Atrial Tachyarrhythmia Recurrence Research Articles

Effect of Prolonged Use of Dronedarone on Recurrence in Patients with Non-Paroxysmal Atrial Fibrillation After Radiofrequency Ablation (DORIS): Rationale and Design of a Randomized Multicenter, Double-Blinded Placebo-Controlled Trial.

Prolonged use of anti-arrhythmic drugs (AAD) beyond the post-ablation blanking period to maintain sinus rhythm has been adopted in clinical practice but without sufficient evidence. Dronedarone is an AAD valid for maintaining sinus rhythm with fewer side effects than other AAD for long-term use. We sought to investigate the effect of prolonged use of dronedarone on the recurrence of non-paroxysmal AF patients beyond 3 months within the first year after ablation. Non-paroxysmal AF patients will receive dronedarone for 3 months after radiofrequency ablation. Patients without drug side effects and atrial tachyarrhythmia (AT) recurrence will then be randomly divided into dronedarone and placebo groups and followed up until 1 year after ablation. The primary endpoint is the cumulative nonrecurrence rate post 3 months to 1 year after ablation. Patients will receive 7-day Holter monitoring (ECG patch) at 6, 9, and 12 months after ablation to evaluate AT recurrence. Secondary endpoints include dronedarone withdrawal due to side effects or intolerance of AT recurrence, time to the first recurrence, repeat ablation, electrical cardioversion, unscheduled emergency room visit, or re-hospitalization. This trial will evaluate whether prolonged use of dronedarone effectively reduces the recurrence rate after ablation in non-paroxysmal AF patients. The result of this trial will provide evidence for optimizing post-ablation anti-arrhythmic therapy. ClinicalTrials.gov ; NCT05655468, 19-December-2022.

Outcomes and residual gap analysis after the modified cryomaze procedure performed via right minithoracotomy versus sternotomy

ObjectivesDevelopments in both technique and technology have enabled surgeons to perform the maze procedure via right minithoracotomy (RMT) to treat atrial fibrillation (AF). This study aimed to clarify the outcomes of the modified cryomaze procedure via the RMT approach compared with the sternotomy approach. MethodsThe study cohort comprised 803 consecutive patients who underwent a modified cryomaze procedure (130 via RMT and 673 via sternotomy) for paroxysmal AF and persistent AF from January 2001 to March 2022. The Gray test was applied to compare the incidence of recurrent atrial tachyarrhythmias. Additionally, residual electrical gaps were investigated in the patients who underwent additional catheter ablation for recurrent atrial tachyarrhythmias. ResultsThe respective 1-, 2-, and 3-year cumulative incidences of recurrent atrial tachyarrhythmias were 13.1%, 19.5%, and 23.1% in the RMT group, and 9.3%, 10.9%, and 12.8% in the sternotomy group (Gray test P = .036). All 31 patients with recurrent atrial tachyarrhythmias underwent additional catheter ablation, comprising 14 (10.8%) in the RMT group and 17 (2.5%) in the sternotomy group. There was a significant intergroup difference in the site of residual electrical gaps; the RMT group more frequently had residual gaps in the tricuspid annulus than the sternotomy group (6.2% vs 0.4%; P < .001). ConclusionsIn the modified cryomaze procedure via the RMT approach, ablation failure is more likely to occur at the tricuspid annulus, where the surgical field of view is relatively poor compared with the sternotomy approach. Therefore, surgical ablation should be performed with caution when the RMT approach is used.

Predictors and outcomes of tricuspid regurgitation improvement after radiofrequency catheter ablation for persistent atrial fibrillation.

Little has been reported on the predictors and outcomes of improvement of tricuspid regurgitation (TR) after radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF). We enrolled 141 patients with persistent AF and moderate or severe TR assessed by transthoracic echocardiography (TTE) who underwent an initial RFCA between February 2015 and August 2021. These patients underwent follow-up TTE at 12 months after the RFCA, and were categorized into two groups based on the improvement (defined as at least one-grade improvement of TR) and non-improvement of TR: IM group and Non-IM group, respectively. We compared the patient characteristics, ablation procedures, and recurrences after the RFCA between the two groups. In addition, we examined the major event (defined as admission for heart failure or all-cause death) more than 12 months after the RFCA. IM group consisted of 90 patients (64%). A multivariate analysis revealed that age <71 years old and absence of late recurrence (LR, defined as recurrence of atrial tachyarrhythmia between 3 and 12 months after the RFCA) were independently associated with the improvement of TR after the RFCA. Furthermore, IM group had the higher incidence of major event-free survival than Non-IM group. Relatively young age and absence of LR were good predictors of improvement of TR after the RFCA for persistent AF. In addition, the improvement of TR was related to better clinical outcomes.

