Abstract 4362881: Left Bundle Branch Area Pacing Versus Non-Conduction System Pacing After Atrioventricular Node Ablation in Atrial Fibrillation: Impact on Atrial and Ventricular Function

His-bundle pacing is the best approach to physiological pacing.

Funding Acknowledgements Type of funding sources: None. Background Speckle Tracking Echocardiography (STE) provides a comprehensive and quantitative assessment of myocardial function. However, the accuracy of STE-derived indices to predict maintenance of sinus rhythm (SR) following radio-frequency catheter ablation (CA) is still under debate. Therefore, the aim of the present study is to define the accuracy of STE-derived parameters to predict long-term maintenance of SR in patients with paroxysmal AF undergoing CA. Methods We prospectively enrolled 218 consecutive patients (age: 62 ± 10 years, 30% females) with paroxysmal AF undergoing first-CA. All patients with preserved ejection fraction (EF ≥ 50%) underwent comprehensive transthoracic echocardiography at baseline, including assessment of left ventricular (LV) global longitudinal strain (GLS), left atrial (LA) reservoir strain (LASr), LA conduit strain (LAScd) and LA contractile strain (LASct) using two-dimensional STE in apical views. Results At 12 months follow up, a total of 39 (18%) patients had a documented recurrence of AF. Among imaging parameters, LASr > 23% showed the largest area under the curve (0.80) to predict long-term maintenance of SR with sensitivity of 79% and specificity of 72%. Other parameters of LA function, LA diameter, maximum or minimum LA volume index, LV GLS or ejection fraction, and indices of LV diastolic function had lower area under the curve (Figure 1). Using multi-variable logistic regression, LASr (OR 1.19, 95% CI 1.10-1.23, p < 0.001) and LASct (OR 1.21, 95% CI 1.07-1.37, p = 0.002) were independently associated with long-term SR while maximum or minimum LA volume index was not. Conclusion In patients with paroxysmal AF undergoing radio-frequency CA, preserved LA reservoir and contractile strain is independently associated with long-term maintenance of SR, whereas LA diameter or volumes were not. LA strain may therefore be useful in management of patients with paroxysmal AF. Figure 1: Receiver-operating characteristic curves of left atrial reservoir strain (LASr), LA conduit strain (LAScd), LA contractile strain (LASct), LA emptying fraction (LAEF), LA expansion index (LAEI), LA end-systolic (LAES) and end-diastolic (LAED) volume index (VI) to predict long-term maintenance of sinus rhythm. Abstract Figure.

Funding Acknowledgements Type of funding sources: None. Background The early AF treatment by radio-frequency catheter ablation is very important for improving clinical outcome in patients with history of atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). Left atrial (LA) strain showed to be a useful index to monitor atrial function in AF and HFpEF states. However, the accuracy of LA strain to predict the long-term maintenance of sinus rhythm (SR) in HFpEF patients with paroxysmal AF undergoing catheter ablation is still under debate. Aims To define the best echocardiography derived parameters to predict the long-term maintenance of SR in paroxysmal AF patients with high probability of HFpEF undergoing catheter ablation. Methods We prospectively enrolled (between September 2017 and May 2019) 200 consecutive patients (62 ± 10 years, 58% males) with dyspnea (NYHA≥II), paroxysmal AF and preserved LV ejection fraction (≥50%). All patients had a H2FPEF score suggesting high probability of HFpEF. During sinus rhythm, all patients underwent comprehensive transthoracic echocardiography at baseline, including assessment of left ventricular (LV) global longitudinal strain (GLS), left atrial (LA) reservoir strain (LASr), LA conduit strain (LAScd) and LA contractile strain (LASct) using two-dimensional speckle tracking in apical views. Results After 42+/-8 months follow-up, a total of 34 (17%) patients had a documented recurrence of AF. Patients with AF recurrence had lower LASr (22.2% vs. 28.3%, p < 0.001) and LASct (10.9% vs. 13.2%, p < 0.01) compared to patients who keep on SR. Among speckle tracking derived LA phasic strain indices, LASr showed the largest area under the curve (AUC = 0.8, p < 0.001) and the strongest independent predictive value (LASr > 22%) of long-term maintenance of SR with sensitivity of 80% and specificity of 66% (Figure 1). Other parameters of LA function, LA diameter, maximum or minimum LA volume index, LV GLS or ejection fraction, and indices of LV diastolic function had lower area under the curve. Using multivariable logistic regression, only LASr (OR 0.89, 95% CI 0.81-0.97, p=0.013) was independently associated with long-term SR maintenance while other LA size and function indices were not. Conclusion In HFpEF patients with paroxysmal AF undergoing catheter ablation, LASr is more accurate predictor of SR maintenance than other standard echocardiographic parameters in long-term follow-up. Figure 1: Receiver-operating characteristic curves of left atrial reservoir strain (LASr), LA conduit strain (LAScd) and LA contractile strain (LASct), LA emptying fraction (LAEF), LA expansion index (LAEI), LA end-systolic (LAES) and end-diastolic (LAED) volume index (VI) to predict long-term maintenance of sinus rhythm.

