLS had the worst outcomes over 5 years (Figure, Log-rank, p = 0.008). In the sequential Cox model, predictive value of baseline LV ejection fraction (χ2 = 4.9) was improved by the addition of GLS (χ2 = 9.2, p = 0.037), and further improved by the addition of LAS (χ2 = 15.8, p = 0.005). C-statistics also improved from 0.62 to 0.73. Conclusions: Baseline left atrio-ventricular functional deterioration by deformation analysis were significantly associated with poor outcome after CRT implantation.

Abstract 15329: Heart Failure is an Adverse Risk Factor for Peri-Procedural Complications in Patients Undergoing Pulmonary Vein Isolation and Ablation for Atrial Fibrillation

Introduction: Percutaneous catheter ablation (PCA) for non-valvular atrial fibrillation (AF) is rapidly becoming commonplace for recently diagnosed paroxysmal AF. Heart failure (HF) and AF commonly coexist in patients. Elevated left ventricular and atrial pressures result in progressive left atrial dilation and remodeling which in turn predisposes to the generation of AF. Since many who undergo PCA for AF could have HF, we aimed to assess peri-procedural outcomes in this population. Methods: We utilized the National Inpatient Sample from 2016-2019 to identify 74,205 hospitalized adults who underwent PCA for AF. These hospitalizations were further stratified based on the presence of HF. A multivariate regression model was used to adjust for confounders and analyze the variables. Results: Of those who underwent PCA for AF, 33,435 (45%) had HF. In-hospital mortality was higher in those with HF (1.9% vs 1.14%; p=0.0001). Figure 1 shows the Forrest plot for multivariate analysis of peri-procedural complications when adjusted for patient demographics, co-morbidities, and hospital characteristics. When adjusted similarly, patients with HF who underwent PCA for AF had longer length of stay (LOS) by 1.5 days (p&lt;0.001) and had additional hospital costs (HC) of $14,726 (p&lt;0.001). Conclusions: In this study, patients undergoing Percutaneous catheter ablation (PCA) for AF with co-existing acute HF had significantly worse end points in terms of in-hospital mortality, LOS, HC, atrial flutter, AKI, sepsis, pneumonia, endotracheal intubation. One major limitation of our study is the lack of outpatient follow up. Although outcomes are worse in the acute setting of HF, there have been several studies such as CASTLE-AF, outlining that early ablation for AF in HF is associated with positive long-term effects including lower rates of death and hospitalization for HF. Despite unfavorable peri-procedural outcomes of HF in PCA, the long-term benefits should not be overlooked.

Abstract 11062: Temporal Change of Severity of Atrial Functional Mitral Regurgitation

Introduction: Left atrial (LA) remodeling due to long burden of atrial fibrillation can cause atrial functional mitral regurgitation (A-FMR). However, longitudinal echocardiographic follow-up of patients with A-FMR has rarely been reported. Methods: We retrospectively identified 23 outpatients diagnosed with significant (≥ moderate) A-FMR on transthoracic echocardiography (TTE), with at least two studies performed more than one year apart. A-FMR was defined as 1) left ventricular ejection fraction ≥ 50% without regional wall motion abnormalities; 2) absence of primary valvular pathology; and 3) presence of atrial fibrillation. We excluded patients with significant aortic valve disease or mitral stenosis, treated valvular or congenital disease, any form of cardiomyopathy or carditis, or previous heart transplant. Follow-up was censored at the time of any interventions for valvular disease. The mitral regurgitation (MR) severity was graded based on the current guidelines, and classified as none (0); mild (1+); moderate (2+); moderate-to-severe (3+); or severe (4+). The change (Δ) of the echocardiographic variables between baseline and latest follow-up was assessed. Results: The median observation period was 3.4 [interquartile range: 2.6-6.6] years. At baseline, the mean LA diameter was 51 ± 7 mm and MR vena contracta width was 4.4 ± 1.1 mm. As shown in Figure 1a, 1b , there was a moderate positive correlation between observation period and Δ LA diameter (r = 0.504, P = 0.014). However, there was no significant correlation between observation period and Δ MR vena contracta width (r = -0.041, P = 0.85). During the observation period, guideline-based MR severity progressed in 4 (17%), unchanged in 12 (52%), and decreased in 7 (30%). The MR severity was not significantly different between baseline and follow-up (P = 0.60) ( Figure 1c ). Conclusion: In patients with A-FMR, LA size increased over time, whereas the severity of A-FMR did not progress significantly over time.

