Mechanisms and clinical significance of early recurrences of atrial arrhythmias after catheter ablation for atrial fibrillation

Relevance of Targeting Oxidative Stress, Inflammatory, and Pro-Resolution Mechanisms in the Prevention and Management of Postoperative Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia. AF can lead to severe complications, including stroke, myocardial infarction, and sudden death. AF risk factors include pathological aging and conditions such as obesity, diabetes, and hypertension. Clinical data revealed that cardiothoracic and non-cardiothoracic surgeries are also important risk factors for AF. Post-operative AF (POAF) is associated with important public health costs caused by increased hospitalization, frequent emergency room visits, and enhanced healthcare utilization, which altogether lead to a low quality of life for the patients. Hence, POAF is a major clinical challenge, and there is an urgent need for the development of novel therapeutic strategies. Interestingly, evidence from clinical and fundamental research converges to identify cardiac oxidative stress and atrial inflammation as the common denominators of all AF risk factors. Unresolved inflammation is suspected to provoke cardiac fibrosis, which is an important contributor to cardiac arrhythmias and AF. Antioxidant, anti-inflammatory, and pro-resolution strategies may help to combat post-operative cardiac remodeling and POAF. This article aims to review the current scientific evidence supporting the role of inflammation in the pathogenesis of POAF and explore potential novel therapeutic strategies to prevent and mitigate inflammation in the management of AF.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

Beyond Clinical Factors: Harnessing Artificial Intelligence and Multimodal Cardiac Imaging to Predict Atrial Fibrillation Recurrence Post-Catheter Ablation

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia, with catheter ablation being a key alternative to medical treatment for restoring normal sinus rhythm. Despite advances in understanding AF pathogenesis, approximately 35% of patients experience AF recurrence at 12 months after catheter ablation. Therefore, accurate prediction of AF recurrence occurring after catheter ablation is important for patient selection and management. Conventional methods for predicting post-catheter ablation AF recurrence, which involve the use of univariate predictors and scoring systems, have played a supportive role in clinical decision-making. In an ever-changing landscape where technology is becoming ubiquitous within medicine, cardiac imaging and artificial intelligence (AI) could prove pivotal in enhancing AF recurrence predictions by providing data with independent predictive power and identifying key relationships in the data. This review comprehensively explores the existing methods for predicting the recurrence of AF following catheter ablation from different perspectives, including conventional predictors and scoring systems, cardiac imaging-based methods, and AI-based methods developed using a combination of demographic and imaging variables. By summarising state-of-the-art technologies, this review serves as a roadmap for developing future prediction models with enhanced accuracy, generalisability, and explainability, potentially contributing to improved care for patients with AF.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Influence of ABC stroke score on late recurrence of paroxysmal atrial fibrillation following radiofrequency catheter ablation

BACKGROUND

In this study we investigated the impact of ABC stroke score on the recurrence of paroxysmal atrial fibrillation (PAF) following radiofrequency catheter ablation (RFCA).

METHODS

A total of 132 patients with PAF who underwent RFCA from October 2018 to September 2019 were included in this study. During the first phase of this study the patients were categorized into two groups based on late recurrence of atrial fibrillation after RFCA. In the second phase, the patients were further divided into two groups based on whether their ABC stroke score was ≥ 6.5.

RESULT

The univariate analysis indicated that the risk factors for late recurrence of PAF included early recurrence, ABC stroke score, CHA2DS2-VASc score, and NT-proBNP (P < 0.05). Cox multivariate regression analysis revealed that ABC stroke score (P = 0.006) and early recurrence (P = 0.000) were independent predictors of late recurrence, and ABC stroke score ≥ 6.5 was a risk for predicting recurrence of PAF after RFCA with a sensitivity of 66.7% and specificity of 65.7%. After the completion of the 1:1 matching, the univariate Cox analysis indicated that an elevated score of ABC stroke (≥ 6.5) was an independent predictor of late recurrence of PAF (HR = 2.687, 95% CI: 1.036-6.971, P = 0.042). However, using an ABC stroke score cut off at 6.4 predicted the recurrence of atrial tachyarrhythmia with 85% sensitivity and 58.5% specificity.

CONCLUSION

An ABC stroke score ≥ 6.4 is a predictor for late recurrence of PAF after RFCA.

