Catheter Ablation of Atrial Fibrillation: An Overview for Clinicians

Deep neuromuscular blockade during radiofrequency catheter ablation under general anesthesia reduces the prevalence of atrial fibrillation recurrence when compared to moderate neuromuscular blockade: A randomized controlled trial

BACKGROUND

Proper anesthesia management is required to maintain immobilization and stable breathing of the patient to improve catheter contact and stability during catheter ablation for PVI. However, it remains unclear whether the depth of neuromuscular blockade affects the results of RFCA under general anesthesia.

METHODS

The patients were randomly assigned to either the moderate neuromuscular blockade group (Group M, train-of-four 1 to 2) or the deep neuromuscular blockade group (Group D, posttetanic count 1-2). The primary outcome was the 12-month AF recurrence rate using confirmed electrocardiographic diagnosis after the ablation procedure at two different neuromuscular blockade depths.

RESULTS

Total 94 patients (47 in each group) were included in the analysis. Recurrence of AF during the A 12-month follow-up was 12 (25%) in group D and 22 (46%) in group M. The AF recurrence rate was significantly higher in group M (p =  0.03). The relative risk (RR) for the risk of 12-month AF recurrence was 0.545 in group D. AF symptom recurrence was observed during the A 12-month follow-up in 12 (25%) and 26 (54%) patients in groups D and M, respectively.

CONCLUSIONS

Compared to moderate neuromuscular blockade, deep neuromuscular blockade while performing RFCA under general anesthesia reduced 12-month AF recurrence rate. Deep neuromuscular blockade under general anesthesia is thought to increase the success rate by providing a stable surgical environment during the RFCA procedure.

TRIAL REGISTRATION

Clinical trials of Korea KCT 0003371.

Decoding the evidence: A synopsis of indications and evidence for catheter ablation in atrial fibrillation (Review)

The present study reviews the role of catheter ablation (CA) in the management of atrial fibrillation (AF), a widespread arrhythmia associated with increased morbidity and mortality. The present review explores current indications and recent evidence supporting CA, assessing patient outcomes and identifying common complications associated with the procedure. Emphasis is placed on optimizing risk factors prior to ablation, including weight control and hypertension management, as these measures can significantly enhance post-procedural outcomes. The present review also discusses the use of antiarrhythmic and anticoagulant therapies following CA to minimize recurrence and reduce stroke risk. Additionally, the cost-effectiveness of CA is discussed, comparing its long-term economic impact with that of medical therapy alone. The present comprehensive review provides insight into best practices for AF management, supporting CA as a promising approach when integrated with targeted lifestyle modifications and pharmacological support for improved, patient-centered outcomes.

Heart failure with preserved ejection fraction and atrial fibrillation: catheter ablation vs. standard medical therapy - a systematic review and meta-analysis

BACKGROUND

The latest guidelines advocate for catheter ablation (CA) over standard medical therapy (SMT) for managing atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (HFrEF). However, significant knowledge gaps exist regarding the effectiveness of CA vs. SMT in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS

PubMed, Scopus, and Embase until February 2024 were systematically searched. Given the limited number of randomized studies, propensity score-matched observational studies comparing CA with SMT in AF patients with HFpEF were also included. The primary outcome was a composite endpoint of all-cause mortality and HF hospitalization.

RESULTS

Eight studies that enrolled 17,717 SMT and 2537 CA patients were included. CA was associated with a significantly lower risk of the composite endpoint of all-cause mortality and HF hospitalization (HR 0.61; 95% CI, 0.43-0.85). The risk of HF hospitalization (HR 0.44; 95% CI, 0.23-0.83), cardiovascular mortality (HR 0.43; 95% CI, 0.22-0.84), and AF recurrence (HR 0.53; 95% CI, 0.39-0.73) were also lower in the CA group.

CONCLUSION

CA demonstrated significant cardiovascular morbidity and mortality benefits compared to SMT in the HFpEF population.

Maintenance mechanism of paroxysmal atrial fibrillation from the activation occurring within the pulmonary vein: analysis using non-contact mapping

It is unclear how pulmonary veins (PVs) maintain paroxysmal atrial fibrillation (AF). To clarify the PV's arrhythmogenic role, we examined PV activation sequences during paroxysmal AF. Left superior PV (LSPV) endocardial non-contact mapping was performed after a right PV isolation in 13 paroxysmal AF patients. Activation sequences within the LSPV before and during left-sided PVs ablation were analyzed, and those in complex fractionated atrial electrogram (CFAE) areas were compared with those in non-CFAE areas. CFAEs were observed in the LSPV's proximal half (area; 8.8 ± 3.2cm2) occupying 19.9 ± 6.0% of LSPV. The number of pivoting activations, wave breaks, and fusions over CFAE areas were significantly higher than those over non-CFE areas (25.5 ± 9.3 vs. 4.5 ± 4.8 times/s, p < 0.0001; 9.1 ± 5.3 vs. 1.4 ± 1.8 times/s, p < 0.0001; 13.0 ± 4.6 vs. 5.4 ± 4.4 times/s, p < 0.0001). The conduction velocities in CFAE areas were significantly slower than in non-CFAE areas (0.6 ± 0.2 vs. 1.7 ± 0.8 m/s, p < 0.001). After delivery of ablation lesions around the left-sided PVs (13.2 ± 7.4 applications), the PV activation became organized with a loss of CFAE areas, and the frequency of the LSPV's pivoting activation, wave break, and fusion significantly decreased compared to that pre-ablation (7.3 ± 10.9 vs. 30.0 ± 11.6 times/s, p < 0.001; 2.1 ± 5.3 vs. 10.5 ± 6.2 times/s, p < 0.002; 6.0 ± 6.6 vs. 18.4 ± 8.2 times/s, p < 0.001). Subsequently, AF terminated before the left-sided PV isolation in all patients. In conclusion, high-frequency random reentry associated with pivoting activation, wave break, and fusion within the LSPV, observed mostly over CFAE areas, maintained AF. Linear ablation lesions around the PV suppressed random reentry, resulting in the loss of CFAEs and AF termination.

Impact of inter-lesion distance and first-pass isolation on outcomes of pulmonary venous isolation for paroxysmal atrial fibrillation

BACKGROUND

Contiguity of ablation lesions is a critical determinant of success for paroxysmal atrial fibrillation (PAF) ablation. Evidence supports maintaining an inter-lesional distance (ILD) ≤ 6 mm during pulmonary venous isolation (PVI). Meanwhile, first-pass isolation (FPI) on PVI outcome in follow-up was not deeply studied. The impact of ILD and FPI on PAF ablation outcomes was investigated.

METHODS

Consecutive PAF patients who underwent first-time antral PVI were recruited. Coordinates of ablation points were extracted from the electro-anatomical mapping system and analyzed using custom-developed software to determine the ILD. A gap is defined as ILD greater than 6 mm. FPI was defined as the achievement of PVI by encircling the ipsilateral veins while simultaneously recording their electrical activity using a multipolar catheter. The primary endpoint was freedom from documented atrial arrhythmias including AF, atrial tachycardia (AT), or atrial flutter (AFL) lasting longer than 30 s during follow-up.

RESULTS

A total of 105 patients underwent first-time antral PVI. During 13.3 ± 0.6 months of follow-up, atrial arrhythmias recurrence was noted in 22.9% of the patients. Atrial arrhythmia recurrence was significantly higher in patients with more gaps (> 2) (37.0% versus 11.9%, P < 0.01), and the number of gaps was an independent predictor of AF/AT/AFL recurrence. (Hazard ratio [HR] 1.20, 95% CI 1.03-1.40, P = 0.02). The group with FPI for at least one ipsilateral pair of PVs exhibited a decreased number of gaps (2.0 versus 7.0, P < 0.01) and demonstrated a significant correlation with a reduction of recurrence (HR 0.26, 95% CI 0.09-0.71, P = 0.01). Among 16 patients who underwent repeat ablation, the number of gaps during the index PVI was associated with PV reconnection (PVR) (P < 0.01).

CONCLUSIONS

Gaps created during PVI are a modifiable determinant of AF/AT/AFL recurrence, and avoidance of gaps is crucial to improve clinical outcomes of PAF ablation. In addition, FPI exhibited a strong predictive capability for clinical success in patients with PAF.

