Atrial Fibrillation Recurrence Research Articles

Hyperenhancement of LA Wall by Three-Dimensional High-Resolution Late Gadolinium-Enhanced MRI and Recurrence of AF After Catheter Ablation

Background/Objectives: This study investigated the relationship between LA (LA) enhancement on three-dimensional (3D) late gadolinium enhancement (LGE) MRI and recurrence after catheter ablation in patients with AF (AF). Methods: A total of one hundred patients with AF (mean age: 68 ± 9 years, 50% with paroxysmal AF) were included in this study. Each patient underwent a high-resolution 3D LGE MRI prior to catheter ablation, allowing for detailed imaging of the LA wall. Quantitative analysis of the enhancement was performed using dedicated software designed for volumetric measurements of LA LGE. Recurrence of AF was monitored over a 90-day period following the ablation procedure. The primary outcome was the correlation between the volume of LGE in the LA and the recurrence of AF. Results: Multivariate analysis confirmed that the volume of LA LGE, defined as the volume exceeding 1SD above the mean signal intensity of the LA, was an independent predictor of recurrence [hazard ratio: 1.16 (95%CI: 1.04–1.29, p = 0.0057)]. The area under the curve for recurrence prediction using 3D LGE MRI was 0.74 (95%CI: 0.63–0.86), with an optimal threshold of 11.72 mL, providing a sensitivity of 55% (95%CI: 32–77%) and a specificity of 86% (95%CI: 77–93%). Conclusions: LA enhancement assessed by high-resolution LGE MRI may serve as a valuable imaging marker for predicting the recurrence in patients with AF following catheter ablation.

The association between the recurrence of atrial fibrillation and the shape of left atrial lateral ridge

To investigate the role of the geometry of the left atrial lateral ridge (LLR) in the atrial fibrillation (AF) recurrence after radiofrequency ablation (RFA). A total of 225 patients with AF who underwent RFA for the first time were retrospectively enrolled and divided into the recurrence (n = 53) and non-recurrence (n = 172) groups. The clinical data and the volume of left atrium (LAV) and the LLR geometry were analyzed. The LAV in the recurrence group was greater than that in the non-recurrence group (P < 0.001). There were more rectangular LLR in the recurrence group than the non-recurrence group (43% vs. 77%, P < 0.001). The anteroposterior diameter of the LLR orifice in the recurrence group was smaller than that in the non-recurrence group (P = 0.001), while the length of the LLR in the recurrence group was longer (P = 0.012). Multivariate analysis revealed the shape of the LLR was significant independent predictor of recurrence AF. The shape of the LLR is an independent predictor of recurrence after RFA.

Artificial Intelligence-Based Feature Analysis of Pulmonary Vein Morphology on Computed Tomography Scans and Risk of Atrial Fibrillation Recurrence After Catheter Ablation: A Multi-Site Study.

Atrial fibrillation (AF) recurrence (AF+) is common after catheter ablation. Pulmonary vein (PV) isolation is the cornerstone of AF ablation, but PV remodeling has been associated with the risk of AF+. We aimed to evaluate whether artificial intelligence-based morphological features of primary and secondary PV branches on computed tomography images are associated with AF+ post-ablation. Two artificial intelligence models were trained for the segmentation of computed tomography images, enabling the isolation of PV branches. Patients from Cleveland Clinic (n=135) and Vanderbilt University (n=594) were combined and divided into 2 sets for training and cross-validation (D1, n=218) and internal testing (D2, n=511). An independent validation set (D3, n=80) was obtained from University Hospitals of Cleveland. We extracted 48 fractal-based and 12 shape-based radiomic features from primary and secondary PV branches of patients with AF+ and without recurrence after catheter ablation of AF. To predict AF+, 3 Gradient Boosting classification models based on significant features from primary branch PV model (Mp), secondary branch PV model (Ms), and combined primary and secondary branch PV model (Mc) were built. Features relating to primary PVs were found to be associated with AF+. The Mp classifier achieved area under the curve values of 0.73, 0.71, and 0.70 across the 3 datasets. AF+ cases exhibited greater surface complexity in their primary PV area, as evidenced by higher fractal dimension values compared with AF nonrecurrence cases. The Ms classifier results revealed a weaker association with AF+, suggesting higher relevance to AF+ post-ablation from primary PV branch morphology. This largest multi-institutional study to date revealed associations between artificial intelligence-extracted morphological features of the primary PV branches with AF+ in 809 patients from 3 sites. Future work will focus on enhancing the predictive ability of the classifier by integrating clinical, structural, and morphological features, including left atrial appendage and left atrium-related characteristics.

