Persistent Atrial Fibrillation Research Articles

Ablation therapy following unsuccessful electrical cardioversion in patients with persistent atrial fibrillation

Electrical cardioversion (ECV) a widely utilized intervention for persistent atrial fibrillation (AF) aimed at restoring sinus rhythm. However, ECV can be ineffective, raising questions about subsequent treatment options. This study aimed to compare the outcomes of non-ablation therapy versus ablation therapy following unsuccessful ECV. A total of 125 consecutive patients with persistent AF who underwent unsuccessful ECV between November 2017 and August 2023 was included in this retrospective analysis. Of these, 51.2% received only medical therapy (non-ablation therapy group, n = 64), while 48.8% underwent AF ablation (ablation therapy group, n = 61). Various ablation methods were employed, including catheter and thoracoscopic ablation. Ablation therapy was associated with significantly better AF-free survival compared to non-ablation therapy [hazard ratio (HR), 0.37; 95% confidence interval (CI) 0.22–0.61; p < 0.01]. There was no difference of AF-free survival between catheter ablation and thoracoscopic ablation groups (HR 0.79, 95% CI 0.34–1.83; p = 0.58). AF duration > 5 year (HR 1.51; 95% CI 0.930–2.437; p = 0.10), BMI ≤ 25 kg/m2 (HR 1.61; 95% CI 1.004–2.581; p = 0.05) and diabetes (HR 2.38; 95% CI 0.902–6.266; p = 0.08) were considerable as predictor of AF recurrence. Ablation therapy following unsuccessful ECV was associated with maintaining sinus rhythm, regardless of the specific ablation method utilized.

Effect of Pulmonary Vein Isolation with Left Atrial Wall Isolation Plus Selective CFAE Ablation in Patients with Persistent Atrial Fibrillation.

Pulmonary vein isolation (PVI) is a foundational treatment for persistent atrial fibrillation (PeAF), but the effectiveness of adding posterior wall isolation (PWI) and selective complex fractionated atrial electrogram (CFAE) ablation in the roof and anterior wall remains debated. The potential of these additional ablation techniques to improve long-term outcomes for PeAF patients is still uncertain. This retrospective study included 151 PeAF patients who underwent first-time catheter ablation at our center. The choice of ablation strategy was based on the operator's clinical judgment, taking into account the patient's specific condition and anatomical features. Patients were divided into two groups: the PVI group, which received PVI alone, and the modified PWI (MPWI) group, which received PVI along with additional PWI and selective CFAEs ablation in the roof and anterior wall. The primary endpoint was the absence of atrial arrhythmia lasting more than 30 s, without antiarrhythmic drugs, at 12 months. At the 12-month follow-up, 77.3% of the patients in the MPWI group and 52.1% of the patients in the PVI group remained in sinus rhythm without an atrial arrhythmia recurrence (p = 0.001). The BIC-based Cox regression analysis identified the ablation strategy and atrial fibrillation (AF) duration as independent predictors of recurrence across the cohort. It was found that MPWI significantly reduced the risk of recurrence, while a longer AF duration increased it. In the MPWI group, AF duration, left ventricular internal diameter in systole (LVIDs), and moderate or greater tricuspid regurgitation were independent predictors of recurrence. In the PVI group, only the left atrial low voltage area (LVA) index was a significant predictor. The addition of PWI and selective CFAE ablation to PVI significantly improves 12-month arrhythmia-free survival compared to PVI alone, demonstrating the superiority of this combined approach in improving long-term outcomes for patients with persistent AF.

Impact of sacubitril/valsartan on atrial fibrillation burden in heart failure: a retrospective observational study

AbstractBackgroundSacubitril/valsartan (an angiotensin receptor‐neprilysin inhibitors [ARNI]) might improve atrial fibrillation (AF) condition, but its added value remains controversial.AimWe aimed to analyse the effect of ARNI on AF burden.MethodWe conducted a single‐centre, retrospective self‐controlled study in a tertiary centre. Data were retrieved from January 2019–January 2023. All cardiac resynchronisation therapy‐implantable cardioverter defibrillator (CRT‐D) carriers on ARNI were included if implantation had been at least 3 months before drug initiation. Proarrhythmic events, equal time length control (before ARNI initiation), and exposure (after ARNI initiation) periods were defined. Echocardiographic data were retrieved if they were up to 1 year old before ARNI initiation and if they were available 3 months to 1 year after initiation. AF burden was defined by frequency and median value of paroxysmal events and the overall variation in AF status was determined. Ethical approval was granted by the Ethics Committee of the Centro Hospitalar e Universitário de Coimbra (Reference no: PI OBS.SF.174‐2022) and the study conforms with the Declaration of Helsinki.ResultsSeventy‐two patients were included in the study (73.3% men). After ARNI, there was a reduction in New York Heart Association functional class ± standard deviation (2.00 ± 0.75 to 1.85 ± 0.61, p = 0.043) and an increase in left ventricular ejection fraction ± standard deviation (from 31.67% ± 9.28% vs 37.33% ± 14.49%, p = 0.027). Before ARNI initiation, 34 patients did not have AF, 19 had paroxysmal AF, 15 had permanent AF, and 2 had persistent AF. The total amount of AF episodes (91 vs 44, p = 0.808) and median paroxysmal episodes (among those with paroxysmal AF or no AF) (5 vs 3, p = 0.121) were numerically reduced after ARNI initiation, though variation was not statistically significant. No differences were found as well regarding ventricular arrhythmias or device therapies.ConclusionARNI did not significantly decrease the number of AF paroxysmal episodes or median number of paroxysmal events per patient. Even though ARNI may have a positive impact on AF burden of heart failure patients, larger studies are needed to provide unequivocal evidence.