Analysis of complex excitation patterns using Feynman-like diagrams

Many extended chemical and biological systems self-organise into complex patterns that drive the medium behaviour in a non-linear fashion. An important class of such systems are excitable media, including neural and cardiac tissues. In extended excitable media, wave breaks can form rotating patterns and turbulence. However, the onset, sustaining and elimination of such complex patterns is currently incompletely understood. The classical theory of phase singularities in excitable media was recently challenged, as extended lines of conduction block were identified as phase discontinuities. Here, we provide a theoretical framework that captures the rich dynamics in excitable systems in terms of three quasiparticles: heads, tails, and pivots. We propose to call these quasiparticles 'cardions'. In simulations and experiments, we show that these basic building blocks combine into at least four different bound states. By representing their interactions similarly to Feynman diagrams in physics, the creation and annihilation of vortex pairs are shown to be sequences of dynamical creation, annihilation, and recombination of the identified quasiparticles. We draw such diagrams for numerical simulations, as well as optical voltage mapping experiments performed on cultured human atrial myocytes (hiAMs). Our results provide a new, unified language for a more detailed theory, analysis, and mechanistic insights of dynamical transitions in excitation patterns.

A randomized controlled trial of a "Small Changes" behavioral weight loss treatment delivered in cardiac rehabilitation for patients with atrial fibrillation and obesity: study protocol for the BE-WEL in CR-AF study

BACKGROUND

Atrial fibrillation (AF) represents a global epidemic. Although international AF practice guidelines indicate weight loss for patients with AF and comorbid obesity (BMI ≥ 30 kg/m2) to alleviate symptom burden and improve prognosis, few cardiac rehabilitation (CR) programs include targeted weight loss treatment.

AIMS

This RCT protocol will evaluate the efficacy of a "Small Changes" behavioral weight loss treatment (BWLT) to produce clinically relevant (≥ 10%) weight loss among patients with AF and obesity undergoing CR, relative to CR alone. Secondary aims are to establish efficacy of CR + BWLT for improving AF symptoms, AF risk factors, and health-related quality of life.

METHODS

Adults (18 +) with AF and obesity will be recruited and randomized to receive CR + BWLT (intervention) or CR-only (control). Controls will receive CR consisting of supervised exercise and risk factor self-management for 12 weeks. The intervention group will receive CR plus BWLT (12 weekly, group-based virtual sessions, followed by 12 weeks of follow-up support). Weight and AF-risk factors will be assessed at pre-randomization, 12 weeks, 24 weeks, and 52 weeks. AF burden will be assessed using 30-s ECGs recorded bidaily and with AF symptoms. The primary endpoint of weight loss will be calculated from baseline to 52 weeks as a percentage of starting weight. Intention-to-treat analyses will compare the proportion in each group achieving ≥ 10% weight loss. Assuming success rates of 5% and 30% among controls and intervention groups, respectively, and a 30% loss to follow-up, 120 patients (60 per group) will provide 80% power to detect a difference using a two-sided independent test of proportions (alpha = 5%).

IMPACT

This clinical trial will be the first to demonstrate that adding BWLT to CR promotes clinically meaningful weight loss among patients with AF and comorbid obesity. Findings will inform design and execution of a large efficacy trial of long-term (e.g., 5-year) clinical endpoints (e.g., AF severity, mortality). Implementing weight control interventions designed to target the AF substrate in CR could dramatically reduce morbidity and enhance quality of life among patients living with AF in Canada.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT05600829. Registered October 31, 2022.

Restoring the Autonomic Balance in an Atrial Fibrillation Rat Model by Electroacupuncture at the Neiguan Point

OBJECTIVES

Autonomic nervous activity imbalance plays an important role in atrial fibrillation (AF). AF can be treated by acupuncture at the Neiguan point (PC6), but the mechanism remains elusive. Here, we investigated autonomic nervous system activity in electroacupuncture (EA) at PC6 in a rat AF model.

MATERIAL AND METHODS

In this study, we established a rat AF model via tail vein injection with ACh-CaCl2 for ten consecutive days with or without EA at PC6. AF inducibility and heart rate variability (HRV) were assessed by electrocardiogram. Next, we completed in vivo recording of the activity of cervical sympathetic and vagal nerves, respectively. Finally, the activities of brain regions related to autonomic nerve regulation were assessed by c-Fos immunofluorescence and multichannel recording.

RESULTS

EA at PC6 decreased AF inducibility and prevented changes in HRV caused by ACh-CaCl2 injection. Meanwhile, EA at PC6 reversed the increased sympathetic and decreased vagal nerve activity in AF rats. Furthermore, EA treatment downregulated increased c-Fos expression in brain regions, including paraventricular nucleus, rostral ventrolateral medulla, and dorsal motor nucleus of the vagus in AF, while c-Fos expression in nucleus ambiguus was upregulated with EA.

CONCLUSION

The protective effect of EA at PC6 on AF is associated with balance between sympathetic and vagal nerve activities.

Rethinking appropriate blanking period after atrial fibrillation ablation

BACKGROUND

Early recurrence (ER) within a 90-day blanking period (BP) in catheter ablation (CA) for atrial fibrillation (AF) is a risk factor for late recurrence (LR) after 90 days postoperatively. However, few reports have examined them in the second CA and compared them to the first CA. Moreover, in recent years, there have been reports suggesting that BP should be reduced from 90 to 30 days. Therefore, the association between ER and LR in the first and the second CA was examined, and the validity of a 30-day BP was evaluated.

METHODS

A total of 511 consecutive patients undergoing the first CA and 116 of these patients undergoing the second CA for AF at a single institution from November 2016 to December 2020 were analyzed retrospectively.

RESULTS

When ER within a 90-day BP was divided into 0-30 days and 31-90 days according to the timing of the last ER episode, the hazard ratios on LR of them relative to no ER were 2.7 {95% confidence interval (CI) 1.7-4.2} and 9.7 (95% CI 6.6-14.3), respectively, for the first CA and 15.3 (95% CI 4.7-50.1) and 44.1 (95% CI 14.0-139.4), respectively, for the second CA.

CONCLUSIONS

ER was strongly associated with LR, especially in patients with the last episode of ER more than 30 days after CA. This was pronounced in cases after the second CA, when PVI appeared to be completed. With the current improvement in PVI durability, BP may be acceptable for 30 days.

Simulating left atrial arrhythmias with an interactive N-body model

BACKGROUND

Heart disease and strokes are leading global killers. While atrial arrhythmias are not deadly by themselves, they can disrupt blood flow in the heart, causing blood clots. These clots can travel to the brain, causing strokes, or to the coronary arteries, causing heart attacks. Additionally, prolonged periods of elevated heart rates can lead to structural and functional changes in the heart, ultimately leading to heart failure if untreated. The left atrium, with its more complex topology, is the primary site for complex arrhythmias. Much remains unknown about the causes of these arrhythmias, and computer modeling is employed to study them.

METHODS

We use N-body modeling techniques and parallel computing to build an interactive model of the left atrium. Through user input, individual muscle attributes can be adjusted, and ectopic events can be placed to induce arrhythmias in the model. Users can test ablation scenarios to determine the most effective way to eliminate these arrhythmias.

RESULTS

We set up muscle conditions that either spontaneously generate common arrhythmias or, with a properly timed and located ectopic event, induce an arrhythmia. These arrhythmias were successfully eliminated with simulated ablation.

CONCLUSIONS

We believe the model could be useful to doctors, researchers, and medical students studying left atrial arrhythmias.

Soluble ST2: A Novel Biomarker for Diagnosis and Prognosis of Cardiovascular Disease

The increasing incidence of cardiovascular disease (CVD) is a significant global health concern, affecting millions of individuals each year. Accurate diagnosis of acute CVD poses a formidable challenge, as misdiagnosis can significantly decrease patient survival rates. Traditional biomarkers have played a vital role in the diagnosis and prognosis of CVDs, but they can be influenced by various factors, such as age, sex, and renal function. Soluble ST2 (sST2) is a novel biomarker that is closely associated with different CVDs. Its low reference change value makes it suitable for continuous measurement, unaffected by age, kidney function, and other confounding factors, facilitating risk stratification of CVDs. Furthermore, the combination of sST2 with other biomarkers can enhance diagnostic accuracy and prognostic value. This review aims to provide a comprehensive overview of sST2, focusing on its diagnostic and prognostic value as a myocardial marker for different types of CVDs and discussing the current limitations of sST2.

Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry) - Clinical Impact of Early Recurrence

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.

METHODS AND RESULTS

Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1-2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62).

CONCLUSIONS

ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

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.

Predictors of low-voltage zones in patients with persistent atrial fibrillation eligible for catheter ablation: An observational study

INTRODUCTION

The presence of low-voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF.

METHODS

The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm2 exhibiting a peak-to-peak bipolar voltage of <0.5 mV.

RESULTS

The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03-1.13, p = .002); female sex (OR = 4.83, 95% CI = 2.66-8.76, p < .001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32-7.77, p = .01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04-1.17, p = .001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829.

CONCLUSION

Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient.

Treatment Outcomes of Catheter Ablation Versus Medical Therapy in Patients With Atrial Fibrillation: A Systematic Review

Atrial fibrillation (AF) management has witnessed a paradigm shift, with an increasing emphasis on rhythm control strategies. This systematic review aims to comprehensively assess and compare the efficacy and safety of catheter ablation versus medical therapy in the treatment of AF. A systematic search was conducted across major electronic databases, including PubMed, Embase, and the Cochrane Library, from inception to the present. Randomized controlled trials (RCTs) and observational studies comparing catheter ablation with medical therapy for AF were included. The primary outcomes included rhythm control success, recurrence rates, and adverse events. Secondary outcomes encompassed quality of life, hospitalization rates, and mortality. A total of six studies met the inclusion criteria, comprising 2,859 participants. Catheter ablation significantly improved rhythm control success compared to medical therapy. Subgroup analyses demonstrated variations in outcomes based on patient characteristics, procedural techniques, and follow-up durations. Recurrence rates favored ablation; however, ablation was associated with a higher incidence of minor complications and major adverse events. Catheter ablation demonstrates superior efficacy in achieving and maintaining rhythm control compared to medical therapy in the management of AF. Despite the increased risk of procedural complications, the overall safety profile remains acceptable. This systematic review provides valuable insights for clinicians and informs shared decision-making between patients and healthcare providers when choosing between catheter ablation and medical therapy for AF treatment.

Machine learning identifies esophageal luminal temperature patterns associated with thermal injury in catheter ablation for atrial fibrillation

INTRODUCTION

Luminal esophageal temperature (LET) monitoring during atrial fibrillation (AF) ablation is widely used to reduce the incidence of endoscopically detected esophageal lesion (EDEL). We sought to assess whether specific patterns of LET variation are associated with EDEL.

METHODS

A high-fidelity multisensor probe was used to record LET in AF patients undergoing radiofrequency ablation (RFA) or cryoballoon ablation (CBA). Explainable machine learning and SHapley Additive exPlanations (SHAP) analysis were used to predict EDEL and assess feature importance.

RESULTS

A total of 94 patients (38.3% persistent AF, 71.3% male, 72 RFA, and 22 CBA) were included. EDEL was detected in 11 patients (10 RFA and one CBA). In the RFA group, the highest LET recorded was similar between patients with and without EDEL (40.6 [40.1-41]°C vs. 40.2 [39.1-40.9]°C; p = .313), however, the rate of LET rise for the highest recorded peak was higher (0.08 [0.03-0.12]°C/s vs. 0.02 [0.01-0.05]°C/s; p = .033), and the area under the curve (AUC) for the highest peak was smaller (412.5 [206.8-634.1] vs. 588.6 [380.4-861.1]; p = .047) in patients who had EDEL. In case of CBA, the patient with EDEL had a faster LET decline (0.12 vs. 0.07 [0.02-0.14]°C/s), and a smaller AUC for the lowest trough (2491.3 vs. 2629.3 [1712.6-5283.2]). SHAP analysis revealed that a rate of LET change higher than 0.05°C/s and an AUC less than 600 were more predictive of EDEL in RFA.

CONCLUSION

The rate of LET change and AUC for the recorded temperature predicted EDEL, whereas absolute peak temperatures did not.

Esophageal injury, perforation, and fistula formation following atrial fibrillation ablation

BACKGROUND

Esophageal perforation and fistula formation are rare but serious complications following atrial fibrillation ablation. In this review article, we outline the incidence, pathophysiology, predictors, and preventative strategies of this dreaded complication.

METHODS

We conducted an electronic search in 10 databases/electronic search engines to access relevant publications. All articles reporting complications following atrial fibrillation ablation, including esophageal injury and fistula formation, were included for systematic review.

RESULTS

A total of 130 manuscripts were identified for the final review process. The overall incidence of esophageal injury following atrial fibrillation ablation was significantly higher with thermal ablation modalities (radiofrequency 5-40%, cryoballoon 3-25%, high-intensity focused ultrasound < 10%) as opposed to non-thermal ablation modalities (no cases reported to date). The incidence of esophageal perforation and fistula formation with the use of thermal ablation modalities is estimated to occur in less than 0.25% of all atrial fibrillation ablation procedures. The use of luminal esophageal temperature monitoring probe and mechanical esophageal deviation showed protective effect toward reducing the incidence of this complication. The prognosis is very poor for patients who develop atrioesophageal fistula, and the condition is rapidly fatal without surgical intervention.

CONCLUSIONS

Esophageal perforation and fistula formation following atrial fibrillation ablation are rare complications with poor prognosis. Various strategies have been proposed to protect the esophagus and reduce the incidence of this fearful complication. Pulsed field ablation is a promising new ablation technology that may be the future answer toward reducing the incidence of esophageal complications.

A pilot clinical assessment of biphasic asymmetric pulsed field ablation catheter for pulmonary vein isolation

Pulsed field ablation (PFA) is a new treatment for atrial fibrillation (AF), and its selective ablation characteristics give it a significant advantage in treatment. In previous cellular and animal experiments, we have demonstrated that biphasic asymmetric pulses can be used to ablate myocardial tissue. However, small-scale clinical trials are needed to test whether this approach is safe and feasible before extensive clinical trials can be performed. Therefore, the purpose of this experiment is to determine the safety and feasibility of biphasic asymmetric pulses in patients with AF and is to lay the foundation for a larger clinical trial. Ablation was performed in 10 patients with AF using biphasic asymmetric pulses. Voltage mapping was performed before and after PFA operation to help us detect the change in the electrical voltage of the pulmonary veins (PV). 3-Dimensional mapping system showed continuous low potential in the ablation site, and pulmonary vein isolation (PVI) was achieved in all four PV of the patients. There were no recurrences, PV stenosis, or other serious adverse events during the 12 months follow-up. The results suggest that PFA using biphasic asymmetric waveforms for patients with AF is safe, durable, and effective and that a larger clinical trial could begin.

Clinical Trial Registration

https://www.chictr.org.cn/, identifier, ChiCTR2100051894.

Transesophageal echocardiography and computerized tomography angiography mismatch in left atrial appendage thrombus evaluation

BACKGROUND

Transesophageal echocardiography (TEE) is the gold standard test for the diagnosis of left atrial appendage (LAA) thrombus. Nonetheless, computerized tomography angiography (CTA) is readily used to exclude LAA thrombus before pulmonary vein isolation (PVI) and LAA closure procedures. We aimed to assess the comparability of LAA thrombus diagnosis using chest CTA scans in patients with atrial fibrillation who underwent TEE.

METHODS

Retrospective collection of consecutive patients with atrial fibrillation who underwent TEE and chest CTA within 30 days and had evidence of spontaneous echo contrast (SEC) or LAA thrombus on TEE. Clinical, demographic, and echo data were collected. Prospective analysis of the CTA for evidence of LAA thrombus in the same group of patients was performed. We compared the findings of the two modalities.

RESULTS

Out of 1550 patients with atrial fibrillation who underwent TEE examinations in the study period, 63 patients underwent TEE within 30 days of a chest CTA scan. Twenty-three patients had LAA thrombus and 40 had some degree of SEC according to TEE. On CTA, 11 were interpreted as positive with a high level of suspicion for the presence of an LAA thrombus. Six patients (26.1%) had LAA thrombus according to both CT and TEE. Therefore, low concordance was found between test results (chi-squared continuity correction = 5.5, df  = 1, and P -value = 0.01902).