Beyond Anticoagulation: Limitations of Oral Anticoagulants in Preventing Stroke Recurrence in Atrial Fibrillation

Background/Objectives: Despite the widespread use of oral anticoagulants (OACs), acute ischemic stroke (AIS) remains a significant risk for patients with atrial fibrillation (AF). The real-world effectiveness of OACs in preventing recurrent strokes, particularly following an initial stroke of cardioembolic (CE) origin, continues to be a major challenge for clinicians managing AF patients. This study evaluated the efficacy of OACs in secondary stroke prevention and investigated the influence of anticoagulation type and quality on recurrence risk. Methods: We analyzed data from 128 AF patients in the prospective Transzlációs Idegtudományi Nemzeti Laboratórium (TINL) STROKE-registry, admitted with CE stroke between February 2023 and September 2024. Patients were categorized by anticoagulation status at admission (OAC-users, n = 89; anticoagulation-naïve, n = 39). Recurrence rates were assessed using logistic regression models, adjusted for age, sex, hypertension, diabetes, and pre-stroke disability. Subgroup analyses explored the effects of anticoagulation type and quality. Results: Recurrence rates were similar between the OAC-treated and anticoagulation-naïve patients after adjusting for confounders (19.10% vs. 17.95%, p = 0.870). Among the anticoagulated patients, neither anticoagulation type nor quality alone significantly influenced the recurrence risk. However, their interaction was statistically significant (p = 0.049), suggesting that the effectiveness of anticoagulation in preventing strokes is strongly affected by treatment quality. Conclusions: Although OACs are a cornerstone of stroke prevention in patients with AF, their efficacy in reducing recurrence depends on optimal management. These findings highlight that adequate anticoagulation, not just its use, is critical to minimize recurrence risk. To effectively prevent strokes in high-risk AF patients, future strategies must focus on standardized protocols, tailored monitoring, and individualized dosing regimens.

Malnutrition and risks of atrial fibrillation recurrence after catheter ablation

AbstractBackgroundRecent data showed an association between malnutrition and increased all‐cause mortality and thromboembolic risk in patients with atrial fibrillation (AF). However, the impact of malnutrition on the clinical outcomes for patients undergoing catheter ablation for AF is still debated. Our study aimed to examine this relationship using all existing available data.MethodsWe conducted a systematic review of MEDLINE and EMBASE databases from inception to April 2024, analyzing the association between malnutrition, assessed by the Geriatric Nutritional Risk Index (GNRI), and the risk of AF recurrence in patients who underwent catheter ablation for AF, compared to those without malnutrition. Relative Risk (RR) or hazard ratio (HR) and 95% CIs were retrieved from each study and combined using the generic inverse variance method.ResultsWe included 3 cohort studies with 1697 participants undergoing AF ablation (10.9%) who had malnutrition indicated by GNRI score below 98. Patients with malnutrition had a higher risk of AF recurrence following catheter ablation for AF compared to those without malnutrition (Pooled RR = 2.74, 95% CI 1.36–5.51, I2 = 67%, p = .005).ConclusionsOur pooled analysis indicates that malnourished patients undergoing catheter ablation for AF have an increased risk of AF recurrence compared to non‐malnourished patients.

Electrophysiological predictors of susceptible atrial substrate for the onset and recurrence of atrial fibrillation.