Anatomical Treatment Strategies for Persistent Atrial Fibrillation with Ethanol Infusion within the Vein of Marshall—Current Challenges and Future Directions

Currently, pulmonary vein isolation (PVI) is the gold standard in catheter ablation for atrial fibrillation (AF). However, PVI alone may be insufficient in the management of persistent AF, and complementary methods are being explored. One such method takes an anatomical approach—improving both its success rate and lesion durability may lead to improved treatment outcomes. An additional approach complementary to the anatomical one is also attracting attention, one that focuses on epicardial conduction. This involves ethanol ablation of the vein of Marshall (VOM) and can be very effective in blocking epicardial conduction related to Marshall structure; it is becoming incorporated into standard treatment. However, the pitfall of this “Marshall-PLAN”, a method that combines an anatomical approach with ethanol infusion within the VOM (Et-VOM), is that Et-VOM and other line creations are not always successfully completed. This has led to cases of AF and/or atrial tachycardia (AT) recurrence even after completing this lesion set. Investigating effective adjunctive methods will enable us to complete the lesion set with the aim to lower the rates of recurrence of AF and/or AT in the future.

A-174 Comparison of Bleeding Risk Scales in Elderly Patients With Persistent Atrial Fibrillation

Abstract Background Atrial fibrillation is a significant cause of thromboembolism and sudden death in the world making anticoagulant treatment a cornerstone; however, it is associated with bleeding risk. Currently, there are no studies in Ecuador that support the prognostic validity of the recent bleeding risk scales, as well as the lack of research to discover novel methods that are applicable and more accessible to use within the medical care setting.The Hemorr2hages, ORBIT and ATRIA scores represent a promising approach for those health centers that do not have INR available and consequently cannot measure risk through HASBLED (internationally recommended score). In this way, hemorrhagic events can be prevented in patients with atrial fibrillation with anticoagulant treatment without exception. Our main goal is to compare the predictive bleeding risk scores of 3 scales (Hemorr2hages, ORBIT, ATRIA) versus traditional HASBLED score. Methods In this retrospective cohort study, we assessed chronic persistent atrial fibrillation in 100 patients using the electronic medical records in an outpatient clinic in Guayaquil, Ecuador. We calculated 3 bleeding risk scores for each patient according to the variables measured in each one of them and used those to compare the categories against HASBLED’s. A Pearson correlation index was obtained, and ROC performance curves were made. P value &amp;lt;0.05 was deemed statistically significant. Results Of the 100 patients included, 65% were males, and mean age was 75±10.73. We reported only 6% bleeding events during the follow up. According to HASBLED score: 31% were at high risk. In comparison: 40% and 37% were also at high risk in Hemorr2hages and ATRIA scores, respectively. HASBLED was fairly correlated with Hemorr2hages and ATRIA scores (Pearson’s R: 0.617, p:&amp;lt;0.001; R:0.528, p:&amp;lt;0.001, respectively). Only 22% were classified at high risk by the ORBIT score. ROC curve analysis showed ORBIT’s AUC was 0.963, while Hemorr2hages, ATRIA and HASBLED were 0.931, 0.925, and 0.732 (p:&amp;lt;0.001), respectively. Conclusions In our sample, ORBIT score was better correlated with bleeding episodes than the other scales. This a promising approach for those health centers that do not count with INR reactive materials available for it to be measured at their laboratories. Further research is needed to accurately analyze whether criterion included in ORBIT score might predict bleeding scores better than HASBLED, Hemorr2hages and ORBIT tools; since the items required to calculate it are more readily accessible.