CONCLUSION

The discrepancy between CTA and TEE results suggests these examinations might be more suitable as complementary examinations to exclude LAA thrombus.

Cardiac Radiofrequency Ablation Exacerbates Myocardial Injury through Pro-Inflammatory Response and Pro-Oxidative Stress in Elderly Patients with Persistent Atrial Fibrillation

BACKGROUND

There is a need to assess myocardial damage after radiofrequency ablation of the pulmonary veins (PV) for persistent atrial fibrillation (PAF) in elderly patients.

OBJECTIVE

To evaluate oxidative stress, inflammatory response and myocardial damage in elderly patients with PAF after radiofrequency ablation of the PV.

METHODS

High-sensitivity troponin T (hsTnT), malondialdehyde-modified low-density lipoprotein (MDA-LDL), acrolein (ACR), lipid hydroperoxide (LHP), toll-like receptor 4 (TLR4), soluble growth stimulation expressed gene 2 (sST2), angiotensin II (Ang II) and myocardial blood flow (MBF) were determined before ablation and at 1, 3 and 5 months after radiofrequency ablation.

RESULTS

The levels of hsTnT, MDA-LDL, ACR, LHP, TLR4, sST2 and Ang II were increased 3 months after ablations compared with before ablation and 1 month after ablation, respectively (P<0.001); they were further increased at 5 months after ablation compared with the 1- and 3-month groups, respectively (P<0.001). MBF was decreased in the 3 months group after ablations compared with before ablation and 1-month after ablation, respectively (P<0.001), and was further decreased in 5-months after ablations compared with 1-month and 3-month groups, respectively (P<0.001). Patients with epicardial monopolar radiofrequency ablation had higher levels of hsTnT, MDA-LDL, ACR, LHP, TLR4, sST2, Ang II and lower MBF than patients with endocardial monopolar and bipolar radiofrequency ablations, respectively (P<0.001).

CONCLUSION

Monopolar radiofrequency ablation method could result in more myocardial injury than bipolar radiofrequency ablation. Oxidative stress and inflammatory response may be involved in cardiac radiofrequency ablation-induced myocardial injury, resulting in myocardial ischemia in elderly patients with PAF.

Detection and modification of biomarkers of inflammation determining successful rhythm control in patients with atrial fibrillation

INTRODUCTION

Multiple pathophysiological mechanisms are involved in the pathogenesis of atrial fibrillation (AF). Growing evidence suggests that both local and systemic inflammation plays a key role even in early stages and its progression towards persisting and permanent AF. Rhythm control therapy via pulmonary vein isolation or cardioversion is the cornerstone of AF therapy for most symptomatic patients, yet arrhythmia recurrence after treatment is still common, especially in patients with persistent AF.

MATERIAL AND METHODS

In this review, we summarize the current state of knowledge of biomarkers of inflammation with prognostic value in patients with atrial fibrillation as well as anti-inflammatory medication with potential benefits after rhythm control therapy.

RESULTS AND DISCUSSION

Both onset of AF, progression and arrhythmia recurrence after rhythm control therapy can be caused by local and systemic inflammation. Various inflammatory biomarkers have been established to predict treatment success. Furthermore, additional anti-inflammatory therapy may significantly improve success rates.

Impact of general anesthesia on ablation catheter stability during pulmonary vein isolation based on a novel measurement approach

Catheter ablation for atrial fibrillation (AF) during pulmonary vein isolation (PVI) is performed under general anesthesia (GA) or conscious sedation (CS). GA during PVI may improve treatment outcomes by improving catheter stability. However, the magnitude of GA-derived catheter stability compared with that of CS is unclear. We directly assessed catheter movement and determined the impact of GA compared with that of CS on ablation catheter stability during PVI. Patients who underwent initial ablation using the EnSite Precision™ mapping system were recruited and divided into two groups (GA and CS groups). The two groups were compared for ablation catheter stability during PVI based on the distance traveled by the catheter distal tip per second, clinical periprocedural characteristics, and periprocedural complications. Among 69 consecutively admitted patients, data of 30 patients (17 in the GA group and 13 in the CS group) and the distance traveled per second by the catheter on 148,976 points/patient were evaluated. The GA group had a significantly smaller catheter tip travel distance than the CS group (0.92 [0.82‒1.16] vs. 1.25 [1.14‒1.38], p = 0.01). Therefore, GA during PVI for AF provides greater catheter stability than CS and will contribute to more accessible and safer PVI procedures.

Interplay between natriuretic peptides and left atrial mechanics and the relation to recurrence of atrial fibrillation following catheter ablation

The relationship between natriuretic peptides and atrial distension is not fully understood. We sought to examine their interrelationship and how they relate to atrial fibrillation (AF) recurrence following catheter ablation. We analyzed patients enrolled in the AMIO-CAT trial (amiodarone vs. placebo for reducing AF recurrence). Echocardiography and natriuretic peptides were assessed at baseline. Natriuretic peptides included mid-regional proANP (MR-proANP) and N-terminal proBNP (NT-proBNP). Atrial distension was assessed by left atrial strain measured by echocardiography. The endpoint was AF recurrence within 6 months after a 3-month blanking period. Logistic regression was used to assess the association between log-transformed natriuretic peptides and AF. Multivariable adjustments were made for age, gender, randomization, and left ventricular ejection fraction. Of 99 patients, 44 developed AF recurrence. No differences in natriuretic peptides nor echocardiography were observed between the outcome groups. In unadjusted analyses, neither MR-proANP nor NT-proBNP were significantly associated with AF recurrence [MR-proANP: OR = 1.06 (0.99-1.14), per 10% increase; NT-proBNP: OR = 1.01 (0.98-1.05), per 10% increase]. These findings were consistent after multivariable adjustments. However, atrial strain significantly modified the association between MR-proANP and AF (p for interaction = 0.009) such that MR-proANP was associated with AF in patients with high atrial strain [OR = 1.24 (1.06-1.46), p = 0.008, per 10% increase] but not in patients with low atrial strain. In patients with high atrial strain, an MR-proANP > 116 pmol/L posed a fivefold higher risk of AF recurrence [HR = 5.38 (2.19-13.22)]. Atrial natriuretic peptide predicts AF recurrence in patients with preserved atrial distension. Assessing atrial strain may assist the interpretation of natriuretic peptides.

Efficacy of ablation therapy on clinical outcomes in patients with atrial fibrillation: a systematic review and meta-analysis

Background

Optimal treatment regimen for patients with atrial fibrillation (AF) remains unclear. Therefore, the authors sought to compare the outcomes of ablation therapy versus pharmacological regimens in patients with AF.

Methods

MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials and observational studies comparing clinical outcomes between of ablation and pharmacological therapy in patients with AF. Stroke, all-cause mortality, cardiovascular mortality, cardiovascular hospitalization, heart failure (HF), and bleeding were among outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate relative risks (RRs) with 95 % CIs.

Results

The analysis included ~200 000 patients from 4 randomized controlled trials and 7 observational studies. Meta-analysis showed statistically significant reduction in stroke among patients on ablation therapy [hazard ratio (HR) 0.51, 95% CI (0.43, 0.60), P<0.00001, I2=10%], all-cause mortality [HR 0.64, 95% CI (0.45, 0.93), P=0.02, I2=58%], cardiovascular mortality [HR 0.35, 95% CI (0.25, 0.50), P<0.0001, I2=0%], and HF [HR 0.40, 95% CI (0.31, 0.53), P<0.00001, I2=30%]. However, no significant difference was revealed in the risk of cardiovascular hospitalization [HR 1.04, 95% CI (0.88, 1.23), P=0.66, I2=89%] and bleeding [HR 1.11, 95% CI (0.97, 1.27), P=0.13, I2=0%].

Conclusion

Ablation significantly reduces the risk of stroke, cardiovascular mortality, all-cause mortality, and HF in AF patients, compared with medical therapy alone, supporting its use in clinical practice.