Hemodynamic Determinants of Left Atrial Strain in Symptomatic Patients With Significant Primary Mitral Regurgitation.

POSTER PRESENTATIONS

Background The early AF treatment by radio-frequency catheter ablation (CA) is very important for improving clinical outcome in patients with history of atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). Left atrial (LA) strain showed to be a useful index to monitor atrial function in AF and HFpEF states. However, the accuracy of LA strain to predict the long-term maintenance of sinus rhythm (SR) in HFpEF patients with paroxysmal AF undergoing CA is still under debate. Aims To define the best echocardiography derived parameters to predict the long-term maintenance of SR in paroxysmal AF patients with high probability of HFpEF undergoing CA. Methods We prospectively enrolled 200 consecutive patients (62 ± 10 years, 58% males) with dyspnea (NYHA≥II), paroxysmal AF and preserved LV ejection fraction (≥50%). All patients had a H2FPEF score suggesting high probability of HFpEF. During sinus rhythm, all patients underwent comprehensive transthoracic echocardiography at baseline, including assessment of left ventricular (LV) global longitudinal strain (GLS), left atrial (LA) reservoir strain (LASr), LA conduit strain (LAScd) and LA contractile strain (LASct) using two-dimensional speckle tracking in apical views. Results After 42+/-8 months follow-up, a total of 34 (17%) patients had a documented recurrence of AF. Patients with AF recurrence had lower LASr (22.2% vs. 28.3%, p < 0.001) and LASct (10.9% vs. 13.2%, p < 0.01) compared to patients who keep on SR. Among speckle tracking derived LA phasic strain indices, LASr showed the largest area under the curve (AUC = 0.8, p < 0.001) and the strongest independent predictive value (LASr > 22%) of long-term maintenance of SR with sensitivity of 80% and specificity of 66% (Figure 1). Other parameters of LA function, LA diameter, maximum or minimum LA volume index, LV GLS or ejection fraction, and indices of LV diastolic function had lower area under the curve. Using multivariable logistic regression, only LASr (OR 0.89, 95% CI 0.81-0.97, p=0.013) was independently associated with long-term SR maintenance while other LA size and function indices were not. Conclusion In HFpEF patients with paroxysmal AF undergoing CA, LASr is more accurate predictor of SR maintenance than other standard echocardiographic parameters in long-term follow-up.