Quantifying the frequency modulation in electrograms during simulated atrial fibrillation in 2D domains

Atrial fibrillation (AF) affects millions of people in the world, causing increased morbidity and mortality. Treatment involves antiarrhythmic drugs and catheter ablation, showing high success for paroxysmal AF but challenges for persistent AF. Experimental evidence suggests reentrant waves and rotors contribute to AF substrates. Ablation procedures rely on electroanatomical maps and electrogram (EGM) signals; however, current methods used in clinical practice lack consideration for time–frequency varying EGM components. The fractional Fourier transform (FrFT) can be adopted to capture time-varying frequency components, thereby enhancing the comprehension of arrhythmogenic substrates during AF for improved ablation strategies. To this end, a FrFT-based algorithm is developed to characterize non-stationary components in EGM signals from simulated AF episodes. The proposed algorithm comprises a pre-processing step to enhance the coarser features of the EGM waveform, a windowing process for dynamic assessment of the EGM, and a FrFT order optimization stage that seeks compact signal representations in fractional Fourier domains. The resulting order is related to the rate of frequency change in the signal, making it a useful indicator for frequency-modulated components. The FrFT-based algorithm is implemented on EGM signals from AF simulations in 2D domains representing a region of the atrial tissue. Consequently, the computed optimum FrFT orders are used to build maps that are spatially correlated to the underlying propagation dynamics of the simulated AF episode. The results evince that the extreme values in the optimum orders map pinpoint the localization of fibrillatory mechanisms, generating EGM activation waveforms with varying frequency content over time.

A digital twin approach for stroke risk assessment in Atrial Fibrillation Patients

Atrial fibrillation (AF) is associated with a fivefold increased risk of cerebrovascular events, contributing to 15–18 % of all strokes. Stroke prevention in clinical practice is typically guided by the CHA2DS2-VASc score, which depends on general clinical risk factors but falls short in predicting risk at an individual patient level. In this study, we introduce a digital twin model of the left atrium (LA) combined with computational fluid dynamics (CFD) simulations to enhance personalized stroke risk assessment. Simulations were performed on patient-specific dynamic LA models in sinus rhythm (SR) across three patient groups: 10 controls (CTRL), 10 with paroxysmal AF (PAR-AF), and 10 with persistent AF (PER-AF). Blood flow velocity and areas susceptible to thrombogenesis, based on several factors including endothelial damage, were identified in the left atrial appendage (LAA). In general, control subjects exhibited higher average blood velocity in both the LAA and its ostium (0.11 ± 0.03 m/s and 0.28 ± 0.05 m/s, respectively) compared to those with AF. In the AF groups, the velocities were lower (LAA: PAR-AF 0.05 ± 0.02 m/s, PER-AF 0.04 ± 0.02 m/s; LAA ostium: PAR-AF 0.14 ± 0.03 m/s, PER-AF 0.11 ± 0.04 m/s). CFD analysis revealed that endothelial cell activation potential (ECAP) was significantly higher in AF patients (PAR-AF: 3.96 ± 3.28 Pa⁻1, PER-AF: 4.77 ± 2.08 Pa⁻1) compared to controls (0.93 ± 0.63 Pa⁻1). These findings suggest that AF patients experience slower and more oscillatory blood flow in the LAA, increasing their risk of thrombosis. Additionally, blood tends to stagnate within the LAA, further raising the likelihood of clot formation. This proposed method could be used to enhance stroke risk stratification in AF patients by incorporating an index that integrates blood velocity-derived parameters.

Relationship between left atrial isolated surface area and early-term recurrence in patients with persistent atrial fibrillation after cryoballoon ablation

ObjectiveTo investigate the effect of pulmonary vein antrum enlargement combined with left atrial roof cryoballoon ablation in patients with persistent atrial fibrillation (PeAF) by analyzing the relationship between left atrial isolation area surface area (ISA) and early postoperative recurrence.Methods93 patients with PeAF were classified into recurrence and non-recurrence groups according to the results of the 1-year follow-up. Three-dimensional electroanatomical labeling map was constructed and merged with that of the left atrial pulmonary vein CTA, and the ISA and the left atrial surface area (LASA) were measured and analyzed to determine the relationship between ISA/LASA in relation to early postoperative recurrence.Results93 patients were included and followed up for 1 year with AF-free recurrence rate of 75.3%. The ISA of the recurrence group was lower than that of the non-recurrence group. Left atrial internal diameter (LAD), left common pulmonary vein, the ISA, the ISA/LASA and early-term recurrence had statistical significance in both groups. The factors that significantly predicted early-term recurrence were left common pulmonary vein and the ISA/LASA. ISA/LASA (HR 0, 95% CI 0–0.005, P = 0.008) and left common pulmonary vein trunk (HR 7.754, 95% CI 2.256–25.651, P = 0.001) were the independent risk factors for early recurrence. ROC curve analysis showed that ISA/LASA predicted the best early recurrence after operation with a cut-off value of 15.2%.ConclusionA greater ISA/LASA reduces early recurrence after cryoablation in patients with PeAF. An ISA/LASA of 15.2% may be the best cut-off value for predicting early recurrence after cryoablation for PeAF.