Tic-Tac: A Translational Approach in Mechanisms Associated with Irregular Heartbeat and Sinus Rhythm Restoration in Atrial Fibrillation Patients

Atrial fibrillation (AF) is a prevalent cardiac condition predominantly affecting older adults, characterized by irregular heartbeat rhythm. The condition often leads to significant disability and increased mortality rates. Traditionally, two therapeutic strategies have been employed for its treatment: heart rate control and rhythm control. Recent clinical studies have emphasized the critical role of early restoration of sinus rhythm in improving patient outcomes. The persistence of the irregular rhythm allows for the progression and structural remodeling of the atria, eventually leading to irreversible stages, as observed clinically when AF becomes permanent. Cardioversion to sinus rhythm alters this progression pattern through mechanisms that are still being studied. In this review, we provide an in-depth analysis of the pathophysiological mechanisms responsible for maintaining AF and how they are modified during sinus rhythm restoration using existing therapeutic strategies at different stages of clinical investigation. Moreover, we explore potential future therapeutic approaches, including the promising prospect of gene therapy.

Outcomes of catheter ablation vs. medical treatment for atrial fibrillation and heart failure: a meta-analysis

Background

The benefit of catheter ablation vs. medical treatment has been reported to be inconsistent in randomized controlled trials (RCTs) for patients with atrial fibrillation (AF) and heart failure (HF) due to different enrollment criteria. This meta-analysis aimed to decipher the differential outcomes stratified by different left ventricular ejection fractions (LVEFs) and AF types.

Methods

We searched PubMed, Embase, ProQuest, ScienceDirect, Cochrane Library, ClinicalKey, Web of Science, and ClinicalTrials.gov databases for RCTs comparing medical treatment and catheter ablation in patients with AF and HF published before March 31, 2023. Nine studies were included.

Results

When patients were stratified by LVEF, improved LVEF and 6-min walk distance, less AF recurrence, and lower all-cause mortality in favor of catheter ablation were observed in patients with LVEF ≤50% but not in patients with LVEF ≤35%, and short HF hospitalization was observed in patients with LVEF ≤50% and LVEF ≤35%. When patients were stratified by AF types, improved LVEF and 6-min walk distance, better HF questionnaire score, and short HF hospitalization in favor of catheter ablation were observed both in patients with nonparoxysmal AF and mixed AF (paroxysmal and persistent) and less AF recurrence and lower all-cause mortality in favor of catheter ablation were observed in only patients with mixed AF.

Conclusions

This meta-analysis showed improved LVEF and 6-min walk distance, less AF recurrence, and lower all-cause mortality in favor of catheter ablation vs. medical treatment in AF patients with HF and LVEF of 36%-50%. Compared with medical treatment, catheter ablation improved LVEF and had better HF status in patients with nonparoxysmal AF and mixed AF; however, AF recurrence and all-cause mortality in favor of catheter ablation were observed in only HF patients with mixed AF.

Long-Term Renal Function after Catheter Ablation of Atrial Fibrillation

Background: Atrial fibrillation (AF) is associated with the development and progression of chronic kidney disease (CKD). This study evaluated the impact of long-term rhythm outcome after catheter ablation (CA) of AF on renal function. Methods and results: The study group included 169 consecutive patients (the mean age was 59.6 ± 10.1 years, 61.5% were males) who underwent their first CA of AF. Renal function was assessed by eGFR (using the CKD-EPI and MDRD formulas), and by creatinine clearance (using the Cockcroft–Gault formula) in each patient before and 5 years after index CA procedure. During the 5-year follow-up after CA, the late recurrence of atrial arrhythmia (LRAA) was documented in 62 patients (36.7%). The mean eGFR, regardless of which formula was used, significantly decreased at 5 years following CA in patients with LRAA (all p < 0.05). In the arrhythmia-free patients, the mean eGFR at 5 years post-CA remained stable (for the CKD-EPI formula: 78.7 ± 17.3 vs. 79.4 ± 17.4, p = 0.555) or even significantly improved (for the MDRD formula: 74.1 ± 17.0 vs. 77.4 ± 19.6, p = 0.029) compared with the baseline. In the multivariable analysis, the independent risk factors for rapid CKD progression (decline in eGFR > 5 mL/min/1.73 m2 per year) were the post-ablation LRAA occurrence (hazard ratio 3.36 [95% CI: 1.25–9.06], p = 0.016), female sex (3.05 [1.13–8.20], p = 0.027), vitamin K antagonists (3.32 [1.28–8.58], p = 0.013), or mineralocorticoid receptor antagonists’ use (3.28 [1.13–9.54], p = 0.029) after CA. Conclusions: LRAA after CA is associated with a significant decrease in eGFR, and it is an independent risk factor for rapid CKD progression. Conversely, eGFR in arrhythmia-free patients after CA remained stable or even improved significantly.

Prognostic value of heart rate variability in atrial fibrillation recurrence following catheter ablation: A systematic review and meta-analysis

Background

Atrial fibrillation (AF) has been a worldwide health issue with increasing prevalence and mortality. Recently, increasing attention has been gained to the relationship between heart rate variability (HRV) and the clinical prognosis of AF catheter ablation. We aimed to evaluate the prognostic value of HRV in AF recurrence.

Methods

We systematically searched Web of Science, PubMed, and Embase from inception until 17 August 2022 to conduct the systematic review and meta-analysis. We included the studies reporting the predictive value of HRV parameters for AF recurrence or in which HRV parameters in AF recurrence and non-recurrence groups were individually reported.

Results

Finally, we enrolled 16 studies, including 2,352 patients. Higher rMSSD could independently predict AF recurrence following catheter ablation (OR: 1.02, 95% CI: 1.00-1.04; p = 0.03). Higher HF (OR: 1.55, 95% CI: 1.05-2.28; p = 0.03) and lower LF/HF (OR: 1.12, 95% CI: 1.03-1.20; p = 0.004) could independently predict AF recurrence within 1 year. Higher SDNN (OR: 1.02, 95% CI: 101-1.02; p = 0.0006) could independently predict AF recurrence among patients with paroxysmal AF. Almost all HRV parameters within 3 days after catheter ablation and lnHF, lnLF, and rMSSD at 3 months after catheter ablation performed significant differences in AF recurrence and non-recurrence groups.

Conclusion

Heart rate variability, especially higher rMSSD (within short-term and long-term periods), was closely related to recurrent AF following catheter ablation, highlighting the clinical importance of HRV in the prognosis of AF following catheter ablation.

Efficacy and safety of novel pulsed field ablation (PFA) technique for atrial fibrillation: A systematic review and meta-analysis

Background and Aim

Pulse field ablation (PFA) has emerged as a safe alternative to other catheter ablation energy sources for patients. Although early results are encouraging, secondary data about outcomes are lacking. Herein, we aimed to assess the safety and efficacy of the novel technique.

Methods

We searched PubMed, Ovid, Google Scholar, Web of Science, and Scopus databases and several major scientific conferences for studies reporting results regarding PFA.

Results

Sixteen studies were included, reporting 485 patients with atrial fibrillation who underwent pulsed field operations. Patients averaged 60 years of age. The total duration of the procedure is 94 min. The average Fluoro procedure takes 17 min. Isolation of all pulmonary veins was 100% with a 95% confidence interval (CI) (p > 0.05). Overall, the recurrence rate of arrhythmia in the participants was 2.84% (95% CI) (p > 0.05). Complications were detected during or after the PFA procedure at a rate of 2.23% (p < 0.05), with 95% CI indicating the high safety of the PFA procedure.

Conclusion

Using pulsed-field ablation as a new treatment for atrial fibrillation has proven safe and effective.

Improved hospital discharge and cost savings with esophageal cooling during left atrial ablation

BACKGROUND

Left atrial ablation to obtain pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF) is a technologically intensive procedure utilizing innovative and continually improving technology. Changes in the technology utilized for PVI can in turn lead to changes in procedure costs. Because of the proximity of the esophagus to the posterior wall of the left atrium, various technologies have been utilized to protect against thermal injury during ablation. The impact on hospital costs during PVI ablation from utilization of different technologies for esophageal protection during ablation has not previously been evaluated.

OBJECTIVE

To compare the costs of active esophageal cooling to luminal esophageal temperature (LET) monitoring during left atrial ablation.