Long-term outcome of thoracoscopic ablation and radiofrequency catheter ablation for persistent atrial fibrillation as a de novo procedure

Limited data are available regarding the efficacy of thoracoscopic ablation as the first procedure for persistent atrial fibrillation (AF). We sought to compare the long-term efficacy of thoracoscopic ablation vs. radiofrequency (RF) catheter ablation as the first procedure for persistent AF. Between February 2011 and December 2020, 575 patients who underwent ablation for persistent AF were studied. Among them, thoracoscopic ablation was performed in 281 patients, RF catheter ablation in 228, and hybrid ablation in 66. Rhythm, clinical, and safety outcomes during 7-year follow-up were compared. The patients who underwent thoracoscopic ablation were older, had a higher prevalence of stroke, and had a larger left atrial volume than those who underwent RF catheter ablation. In the propensity score-matched population (n = 306), incidences of atrial tachyarrhythmia recurrence were 51.4% in the thoracoscopic ablation group and 62.5% in the RF catheter ablation group [adjusted hazard ratio (HR) 0.869, 95% confidence interval (CI) 0.618-1.223, P = 0.420]. Stroke and total procedural adverse events were not significantly different between thoracoscopic and RF catheter ablation (2.7 vs. 2.5%, P = 0.603, and 7.1 vs. 4.8%, P = 0.374, respectively). The hybrid ablation group showed similar rhythm outcomes compared with both the thoracoscopic and the RF catheter ablation groups. At the redo procedure, pulmonary vein gaps were more frequently observed in the RF catheter ablation group (32.6%) than in the thoracoscopic ablation group (7.9%) and in the hybrid ablation group (8.8%) (P < 0.001). As a first procedure in persistent AF, thoracoscopic ablation and RF catheter ablation showed comparable efficacy, clinical, and safety outcomes during long-term follow-up.

The spatiotemporal electrogram dispersion ablation targeting rotors is more effective for elderly patients than non-elderly population.

Modulating atrial fibrillation (AF) drivers has been proposed as one of the effective ablation strategies for non-paroxysmal AF (non-PAF). However, the optimal non-PAF ablation strategy is still under debate because the exact mechanisms of AF persistence including focal activity and/or rotational activity, are not well-understood. Recently, spatiotemporal electrogram dispersion (STED) assumed to indicate rotors in the form of rotational activity is proposed as an effective target for non-PAF ablation. We aimed to clarify the effectiveness of STED ablation for modulating AF drivers. STED ablation plus pulmonary vein isolation was applied in 161 consecutive non-PAF patients not undergoing previous ablation. STED areas within the entire left and right atria were identified and ablated during AF. After the procedures, the STED ablation's acute and long-term outcomes were investigated. (1) Despite a more effective acute outcome of the STED ablation for both AF termination and non-inducibility of atrial tachyarrhythmias (ATAs), Kaplan-Meier curves showed that the 24-month freedom ratio from ATAs was 49%, which resulted from the higher recurrence ratio of atrial tachycardia (AT) rather than AF. (2) A multivariate analysis showed that the determinant of ATA recurrences was only a non-elderly age, not long-standing persistent AF, and an enlarged left atrium, which were conventionally considered as key factors. STED ablation targeting rotors was effective in elderly non-PAF patients. Therefore, the main mechanism of AF persistency and the component of the fibrillatory conduction might vary between elders and non-elders. However, we should be careful about post-ablation ATs following substrate modification.