Predictors of late recurrence after second catheter ablation for persistent atrial fibrillation

BackgroundLittle has been reported on the predictors of late recurrence (LR) after second radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF). ObjectiveThis study aimed to identify the predictors of LR after second RFCA in patients with persistent AF. MethodsWe retrospectively analyzed 123 patients who underwent a second RFCA because of LR after the initial RFCA for persistent AF. LR was defined as a recurrence of atrial tachyarrhythmia >3 months after the ablation procedure. The initial RFCA included pulmonary vein isolation alone or pulmonary vein isolation plus cavotricuspid isthmus block. The predictors of LR were evaluated by the Cox proportional hazards model. ResultsIn the univariate analysis, elevated brain natriuretic peptide levels, absence of pulmonary vein reconnections at the beginning of the second RFCA, and presence of early recurrence (ER, defined as a recurrence of atrial tachyarrhythmia within 3 months) after the second RFCA were associated with LR (P = .025, P = .018, and P < .001, respectively). The multivariate analysis revealed that absence of pulmonary vein reconnections and presence of ER were independent predictors of LR after the second RFCA (P = .004 and P < .001, respectively). ConclusionAbsence of pulmonary vein reconnections and presence of ER were strongly associated with LR after the second RFCA in patients with persistent AF.

PVI-only is not enough for all patients with persistent AF: A FLOW-AF subgroup analysis

BackgroundSince the Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II (STAR-AF II), there has been a trend toward pulmonary vein isolation (PVI)-only ablation strategies for persistent atrial fibrillation (PeAF). Electrographic flow (EGF) mapping can identify active sources of atrial fibrillation (AF) and estimate the electrographic flow consistency (EGFC) of wavefront propagation through substrate, revealing functional AF mechanisms. ObjectiveWe sought to examine the success of a PVI-only ablation strategy for a redo PeAF/longstanding PeAF population. MethodsElectrographic Flow-Guided Ablation in Redo Patients With Persistent Atrial Fibrillation (FLOW-AF [NCT04473963]) prospectively enrolled patients with nonparoxysmal AF undergoing redo ablation at 4 centers. One-minute EGF recordings using 64-pole basket catheters were obtained both pre-PVI and post-PVI following a 20-minute wait and confirmation of electrical isolation of veins. Patients with EGF-identified sources were randomized 1:1 to EGF-guided source ablation vs PVI-only. Patients with no sources were not randomized and mostly received PVI only. ResultsStudy of 85 patients enrolled 24 with EGF-identified sources randomized to PVI only and 23 with no sources receiving PVI only. Of these 47 patients, those with sources (Group 2) had different clinical characteristics including older age and higher CHA2DS2-VASc scores compared with those with sources (Group 1). After PVI only, Group 1 had 70% (16 of 23) freedom from recurrent AF (FFAF) within 1 year vs Group 2 with 35% (8 of 23), P = .018. In addition, patients with high electrographic flow consistency (EGFC) indicative of healthy or normal substrate had 67% (10 of 15) FFAF vs 45% (14 of 31) in those with low EGFC suggestive of abnormal substrate, P = .011. ConclusionSuccess rates in no-sources patients receiving PVI only are better than in those with sources randomized to PVI only. For the clinically heterogenous population of patients with PeAF, the presence of EGF-identified sources matters clinically, and PVI only will not be enough for all patients.

Left atrial posterior wall isolation in addition to pulmonary vein isolation using a pentaspline catheter in pulsed-field ablation for atrial fibrillation: A systematic review and meta-analysis.