METHODS

We performed a time-driven activity-based costing (TDABC) analysis to determine costs for PVI procedures. Published data and literature review were utilized to determine differences in procedure time and same-day discharge rates using different esophageal protection technologies and to determine the cost impacts of same-day discharge versus overnight hospitalization after PVI procedures. The total costs were then compared between cases using active esophageal cooling to those using LET monitoring.

RESULTS

The effect of implementing active esophageal cooling was associated with up to a 24.7% reduction in mean total procedure time, and an 18% increase in same-day discharge rate. TDABC analysis identified a $681 reduction in procedure costs associated with the use of active esophageal cooling after including the cost of the esophageal cooling device. Factoring in the 18% increase in same-day discharge resulted in an increased cost savings of $2,135 per procedure.

CONCLUSIONS

The use of active esophageal cooling is associated with significant cost-savings when compared to traditional LET monitoring, even after accounting for the additional cost of the cooling device. These savings originate from a per-patient procedural time savings and a per-population improvement in same-day discharge rate.

Validation of seven risk scores in an independent cohort: the challenge of predicting recurrence after atrial fibrillation ablation

Purpose

Several predictive scores for atrial fibrillation (AF) recurrence after AF ablation have been developed. We compared the predictive value of seven previously described risk scores ((CHADS2 and CHA2DS2-VASC, HATCH, APPLE, CAAP-AF, BASE-AF2, MB-LATER) for prediction of AF recurrence risk at 12 months after AF ablation in our patient cohort. Further, we aimed to identify additional variables to predict recurrences after AF ablation.

Methods

We used data from our digital AF ablation registry to compare the previously published scores in an independent cohort (n = 883, 50.8% with paroxysmal AF). The scores were chosen based on earlier publications and availability of relevant data.

Results

The BASE-AF2 (AUC 0.630, p < 0.001), MB-LATER (AUC 0.612, p < 0.001), CAAP-AF (AUC 0.591, p < 0.001), APPLE (AUC 0.591, p < 0.001) and CHA2DS2-VASC (AUC 0.547, p = 0.018) scores had a statistically significant but modest predictive value for 12-month AF recurrence. None of the scores were significantly superior. Other analyzed scores had no predictive value. There was no difference in the predictive value for 12-month recurrence of AF between first procedure vs. redo procedure and RF ablation vs. cryoablation. Unlike other scores, MB-LATER showed better predictive value for paroxysmal vs. persistent AF (AUC 0.632 vs. 0.551, p = 0.038). In the multivariate logistic regression, only age (p = 0.006), number of prior electrical cardioversions (p < 0.001) and early AF recurrence (p < 0.001) were independent predictors of AF recurrence.

Conclusion

Despite numerous available scores, predicting recurrences after AF ablation remains challenging. New predictors are needed, potentially based on interventions, as well as novel genetic, functional and anatomic parameters.

Characterization of high-power and very-high-power short-duration radiofrequency lesions performed with a new-generation catheter and a temperature-control ablation mode

INTRODUCTION

High-power short-duration (HPSD) has been proposed to shorten procedure times while maintaining efficacy and safety. We evaluated the differences in size and geometry between radiofrequency lesions obtained with this method and conventional ones.

METHODS AND RESULTS

Twenty-eight sets of 10 perpendicular radiofrequency applications were performed with two commercially available catheters: a temperature-controlled HPSD catheter (QDot-Micro) and a conventional power-controlled catheter (Thermocool SmartTouch) on porcine left ventricle. Different power settings (35, 40, 50, and 90 W), contact force (CF; 10 and 20 g), ablation index (AI; 400 and 550), and application times were combined to create conventional (35-40 W), HPSD (50 W) and very-high-power short-duration (VHPSD; 90 W) lesions, that were cross-sectioned and measured. About 4-s VHPSD lesions were smaller, shallower, and thinner than HPSD performed with the QDot-Micro catheter in any scenario of CF or AI (61 ± 7.8 mm³ , 6.1 ± 0.3 mm wide, and 2.9 ± 0.1 mm deep with 10 g; 72.2 ± 0.5 mm³ , 6.8 ± 0.3 mm wide, and 2.9 ± 0.2 mm deep with 20 g). Conventional and HPSD lesions performed with the temperature-controlled catheter were generally bigger, deeper, and wider than the ones obtained with the power-controlled catheter, as well as more consistent in size. This was especially true with the lower CF and AI scenario, while differences were less notable with other setting combinations.

CONCLUSION

VHPSD lesions performed with QDot-Micro catheter were smaller than any other lesions, which is especially attractive for posterior left atrial wall ablation. On the contrary, conventional-powered and HPSD lesions performed with this catheter were equally sized (or even bigger with lower CF and AI objectives), as well as more consistent in size, which would guarantee transmurality in other locations.

Rhythm monitoring, success definition, recurrence, and anticoagulation after atrial fibrillation ablation: results from an EHRA survey

Atrial fibrillation (AF) is a major challenge for the healthcare field. Pulmonary vein isolation is the most effective treatment for the maintenance of sinus rhythm. However, clinical endpoints for the procedure vary significantly among studies. There is no consensus on the definition of recurrence and no clear roadmap on how to deal with recurrences after a failed ablation. The purpose of this study was to perform a survey in order to show how clinicians currently approach this knowledge gap. An online survey, supported by the European Heart Rhythm Association (EHRA) Scientific Initiatives Committee, was conducted between 1 April 2022 and 8 May 2022. An anonymous questionnaire was disseminated via social media and EHRA newsletters, for clinicians to complete. This consisted of 18 multiple-choice questions regarding rhythm monitoring, definitions of a successful ablation, clinical practices after a failed AF ablation, and the continuance of anticoagulation. A total of 107 replies were collected across Europe. Most respondents (82%) perform routine monitoring for AF recurrences after ablation, with 51% of them preferring a long-term monitoring strategy. Cost was reported to have an impact on the choice of monitoring strategy. Self-screening was recommended by most (71%) of the respondents. The combination of absence of symptoms and recorded AF was the definition of success for most (83%) of the respondents. Cessation of anticoagulation after ablation was an option mostly for patients with paroxysmal AF and a low CHA2DS2-VASc score. The majority of physicians perform routine monitoring after AF ablation. For most physicians, the combination of the absence of symptoms and electrocardiographic endpoints defines a successful result after AF ablation.

Nano drugs delivery system: A novel promise for the treatment of atrial fibrillation

Atrial fibrillation (AF) is one of the most common sustained tachyarrhythmias worldwide, and its prevalence is positively correlated with aging. AF not only significantly reduces the quality of life of patients but also causes a series of complications, such as thromboembolism, stroke, and heart failure, increases the average number of hospitalizations of patients, and places a huge economic burden on patients and society. Traditional drug therapy and ablation have unsatisfactory success rates, high recurrence rates, and the risk of serious complications. Surgical treatment is highly traumatic. The nano drug delivery system has unique physical and chemical properties, and in the application of AF treatment, whether it is used to assist in enhancing the ablation effect or for targeted therapy, it provides a safer, more effective and more economical treatment strategy.

Higher serum tissue inhibitor of metalloproteinase-1 predicts atrial fibrillation recurrence after radiofrequency catheter ablation

Background

Tissue inhibitor of metalloproteinase-1 (TIMP-1) levels is strongly associated with cardiac extracellular matrix accumulation and atrial fibrosis. Whether serum levels of TIMP-1 are associated with atrial fibrillation (AF) recurrence following radiofrequency catheter ablation (RFCA) remains unknown.

Materials and methods

Serum TIMP-1 levels of patients with AF before they underwent initial RFCA were measured using ELISA. Univariate and multivariate-adjusted Cox models were constructed to determine the relationship between TIMP-1 levels and AF recurrence. Multivariate logistic regression analyses were performed to determine predictors of AF recurrence.