Association of Paroxysmal Versus Persistent Atrial Fibrillation with In-hospital Outcomes and 30-day Readmission After Inpatient Atrial Fibrillation Ablation

Knowledge of the impact of paroxysmal and persistent atrial fibrillation (AF) after catheter ablation on in-hospital outcomes and 30-day readmission remains limited. This study aimed to evaluate the procedural outcomes and 30-day readmission rates among patients with paroxysmal or persistent AF who were hospitalized for AF ablation. Using the Nationwide Readmissions Database, our study included patients aged ≥18 years with AF who were hospitalized and underwent catheter ablation during 2017-2020. Then, we compared the in-hospital procedural outcomes and 30-day readmission rates between patients with paroxysmal and persistent AF, respectively. Our study included 7310 index admissions for paroxysmal AF ablation and 9179 index admissions for persistent AF ablation. According to our analysis, there was no significant difference in procedural complications-namely, cerebrovascular accident, vascular complications, major bleeding requiring blood transfusion, phrenic nerve palsy, pericardial complications, and systemic embolization-between the persistent and paroxysmal AF groups. There was also no significant difference in early mortality between these groups (0.5% vs. 0.7%; P = .22). Persistent AF patients had significantly higher rates of prolonged index hospitalization (9.9% vs. 7.2%; P < .01) and non-home discharge (4.8% vs. 3.1%; P < .01). The 30-day readmission rates were comparable in both groups (10.0% vs. 9.5%; P = .34), with recurrent AF and heart failure being two of the most common causes of cardiac-related readmissions. Catheter ablation among hospitalized patients with paroxysmal or persistent AF resulted in no significant difference in procedural complications, early mortality, or 30-day readmission. This suggests that catheter ablation of AF can be performed with a relatively similar safety profile for both paroxysmal and persistent AF.

Prognostic value of cardiac deceleration capacity in patients with atrial fibrillation after catheter ablation: A systematic review and meta-analysis

INTRODUCTION

Cather ablation (CA) is a well-recognized treatment alternative for atrial fibrillation (AF) patients despite more than 20% ablation-treated patients suffering from AF recurrence. The underlying mechanism of AF recurrence postablation is probably associated with high cardiac parasympathetic activity, which can be assessed with deceleration capacity (DC) of heart rate. Given that the relationship between DC and AF recurrence is still controversial, this systematic review and meta-analysis was performed to investigate the characteristics of DC in patients with and without AF recurrence, evaluating the prognostic value of DC in AF patients after CA.

METHODS

A literature search was systematically performed in the Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases until October 01, 2023. The observational studies reporting either the pre- and postablation DC in both recurrence and non-recurrence groups or the ratios based on DC for predicting AF recurrence were mainly included. Weighted mean differences (WMD) or odds ratios (OR) based on DC would be calculated with a random-effect model, if heterogeneity estimated with the I2 index and Q statistic was significant (I2 > 50% or p < .05); otherwise, a fixed-effect model would be utilized.

RESULTS

A total of eight observational studies involving 914 AF patients treated with radiofrequency or cryoballoon ablation were included in this study. Ablation-treated patients with AF recurrence had the higher DC postablation in relation to those without recurrence (WMD, 1.00; 95% confidence interval [CI], 0.33-1.67; p < .01), which was present up to 3 months of follow-up (WMD, 1.54; 95% CI, 1.11-1.96; p < .01), whereas there was no statistical significance in DC before ablation between recurrence and non-recurrence groups (WMD, 0.34; 95% CI, -0.12 to 0.79; p = .15). The high DC postablation was a risk factor for AF recurrence in ablation-treated patients (OR, 2.17; 95% CI, 1.44-3.25; p < .01).

CONCLUSION

The high DC postablation was associated with the risk of AF recurrence, suggesting that DC may act as a prognostic indicator in AF patients treated with CA.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Atrial fibrillation recurrences during the blanking period after catheter ablation with the laser balloon technique

INTRODUCTION

Regardless of the catheter ablation (CA) for atrial fibrillation (AF) strategy, the role of early recurrences during the blanking period (BP) is still unclear. Our aim was to evaluate atrial tachyarrhythmias (ATAs) recurrences during the BP after CA with the laser-balloon (LB) technique.

METHODS

Consecutive patients undergoing LBCA were enrolled. Primary outcome of the study was the overall crude ATA recurrence rate during the BP. ATA recurrences after the BP and in-hospital readmissions during the BP were deemed secondary outcomes.