Persistent atrial fibrillation (AF) may require extensive ablation strategies. Left atrial posterior wall isolation (LAPWI) might address potential substrates for recurrence during pulsed-field ablation (PFA). This meta-analysis aimed to investigate the feasibility and effectiveness of LAPWI in addition to pulmonary vein isolation (PVI) using a pentaspline catheter in PFA for AF. Comprehensive search was conducted using PubMed, SCOPUS, ScienceDirect, and EuropePMC for studies reporting LAPWI+PVI using a pentaspline catheter in PFA ablation for AF. The primary outcome was atrial tachyarrhythmia (ATa) recurrence, defined as AF/atrial flutter/atrial tachycardia after blanking period. There were 882 patients from 7 studies. The success rate of LAPWI was 100% using mean/median of 16 to 20 added PFA applications with no reported acute left atrial posterior wall reconnection and esophageal complications. In mean follow-up of 240 ± 91 days, ATa recurrence was 21% (95% CI 13%-29%; I2 = 84.8%) in the LAPWI+PVI group. Meta-regression analysis showed that age, left ventricular ejection fraction, and repeat procedure did not significantly influence ATa recurrence (P > .05). Each 1-mm increase in left atrial diameter, increases the chance of ATa recurrence by 6% (R2 = 100%, P < .001, I2 = 0%). Meta-analysis showed no difference in terms of ATa recurrence among LAPWI+PVI patients compared with those without LAPWI (odds ratio 0.78, 95% confidence interval 0.50-1.21, P = .27; I2 = 0%, P = .86). Procedure time and fluoroscopy time did not significantly differ (P > .05). LAPWI using a pentaspline catheter during PFA was feasible and did not prolong the procedure/fluoroscopy but did not reduce ATa recurrence. LAPWI may be considered during PFA, although the benefit is uncertain.

Clinical Characteristics and Outcomes inPatients With Atrial Fibrillation and Pathogenic TTN Variants.

TTN encodes a sarcomeric protein called titin. Pathogenic rare variants in TTN are the most common finding in patients with atrial fibrillation (AF) and positive genetic testing. This study sought to define the characteristics and outcomes in patients with AF and pathogenic TTN variants compared with genotype-negative patients with AF. Patients who presented initially with AF were enrolled in an AF registry. Retrospectively they underwent research sequencing for cardiomyopathy and arrhythmia genes. TTN(+) AF cases were defined as participants with pathogenic or likely pathogenic (P/LP) rare variants located in exons with high cardiac expression. They were matched 1:2 with control subjects with no P/LP variants. Phenotyping used retrospective manual chart review. Among 2794 participants; 57 (2.0%) TTN(+) AF cases were identified and matched with 114 control subjects. Low QRS complex voltage was present more often in TTN(+) AF cases (18% vs 5%; P< 0.01), with no difference in PR, QRS interval, or QTc. More TTN(+) AF cases had persistent AF at enrollment (44% vs 30%; P = 0.028) and had undergone multiple cardioversions (61% vs. 37%; P< 0.01). By end of follow-up (median 8.3 years; Q1, Q3: 4.5, 13.7 years), 11% of TTN(+) AF cases developed sustained ventricular tachycardia/ventricular fibrillation, 44% left ventricular (LV) systolic dysfunction (LV ejection fraction<50%), and 47% met a combined endpoint of sustained ventricular tachycardia/ventricular fibrillation or LV systolic dysfunction. TTN(+) AF patients undergo more cardioversions and have more persistent forms of AF. Approximately 50% develop LV systolic dysfunction and/or malignant ventricular arrhythmias. These results highlightthe need for diagnostic evaluation and management in TTN(+) patients beyond the usual care for AF.

The Utility of Speckle Tracking Echocardiographic Parameters in Predicting Atrial Fibrillation Recurrence After Catheter Ablation in Patients with Non-Valvular Atrial Fibrillation.

Despite the efficacy of catheter ablation (CA) as a treatment for non-valvular atrial fibrillation (NVAF), many patients still experience atrial fibrillation (AF) recurrence after CA. This study aimed to evaluate the predictive value of speckle tracking echocardiographic (STE) parameters for AF recurrence post-ablation. A total of 380 NVAF patients treated with CA at the First Affiliated Hospital of Guangxi Medical University from January 2020 to March 2023 were prospectively recruited. The mean age was 59.4 ± 10.8 years, and 72.1% were male, including 150 patients (39.5%) with persistent AF and 230 patients (60.5%) with paroxysmal AF. STE was used to evaluate baseline left atrial (LA) function before CA within 48h. Over a median follow-up of 9 (interquartile range, 4-17) months, AF recurrence occurred in 132 patients (34.7%). The recurrence group showed lower left ventricular ejection fraction, LA reservoir strain (LASr), and conduit strain (LAScd), but higher LA stiffness than non- recurrence group (all P < 0.05). Multivariable Cox regression identified LA stiffness and LASr as independent risk factors. Time-dependent ROC analysis showed that LA stiffness (AUC 0.768, 95% CI 0.705-0.831) and LASr (AUC 0.755, 95% CI 0.691-0.820) were better at predicting 1-year AF recurrence than other risk factors. For 2-year AF recurrence post-catheter ablation, LA stiffness (AUC 0.866, 95% CI 0.804-0.928) and LASr (AUC 0.860, 95% CI 0.800-0.920) also demonstrated superior predictive performance. Kaplan-Meier curves showed a significant difference in AF recurrence rate for patients with LA stiffness > 0.55 and LASr ≤ 24.3% (Log rank P < 0.01). Evaluation of LA function using STE assists in stratifying the risk of AF recurrence in NVAF patients and guiding follow-up management. LASr and LA stiffness are independent predictors of AF recurrence following CA in NVAF patients, and potentially outperforming other morphological parameters.