Results

Of the 194 enrolled patients, 61 (31.4%) had AF recurrence within the median 30.0 months (interquartile range: 16.5–33.7 months) of follow-up. These patients had significantly higher baseline TIMP-1 levels than those without AF recurrence (129.8 ± 65.7 vs. 112.0 ± 51.0 ng/ml, P = 0.041). The same was true of high-sensitivity C-reactive protein (3.9 ± 6.0 vs. 1.9 ± 2.8 ng/ml, P = 0.001). When a TIMP-1 cutoff of 124.15 ng/ml was set, patients with TIMP-1 ≥ 124.15 ng/ml had a higher risk of recurrent AF than those with TIMP-1 < 124.15 ng/ml (HR, 1.961, 95% CI, 1.182–2. 253, P = 0.009). Multivariate Cox regression analysis revealed that high TIMP-1 was an independent risk factor for AF recurrence. Univariate Cox regression analysis found that substrate modification surgery does not affect AF recurrence (P = 0.553). Subgroup analysis revealed that female sex, age < 65 years, hypertension (HTN), body mass index (BMI) ≥ 24 kg/m², CHA2DS2-VASc score < 2, HAS-BLED score < 3, and EHRA score = 3 combined with high TIMP-1 level would perform well at predicting AF recurrence after RFCA.

Conclusion

Elevated preoperative TIMP-1 levels are related to a higher risk of AF recurrence and can independently predict AF recurrence following RFCA.

Cardiac 123I-mIBG scintigraphy for prediction of catheter ablation outcome in patients with atrial fibrillation

BACKGROUND

Previous studies show inconsistent results on the role of innervation imaging (with 123I-mIBG) in predicting late atrial fibrillation (AF) recurrence after catheter ablation (CA). These studies included patients with paroxysmal AF and studied prognostic value of post-CA I-123-mIBG parameters. Current study investigated the ability of pre CA 123-I-mIBG imaging to predict late AF recurrence in patients with persistent AF.

METHODS

123I-mIBG cardiac imaging was performed before CA in 82 patients with persistent AF. Patient was followed for 12 months.

RESULTS

Multivariable analysis demonstrated that late heart-to-mediastinum ratio (H/Mlate) and washout rate (WR) were independent predictors of AF recurrence. ROC-curve analysis data showed that H/Mlate <1.6 (sensitivity 73.53%, specificity 81.3%, AUC 0.792, P < .001) and WR > 25.11 (sensitivity 70.6%, specificity 70.8.3%, AUC 0.712, P < .001) indicate high probability of AF relapses during 12 months after CA.

CONCLUSION

Pre-CA parameters of global cardiac sympathetic activity estimated by 123I-mIBG scintigraphy are associated with late AF relapses in persistent AF patients with normal LVEF and absence of significant CAD.

Higher serum sST2 is associated with increased left atrial low-voltage areas and atrial fibrillation recurrence in patients undergoing radiofrequency ablation

OBJECTIVE

To conduct a comprehensive analysis of prospectively measuring the concentration of soluble suppression of tumorigenicity 2 (sST2) to predict left atrial (LA) low-voltage areas (LVAs) and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFA).

METHODS

This was a prospective cohort study. A total of 84 patients, including 54 paroxysmal AF cases and 30 persistent AF cases who underwent RFA, were recruited. Electroanatomical voltage mapping determined the extent of LVAs. The serum level of sST2 was measured by enzyme-linked immunosorbent assay. All patients were followed for 12 months after the RFA procedure to verify AF recurrence.

RESULTS

The concentration of sST2 measured in the sample was 17.90-198.77 pg/mL, and the range of LA LVAs was 0-85.6%. The sST2 level positively correlated with LVAs (r = 0.40; P = 0.005). When comparing the top and bottom quartile, sST2 is significantly associated with LA LVAs (OR = 1.833, 95% CI: 1.582-2.011, P = 0.004). When compared with the 1st quartile group, the multivariable adjusted hazard ratios for AF recurrence after RFA were 1.57 (95% CI: 1.182-1.795) for the 4th quartile group, 1.44 (95% CI: 1.085-1.598) for the 3rd quartile group, and 1.27 (95% CI: 0.954-1.318) for the 2nd quartile group. The AF-free survival rates of patients with 1st quartile and 4th quartile sST2 levels after ablation were 95% and 59.6%, respectively (Log Rank test, P = 0.027).

CONCLUSION

Elevated sST2 levels of AF patients were associated with higher LA LVAs and a significantly increased risk of recurrence. The circulating sST2 concentration might be a pre-diagnostic marker of AF recurrence after RFA.

Clinical utility of left atrial strain in predicting atrial fibrillation recurrence after catheter ablation: An up-to-date review

Rhythm control is the core part of the integrated management of atrial fibrillation (AF), especially in the early stages. Despite advances in catheter ablation (CA), the recurrence rate of AF after CA remains high. As a result, stratification and early management of AF recurrence after CA are critical. Currently, predictors of recurrence of AF after CA are mostly based on dysfunction caused by structural remodeling, apart from traditional risk factors. Atrial strain is a recently developed important parameter for detecting the deformability of atrial myocardium during the cardiac cycle prior to atrial remodeling. Although there is only preliminary evidence, atrial strain is still a promising parameter in predicting the recurrence of AF after CA at an early stage. This review focuses on the evaluation of atrial strain, the current applications of atrial strain in assessing atrial function, and predicting the recurrence of AF after CA. We summarize the contents related as follows: (1) CA for rhythm control in AF; (2) Evaluation methods of atrial strain; (3) Atrial strain in the remodeling and reverse remodeling of AF; and (4) Clinical applications of atrial strain in predicting the recurrence of AF after CA. Although there is accumulating evidence on the role of decreased atrial strain in the early prediction of AF recurrence, atrial strain is limited in clinical practice for lacking exact cut-off values and difficulty in distinguishing specific function phases of the atrium. More research is needed in the future to add strength to the early prediction value of atrial strain in AF recurrences.

Effect of social support on illness perception in patients with atrial fibrillation during "Blanking Period": Mediating role of sense of mastery

AIM

To explore whether sense of mastery can mediate the relationship between social support and illness perception in patients with atrial fibrillation (AF) who were at the "Blanking Period."

DESIGN

A cross-sectional design.

METHODS

405 patients with AF who were at the "Blanking Period" in the Affiliated Hospital of Qingdao University were recruited; they completed a set of questionnaires, including the Perceived Social Support Scale, the Personal Mastery Scale and the Brief Illness Perception Questionnaire.

RESULTS

Social support and sense of mastery were both adversely connected to illness perception. The indirect effect of social support on illness perception through sense of mastery was negative, accounting for 86.04% of the total effect.

CONCLUSION

During the "Blanking Period," better social support and sense of mastery contribute to a positive illness perception of AF patients. Social support also can influence patients' illness perception indirectly via the mediator of sense of mastery.

Sex Differences and Temporal Trends in Hospitalization for Catheter Ablation of Nonvalvular Atrial Fibrillation: A Single-Center Experience for 15 Years

Background

There exist sex differences in the clinical profile, management, and outcome of atrial fibrillation (AF). Catheter ablation of AF has become a first-line therapy and has markedly made headway over the recent decades. Little is known about sex differences and temporal trends in hospitalization for catheter ablation of AF in the real-world setting.

Methods

We retrospectively retrieved medical records of patients at Beijing Anzhen Hospital between January 2005 and December 2019. The patients undergoing catheter ablation of AF were enrolled. Demographical and clinical data were compared between sexes. The temporal trends of sex differences were evaluated.

Results

We identified 13502 male patients (66.8%) and 6713 female patients (33.2%). The number of patients undergoing AF ablation had remarkably increased over time, but no sex differences were observed (p=0.17). The median age of women was five years older than that of men (p < 0.001). The median time of in-hospital stay for the women decreased from 11 days to 4 days and for the men from 9 to 4 days. In-hospital mortality was 0.03% and 0.01% for women and men, respectively, with no significant difference between sexes. The women were more likely to have a comorbid diagnosis of hypertension and heart failure than men (p < 0.001). The CHA2DS2-VA score was higher in women than in men (1.64 vs. 1.28, p < 0.001). The temporal trend in the score increased in women from 1.17 to 1.81 (p < 0.001) and in men from 0.91 to 1.41 (p < 0.001). The percentage of patients with CHA2DS2-VA score ≥2 was higher in women than in men (49.8% vs. 35.8%, p < 0.001), and the temporal trend of this sex gap was nearly doubled (8.0% in 2005-2007 vs. 15.5% in 2017-2019, p=0.03).