Background/Introduction: There is an increased incidence of atrial fibrillation (AF) in endurance athletes. We sought to evaluate the likely mechanistic basis for this phenomenon. Methods 36 endurance athletes in sinus rhythm, with a previous history of AF (ATH-AF) were compared to age and gender matched endurance athletes with no prior history of AF (ATH), non athletes with paroxysmal AF (NONATH-AF) and age and gender matched healthy controls (CONTROL). A detailed transthoracic echocardiogram was performed with all groups in sinus rhythm, with detailed left atrial (LA) and left ventricular (LV) measurements, including strain analysis. Results All athletes had increased LA and LV size when compared with healthy controls (Table 1). Non athletes with paroxysmal AF had increased LA size when compared with controls. However, indexed LA/LV ratio was preserved in athletes and similar to healthy individuals, whilst AF patients had significantly increased LA/LV ratio. Athletes with AF had higher e’ velocity and lower E/e’, whereas e’ was reduced and E/e’ elevated in non-athlete AF patients. Athletes had impaired LA reservoir and contractile strain, and reduced LV global longitudinal strain (GLS) compared with healthy controls. Conclusions Compared to healthy controls, athletes have reduced LA and LV strain, with preserved LV diastolic function and LA/LV ratio. In contrast, altered diastolic function with differential increase in LA volume was observed in AF patients. The increased risk of AF in athletes is likely mediated by different mechanistic processes other than an atrial myopathy consequent to diastolic dysfunction as observed in non-athletes with AF. Table 1. LA and LV parameters Parameter ATH-AF ATH NONATH-AF CONTROL P value LVEDV indexed (ml/m2) 84 ± 12 79 ± 14 57 ± 10 51 ± 13 <0.001 LVESV indexed (ml/m2) 35 ± 6 34 ± 7 25 ± 8 27 ± 33 0.02 LV ejection fraction (%) 58 ± 4 56 ± 4 56 ± 10 58 ± 8 0.586 LV global longitudinal strain (%) 19.2 ± 1.7 18.9 ± 2.1 21 ± 3.1 21.7 ± 2.9 <0.001 e’ vel (cm/s) 10 ± 2 10 ± 3 8 ± 2 9 ± 2 0.007 E/e’ 5.7 ± 1.3 5.9 ± 1.8 9.1 ± 3.3 7.5 ± 1.5 <0.001 LAV max indexed (ml/m2) 45 ± 11 43 ± 12 38 ± 11 27 ± 8 <0.001 Indexed LAV/LVEDV ratio 0.5 ± 0.1 0.6 ± 0.2 0.7 ± 0.2 0.5 ± 0.1 <0.001 LA reservoir strain (%) 27.2 ± 4.8 28.2 ± 3.7 27.9 ± 8.4 33.2 ± 7.0 <0.001 LA conduit strain (%) 14.2 ± 4.5 14.4 ± 4.0 14.9 ± 5.5 16.6 ± 6.3 0.182 LA contractile strain (%) 13.0 ± 3.1 13.8 ± 3.6 13.0 ± 5.1 16.6 ± 3.1 <0.001 LV = left ventricular, LAV = left atrial volume, LA = left atrial

Atrial Cardiomyopathy with Impaired Functional Reserve in Patients with Paroxysmal Atrial Fibrillation

BACKGROUND There have been many reports of heart failure due to diabetic cardiomyopathy and decreased left ventricular (LV) function with increasing age in patients with type 1 diabetes mellitus (T1DM). Recently, although left atrial (LA) function has been occasionally reported to be a more useful prognostic indicator than LV function in acquired heart diseases, LA function in patients with T1DM has not yet been studied. PURPOSE To investigate LA dysfunction in patients with T1DM. METHODS Fifty patients with T1DM were recruited (age, 5–41 years). We excluded patients who had a history of heart disease, hypertension, and those taking cardioprotective agents. The patients and 50 age-matched controls were classified into 3 age groups (D1, C1, 5–14 years; D2, C2, 15–29 years; D3, C3, 30–41 years). The LA phasic function serving as the reservoir, conduit, and pump strains; the LA strain rate (SR) in the systole, early diastole, and late diastole; and the LV global longitudinal strain (LV-LS) as determined via 2-dimensional speckle tracking imaging were measured from the apical four- and two-chamber views. We also calculated the LA stiffness index as the ratio of E/e’ to the LA reservoir strain. RESULTS There was no significant difference in left ventricular ejection fraction in each age group. The LA reservoir strains in D2 and D3 were significantly lower than those in C2 (40.8 ± 5.7% vs. 47.2 ± 5.5%, p = 0.005) and C3 (39.2 ± 5.5% vs. 47.3 ± 5.7%, p = 0.004), respectively. The LA conduit strain in D2 was significantly lower than that in C2 (28.9 ± 5.8% vs. 35.0 ± 5.0%, p = 0.006). The LA pump strain and the three phases of LA SR were not significantly different among the age groups. The LA stiffness index in D3 increased significantly compared to that in N3 (0.18 ± 0.05 vs. 0.13 ± 0.01, p <0.001). The LV-LS in D2 and D3 was significantly lower than that in C2 (-15.7 ± 1.7% vs. -18.7 ± 2.1%, p <0.001) and C3 (-15.3 ± 1.8% vs. -19.3 ± 2.0%, p <0.001), respectively. The LA reservoir strain significantly correlated with LV-LS (r = -0.468, p < 0.001). Both the LA reservoir strain and LV-LS in patients with T1DM decreased significantly (p = 0.028, p < 0.042, respectively) and correlated with increasing age (r = -0.323, r = 0.286, respectively). The LV stiffness index did not correlate with age or LV-LS. CONCLUSIONS The LA reservoir strain might be as useful as LV-LS as an early marker of cardiac dysfunction in patients with T1DM. The correlation coefficient between the LA reservoir strain and LV-LS was not strong. Therefore, although LV-LS might affect the LA reservoir strain, it might represent other aspects of cardiac dysfunction. The increase of LA stiffness might represent the changes in LA wall properties and could be another useful indicator of cardiac dysfunction during long-term follow-ups, which is independent of LV-LS. Overall, these findings provide new insights into cardiac dysfunction in patients with T1DM.