Multielectrode catheter-based pulsed field ablation of persistent and long-standing persistent atrial fibrillation.

Rhythm control of non-paroxysmal atrial fibrillation (AF) is significantly more challenging, as a result of arrhythmia perpetuation promoting atrial substrate changes and AF maintenance. We describe a tailored ablation strategy targeting multiple left atrial (LA) sites via a pentaspline pulsed field ablation (PFA) catheter in persistent AF sustained beyond 6 months (PerAF > 6 m) and long-standing persistent AF (LSPAF). The ablation protocol included the following stages: pulmonary vein antral and posterior wall isolation plus anterior roof line ablation (Stage 1); electrogram-guided substrate ablation (Stage 2); atrial tachyarrhythmia regionalization and ablation (Stage 3). Seventy-two [age:68 ± 10years, 61.1%males; AF history: 25 (18-45) months] patients with PerAF > 6 m (52.8%) and LSPAF (47.2%) underwent their first PFA via the FarapulseTM system. LA substrate ablation (Stage 1 and 2) led to AF termination in 95.8% of patients. AF organized into a left-sided atrial flutter (AFlu) in 46 (74.2%) patients. The PFA catheter was used to identify LA sites showing diastolic, low-voltage electrograms and entrainment from its splines was performed to confirm the pacing site was inside the AFlu circuit. Left AFlu termination was achieved in all cases via PFA delivery. Total procedural and LA dwell times were 112 ± 25 min and 59 ± 22 min, respectively. Major complications occurred in 2 (2.8%) patients. Single-procedure success rate was 74.6% after 14.9 ± 2.7 months of follow-up; AF-free survival was 89.2%. In our cohort, PFA-based AF substrate ablation led to AF termination in 95.8% of cases. Very favourable clinical outcomes were observed during >1 year of follow-up.

Automatic Echocardiographic Assessment of Left Atrial Function for Prediction of Low-Voltage Areas in Non-Valvular Atrial Fibrillation.

Left atrial low-voltage areas (LA-LVAs) identified by 3D-electroanatomical mapping are crucial for determining treatment strategies and prognosis in patients with atrial fibrillation (AF). However, convenient and accurate prediction of LA-LVAs remains challenging. This study aimed to assess the viability of utilizing automatically obtained echocardiographic parameters to predict the presence of LA-LVAs in patients with non-valvular atrial fibrillation (NVAF). This retrospective study included 190 NVAF patients who underwent initial catheter ablation. Before ablation, echocardiographic data were obtained, left atrial volume and strain were automatically calculated using advanced software (Dynamic-HeartModel and AutoStrain). Electroanatomic mapping (EAM) was also performed. Results were compared between patients with LA-LVAs ≥5% (LVAs group) and <5% (non-LVAs group). LA-LVAs were observed in 81 patients (42.6%), with a significantly higher incidence in those with persistent AF than paroxysmal AF (55.6% vs 19.3%, P <0.001). Compared with the non-LVAs group, the LVAs group included significantly older patients, lower left ventricular ejection fraction, higher heart rate, and higher E/e' ratio (P <0.05). The LVAs group exhibited higher left atrial volumemax index (LAVimax) and lower left atrial reservoir strain (LASr) (P <0.001). In multivariate analysis, both LAVimax and LASr emerged as independent indicators of LVAs (OR 0.85; 95% CI 0.80-0.90, P<0.001) and (OR 1.15, 95% CI 1.02-1.29, P =0.021). ROC analysis demonstrated good predictive capacity for LA-LVAs, with an AUC of 0.733 (95% CI 0.650-0.794, P <0.001) for LAVimax and 0.839 (95% CI 0.779-0.898, P <0.001) for LASr. Automatic assessment of LAVimax and LASr presents a promising non-invasive modality for predicting the presence of LA-LVAs and evaluating significant atrial remodeling in NVAF patients. This approach holds potential for aiding in risk stratification and treatment decision-making, ultimately improving clinical outcomes in patients.