Conclusions

Safety of catheter ablation for AF was comparable in both sexes. In contrast, the women showed a higher CHA2DS2-VA score than men. The percentage of patients with CHA2DS2-VA score ≥2 increased more quickly in women than in men. Furthermore, sex-specific research is warranted to reduce this sex disparity.

US Hospital Webpages on Atrial Fibrillation Ablation: A Potential Source for Misinformation

OBJECTIVE

To assess accuracy of information delivered to the public on hospital websites in regard to AF ablation.

BACKGROUND

Atrial fibrillation (AF) ablation is performed worldwide. To attract patients, hospitals frequently have webpages that tout the success of the procedure. The information disseminated to the public via these webpages has not been systematically reviewed.

METHODS

From July 2019 to January 2020, we performed a Google search for all US hospitals registered with Medicare to see if they had a webpage describing AF ablation. Resulting hospital webpages were abstracted for data on AF ablation success rates and risks. Success rates over 86%, the highest success rate in the medical literature, were deemed exaggerated.

RESULTS

Among 4,805 hospitals, 487 had webpages describing AF ablation and 33 discussed success rates of AF ablation. 12% reported exaggerated success rates, 3% referred to ablation as a cure, and 2.8% referred to ablation as a tool to eliminate AF. Less than 10% of webpages describing AF ablation noted the potential need for a 2^nd ablation to achieve the stated success rate and merely 16% mentioned risks of the procedure. 1% of webpages directly suggested AF ablation could reduce risk of stroke while others indirectly suggested it by discussing cessation of anticoagulation. 2 webpages mentioned reduced mortality.

CONCLUSION

US hospital webpages rarely discuss AF ablation. When discussed, there were concerning unsubstantiated claims regarding mortality, stroke prevention, and need for medical therapy. This could lead to some patients undergoing AF ablation based on faulty understanding. This article is protected by copyright. All rights reserved.

Transesophageal Echocardiography-Guided Transseptal Left Atrial Access to Improve Safety in Patients Undergoing Pulmonary Vein Isolation

Background: Endovascular pulmonary vein isolation (PVI) has become an important strategy for rhythm control in patients with symptomatic atrial fibrillation (AF). Transseptal access is a critical step of this procedure and can result in potentially life-threatening complications. This retrospective study evaluates the safety of standardized, transesophageal echocardiography (TEE)-guided transseptal access to the left atrium in consecutive patients who underwent PVI. Methods: After the implementation of a standardized, TEE-guided procedure for transseptal access, the data of 404 consecutive PVI procedures using radiofrequency ablation and 3D-mapping were prospectively collected over 5 years. TEE-guided transseptal punctures were performed on 375 patients undergoing one to three PVIs. The patient cohort was retrospectively analyzed for major and minor complications, fluoroscopy time, fluoroscopy dose and ablation outcomes. Results: No single complication related to transseptal access occurred, affirming the safety of the TEE-guided approach. Fluoroscopy time and fluoroscopy dose decreased significantly after 152 procedures. PVI-related minor complications occurred in 11 procedures (2.6%) and included 10 vascular-access-related complications (2.4%) and 1 TEE-related esophageal hematoma (0.2%), which healed spontaneously. Conclusion: Our single-center study shows that TEE guidance may allow safe transseptal access to the left atrium in patients undergoing PVI.

Epicardial adipose tissue, obesity and the occurrence of atrial fibrillation: an overview of pathophysiology and treatment methods

INTRODUCTION

Obesity is a chronic disease, which has significant health consequences and is a staggering burden to health care systems. Obesity can have harmful effects on the cardiovascular system, including heart failure, hypertension, coronary heart disease, and atrial fibrillation (AF). One of the possible substrates might be epicardial adipose tissue (EAT), which can be the link between AF and obesity. EAT is a fat deposit located between the myocardium and the visceral pericardium. Numerous studies have demonstrated that EAT plays a pivotal role in this relationship regarding atrial fibrillation.

AREAS COVERED

This review will focus on the role of obesity and the occurrence of atrial fibrillation (AF) and examine the connection between these and epicardial adipose tissue (EAT). The first part of this review will explain the pathophysiology of EAT and its association with the occurrence of AF. Secondly, we will review bariatric and metabolic surgery and its effects on EAT and AF.

EXPERT COMMENTARY

In this review, the epidemiology, pathophysiology, and treatments methods of AF are explained. Secondly the effects on EAT were elucidated. Due to the complex pathophysiological link between EAT, AF, and obesity, it is still uncertain which treatment strategy is superior.

Prednisone Ameliorates Atrial Inflammation and Fibrosis in Atrial Tachypacing Dogs

Atrial inflammation and fibrosis have long been considered culprits in the development of atrial fibrillation (AF). Prior clinical studies showed that corticosteroid therapy is beneficial in patients with AF. Here we sought to determine whether prednisone treatment prevents atrial tachypacing (ATP) induced atrial fibrosis.Dogs were randomized into the sham, ATP, ATP + low-dose prednisone (ALP), and ATP + high-dose prednisone (AHP) groups. After 6 days of recovery from surgery, dogs were subjected to ATP at 400 beats per minute for 4 weeks while being treated with prednisone (15 or 40 mg/day) or a placebo. Pacemakers were not activated in the sham group.Compared with the ATP group, the expression of collagen I, collagen III, α-smooth muscle actin, transforming growth factor-β1 and connective tissue growth factor were significantly reduced in the ALP and AHP groups. Fluorescence assays showed that reactive oxygen species formation in the right atrium was suppressed in the ALP and AHP groups compared with the ATP group. The protein level of NADPH oxidase 2 was reduced in the ALP and AHP groups' versus ATP group, while NOX4 and NOX5 were unchanged. ATP-induced downregulation of BH4 and eNOS uncoupling in the atria was partially restored in the prednisone-treated groups.Our study demonstrated that atrial fibrosis induced by ATP were suppressed by prednisone. Low-dose prednisone was also effective in suppressing the development of atrial fibrosis.

NATIONWIDE SURVEY OF RADIATION EXPOSURE FOR RADIOFREQUENCY CATHETER ABLATION FOR PULMONARY VEIN ISOLATION AND NONPULMONARY VEIN ISOLATION IN JAPAN

To propose typical values for the arrhythmia region between pulmonary vein isolation (PVI) and nonpulmonary vein isolation (non-PVI) in Japan. A nationwide questionnaire was posted to 343 facilities, to which 125 facilities (36.4%) responded. Results is the median for PVI and non-PVI were in terms of Ka,r (317 and 196 mGy), PKA (40.8 and 26.3 Gy.cm2), FT (43.0 and 27.3 min), and CI (326 and 102 images). When comparing PVI and non-PVI procedures, there were significant differences in Ka, r, PKA, FT, and CI (p < 0.05). In other words, by classifying into two types, PVI and non-PVI, we contributed to the establishment of typical values in Japan's RFCA.

Anxiety is associated with higher recurrence of atrial fibrillation after catheter ablation: A meta‐analysis

Previous studies that evaluated the influence of anxiety on recurrence of atrial fibrillation (AF) after catheter ablation showed inconsistent results. We performed a meta‐analysis of cohort study to systematically evaluate the association between anxiety and AF recurrence after catheter ablation. Electronic databases of PubMed, Embase, and Web of Science were searched for relevant cohort studies from inception to January 20, 2021. We applied the random‐effect model to combine the results to incorporate the potential influence of heterogeneity among studies. Five cohort studies were eligible for the meta‐analysis, which included 549 patients with AF that received catheter ablation. No significant heterogeneity was observed among the included studies (I² = 7%, P for Cochrane's Q test = 0.37). During a mean follow‐up of 9.7 months, 216 (39.3%) cases of recurrent AF occurred. Results of the meta‐analysis showed that anxiety was independently associated with an increased risk of AF recurrence after catheter ablation (adjusted relative risk: 2.36, 95% confidence interval: 1.71–3.26; p < .001). Subgroup analyses did not show that differences in study characteristics including study design, ethnicity of the patients, sample size, AF type, anxiety evaluation method, follow‐up duration, or adjustment of LAD may significantly affect the association between anxiety and AF recurrence (p for subgroup difference all > .10). Anxiety may be an independent risk factor for AF recurrence after catheter ablation. Whether alleviating anxiety mood could reduce the risk of AF recurrence after catheter ablation should also be investigated.