PO-02-038 LESION SIZE PREDICTION MODULE-GUIDED RADIOFREQUENCY ABLATION VERSUS CRYOBALLOON ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: A PROPENSITY SCORE MATCHED ANALYSIS

In previous studies show cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are similar results. However, RFA technology has progressed in few years, lesion size assessment module developed to improve lesion durability. The aim of this study was to compare clinical outcome of RFA guided by lesion size prediction module and second or fourth-generation CBA in patients with paroxysmal atrial fibrillation (PAF). We enrolled 1905 patients with PAF (65.2 ± 11.3years, male 68.0%). 205 patients after RFA who underwent ablation guided by lesion size prediction module, Ablation Index or Lesion Size Index, and 1700 patients after second or fourth-generation CBA in September 2014 to August 2020, and evaluated retrospectively. We performed pulmonary vein isolation with CBA or RFA followed by additional non-pulmonary vein foci ablation. We selected 194 patients treated with RFA (follow-up period 14.1 ± 7.9months) and 194 patients treated with CBA (follow-up period 23.9 ± 12.9months) using propensity score matching. During a follow-up period, atrial tachyarrhythmia recurrence was documented in 34 patients (17.5%) in RFA and 38 patients (19.6%) in CBA. Freedom from atrial tachyarrhythmia recurrence without anti-arrhythmic-drugs after single procedure was a similar in 2 groups (1-year Kaplan–Meier survival rate estimates, RFA:84.9% and CBA:88.9%, p=0.358). The mean total procedure time was shorter in CBA than in RFA (109 ± 45 vs 148 ± 54 minutes, P<0.001), and the mean total fluoroscopy time was shorter in RFA than in CBA (20 ± 18 vs 33 ± 21 minutes, P<0.001). The proportion of non-pulmonary vein foci was slightly higher for CBA (42patients, 21.7%) than for RFA (36patients, 18.6%), but this difference was not significant (P=0.447). Similarly, there was no significant difference in ablation of non-pulmonary vein foci in the left atrium, although CBA was slightly more common (CBA: 16 patients, 8.3% and RFA: 10 patients 5.2%, p=0.223). [image] And, A second procedure was treated to 20 patients in the RFA and 32 in the CBA. The number of people with pulmonary vein reconnection in each was 10 patients (50.0%) in RFA and 15 patients (46.9%) in CBA, respectively, with no difference as a percentage(P=0.83). We found that in the treatment of patients with PAF, lesion size prediction module-guided procedure was not statistically significant efficacy to CBA. CBA and RFA are still similar results even today.

PO-02-066 ABLATION STRATEGIES FOR PATIENTS WITH NON-PAROXYSMAL ATRIAL FIBRILLATION- NETWORK META-ANALYSIS OF RANDOMIZED CLINICAL TRIALS

Pulmonary vein isolation (PVI) is the preferred ablation strategy for patients with paroxysmal atrial fibrillation (AF). However, for patients with non-paroxysmal AF (NPAF), there is no consensus on the most efficient ablation strategy (AS). We aimed to compare the efficacy and safety of different ablation strategies for patients with non-paroxysmal Atrial Fibrillation . We performed a comprehensive systematic search using four large databases to include randomized clinical trials (RCT) evaluating different AS in patients with NPAF. We excluded studies with <100 participants. We defined the efficacy endpoint as a recurrence of atrial tachyarrhythmia (AT) >30 seconds after catheter ablation during a minimum follow-up time of 6 months (or the longest reported). We estimated log risk ratios (log RRs) using random effects network meta-analysis (NMA). Surface under the cumulative ranking curve (SUCRA) was used to rank CA strategies (higher rank suggesting higher efficacy). Safety endpoint was defined as a occurence of one of the above: femoral vascular access complication, pericarditis, stroke/transitory ischemic attack/arterial embolism, pulmonary vein stenosis, cardiac tamponade/hemopericardium/effusion, atrioesophageal fistula, septicemia, internal bleeding, phrenic nerve palsy, and death. We included data from 32 eligible RCTs, with a total of 6950 participants, mean age 59.4±8.2 and 69.3% male, randomized to 15 different AS arms in our NMA (Figure 1a). PVI isolation with concomitant posterior wall isolation (PWI) was associated with reduced incidence of AT (log RR 0.67( 0.47; 0.96) compared to PVI alone. Otherwise, there was no significant difference in the rate of AT recurrence. The top 3 rankings based on SUCRA were hybrid ablation, PVI with ethanol ablation, followed by PVI with PWI. There was a low prevalence of safety outcome- 281 (4.1%), driven predominantly by access complications - 243 (86%).There were no differences in safety endpoint between compared strategies. Our analysis suggests PVI with PWI is linked to decreased AT recurrence compared to PVI. Hybrid ablation represents an attractive treatment option to study in patients with non-paroxysmal atrial fibrillation. Compared strategies were safe without apparent difference in incidency of safety endpoints.