RESULTS

Two hundred and twenty-four patients underwent CA with the LB. Median age was 63.0 (55.5-69.5) years and 74.1% were males. 28.6% were persistent AF patients, and 34.8% of patients were followed up with a loop recorder. 15.6% of patients experienced at least an ATA recurrence during the BP. Male sex, chronic heart failure, persistent AF, and recurrences during the BP were found to be associated with long-term ATA recurrences. Recurrences during the BP remained associated with the outcome of interest at multivariate analysis (hazard ratio [HR] = 12.393, 95% confidence interval [95% CI] = 3.699-41.865, p < .001). An association over time was found between early and late recurrences, with 73.7%, 45.5%, and 10.8% of patients presenting with recurrences at 1-, 2-, and 3-month follow-up being free from recurrences after the BP, respectively. 8.0% of patients were readmitted during the BP: 4.5% for AF electrical cardioversion, and 1.8% for CA of other atrial arrhythmias; no redo CA was performed.

CONCLUSION

After adjusting for confounders, ATA recurrences during the BP represent the most significant predictor of ATA recurrences after the BP, regardless of AF pattern.

Development and Validation of a Predictive Model Based on LASSO Regression: Predicting the Risk of Early Recurrence of Atrial Fibrillation after Radiofrequency Catheter Ablation

BACKGROUND

Although recurrence rates after radiofrequency catheter ablation (RFCA) in patients with atrial fibrillation (AF) remain high, there are a limited number of novel, high-quality mathematical predictive models that can be used to assess early recurrence after RFCA in patients with AF.

PURPOSE

To identify the preoperative serum biomarkers and clinical characteristics associated with post-RFCA early recurrence of AF and develop a novel risk model based on least absolute shrinkage and selection operator (LASSO) regression to select important variables for predicting the risk of early recurrence of AF after RFCA.

METHODS

This study collected a dataset of 136 atrial fibrillation patients who underwent RFCA for the first time at Peking University Shenzhen Hospital from May 2016 to July 2022. The dataset included clinical characteristics, laboratory results, medication treatments, and other relevant parameters. LASSO regression was performed on 100 cycles of data. Variables present in at least one of the 100 cycles were selected to determine factors associated with the early recurrence of AF. Then, multivariable logistic regression analysis was applied to build a prediction model introducing the predictors selected from the LASSO regression analysis. A nomogram model for early post-RFCA recurrence in AF patients was developed based on visual analysis of the selected variables. Internal validation was conducted using the bootstrap method with 100 resamples. The model's discriminatory ability was determined by calculating the area under the curve (AUC), and calibration analysis and decision curve analysis (DCA) were performed on the model.

RESULTS

In a 3-month follow-up of AF patients (n = 136) who underwent RFCA, there were 47 recurrences of and 89 non-recurrences of AF after RFCA. P, PLR, RDW, LDL, and CRI-II were associated with early recurrence of AF after RFCA in patients with AF (p < 0.05). We developed a predictive model using LASSO regression, incorporating four robust factors (PLR, RDW, LDL, CRI-II). The AUC of this prediction model was 0.7248 (95% CI 0.6342-0.8155), and the AUC of the internal validation using the bootstrap method was 0.8403 (95% CI 0.7684-0.9122). The model demonstrated a strong predictive capability, along with favorable calibration and clinical applicability. The Hosmer-Lemeshow test indicated that there was good consistency between the predicted and observed values. Additionally, DCA highlighted the model's advantages in terms of its clinical application.

CONCLUSIONS

We have developed and validated a risk prediction model for the early recurrence of AF after RFCA, demonstrating strong clinical applicability and diagnostic performance. This model plays a crucial role in guiding physicians in preoperative assessment and clinical decision-making. This novel approach also provides physicians with personalized management recommendations.

Smartphone AF Burden During the Blanking Period Predicts Catheter Ablation Outcomes: Insights From DECAAF II

BACKGROUND

Atrial fibrillation (AF) recurrence during the blanking period is under investigated. With the rise of smartphone-based electrocardiogram (ECG) monitoring, there's potential for better prediction and understanding of AF recurrence trends.

OBJECTIVES

In this study the authors hypothesize that AF burden derived from a single-lead Smartphone ECG during the blanking period predicts recurrence of atrial arrhythmias after ablation.

METHODS

630 patients with persistent AF undergoing ablation were included from the DECAAF II (Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation) trial. Patients recorded daily ECG strips using a smartphone device. AF burden was defined as the ratio of ECG strips with AF to the total number of strips submitted. The primary outcome was the recurrence of atrial arrhythmia.

RESULTS

Recurrence occurred in 301 patients during the 18-month follow-up period. In patients who developed recurrent arrhythmia after 90 days of follow-up, AF burden during the blanking period was significantly higher when compared with patients who remained in sinus rhythm (31.3% vs 7.5%; P < 0.001). AF burden during the blanking period was an independent predictor of arrhythmia recurrence (HR: 1.41; 95% CI: 1.36-1.47; P < 0.001). Through grid searching, an AF burden of 18% best discriminates between recurrence and no-recurrence groups, yielding a C-index of 0.748. After a follow-up period of 18 months, recurrence occurred in 33.7% of patients (147 of 436) with an AF burden <18% and in 79.4% of patients (154 of 194) with an AF burden >18% (HR: 4.57; 95% CI: 3.63-5.75; P < 0.001).