The atrial electroanatomic substrate is an essential component in the pathogenesis of atrial fibrillation (AF). However, the electrophysiological markers of susceptible atria for AF are not well-characterized. This study aimed to assess atrial conduction indices on surface electrocardiogram (ECG) and intracardiac electrogram (EGM) as predictors of initiation and recurrence of AF after successful ablation. We studied all consecutive patients who underwent electrophysiological study and catheter ablation for AF (study group) or atrioventricular nodal reentrant tachycardia (AVNRT) (control group) from 2013 to 2018. Atrial conduction indices were measured on ECG and EGM during the electrophysiology study. Clinical data was obtained from the medical record. A total of 387 patients with AF (mean age 63years, 31% female) were studied and compared to 94 patents in control group. The initiation of AF was associated with significant prolongation of atrial conduction indices on ECG and EGM (p < 0.05). During a mean follow up of 5 ± 2years, recurrence of AF (48%) after successful ablation occurred in patients with prolonged P wave duration, left atrial (LA) conduction interval, proximal to distal coronary sinus (pCS-dCS) interval, and P wave to dCS interval (p < 0.05). Machine learning modeling determined that pCS-dCS interval, QRS duration, and LA duration in leads V1 and II are most impactful conduction indices in association with AF recurrence. Prolonged atrial conduction intervals, particularly LA (pCS-dCS), indicate susceptible substrate for the onset and the recurrence of AF after ablation. LA conduction indices can facilitate early detection and management of AF.

Left Atrial Wall Thickness Measured by a Machine Learning Method Predicts AF Recurrence After Pulmonary Vein Isolation.

Left atrial (LA) remodeling plays a significant role in the progression of atrial fibrillation (AF). Although LA wall thickness (LAWT) has emerged as an indicator of structural remodeling, its impact on AF outcomes remains unclear. We aimed to determine the association between LAWT and AF recurrence after pulmonary vein isolation (PVI), as well as to evaluate the relationship between LAWT and LA fibrosis. Single-center registry of patients enrolled for radiofrequency PVI from 2016 to 2018. In all cases, a pre-ablation CT was performed within less than 48 h. Mean LAWT was retrospectively measured by a semi-automated machine learning method (ADAS 3D). A subgroup of patients also underwent pre-ablation cardiac MRI. The primary endpoint was time to AF recurrence after a 3-month blanking period. A total of 439 patients (mean age 61 ± 12 years, 62% male, 78% with paroxysmal AF) were included. The mean LAWT was 1.4 ± 0.2 mm (0.9-1.9 mm). During a median follow-up of 5.8 (IQR: 4.9-6.6) years, 238 patients (54%) had an AF relapse. After adjusting for 8 clinical and imaging potential confounders, LAWT remained an independent predictor of time-to-recurrence (aHR: 4.25 [95% CI: 1.65-10.95], p = 0.003). AF recurrence rates were 11%, 15%, and 21%/year across terciles of increasing LAWT (log-rank p < 0.001). Additionally, the AF recurrence rate increased across the spectrum of LA structural remodeling, ranging from 8% (normal LAWT and LAVI) to 30%/year (LAWT and LAVI both increased). In the 62 patients who also underwent pre-ablation MRI, a moderate relationship between LAWT and fibrosis (assessed by late-gadolinium enhancement) was found (Spearman R 0.468; p < 0.001). Mean LAWT, easily assessed by commercially available machine learning software, is an independent predictor of time to AF recurrence after PVI in the long term. Whether patients with increased LAWT should receive tailored therapy deserves further investigation.