PO-01-064 IMPROVED METHOD FOR VEIN OF MARSHALL ALCOHOL ABLATION: CASE SERIES

Vein of Marshall (VoM) alcohol ablation has emerged as a successful method to reduce recurrence of atrial fibrillation (AF) and atrial tachyarrhythmias in patients with persistent AF. Cannulation of the VoM close to the coronary sinus (CS) ostium with an IMA guiding catheter through an unsupported CS access catheter can be challenging; extending procedure/fluoroscopy time, contrast use, and increase the risk of complications. To describe new tools & techniques for VoM alcohol ablation that make the procedure easier. We describe here an improved method for VoM alcohol ablation in 4 patients following AF ablation. A baseline 3D left atrium voltage map was obtained to assess pre-existing scar (local bipolar voltage of <0.1 mV). The CS was cannulated via the right femoral vein with either a 6 French (F) decapolar catheter or a hand-shaped 6F multipurpose guiding catheter telescoped inside a long curved 9F inner diameter (ID) sheath. The sheath was then advanced into the CS body. Next, a 0.035 in Amplatz wire (short taper) was introduced through the sheath into the CS using a 5F outer diameter (OD) vein selector to provide extra support and facilitate easy re-cannulation of the CS in case the outer sheath disengaged. An occlusive venogram was conducted in RAO 20 view. After the identification of the VoM, a 5F vein selector was used to engage it and a 0.014 mm floppy wire was advanced. An over-the-wire angioplasty balloon (size 1.5 to 2mm x 6mm) was advanced in the VoM and dilated to occlude the vessel. Three ml of 98% ethanol were delivered over 1 minute. This process was repeated twice. The balloon was deflated, and the apparatus was retracted into the sheath. We then proceeded with repeat 3D voltage mapping to assess the ethanol-induced scar. Application of this workflow using these tools reduced the use of contrast, fluoroscopy time, and total procedural time in this case series. What is new: 1. The ID of the CS access sheath was increased to 9F. 2. An Amplatz (short taper) stabilizing/support wire was added to the CS access sheath. 3. The shape of the catheter used to engage the VOM was changed from IMA to vertebral. Application of these tools reduced the use of contrast, fluoroscopy time, and total procedural time.

PO-02-067 PREDICTORS AND IMPACT OF PULMONARY VEIN NON-RECONNECTION IN THE SECOND PROCEDURE AFTER ABLATION INDEX-GUIDED PULMONARY VEIN ISOLATION FOR ATRIAL FIBRILLATION

Reconnection of the pulmonary vein (PV) is the primary mechanism of atrial tachyarrhythmia (AT) recurrence after atrial fibrillation (AF) ablation. In patients with AT recurrence after the first ablation index (AI)-guided AF ablation, we examined the predictors of PV non-reconnection and its impact on the outcome after the second procedure. We aimed to elucidate the predictor of PV non-reconnection and its impact on the outcome after the second ablation procedure. Among the consecutive 2089 patients undergoing the first AI-guided AF ablation, we studied 289 with AT recurrence undergoing the second procedure. We compared clinical characteristics and outcomes between the patient groups with and without PV reconnection at the beginning of the second procedure. Of the 289 patients, 134 (46%) had non-reconnection, while the other 155 (54%) had reconnection at least in one PV. Patients' characteristics, including AF type (paroxysmal AF, 41% versus 48%; persistent AF, 28% versus 26%; long-standing persistent AF, 31% versus 26%, respectively, P=0.50), were similar between the two groups. The percentage of first-pass PV isolation (FPI) in both PV sides in the first ablation procedure was significantly higher in PV non-reconnection than in those with reconnection group (77% versus 43%, respectively, p<0.001). Multivariate logistic regression analysis revealed that FPI at the first procedure (odds ratio, 0.23 (95% confidence interval (CI), 0.13-0.38), p<0.001) was the only independent predictor of PV reconnection. After the second procedure, Kaplan-Meier analysis revealed that AT recurrence rate was significantly higher in patients with PV non-reconnection than in those with reconnection (Log-rank test, p=0.005). Multivariate Cox proportional hazard model analysis revealed that PV non-reconnection (hazard ratio (HR), 1.71 (95%CI, 1.14-2.55), p=0.008), left atrial dimension (1.04 (1.01-1.07), p=0.006), and left ventricular ejection fraction (0.98 (0.96-0.99), p=0.005) were independent predictors of AT recurrence. However, AF type was not: HR to paroxysmal AF (reference) was 1.10 (95%CI, 0.67-1.83) (p=0.70) in persistent AF and 1.30 (0.82-2.03) (p=0.26) in long-standing persistent AF. FPI in the first procedure was the only independent predictor of PV non-reconnection. After the second procedure, PV non-reconnection was an independent worsening predictor of AT recurrence, suggesting a need for an aggressive search for non-PV mechanisms.