CONCLUSIONS

A high AF burden derived from a smartphone ECG during the blanking period is a strong predictor of atrial arrhythmia recurrences after ablation.

Identifying the prognostic significance of early arrhythmia recurrence during the blanking period and the optimal blanking period duration: insights from the DECAAF II study

OBJECTIVE

Early atrial arrhythmia recurrence following atrial fibrillation (AF) ablation is common. Current guidelines promulgate a 3-month blanking period. We hypothesize that early atrial arrhythmia recurrence during the blanking period may predict longer-term ablation outcomes.

METHODS AND RESULTS

A total of 688 patients with persistent AF undergoing catheter ablation were included in the DECAAF II trial database. The primary endpoint of the study was the first confirmed recurrence of atrial arrhythmia. Recurrence was also monitored during the 90-day blanking period. A total of 287 patients experienced recurrent atrial arrhythmia during the blanking period, while 401 remained in sinus rhythm. Rates of longer-term arrhythmia recurrence were substantially higher among those who developed recurrence during the blanking period compared to those who remained in sinus rhythm throughout the blanking period (68% vs. 32%, P < 0.001). The study cohort was divided into three groups according to the timing of arrhythmia recurrence during the blanking period. Of those who had recurrent arrhythmia during the first month of the blanking period (Group 1), 43.9% experienced longer-term recurrence, compared to 61.6% who recurred during the second month of the blanking period (Group 2), and 93.3% of those who had arrhythmia recurrence during the third month (Group 3, P < 0.001). The risk of recurrent arrhythmia was highest in Group 3 (HR = 10.15), followed by Group 2 (HR = 2.35) and Group 1 (HR = 1.5). Receiver operating characteristic analysis was performed to assess the relationship between the timing of arrhythmia recurrence and the primary outcome (AUC = 0.746, P < 0.001). The optimal blanking period duration was identified as 34 days. Atrial fibrillation burden determined by smartphone electrocardiogram technology over the 18 months follow-up period was significantly higher in Group 3 (29%) compared to Groups 1 (6%) and 2 (7%) and in patients who stayed in sinus rhythm during the blanking period (5%) (P < 0.0001).

CONCLUSION

Early atrial arrhythmia recurrence during the blanking period, particularly during the third month, is significantly associated with later recurrence. Although a blanking period is warranted, it should be abbreviated.

Insertable cardiac monitor-guided early intervention to reduce atrial fibrillation burden following catheter ablation: Study design and clinical protocol (ICM-REDUCE-AF trial)

BACKGROUND

Percutaneous catheter ablation (CA) to achieve pulmonary vein isolation is an effective treatment for drug-refractory paroxysmal and persistent atrial fibrillation (AF). However, recurrence rates after a single AF ablation procedure remain elevated. Conventional management after CA ablation has mostly been based on clinical AF recurrence. However, continuous recordings with insertable cardiac monitors (ICMs) and patient-triggered mobile app transmissions post-CA can now be used to detect early recurrences of subclinical AF (SCAF). We hypothesize that early intervention following CA based on personalized ICM data can prevent the substrate progression that promotes the onset and maintenance of atrial arrhythmias.

METHODS

This is a randomized, double-blind (to SCAF data), single-tertiary center clinical trial in which 120 patients with drug-refractory paroxysmal or persistent AF are planned to undergo CA with an ICM. Randomization will be to an intervention arm (n = 60) consisting of ICM-guided early intervention based on SCAF and patient-triggered mobile app transmissions versus a control arm (n = 60) consisting of a standard intervention protocol based on clinical AF recurrence validated by the ICM. Primary endpoint is AF burden, which will be assessed from ICMs at 15 months post-AF ablation. Secondary endpoints include healthcare utilization, functional capacity, and quality of life.

CONCLUSION

We believe that ICM-guided early intervention will provide a novel, personalized approach to post-AF ablation management that will result in a significant reduction in AF burden, healthcare utilization, and improvements in functional capacity and quality of life.