The predictive value of pan-immune inflammatory index for early recurrence of atrial fibrillation after cryoablation

ObjectiveThe pan-immune inflammatory (PIV) index holds prognostic value for cardiovascular diseases. This study aimed to investigate the predictive value of the PIV index regarding recurrence of atrial fibrillation (AF) after cryoballoon ablation (CBA).MethodsThe study included 307 patients with AF. Four inflammatory markers, namely, the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune inflammation (SII) index, and PIV index, were used as indicators. COX regression analysis was conducted to evaluate the predictive value of AF recurrence after CBA. A receiver operating characteristic (ROC) curve was plotted, and the area under the curve (AUC) was calculated to evaluate the discriminative power of the indicators.ResultThe PIV index [94.9 (168.9,504.9) vs. 143.2 (98.2,210.6), P < 0.01] and SII index [366.3 (256.6,491.9) vs. 569.9 (658.1,438.4), P < 0.01] were significantly higher in the recurrence group. Univariable COX regression analysis showed that these four indices, persistent AF, and left atrial diameter (LAD) were all associated with AF recurrence. In multivariable regression analysis, the PIV index, persistent AF, and LAD (all P < 0.05) were independent predictors of postoperative AF recurrence. The ROC curve analysis showed that the PIV index had a higher predictive value for AF recurrence (AUC = 0.768, P < 0.01, 95% CI: 0.696–0.840) than the SII index and NLR. Kaplan–Meier analysis showed that patients with a PIV index > 260.7 had a higher recurrence rate at 1-year follow-up (P < 0.01). Subgroup analysis indicated that PIV had a predictive value in patients with different types of AF.ConclusionPIV index may be a potential biomarker for predicting relapse in patients with AF after CBA.

Serum Homocysteine and Atrial Fibrillation Recurrence after Catheter Ablation: A Meta-Analysis of 11 Cohort Studies Involving 2147 Patients.

The relationship between serum homocysteine (Hcy) levels and atrial fibrillation (AF) recurrence following catheter ablation remains unclear. This meta-analysis aims to investigate this association. Comprehensive searches in PubMed, Web of Science, Embase, Wanfang, and China National Knowledge Infrastructure (CNKI) databases identified relevant studies published up to May 25, 2024. Cohort studies that measured pre-ablation serum Hcy levels and reported AF recurrence post-ablation were included. Data were analyzed using random-effects models by incorporating the potential influence of heterogeneity, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated for the association between serum Hcy levels and AF recurrence. Eleven retrospective cohort studies involving 2147 patients with AF who underwent catheter ablation were analyzed. Higher pre-ablation serum Hcy levels were associated with an increased risk of AF recurrence (OR for per 1 μmol/l increment of Hcy: 1.22, 95% CI: 1.17 to 1.28, p<0.001; I²=0%). Additionally, studies that categorized Hcy levels also found a higher risk of AF recurrence in patients with elevated Hcy (OR for patients with a high versus a low serum Hcy: 2.75, 95% CI: 2.02 to 3.75, p <0.001; I²=0%). Funnel plots and Egger's regression test indicated low risks of publication bias. In conclusions, elevated pre-ablation serum Hcy levels are significantly associated with an increased risk of AF recurrence post-catheter ablation. These findings suggest that Hcy could be a valuable biomarker for predicting AF recurrence and may inform pre-ablation risk stratification. Further prospective studies are warranted to confirm these results.

Catheter Ablation or Surgical Therapy in Severe Atrial Functional Mitral Regurgitation Caused by Long-Standing Persistent Atrial Fibrillation-Propensity Score Analysis.

There is no consensus on the treatment strategy for patients with severe atrial functional mitral regurgitation combined with heart failure (HF), with a lack of comparative studies in patients with long-standing persistent atrial fibrillation and severe atrial functional mitral regurgitation. We aim to compare mitral valve repair combined with the maze procedure with catheter ablation in patients with severe atrial functional mitral regurgitation due to long-standing persistent atrial fibrillation. Patients with severe atrial functional mitral regurgitation and long-standing persistent atrial fibrillation were included in this retrospective cohort study. Surgical patients underwent mitral valve repair combined with the Cox maze procedure, whereas catheter patients underwent catheter radiofrequency ablation. Mortality, atrial fibrillation recurrence, and HF readmission were assessed using overlap propensity score weighting. Then, between 2018 and 2022, we identified 302 patients: 215 in the surgical group and 87 in the catheter group. There were significant differences in the baseline characteristics between groups. The surgical group had lower rates of atrial fibrillation recurrence (P=0.03), HF readmission (P=0.03), and mitral regurgitation grade >2 at discharge (P<0.01) and follow-up (P<0.01). However, there were no significant differences in the 5-year freedom from death (log-rank P=0.87), atrial fibrillation recurrence (log-rank P=0.36), or HF readmission rates (log-rank P=0.18). Compared with surgical patients, the catheter group had higher atrial fibrillation recurrence and HF readmission rates; however, the difference was not significant after overlap propensity score weighting. Although the proportion of patients with significant mitral regurgitation at the last follow-up was higher after catheter ablation, most patients still showed an effective decrease in mitral regurgitation severity.