AB-452675-1 ELECTROPHYSIOLOGICAL FINDINGS DURING REDO PROCEDURES AFTER PULSED FIELD ABLATION USING A PENTASPLINE CATHETER TO TREAT ATRIAL FIBRILLATION IN ROUTINE CLINICAL PRACTIC

Data from clinical trials of pulsed field ablation (PFA) to treat atrial fibrillation (AF) indicate highly-efficient workflow, an excellent safety profile, good clinical outcomes with few AF recurrences. Also strikingly, protocol-directed invasive remapping procedures revealed a high degree of durability of the pulmonary vein isolation (PVI) lesion sets. While quite favorable, PVI durability in carefully-monitored protocols may not translate to day-to-day clinical practice. Assessing durability with routine invasive remapping is not possible in routine clinical practice, but the “electrical status” of the PVs during clinical redo procedures provides compelling insights into the technical efficacy of the index procedure. To evaluate the electrophysiologic findings during redo procedures in AF patients initially treated with PFA. This single-center study included all redo ablations after an index PFA using the pentaspline catheter (Farapulse; BSC Inc.); patients in clinical trials were excluded. During the redo case, all PVs and any other lesions we assessed. Redo ablation was performed using either RF or PF energy, per operator preference. Between April 2021 (time of PFA approval) and Nov 2022, 863 consecutive AF ablations were performed using the pentaspline PFA catheter in our center. Clinically-indicated redo procedures were performed in 28 (3.2%) patients: mean age 66 yrs, 17M/11W, BMI 29, LA size 46 mm, PAF/PerAF 17/11. Mapping revealed reconductions (gaps) in 33 of 110 (30%) PVs (gaps seen in 18 pts). The distribution of the reconnections was slightly higher in the right PVs: RSPV 9, RIPV 11, LSPV 7, LIPV 6, LCPV 2. For other lesions placed during the index procedure, reconduction was observed in: 3 of 6 (50%) pts with mitral lines, 1 of 6 (17%) pts with posterior box, and 2 of 2 (100%) pts with left atrial appendage isolation. In 2 pts with initially paroxysmal AF and durable PVI, peri-mitral flutter was the clinical tachycardia, in 1 patient the symptomatic tachycardia was typical AVNRT. Only a minimal number (3,2%) of 863 patients (outside of those enrolled in clinical trials) after PF ablation of atrial fibrillation using Farapulse system underwent reablation for recurrent atrial tachyarrhythmia in our center. Even after PF ablation, gaps in the pulmonary veins remain the most common finding – 30% of treated veins were not permanently isolated.

Growing thrombus adhesion on the left atrial wall after catheter ablation of atrial fibrillation.

Growing thrombus adhesion on the left atrial wall after catheter ablation of atrial fibrillation.

Comparison of efficacy of pulmonary vein isolation between cryoballoon ablation and high-power short-duration ablation