The association between left atrial appendage emptying velocity and atrial fibrillation recurrence after radiofrequency catheter ablation in patients with early persistent atrial fibrillation

ObjectiveIn the present study, we aimed to explore the association between left atrial appendage emptying velocity (LAAEV) measured by transesophageal echocardiography and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) in patients with early persistent atrial fibrillation (PeAF).MethodsWe retrospectively analyzed patients with early PeAF who underwent their initial ablation procedure. The echocardiographic and clinical data of the enrolled patients were collected and recorded prior to the operation. Following adjustment for confounding factors, we investigated the relationship between the LAAEV and AF recurrence in patients with early PeAF after radiofrequency ablation.ResultsThe proportions of AF recurrence in the low, medium, and high LAAEV groups were 48.8%, 16.0%, and 13.1%, respectively. After adjusting for potential confounding factors, we observed a gradual decrease in the risk of AF recurrence with increasing LAAEV (odds ratio: 0.882, 95% confidence interval: 0.842—0.924, p<0.001). This trend was statistically significant (p<0.001), particularly when comparing the high and low LAAEV groups (odds ratio: 0.033, 95% confidence interval: 0.009―0.116, p<0.001). Curve fitting analysis demonstrated an approximate negative linear association between LAAEV and the probability of AF recurrence.ConclusionsAmong patients with early PeAF who successfully underwent their first RFCA, we found that the LAAEV within 24 h before the procedure was independently correlated with the risk of AF recurrence. Notably, this association was negative, indicating that higher LAAEV was associated with a lower risk of AF recurrence.

Predictors of left atrial appendage emptying velocity: Derivation and validation of CHIRP3(M-1) score

BackgroundAtrial fibrillation (AF) leads to impaired left atrial appendage contractility, increasing the risk of thromboembolic stroke. The left atrial appendage emptying velocity (LAAev) measured on transesophageal echocardiogram (TEE) is a marker of increased thromboembolic risk. ObjectivesThe purpose of this study was to evaluate predictors of reduced LAAev for identifying individuals at increased risk for cardioembolic stroke. MethodsThis was a single-center retrospective review of TEEs and clinical charts. Predictors of LAAev <30 cm/s were identified using logistic regression. A risk prediction model was created using stepwise selection in a derivation set (n = 695) and separately tested in a validated set (n = 300). ResultsWe included TEEs on 995 patients (age 71.3±12.7 years; female 38.1%; history of AF 82.1%; in AF at evaluation 27.7%; CHA2DS2-VASc score 4.1 ± 1.9; LAAev 41.6 ± 21.0 cm/s). Significant multivariable predictors of LAAev <30 cm/s in derivation set were used to create the CHIRP3M-1 score containing 8 variables: Coronary artery disease (1), congestive Heart failure (1), Increased left atrial volume index ≥42 mL/m2 (1), current Rhythm AF (1), Paroxysmal AF (2), Persistent AF (3), longstanding Persistent/permanent AF (4), and greater than moderate Mitral regurgitation (-1). In the validation set, as compared to intermediate scores (3–4), those with low scores (≤2) and high scores (≥5) had odds ratios for LAAev <30 cm/s of 0.41 (0.21, 0.78, P = .007) and 2.58 (95% confidence interval 1.45–4.61, P = .001), respectively. ConclusionWe developed and validated a novel risk stratification system to predict reduced LAAev using clinical and echocardiographic variables. This may help refine the stratification of cardioembolic stroke risk.

Frequency and Outcome of Postoperative Atrial Fibrillation Following Mitral Valve Replacement for Mitral Stenosis.

To determine the frequency and outcome of postoperative atrial fibrillation (POAF) in terms of in-hospital and 30-day mortality and morbidity after mitral valve replacement (MVR). Observational study. Place and Duration of the Study: Department of Cardiac Surgery, Northwest General Hospital and Research Centre, Peshawar, Pakistan, from September 2017 to March 2023. A total of 186 patients between the ages of 20 and 70 years, who had severe mitral stenosis and normal sinus rhythm and underwent MVR surgery, were included in the study. The frequency of POAF within 7 days following surgery and outcomes in terms of in-hospital and 30-day mortality / morbidity were recorded. POAF occurred in 19.4% patients. Patients with POAF were predominantly male (p = 0.01), aged over 50 years (p = 0.002), diabetic (p = 0.02), hypertensive (p = 0.02), had impaired LV function (p <0.001), enlarged LA (p = 0.003), pulmonary hypertension (p = 0.009), previous PMBV (p <0.001), and previous infective endocarditis (p <0.001). In-hospital and 30-day mortality rates were 7% and 8.6%, respectively. POAF patients had prolonged ICU stays (p <0.001), hospital stays (p = 0.04), and higher mortality rates (p <0.001). Persistent AF (22%) contributed to 30-day morbidity in the form of embolic stroke, limb ischaemia, and congestive heart failure. POAF commonly occurs following the MVR surgery and significantly impacts perioperative and 30-day morbidity and mortality. Postoperative atrial fibrillation, Mitral stenosis, Mitral valve replacement.

Impact of Non-Valvular Atrial Fibrillation on Mitral Valve Anatomic Features: A Study of Three-Dimensional Mitral Valve by Transesophageal Echocardiography and Automatic Analysis Software.