Serum periostin as a predictor of early recurrence of atrial fibrillation after catheter ablation

Catheter ablation is an effective method of rhythm therapy for atrial fibrillation (AF). AF recurrence is a common problem after catheter ablation. The aim of this study was to investigate influence factors of early recurrence after catheter ablation for AF. One hundred and three consecutive patients with AF were enrolled and underwent catheter ablation. Venous blood (Marked as A) was collected before ablation and left atrial blood (Marked as B) was collected after successful atrial septal puncture to detect serum periostin. After 3 months of follow-up, statistical analysis was made based on the recurrence of AF. 27 (26.2%) patients had a recurrence of atrial arrhythmia after catheter ablation. Patients with recurrent atrial arrhythmia had a larger left atrial volume (162.31 ± 47.76 vs. 141.98 ± 41.64,p = 0.039), and higher serum periostin levels (periostin A. 99.71 ± 16.475 vs. 90.36 ± 13.63, p = 0.005; periostin B. 103.95 ± 13.09 vs. 94.46 ± 15.85, p = 0.006) compared with the non-recurrent group. The numbers of patients with left atrial low-voltage areas (LVAs) were more in the recurrence group (p < 0.001). Left atrial volume, serum periostin and left atrial LVAs were included in univariate and multivariate COX regression analysis. It showed that left atrial LVAs (HR3.81; 95% CI 1.54 to 9.44; p = 0.004) and serum periostin A (HR1.07; 95% CI 1.02 to1.13; p = 0.008) were the independent predictors of AF recurrence. The cut-off value of serum periostin A was 87.95 ng/ ml (AUC, 0.681; sensitivity 88.9% and specificity 53.9%). Kaplan-Meier survival curve showed that the recurrence rate of AF was higher in patients with left atrial LVAs and higher serum periostin. The venous serum periostin level and left atrial LVAs were independent predictors of early recurrence of AF after catheter ablation.

The Blinding Period Following Ablation Therapy for Atrial Fibrillation: Proarrhythmic and Antiarrhythmic Pathophysiological Mechanisms

Atrial fibrillation (AF) causes heart failure, ischemic strokes, and poor quality of life. The number of patients with AF is estimated to increase to 18 million in Europe in 2050. Pharmacological therapy does not cure AF in all patients. Ablative pulmonary vein isolation is recommended for patients with drug-resistant symptomatic paroxysmal AF but is successful in only about 60%. In patients in whom ablative therapy is successful on the long term, recurrence of AF may occur in the first weeks to months after pulmonary vein ablation. The early recurrence (or delayed cure) of AF is not understood but forms the basis for the generally accepted 3-month blinding (or blanking) period after ablation therapy, which is not included in the evaluation of the eventual success rate of the procedures. The underlying pathophysiological processes responsible for early recurrence and the delayed cure are unknown. The implicit assumption of the blinding period is that the AF mechanism in this period is different from the ablation-targeted AF mechanism (ectopy from the pulmonary veins). In this review, we evaluate the temporary and long-lasting pro- and antiarrhythmic effects of each of the pathophysiological processes and interventions (necrosis, ischemia, oxidative stress, edema, inflammation, autonomic nervous activity, tissue repair, mechanical remodeling, and use of antiarrhythmic drugs) occurring in the blinding period that can modulate AF mechanisms. We propose that stretch-reducing ablation scar is a permanent antiarrhythmic mechanism that develops during the blinding period and is the reason for delayed cure.

The association between late-phase early recurrence within the blanking period after atrial fibrillation catheter ablation and long-term recurrence: Insights from a large-scale multicenter study

BACKGROUND

The relationship between the timing of the first early recurrence and late recurrence after a single catheter ablation procedure for atrial fibrillation is controversial.

METHODS

The Efficacy of Short-Term Use of Antiarrhythmic Drugs After Catheter Ablation for Atrial Fibrillation trial followed 2038 patients who underwent radiofrequency catheter ablation for atrial fibrillation.

RESULTS

Of the patients, 907 (45%) had early recurrences within 90 days after the initial ablation. We divided these patients into two groups according to the timing of the first early recurrence episode, namely the ER₁ group (early recurrence during the early phase; 0-30 days, n = 814) and ER₂ group (early recurrence during the late phase; 31-90 days, n = 93). Three years after ablation, patients with early recurrences had a significantly lower event-free rate from late recurrences after a 90-day blanking period than patients without early recurrences (36.2% and 74.2%, respectively; log-rank, P < 0.0001). Three years after ablation, the event-free rate was significantly higher in the ER₁ than the ER₂ group (38.3% and 17.1%, respectively; log-rank, P < 0.0001). Moreover, the event-free rate at 3 years in the ER₂ group was extremely low (5.6%) in patient with non-paroxysmal atrial fibrillation.