BackgroundHigh-power short-duration (HPSD) and cryoballoon ablation (CBA) has been used for pulmonary vein isolation (PVI). ObjectiveWe aimed to compare the efficacy of PVI between CBA and HPSD ablation in patients with paroxysmal atrial fibrillation (PAF). MethodsWe retrospectively analyzed 251 consecutive PAF patients from January 2018 to July 2020. Of them, 124 patients (mean age 57.2 ± 10.1 year) received HPSD and 127 patients (mean age 59.6 ± 9.4 year) received CBA. In HPSD group, the radiofrequency energy was set as 50 W/10 s at anterior wall and 40 W/10 s at posterior wall. In CBA group, 28 mm s generation cryoballoon was used for PVI according the guidelines. ResultsThere was no significant difference in baseline characteristics between these 2 groups. The time to achieve PVI was significantly shorter in cryoballoon ablation group than in HPSD group (20.6 ± 1.7 min vs 51.8 ± 36.3, P = 0.001). The 6-month overall recurrence for atrial tachyarrhythmias was not significantly different between the two groups (HPSD:14.50% vs CBA:11.0%, P = 0.40). There were different types of recurrent atrial tachyarrhythmia between these 2 groups. Recurrence as atrial flutter was significantly more common in CBA group compared to HPSD group (57.1% vs 12.5%, P = 0.04). ConclusionIn PAF patients, CBA and HPSD had a favourable and comparable outcome. The recurrence pattern was different between CBA and HPSD groups.

Oral Class I and III antiarrhythmic drugs for maintaining sinus rhythm after catheter ablation of atrial fibrillation.

Oral Class I and III antiarrhythmic drugs for maintaining sinus rhythm after catheter ablation of atrial fibrillation.

Predictors of Maintenance of Sinus Rhythm After Radiofrequency Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

Little has been reported on the predictors of maintenance of sinus rhythm (SR) after radiofrequency catheter ablation (RFCA) for long-standing persistent atrial fibrillation (AF). We enrolled 151 patients with long-standing persistent AF (defined as AF lasting more than 12months) who underwent an initial RFCA between October 2014 and December 2020 in our hospital. These patients were categorized into 2 groups on the basis of the absence and presence of the late recurrence (LR, defined as a recurrence of atrial tachyarrhythmia between 3 and 12months after RFCA): SR group and LR group. The SR group comprised 92 patients (61%). In the univariate analysis, there were significant differences in gender and preprocedural average heart rate (HR) between the 2 groups (p=0.042 and p=0.042, respectively). A receiver operating characteristics analysis revealed that a cut-off value of preprocedural average HR to predict the maintenance of SR was 85beats/min (sensitivity: 37%, specificity: 85%, area under curve: 0.58). A multivariate analysis showed that preprocedural average HR ≥85beats/min was independently associated with the maintenance of SR after RFCA (odds ratio 3.30, 95% confidence interval 1.47 to 8.04, p=0.003). In conclusion, a relatively high preprocedural average HR might be a prognostic factor of maintenance of SR after RFCA for long-standing persistent AF.

Isolated Atrial Fibrillation, Inflammation and Efficacy of Radiofrequency Ablation: Preliminary Insights Based on a Single-Center Endomyocardial Biopsy Study.

The aim of the study was to evaluate the inflammatory changes in the myocardium, based on endomyocardial biopsy (EMB) data in patients undergoing radiofrequency ablation (RFA) for idiopathic atrial fibrillation (AF). A total of 67 patients with idiopathic AF were enrolled in the study. Patients underwent the intracardiac examination, RFA of AF, and EMB with histological and immunohistochemical studies. The catheter-treatment effectiveness, and occurrence of early and late recurrences of atrial tachyarrhythmias, were assessed depending on the identified histological changes. Nine patients (13.4%) did not have any histological changes in the myocardium according to EMB. Fibrotic changes were detected in 26 cases (38.8%). Inflammatory changes according to the Dallas criteria were observed in 32 patients (47.8%). The follow-up period for patients averaged 19.3 ± 3.7 months. The effectiveness rates of primary RFA were 88.9% in patients with the intact myocardium, 46.2% in patients with fibrotic changes of varying severity, and 34.4% in patients with the presence of criteria for myocarditis. No early recurrence of arrhythmias was observed in patients with unchanged myocardia. The presence of inflammatory and fibrotic changes in the myocardium increased the rates of early and late arrhythmia recurrences and accordingly halved the effectiveness RFA of AF.