ORAL PRESENTATION

PurposeEvidence that left bundle branch area pacing (LBBAP) is more effective than conventional right ventricular (RV) pacing in enhancing left atrial (LA) outcomes is lacking. The aim of this study was to investigate LA outcomes using 2-dimensional speckle tracking echocardiography (2D-STE) and real-time 3-dimensional echocardiography (RT-3DE) at 6-months of follow-up in patients that received LBBAP, RV septal pacing (RVSP), or RV apical pacing (RVAP).MethodsA total of 90 patients with normal left ventricular ejection fraction (LVEF) underwent dual-chamber pacemaker implantation for bradycardia at Beijing Anzhen Hospital between January 2021 and July 2021. Patients were divided into three groups based on the pacing site: LBBAP, RVSP, or RVAP.ResultsThere were no significant differences in baseline characteristics and echocardiographic findings among patients that received LBBAP, RVSP, or RVAP. At 6-months of follow-up, left atrial volume index (LAVI), LA reservoir strain (LASr), LA contractile strain (LASct), global longitudinal strain (GLS), global circumferential strain (GCS), and synchronization parameters (Tmsv-16SD, Tmsv-12SD, Tmsv-6SD, longitudinal Tε-dif, circumferential Tε-dif) were significantly improved in patients that received LBBAP, while they had significantly worsened with RVSP and RVAP. Compared to baseline, at 6-months of follow-up, patients that received LBBAP had significantly improved LASr (28.17±10.12% vs 35.4±17.17%, P=0.024), LASct (−12.03±2.15% vs −17.53±7.37%, P=0.045), E/e’ ratio(12.61±3.8 vs 10.85±3.75,P=0.014) and LVEF (65.74±7.90% vs 68.81±5.92%, P=0.023). The 6-minute walking distance significantly increased at 6-months of follow-up compared to baseline in all patients, but the increase was most prominent for LBBAP (403.00±98.46 m vs. 469.34±59.32m, P=0.015). LBBAP was associated with a lower risk of new-onset atrial fibrillation.ConclusionIn pacemaker-dependent patients, LBBAP achieved better LA strain, LV strain, and LV synchronization than RVSP or RVAP at 6-months of follow-up.

The Left Atrium Makes Headlines

PO-03-023 OUTCOMES OF LEFT BUNDLE BRANCH AREA PACING AND ATRIOVENTRICULAR NODE ABLATION IN PATIENTS WITH GROUP III PULMONARY HYPERTENSION AND ATRIAL FIBRILLATION IN REDUCING RECURRENT HOSPITALIZATION

Comparing Left Bundle Branch Area vs Right-Ventricular Septal Pacing in High-Degree Conduction Disease After Transcatheter Aortic Valve Replacement: Randomized Trial Study Protocol

Background: Pacemaker implantation combined with atrioventricular node ablation (AVNA) could be a practical choice for atrial fibrillation (AF) patients with heart failure (HF). Left bundle branch area pacing (LBBaP) has been widely reported. Objectives: To explore the safety and efficacy of LBBaP combined with AVNA in AF patients with HF. Methods and results: Fifty-six AF patients with HF attempted LBBaP and AVNA from January 2019 to December 2020. Standard LBBaP was achieved in forty-six patients, and another ten received left ventricular septal pacing (LVSP). The cardiac function indexes and pacemaker parameters were evaluated at baseline, and we conducted a 1-month and 1-year follow-up. Result: At the time of implantation and 1-month and 1-year follow-up, QRS duration of LVSP group was longer than that of LBBaP group. The pacemaker parameters remained stable in both the LBBaP and LVSP groups. At 1-month and 1-year follow-up after LBBaP and AVNA, left ventricular ejection fraction, left ventricular end-diastolic diameter, and NYHA classification continued to improve. Baseline left ventricular ejection fraction and QRS duration change at implantation can predict the magnitude of improvement of left ventricular ejection fraction at 1-year after LBBaP. Baseline right atrial left-right diameter, the degree of tricuspid regurgitation, and interventricular septum thickness may be the factors affecting the success of LBBaP. Conclusion: LBBaP combined with AVNA is safe and effective for patients with AF and HF. Baseline right atrial left-right diameter, the degree of tricuspid regurgitation, and interventricular septum thickness may be the factors affecting the success of LBBaP.