CONCLUSION

Early recurrences were strongly associated with late recurrences, especially in patients with the first recurrence episode at >1 month within the blanking period after a single ablation procedure. Therefore, these patients should undergo close observation during follow-up, when they had especially with non-paroxysmal atrial fibrillation.

Prevalence and outcome of early recurrence of atrial tachyarrhythmias in the Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) study

BACKGROUND

Early recurrence of atrial tachyarrhythmia (ERAT) is common after pulmonary vein isolation (PVI) and has been associated with an increased risk of late atrial fibrillation (AF) recurrence.

OBJECTIVE

The purpose of this study was to determine the incidence and outcomes of patients experiencing ERAT after PVI using advanced-generation ablation technologies.

METHODS

This is a prespecified substudy of the CIRCA-DOSE (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double-Short vs Standard Exposure Duration) trial, a prospective, randomized, multicenter study comparing PVI with contact force-guided radiofrequency ablation to secondary-generation cryoballoon ablation for paroxysmal AF. All study patients received an implantable cardiac monitor to allow continuous rhythm monitoring. ERAT was defined as any recurrent atrial tachyarrhythmia within the first 90 days after AF ablation.

RESULTS

ERAT occurred in 61% of the 346 patients at a median of 12 days (range 1-90 days) after ablation. ERAF was a significant predictor of late recurrence (60.1% with ER vs 25.9% without ER; P <.001) and symptomatic atrial tachyarrhythmia (31.6% with ERAF vs 6.7% without ERAF; P <.001). Receiver operating curve analyses revealed a strong correlation between ERAT timing and burden and late recurrence. Multivariate analysis identified ER timing (hazard ratio [HR] 2.90; 95% confidence interval [CI] 1.41-5.95; P = .004) and burden (HR 1.05 per 1% ER burden; 95% CI 1.04-1.07; P <.001) as strong independent predictors of late recurrence. Incidence rate, timing, burden, and prognostic significance of ER did not differ between the study groups.

CONCLUSION

ERAT remains common after PVI despite use of advanced-generation ablation technologies. Early AF recurrence beyond 3 weeks after ablation is associated with increased risk of late recurrence.

Single procedural outcomes in the setting of percutaneous ablation for persistent atrial fibrillation: a propensity-matched score comparison between different strategies

BACKGROUND

Catheter ablation for persistent atrial fibrillation (persAF) is associated with less favorable outcomes than for paroxysmal AF. To improve success rates, left atrial (LA) substrate modification is frequently performed in addition to pulmonary vein isolation (PVI). The purpose of the study was to compare 4 different ablation approaches using radiofrequency catheter ablation (RFCA) or cryoballoon ablation (CB-A) for persAF and to evaluate the respective outcomes on a midterm follow-up of 12 months.

METHODS

We did a propensity score-matched comparison of 30 patients undergoing PVI + LA posterior wall isolation (LAPWI) with CB-A, 30 patients who underwent PVI + linear ablation (roof and mitral lines) using RFCA, 60 patients with PVI alone using CB-A, and 60 patients who had PVI alone using RFCA. The endpoint was recurrence of documented atrial tachyarrhythmias (ATas) > 30 s at 1-year follow-up.

RESULTS

After 12 months, freedom from ATas after a single procedure was 83.3% in the PVI + LAPWI group, 46.7% in the PVI + linear ablation group, 58.3% in the PVI-alone CB-A group, and 61.6% PVI-alone RFCA (p = 0.03). Moreover, freedom from ATas was significantly higher comparing the PVI + LAPWI group with each of the other groups.

CONCLUSIONS

In this propensity-matched comparison of strategies for persAF, LAPW ablation in addition to PVI with CB-A seems to improve 1-year outcome in comparison to PVI + linear ablation using RFCA and to PVI alone using RFCA or CB-A. Randomized comparisons are eagerly awaited.

The Efficacy of Anti-inflammatory Agents in the Prevention of Atrial Fibrillation Recurrences