Risk Factors for Recurrence of Atrial Fibrillation within 3 Years after Radiofrequency Ablation

Background: Atrial fibrillation is chronic cardiovascular disease, particularly in older patients. Radiofrequency ablation can successfully treat this condition and restore sinus rhythm. However, the postoperative recurrence rate is relatively high. This investigation aimed to address the factors that might increase the risk of recurrence after radiofrequency ablation. Methods: We studied patients who had a successful radiofrequency ablation in our center between 2017 and 2020. We collected information about these patients before the procedure, including their age, sex, obesity, medical history, preoperative laboratory test results, and cardiac ultrasound findings. We divided patients into two groups: those who had atrial fibrillation again within three years and those who did not. We compared the information we collected about these two groups to see if there were any differences to explain why some people had atrial fibrillation again and others did not. We used a statistical method called multivariate logistic regression to analyze these data. Results: After reviewing the patients based on specific criteria, we included 297 patients in our final analysis. Within three years after surgery, 109 patients (36.7%) had a recurrence, whereas 188 (63.3%) did not. When we compared the two groups, we found that older patients, those with obesity, a longer history of atrial fibrillation, a larger left atrium, persistent atrial fibrillation, and higher levels of C-reactive protein before surgery were likely to have atrial fibrillation again within three years (p &lt; 0.05). Our statistical analysis revealed that these factors were independent predictors of atrial fibrillation recurrence. Conclusions: Age, obesity, duration of atrial fibrillation, the size of left atrium, the type of atrial fibrillation, and C-reactive protein (CRP) levels before surgery are closely related to atrial fibrillation recurrence within 3 years after radiofrequency ablation.

L-shaped association of plasma low-density lipoprotein cholesterol with atrial fibrillation recurrence after catheter ablation: a prospective cohort study

The association between plasma low-density lipoprotein cholesterol (LDL-C) and atrial fibrillation (AF) recurrence after catheter ablation remains unclear. We aimed to assess the relationship between preprocedural LDL-C and the AF recurrence in patients undergoing catheter ablation. The cohort study consecutively included AF patients who underwent de novo catheter ablation between April 2021 and January 2023 in the Second Affiliated Hospital of Nanchang University in Jiangxi Province, China. Patients were divided into quartiles based on their baseline fasting LDL-C level (Q1-Q4). Multivariable Cox proportional hazards models were used to evaluate the relationship between LDL-C and AF recurrence. Our analysis included the use of a generalized additive model and smooth curve fitting (penalized spline method), and two-piecewise Cox proportional hazards models, to address the nonlinearity between preprocedural LDL-C and AF recurrence. A total of 482 AF patients with de novo catheter ablation were enrolled, with a median follow-up period of 15.00 months, AF recurrence occurred in 96 (19.92%) patients. The relationship between preprocedural LDL-C and AF recurrence after ablation presented as an L-shape, and the inflection point for the curve was found at the LDL-C level of 3.20 mmol/L (Log likelihood ratio P = 0.031). The hazard ratios (HR) [(95% confidence intervals (CI)] for AF recurrence were 0.50 (0.33–0.74) and 2.11 (0.76–5.89) to the left and right of the inflection point, respectively. Lower LDL-C level is associated with increased AF recurrence risk after catheter ablation were consistent across all subgroups.