Abstract 11216: Greater Prognostic Value of Left Atrial Mechanics Compared to Left Atrial Volume in Atrial Functional Mitral Regurgitation

Introduction: Atrial functional mitral regurgitation (AFMR) is associated with increased mortality and morbidity. Optimal management however remains unclear. Mechanism of AFMR is linked to left atrial remodeling yet left atrial (LA) size and function are still poorly characterized. Objectives: To assess LA size and function by reservoir strain (LASr) and reservoir work (LAWr) and their impact on outcome in AFMR. Methods: Consecutive patients examined at our institution between 2001-2019 and with AFMR of at least moderate MR degree were examined. LAWr was estimated as LASr x LA reservoir volume, and patients were grouped by median LASr or LAWr. Outcomes were all-cause death or heart failure hospitalizations. Results: 515 patients with moderate or greater AFMR were followed for a median of 5 [range 1-17] years. All patients had previously documented atrial fibrillation (AF) (38%), heart failure with preserved ejection fraction (HFpEF) without AF (24%), or both (HFpEF+AF, 38%). LA volume was largest in AF patients and smallest in HFpEF while LA function parameters were greater in HFpEF and AF compared to the combined HFpEF+AF group (Fig. A,B).During follow-up, patients with low LASr or LAWr had higher risk of death (p &lt;0.001, Fig. C) and heart failure hospitalizations (p&lt;0.05). In Cox regression analyses, low LASr and LAWr, but not LA volume and left ventricular function, were associated with a higher risk of death (LASr: HR 2.3 (95% CI 1.6-3.5); LAWr HR 3.4 (95% CI 2.4-4.7), both p&lt;0.001) after adjustment for clinical and echocardiographic confounders. Conclusion: LA reservoir function but not LA size is a robust predictor of outcome in AFMR with moderate or greater MR. This provides mechanistic insights into the interplay of functional parameters versus LA geometric changes in AFMR.

Left Atrial Reverse Remodeling in Dilated Cardiomyopathy

Left atrial (LA) dilation is associated with a worse prognosis in several cardiovascular settings, but therapies can promote LA reverse remodeling. The aim of this study was to characterize and define the prognostic implications of LA volume index (LAVI) reduction in patients with dilated cardiomyopathy (DCM). Consecutive patients with DCM from two tertiary care centers, with available echocardiograms at baseline and at 1-year follow-up, were retrospectively analyzed. LA dilation was defined as LAVI > 34mL/m2, and change in LAVI (ΔLAVI) was defined as the 1-year relative LAVI reduction. The outcome was a composite of death, heart transplantation (HTx), or heart failure hospitalization (HFH). Five hundred sixty patients were included (mean age, 54±13years; mean left ventricular ejection fraction, 31±10%; mean LAVI, 45±18mL/m2). Baseline LAVI had a non-linear association with the risk for death, HTx, or HFH, independent of age, left ventricular ejection fraction, mitral regurgitation, and medical therapy (P<.01). At 1-year follow-up, LAVI decreased in 374 patients (67%; median ΔLAVI, -24%; interquartile range, -37% to -11%). Factors independently associated with ΔLAVI were higher baseline LAVI and lower baseline left ventricular ejection fraction. After multivariable adjustment, ΔLAVI showed a linear association with the risk for death, HTx, or HFH (hazard ratio, 0.96 per 5% decrease; 95% CI, 0.93-0.99; P=.042). At 1-year follow-up, patients with reductions in LAVI of >10% and LAVI normalization (i.e., follow-up LAVI≤34mL/m2; 31% of the overall cohort) were at lower risk for death, HTx, or HFH (hazard ratio, 0.37; 95% CI, 0.35-0.97; P=.028). In a large cohort of patients with DCM, 1-year reduction in LAVI was observed in a number of patients. The association between reduction in LAVI and death, HTx, or HFH suggests that LA structural reverse remodeling might be considered an additional parameter useful in the individualized risk stratification of patients with DCM.

Transcriptomic profile analysis of the left atrium in spontaneously hypertensive rats in the early stage

Left atrial remodeling, characterized by enlargement and hypertrophy of the left atrium and increased fibrosis, was accompanied by an increased incidence of atrial fibrillation. While before morphological changes at the early stage of hypertension, how overloaded hypertension influences the transcriptomic profile of the left atrium remains unclear. Therefore, RNA-sequencing was performed to define the RNA expressing profiles of left atrium in spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats as a control group. We also compared the changes in the RNA expression profiles in SHRs treated with an angiotensin receptor blocker (ARB) and angiotensin receptor-neprilysin inhibitor (ARNI) to assess the distinct effects on the left atrium. In total, 1,558 differentially expressed genes were found in the left atrium between WKY rats and SHRs. Bioinformatics analysis showed that these mRNAs could regulate upstream pathways in atrial remodeling through atrial fibrosis, inflammation, electrical remodeling, and cardiac metabolism. The regulated transcripts detected in the left atrial tissue in both the ARB-treated and ARNI-treated groups were related to metabolism. In contrast to the ARB-treated rates, the transcripts in ARNI-treated rats were mapped to the cyclic guanosine monophosphate-protein kinase G signaling pathway.