Several studies have indicated an association between inflammation and the recurrence of Atrial Fibrillation (AF), especially after ablation, which is a therapeutic option leading to local inflammation. On the other hand, each AF can lead to another AF, as a general rule. Thus, preventing recurrences of AF is extremely important for patient outcomes. In this paper, we attempted to review the effect of medicinal agents with anti-inflammatory properties on the prevention of AF recurrence. There are several randomized controlled trials (RCTs) and meta-analyses on the prevention of AF recurrence using agents with anti-inflammatory properties, which include steroids, colchicine, statins, and n-3 fatty acids (n-3 FA). Clinical trials evaluating the efficacy of anti-inflammatory drugs in preventing the recurrence of AF led to inconsistent results for corticosteroids, statins and n-3 FAs. These results may be related to the fact that inflammation is not the only factor responsible for triggering recurrences of AF. For example, the presence of structural, mechanical and electrical remodeling could potentially be the most important factors that trigger recurrences of AF but these factors have not been addressed in most of the reported studies. Therefore, future clinical trials are needed to compare the efficacy of anti-inflammatory drugs in AF patients with, or without other factors. For colchicine, a potent anti-inflammatory drug, there are limited studies. However, all the studies investigating colchicine in the context of AF were consistent and promising, especially when colchicine was used on a short-term basis following ablation in patients with paroxysmal AF. Therefore, colchicine could be a promising candidate for further clinical studies involving recurrent AF.

Delayed sinus rhythm restoration after thoracoscopic left atrium fragmentation (а report of two cases)

The article presents two clinical cases of delayed restoration of the sinus rhythm in patients with long-term persistent atrial fibrillation after the procedure of thoracoscopic radiofrequency fragmentation of the left atrium. The necessity of continuing attempts to restore the sinus rhythm up to the end of the "blind period" (90 days) is discussed.

Redefining the Blanking Period by a Long-Term Follow-Up after Atrial Fibrillation Ablation Using Second-Generation Cryoballoon

On the basis of radiofrequency ablation of atrial fibrillation (AF), some studies suggested that early recurrences of atrial tachyarrhythmia (ERATs) were associated with late AF recurrence (LAFR), and some also suspected and challenged the current recommended 90 day blanking period. We aim to evaluate the impact of ERAT on long-term success and to determine the optimum blanking period after AF ablation using second-generation cryoballoon (sg-CB). From August 2016 to October 2018, 369 consecutive patients who successfully underwent initial AF ablation using sg-CB at the Fuwai Hospital were finally enrolled. All patients were followed up no less than 12 months. Receiver operating characteristic curve analysis was used to determine the optimum blanking period after AF ablation. There were 62 (16.8%) who experienced ERAT. After a median follow-up of 615 days, 74.5% were free of LAFR after the 90 day blanking period. Incidence of freedom from LAFR during the long-term follow-up was markedly lower in patients with ERAT than in those without ERAT (27.4% versus 84.0%; log-rank P < 0.001). Furthermore, only ERAT (HR 8.579; 95% CI 5.604-13.133; P < 0.001) was significantly associated with an increased risk of LAFR after adjusting for other factors. The optimum cut-off time point for the blanking period was 21.5 days (sensitivity: 71.1%, specificity: 94.1%). In conclusion, ERAT was an independent predictor of LAFR after AF ablation using sg-CB. Based on our findings, blanking period was advised to be shorten to 21.5 days or about 3 weeks instead of 90 days after CB ablation.

Comparison of Amiodarone and Propafenone in Blanking Period after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation: A Propensity Score-Matched Study

Background

Amiodarone and propafenone are commonly used to maintain sinus rhythm in patients with atrial fibrillation (AF). However, it is not known which one is better in reducing early recurrence (ER) during the blanking period (the first three months after catheter ablation).

Objective

To compare the efficacy and safety of amiodarone and propafenone in reducing ER during the blanking period after radiofrequency catheter ablation (RFCA) in AF patients.

Materials and Methods

A total of 694 patients who underwent their first RFCA between May 2014 and May 2018 were enrolled in this retrospective study. Subsequently, 202 patients were excluded according to the exclusion criteria. The remaining 492 patients were divided into two groups based on the choice of antiarrhythmic drugs (AADs) (amiodarone or propafenone) in the blanking period. The primary outcomes were incidence of ER and AAD-associated adverse effects during the blanking period after RFCA. Propensity score matching (PSM) analyses were used to compare the outcomes of the two groups while controlling for confounders.

Results

Among the 492 patients who took AADs in the blanking period (187 amiodarone and 305 propafenone), PSM selected 135 unique pairs of patients with similar characteristics. Amiodarone was associated with a lower ER incidence rate (23.7% versus 48.9%, p < 0.001) and a similar rate of AAD-associated adverse effects (2.1% versus 1.5%, p = 0.652). Treatment with amiodarone in the blanking period was significantly associated with a lower ER incidence rate compared to treatment with propafenone (HR = 0.416, 95% CI 0.272–0.637, p < 0.001).

Conclusions

Compared with propafenone, amiodarone was associated with a lower ER incidence rate, and they had similar rates of AAD-associated adverse effects. Treatment with amiodarone in the blanking period was shown to be more effective in reducing ER than propafenone.