The influence of epicardial adipose tissue on the prognosis of atrial fibrillation patients undergoing radiofrequency ablation combined with left atrial appendage occlusion

Atrial fibrillation is the most common arrhythmia in adults. The interplay between epicardial adipose tissue and atrial fibrillation has garnered significant scientific interest. Recently, the combined approach of radiofrequency ablation and left atrial appendage occlusion has become a widely adopted strategy for managing non-valvular atrial fibrillation patients at high risk of thrombus formation. This study aims to assess the prognostic significance of epicardial adipose tissue volume in patients undergoing radiofrequency ablation in conjunction with left atrial appendage occlusion. This study results indicate that in patients undergoing the one-stop procedure, which comprises catheter radiofrequency ablation and percutaneous left atrial appendage occlusion, epicardial adipose tissue volume is significantly associated with AF recurrence post-strategy. Higher EATV predicts AF recurrence (HR = 1.17, 95%CI1.047-1.192, P = 0.001) and thromboembolism (P = 0.002) following the one-stop procedure. Epicardial adipose tissue volume serves as a significant predictor of atrial fibrillation recurrence following the one-stop procedure (area under the curve 0.648, 95%CI0.571-0.725, P = 0.002, sensitivity 0.88, specificity 0.50).

Incomplete ablation as a mechanism of atrial fibrillation recurrence and atrial tachycardia development after maze procedure

ObjectiveAtrial tachyarrhythmias are the most frequent complication after the maze procedure. We examined the mechanism of atrial tachyarrhythmias in association with the ablation energy and technique used at each lesion and by the findings of postoperative electrophysiological study. MethodsFour-hundred fifty-three patients who underwent the maze procedure with biatrial incisions and bilateral pulmonary vein (PV) isolation were examined for the incidence and mechanism of recurrence of atrial fibrillation (AF) and development of atrial tachycardia (AT). PV isolation was performed by radiofrequency (RF) ablation, cryothermia, or cut-and-sew technique. The atrioventricular isthmi and the coronary sinus (CS) were ablated by RF, cryothermia, or a combination of these. ResultsOf 443 patients who survived surgery (98%), 54 patients (12.2%) had recurrent AF and 36 patients (8.1%) developed AT during the median of 28 months (interquartile range, 3-75) postoperatively. Multivariate logistic regression analysis showed preoperative left atrial dimension and nonperformance of intraoperative PV pacing were the independent predictors for AF recurrence. Electrophysiologic study in patients with AT demonstrated incomplete ablation in 24 patients (67%), most frequently at the CS in 16 patients (67%), and non-PV focal activations in 16 patients (44%). Preoperative New York Heart Association functional class of 1 and nonperformance of additional epicardial ablation of the CS were the independent predictors for postoperative AT development. ConclusionsIncomplete ablation is a cause of AF recurrence and AT development after the maze procedure. Intraoperative PV pacing prevents AF recurrence and additional epicardial CS ablation prevents AT development.

Electrophysiological characteristics of pulmonary vein conduction recovery after radiofrequency ablation of atrial fibrillation

This study aimed to identify the specific site of pulmonary vein conduction recovery after radiofrequency ablation (RFA) of atrial fibrillation (AF) for improved outcomes and reduced recurrence. Patients who underwent RFA for AF at our institution were included. The ablation procedure was guided by the ablation index (AI) and left, and right atrial pressures were monitored before and after ablation. Additionally, the recovery time of the sinoatrial node under Burst 400/300 ms stimulation was examined. Among 60 repeat procedure patients, 48 had paroxysmal and 12 had persistent AF. The recovery sites were 36.6% in the left anterior superior, 35% in the right anterior superior, 20% in the left anterior inferior, 20% in the right anterior inferior, 13.3% in the right top, and 11.6% in the left top. Preoperative and postoperative left and right atrial pressures were significantly higher in the persistent AF group compared with the paroxysmal AF group (P < 0.01). Postoperative left atrial pressures were significantly elevated compared to the preoperative levels in both groups (P < 0.01). Sinoatrial node recovery time in the persistent AF group was significantly longer compared with the paroxysmal AF group (P < 0.01). Under the guidance of AI, the recurrence of atrial fibrillation after radiofrequency surgery and the recovery of pulmonary vein potential are mostly concentrated in the upper anterior, lower anterior, and upper left and right pulmonary veins. As the duration of atrial fibrillation prolongs, the left and right atrial pressure increases year by year, while the recovery time of the sinus node gradually prolongs.