Mitral regurgitation (MR) is frequently observed in non-valvular atrial fibrillation (NVAF) patients and is a significant risk factor for its progression. This study aims to investigate the three-dimensional anatomical characteristics of the mitral valve (MV) in patients with different types of NVAF to elucidate the underlying mechanisms of MR. A retrospective analysis was conducted on 82 paroxysmal atrial fibrillation patients (PAF group) and 66 persistent atrial fibrillation patients (PerAF group) who underwent real-time three-dimensional transesophageal echocardiography (RT 3D-TEE) before initial ablation. Additionally, 30 patients undergoing RT 3D-TEE for the assessment of patent foramen ovale were selected as the control group. Basic echocardiographic variables were measured, left atrioventricular volume and strain parameters were calculated using automated software (Dynamic-HeartModel and AutoStrain). MV anatomic features were analyzed using the 4D-MV Assessment software (TomTec Imaging Systems). The maximum left atrial volume (LAVmax) was highest in the PerAF group, followed by the PAF and control groups, with statistically significant differences (p<0.01). Left atrial reservoir strain (LASr) showed an opposite trend, being the lowest in the PerAF group (p<0.01). The proportion of moderate to severe MR was significantly higher in the PerAF group (27.3%) compared to the PAF group (11.0%) (p<0.01). Compared to controls, the AF groups exhibited mitral annular (MA) dilation, flattening of the MA plane, and increased leaflet area (all p<0.05). Correlation analysis between effective regurgitant orifice area (EROA) and left atrioventricular structure and function parameters, as well as various annular parameters, showed that EROA was significantly correlated with left ventricular end-diastolic volume (LVEDV), LAVmax, LASr, anterior and posterior diameter, annular area, ratio of annular height to commissural diameter (AH/CD ratio), posterior leaflet area, posterior leaflet length, and the C-shaped annulus length (all p<0.05). Significant remodeling of the MV apparatus occurs in NVAF patients, with more pronounced changes in PerAF patients, contributing to a higher incidence of moderate to severe MR. RT 3D-TEE-based MV automated assessment offers significant advantages in accurately diagnosing MV remodeling and supporting the evaluation of MR in NVAF patients.

Characterization and Clinical Significance of Hemolysis After Pulsed Field Ablation for Atrial Fibrillation: Results of a Multicenter Analysis.

Pulsed field ablation (PFA) is increasingly used in clinical practice for the treatment of atrial fibrillation. While the susceptibility of erythrocytes to electroporation is well established, the effect of cardiac PFA technologies on hemolysis has remained underreported. The aim of this study was to investigate the incidence, severity, and clinical impact of PFA-induced hemolysis. We included n=145 patients undergoing atrial fibrillation catheter ablation with a pentaspline PFA catheter (biphasic, bipolar pulses of 2 kV) and n=70 patients receiving radiofrequency ablation (40-90 W) at 4 high-volume European centers. The lesion set comprised pulmonary vein isolation for paroxysmal atrial fibrillation and pulmonary vein isolation±additional lesions for persistent atrial fibrillation. Hemolysis and renal function biomarkers were analyzed in blood samples at baseline, at the end of ablation, and 24 hours after the procedure. Baseline characteristics were well balanced between groups (overall mean, 65.7±9.4 years; 69.3% male). The ablation procedures comprised a mean of 61.6±27.4 PFA deliveries and 26.3±15.0 minute RF duration. Hemolysis was detected in 94.3% versus 6.8% of patients after PFA versus radiofrequency ablation (P<0.001): PFA was associated with significantly lower haptoglobin levels (0.5±0.4 versus 1.0±0.4 g/L), while free plasma hemoglobin (592.8±330.6 versus 147.8±183.0 mg/L), bilirubin (21.3±11.3 versus 14.8±8.8 µmol/L), and LDH (lactate dehydrogenase, 352.7±115.7 versus 253.2±56.5 U/L) were significantly higher after PFA versus radiofrequency ablation (all P<0.001). Hemolysis correlated with the number of PFA deliveries (r=0.62 [95% CI, 0.33-0.80]; P<0.001), with the highest severity occurring ≥54 PFA deliveries. After PFA, hemoglobinuria occurred in 36.4%, while creatinine increase was higher in patients with baseline glomerular filtration rate <50 mL/min versus baseline glomerular filtration rate >50 mL/min (Δcrea, 27.0±103.1 versus -0.2±12.1 µmol/L; P=0.010). Intravascular hemolysis is a frequent finding after PFA and increases with the number of PFA deliveries. Until the clinical impact of PFA-associated hemolysis is fully elucidated, a careful titration of PFA deliveries during the ablation procedure is warranted.