Early transient recurrence of ventricular fibrillation after catheter ablation of premature ventricular contraction from Purkinje fibers in two patients with myocardial infarction

Catheter ablation (CA) targeting premature ventricular contraction (PVC) from Purkinje fibers can be an effective therapy for refractory ventricular fibrillation (VF) after myocardial infarction (MI). We experienced two cases in which catheter ablation targeting PVC initiating VF after percutaneous coronary intervention (PCI) in post-MI patients was effective despite transient early recurrences of VF. The first patient (a 68-year-old woman with MI) developed drug-refractory VF 3 days after PCI to the left anterior descending artery (LAD) and left circumflex artery. CA targeting Purkinje potential preceding PVC at the infarcted area eliminated both the PVCs and VF. Three days after the procedure, the VF attacks relapsed by a different type of PVC. However, the VF responded to conventional treatments and disappeared thereafter. In the second patient (an 83-year-old woman with old MI), refractory VF attacks occurred after PCI to the LAD. CA targeting Purkinje potential preceding two distinct types of PVC successfully suppressed the VF. Although the VF relapsed 2 days after CA, it was suppressed by conventional treatment and disappeared the next day. <Learning objective: We report two patients with MI in whom VF attacks were treated by CA targeting triggering PVCs, and these completely disappeared after the process of transient early VF recurrences. Two cases demonstrate that additional CA may not always be necessary even if VF has relapsed within several days after PVC elimination. When recurrences of VF attacks after the first CA are not so frequent, we will be able to observe patient for several days without performing additional CA.>.

The relationship of early recurrence of atrial fibrillation and the 3-month integrity of the ablation lesion set

Early recurrence of atrial fibrillation (ERAF) after catheter-ablation (CA) can be a transient phenomenon due to inflammation, or a harbinger of late AF recurrence due to CA lesion (re)conduction. We studied the relationship between ERAF and the 3-month CA lesions integrity. Forty one consecutive AF patients who underwent a pulmonary vein isolation (PVI), roof line (RL) and mitral isthmus line (MIL) CA were enrolled. At 3 months all patients underwent invasive assessment of the lesion set integrity irrespective of ERAF. The PVI, RL and MIL ablation was successful in 100.0%, 95.1% and 82.9% patients, respectively. At the 3-month remapping, a gap in PVI-lesion(s), RL or MIL was identified in 61.0%, 31.7% and 36.6% patients, respectively. Patients with (n = 17, 41.5%) compared to those without ERAF (n = 24) had a significantly higher rate of any PV-reconnection (88.2% vs. 41.7%), the right PV(s)-reconnection (82.5% vs. 29.2%) and the RL gap (52.9% vs. 16.7%), as well as a higher number of reconnected right PVI-segments, all p < 0.05. On multivariate analysis, only the number of reconnected right PVI-segments was associated with ERAF (OR 4.26, p = 0.004). The ERAF following PVI + RL + MIL ablation was significantly related to 3-month PV-reconnections and the presence of RL gaps.

Rabbit model to simulate the residual conduction gaps after radiofrequency ablation on the anterior wall of left atrial appendage

PURPOSE

Radiofrequency ablation (RFA) is widely used to treat patients with atrial fibrillation (AF), but its recurrence rate is still high mainly due to pulmonary vein reconnection and residual conduction gaps. We aim to establish a rabbit model to simulate the residual conduction gaps after ablation.

METHODS

Sixty-nine adult New Zealand white rabbits were randomly assigned to six groups. RFA on the anterior wall of left atrial appendage (LAA) were performed with the ablation power from 6 to 21 W. The electrophysiological pacing and mapping technology was used to evaluate the bidirectional conduction of LAA. Histological study and fluorescence techniques were used to evaluate the effect of RFA and the accumulation of drug-loaded liposome on the loop ablation lesions of LAA.

RESULTS

Typical loop ablation lesions of LAA could be observed in vivo and vitro of rabbit models. Histological evaluation revealed coagulative necrosis on the loop ablation lesions. Electrical conduction between inside and outside loop lesions recovered after 1 or 2 weeks after initial unidirectional conduction block. The recurrence rates were significantly different among six groups with varying ablation powers (p < 0.05). Compared with exit conduction block, entrance conduction block was significantly different at 5 min after ablation (p = 0.02). IR-775-loaded liposomes were accumulated on the loop ablation lesions at 48 h after RFA.

CONCLUSIONS

RFA associated with electrophysiological pacing and mapping technology successfully established a novel rabbit model to simulate the residual conduction gaps after RFA.