Ablation therapies for paroxysmal atrial fibrillation: A systematic review and patient-level network meta-analysis

Despite promising trials, catheter ablation is still regarded as an adjunct to antiarrhythmic drugs (AADs) in the treatment of paroxysmal atrial fibrillation (PAF). This study aimed to compare the effectiveness of various ablation therapies and AADs. Randomised controlled trials or propensity score-matched studies comparing atrial tachyarrhythmia recurrence among any combination of ablation modalities or AAD were retrieved. Kaplan-Meier curves and risk tables for this outcome were graphically reconstructed to extract patient-level data. Frequentist network meta-analysis (NMA) using derived hazard ratios (HRs), as well as 2 restricted mean survival time (RMST) NMAs, were conducted. Treatment strategies were ranked using P-scores. Across 24 studies comparing 6 ablation therapies (5,132 patients), Frequentist NMA-derived HRs of atrial fibrillation recurrence compared to AAD were 0.35 (95% confidence interval [CI]=0.25-0.48) for cryoballoon ablation (CBA), 0.34 (95% CI=0.25-0.47) for radiofrequency ablation (RFA), 0.14 (95% CI=0.07-0.30) for combined CBA and RFA, 0.20 (95% CI=0.10-0.41) for hot-balloon ablation, 0.43 (95% CI=0.15-1.26) for laser-balloon ablation (LBA), and 0.33 (95% CI=0.18-0.62) for pulmonary vein ablation catheter. RMST-based NMAs similarly showed significant benefit of all ablation therapies over AAD. The combination of CBA + RFA showed promising long-term superiority over CBA and RFA, while LBA showed favourable short-term efficacy. The advantage of ablation therapies over AAD in preventing atrial tachyarrhythmia recurrence suggests that ablation should be considered as the first-line treatment for PAF in patients fit for the procedure. The promising nature of several specific therapies warrants further trials to elicit their long-term efficacy and perform a cost-benefit analysis.

Very High-Power Short-Duration, Temperature-Controlled Radiofrequency Ablation in Paroxysmal Atrial Fibrillation: The Prospective Multicenter Q-FFICIENCY Trial

BackgroundQDOT MICRO (QDM) is a novel contact force–sensing catheter optimized for temperature-controlled radiofrequency (RF) ablation. The very high-power short-duration (vHPSD) algorithm modulates power, maintaining target temperature during 90 W ablations for ≤4 seconds. ObjectivesThis study aims to evaluate safety and 12-month effectiveness of the QDM catheter in paroxysmal atrial fibrillation (AF) ablation using the vHPSD mode combined with conventional-power temperature-controlled (CPTC) mode. MethodsIn this prospective, multicenter, nonrandomized study, patients with drug-refractory, symptomatic paroxysmal AF underwent pulmonary vein (PV) isolation with QDM catheter with vHPSD as primary ablation mode, with optional use of the CPTC mode (25 to 50 W) for PV touch-up or non-PV ablation. The primary safety endpoint was incidence of primary adverse events within ≤7 days of ablation. The primary effectiveness endpoint was freedom from documented atrial tachyarrhythmia recurrence and acute procedural, repeat ablation, and antiarrhythmic drug failure. ResultsOf 191 enrolled participants, 166 had the catheter inserted, received RF ablation, and met eligibility criteria. Median procedural, RF application for ablating PVs, and fluoroscopy times were 132.0, 8.0, and 9.1 minutes, respectively. The primary adverse event rate was 3.6%. Imaging conducted in a subset of participants (n = 40) at 3 months did not show moderate or severe PV stenosis. The Kaplan-Meier estimated 12-month rate for primary effectiveness success was 76.7%; freedom from atrial tachyarrhythmia recurrence was 82.1%; clinical success (freedom from symptomatic recurrence) was 86.0%; and freedom from repeat ablation was 92.1%. ConclusionsTemperature-controlled paroxysmal AF ablation with the novel QDM catheter in vHPSD mode (90 W, ≤4 seconds), alone or with CPTC mode (25 to 50 W), is highly efficient and effective without compromising safety. (Evaluation of QDOT MICRO Catheter for Pulmonary Vein Isolation in Subjects With Paroxysmal Atrial Fibrillation [Q-FFICIENCY]; NCT03775512)

The higher recurrence rate after catheter ablation in younger patients with atrial fibrillation suggesting different pathophysiology.