Effect of acupuncture on quality of life in atrial fibrillation: study protocol for a randomised controlled trial

IntroductionAtrial fibrillation (AF) is the prevalent cardiac arrhythmia and can significantly impair the quality of life (QoL). Although catheter ablation (CA) is an established treatment for AF,post-procedural complications or perceived...

The association between adipokines dysregulation and the occurrence of atrial fibrillation and obese patients, is it relevant?

Atrial fibrillation (AF) is the most common arrhythmia, affecting approximately 33.5 millions of people worldwide. Unfortunately, the prevalence of this arrhythmia will increase within the following two decades, resulting in a higher mortality rate and a higher economic burden for public health services. Obesity, specifically central obesity, plays an essential role in developing AF by increasing pericardial fat and epicardial adipose tissue thickness, generating a chronic inflammation state where dysregulation of the serum concentration of several proinflammatory proteins occurs and indirectly promotes AF. Therefore, recent research has focused on analyzing the circulating concentration of different molecules, including pro and anti-inflammatory adipokines, and their association with AF. Herein, we review several studies addressing the association of adipokines with the onset or recurrence of AF to establish such association as a potential biomarker for the prevention or adequate treatment of this arrhythmia. We concluded that the insight into this topic is very controversial and needs further research.

Abstract 4136182: Usefulness of Lymphocyte-to-Monocyte Ratio in Predicting Late Recurrence of Atrial Fibrillation after Catheter Ablation and its Association With the Type of Atrial Fibrillation

Introduction: Leukocyte activation is reported to be an important inflammatory pathway underlying atrial fibrillation (AF). The lymphocyte-to-monocyte ratio (LMR) is a novel, cost-effective, and widely available marker of inflammation. Research Questions: The usefulness of LMR in predicting late recurrence of AF (LRAF) after catheter ablation (CA), and the impact of AF type on its usefulness, have not yet been elucidated. Goals: We aimed to elucidate the association between LMR measured just before CA and the risk of LRAF in patients who underwent CA for AF, and to investigate whether the type of AF impacts the predictability of LMR for LRAF. Methods: We enrolled 597 consecutive patients with AF (median age, 65 years; 32% female; 334 patients with paroxysmal AF [PAF] and 263 patients with persistent AF [PeAF]) who underwent initial radiofrequency CA. LMR was measured within 3 days prior to the date of CA, and calculated by dividing the absolute lymphocyte count by the absolute monocyte count using the same blood samples. Any detectable atrial tachyarrhythmia lasting for longer than 30 s beyond a 3-month blanking period after the procedure was considered as LRAF. Patients were followed-up for a maximum of 3 years. Results: During a median follow-up of 24 months, LRAF occurred in 215 patients (96 with PAF and 119 with PeAF). Although there was no significant difference in LMR between patients with and without LRAF in PAF (5.3 [4.1–6.7] vs 5.2 [4.0–6.6], p=0.403), LMR in patients with LRAF was significantly lower than those without LRAF in PeAF (4.7 [3.9–6.4] vs 5.6 [4.5–6.8], p=0.015). Multivariate Cox analysis showed that LMR was an independent predictor of LRAF in PeAF (p=0.008), but not in PAF (p=0.662). Receiver operating characteristic curve analysis revealed that an LMR of 4.8 was a fair discriminator for LRAF in PeAF. Although there was no significant difference in the risk of LRAF between the patients with lower (LMR&lt;4.8) and higher LMR (LMR≥4.8) in PAF, patients with lower LMR had a significantly higher risk of LRAF than those with higher LMR in PeAF (Figure). Conclusions: Pre-ablation LMR was shown to be useful for predicting LRAF in patients with PeAF who underwent CA for AF, while not in patients with PAF.

Associations Among Sleep Apnea, Objective or Subjective Sleep Duration, and Recurrence of Atrial Fibrillation in Patients Who Undergo Radiofrequency Catheter Ablation for Persistent Atrial Fibrillation - A Prospective Observational Study.

Sleep apnea (SA), subjective sleep duration (SSD), and objective sleep duration (OSD) were reported as risk factors for atrial fibrillation (AF). However, the association between AF and the combination of SA and OSD has not been clarified. Nor has a mismatch between SSD and OSD been investigated. We assessed SA with polysomnography, OSD with actigraphy, and SSD in patients who underwent radiofrequency catheter ablation for persistent AF. We investigated associations among SA, OSD, OSD×3% oxygen desaturation index (3%ODI), and AF recurrence, considering SSD-OSD (i.e., the difference between SSD and OSD) and OSD. Seventy of 94 (74.4%) participants had moderate-to-severe SA (apnea-hypopnea index [AHI] ≥15). Participants were classified into OSD tertiles. Participants in Tertile 3 (mean OSD: 7.3 h) had decreased SSD-OSD (0.0 h) with increased Stage N1 sleep. Over 27.6 months, 10 AF recurrences occurred in 51 participants without treatment for SA. AHI ≥20 and OSD Tertile 3 were associated with AF recurrence (hazard ratios 5.7 [95% confidence interval 1.1-24.7] and 10.3 [95% confidence interval 1.2-88.4], respectively). Participants with AF recurrence had a higher OSD×3%ODI. SA and long OSD were predictors of recurrent AF through long exposure to intermittent hypoxia during sleep. SSD-OSD was low in patients with long OSD, possibly because of decreased sleep quality.

Abstract 4135923: Predictive Value of Supraventricular Tachycardia on Ambulatory ECG Monitoring for Recurrent Atrial Fibrillation Post-Catheter Ablation

Introduction: Established predictors of recurrent atrial fibrillation (AF) following catheter ablation (CA) have not incorporated findings on post-CA ambulatory ECG monitoring (AECG). Aims: This study examined the predictive value of supraventricular tachycardia (SVT) detected on 7–14-day AECG for recurrent AF within one year post-CA. Methods: This single-center retrospective study included a select subset of patients who underwent CA for AF between 2015 and 2023 and had AECG monitoring within the first year post-CA. SVT presence and characteristics on AECG were analyzed.Data on demographics, AF risk factors, and AF recurrences were extracted from electronic health records. ROC curves determined SVT episode thresholds. A multivariable regression model included established risk factors and SVT thresholds, and best subsets regression identified predictors of AF recurrence. Results: Of 7,481 patients undergoing CA for AF, 1,245 were monitored within one year post-CA. Among this subset, 439 (35.26 %) had recurrent AF during the first year post- CA. Of the 439 patients with recurrent AF, 99 had AECG monitoring before recurrence. These 99 patients were compared with the 672 patients with no AF recurrence. Average duration of AECG monitoring for the entire cohort was 11±2.7 days. Mean SVT episodes per day ≥4.6 and total number of SVT episodes ≥14.5 were significantly associated with recurrent AF (OR =1.99, P =0.030, and OR =2.77, P =0.019, respectively). Significant predictors of AF recurrence were female gender, heart failure, confirmed SVT, cardioversion before ablation, mean SVT episodes per day, and total SVT episodes on AECG. Conclusion: High burden of SVT on AECG monitoring (defined in this study to be ≥4.6 episode per day or ≥14.5 total episodes per monitoring period) was significantly associated with AF recurrence. Longitudinal studies in larger unselected populations are needed to confirm these results.