Young atrial fibrillation (AF) patients have been underrepresented in studies of radiofrequency catheter ablation (RFCA) and the outcome of RFCA has not been widely addressed. We investigated age-related differences in clinical features, the recurrence of atrial tachyarrhythmia, and its predictors of patients who underwent RFCA for AF. This is a multicenter prospective study of 2799 patients who underwent RFCA for AF in 2017-2020. The patients were divided into two groups - group A (age < 60years, n = 1269) and group B (age ≥ 60years, n = 1530) - and a recurrence of any atrial tachyarrhythmia 1year after RFCA following a 90-day blanking period was compared. The mean age was 51.6 ± 6.7 and 66.8 ± 5.2years for groups A and B, respectively. Higher body mass index, smaller left atrium, and more prevalent cardiomyopathy and obstructive sleep apnea were observed in group A. Overall, 1-year atrial tachyarrhythmia-free survival was 85.6% and lower in young patients (83.1% in group A vs. 87.7% in group B, log-rank p < 0.01): adjusted hazard ratio (aHR) of recurrence (95% confidence interval (CI)), 1.45 (1.13-1.86) for group A compared to group B (p < 0.01). The association between younger age and higher recurrence was continuously observed in patients under 60years. Any non-PV ablation was associated with a lower recurrence of atrial tachyarrhythmia in group B (aHR 0.68 (0.47-0.96), p < 0.05), but not in group A. AF patients younger than 60years had a higher 1-year AF recurrence after RFCA. Young AF patients might have distinctive pathophysiology of AF requiring more integrated management.

Laser Balloon Ablation in Patients with a Left Common Pulmonary Vein.

Pulmonary vein isolation (PVI) with a balloon-based visually guided laser ablation (VGLA) is regarded as a useful therapeutic tool for treating atrial fibrillation (AF). The clinical efficacy of a VGLA has never been fully investigated in patients with left common pulmonary vein (LCPV). We investigated the procedural safety as well as clinical usefulness of VGLA in patients with LCPV.This study consisted of 130 consecutive patients who underwent VGLA of de novo nonvalvular paroxysmal AF.Eleven patients (8.5%) had an LCPV (ostium maximal average diameter: 27.5 ± 4.9 mm, ostium minimal average diameter: 17.7 ± 3.5 mm). Nine out of 11 (81.8%) LCPVs were successfully occluded and isolated at the ostium with a VGLA-guided PVI. The ablation procedure time was significantly shorter in the patients with than without an LCPV (61.5 ± 15.4 versus 86.9 ± 32.9 minutes, P = 0.01). There was no difference regarding the atrial tachyarrhythmia recurrence between those with and without an LCPV (P = 0.18). A total of 15 patients underwent a redo procedure, but reconnections were not observed in any of the LCPV patients.The VGLA-guided PVI was a useful therapeutic tool even in patients with an LCPV. The presence of an LCPV might not be associated with an increased risk of any atrial tachyarrhythmia recurrence.

Surgical ablation for atrial fibrillation is efficacious in patients with giant left atria

ObjectiveThe Cox-Maze IV procedure (CMP-IV) is the most effective treatment for atrial fibrillation. Increased left atrial (LA) size has been identified as a risk factor for failure to restore sinus rhythm. This has biased many surgeons against ablation in patients with giant left atrium (GLA), defined as LA diameter >6.5 cm. In this study we aimed to define the efficacy of the CMP-IV in patients with GLA. MethodsFrom April 2004 through March 2020, 786 patients with a documented LA diameter underwent elective CMP-IV, 72 of whom had GLA. Median follow-up duration was 4 years (interquartile range, 1-7 years). Recurrence was defined as any documented atrial tachyarrhythmia (ATA) lasting 30 seconds. ATA recurrence and survival were analyzed across GLA versus non-GLA groups. ResultsMedian age at surgery was 65 (interquartile range, 56-73) years. Median LA diameter within the GLA group was 7.0 (range, 6.6-10.0) cm. There were no differences in rates of postoperative complications for the 2 groups, including rate of postoperative stroke and pacemaker placement (GLA 14%; non-GLA 12%; P = .682). A trend toward increased 30-day mortality in the GLA group did not reach statistical significance (GLA 6%; non-GLA 2%; P = .051). Freedom from ATAs at 5 years postoperatively was comparable for the 2 groups (GLA 82%; non-GLA 84%). ConclusionsThe CMP-IV had good efficacy in patients with GLA. Our results suggest that LA diameter >6.5 cm should not preclude a patient from undergoing surgical ablation for atrial fibrillation.