Impact of high-power short-duration atrial fibrillation ablation technique on the incidence of silent cerebral embolism: a prospective randomized controlled study

BACKGROUND

High-power short-duration (HPSD) ablation strategy has emerged as a popular approach for treating atrial fibrillation (AF), with shorter ablation time. The utilized Smart Touch Surround Flow (STSF) catheter, with 56 holes around the electrode, lowers electrode-tissue temperature and thrombus risk. Thus, we conducted this prospective, randomized study to investigate if the HPSD strategy with STSF catheter in AF ablation procedures reduces the silent cerebral embolism (SCE) risk compared to the conventional approach with the Smart Touch (ST) catheter.

METHODS

From June 2020 to September 2021, 100 AF patients were randomized 1:1 to the HPSD group using the STSF catheter (power set at 50 W) or the conventional group using the ST catheter (power set at 30 to 35 W). Pulmonary vein isolation was performed in all patients, with additional lesions at operator's discretion. High-resolution cerebral diffusion-weighted magnetic resonance imaging (hDWI) with slice thickness of 1 mm was performed before and 24-72 h after ablation. The incidence of new periprocedural SCE was defined as the primary outcome. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) test.

RESULTS

All enrolled AF patients (median age 63, 60% male, 59% paroxysmal AF) underwent successful ablation. Post-procedural hDWI identified 106 lesions in 42 enrolled patients (42%), with 55 lesions in 22 patients (44%) in the HPSD group and 51 lesions in 20 patients (40%) in the conventional group (p = 0.685). No significant differences were observed between two groups regarding the average number of lesions (p = 0.751), maximum lesion diameter (p = 0.405), and total lesion volume per patient (p = 0.669). Persistent AF and CHA2DS2-VASc score were identified as SCE determinants during AF ablation procedure by multivariable regression analysis. No significant differences in MoCA scores were observed between patients with SCE and those without, both immediately post-procedure (p = 0.572) and at the 3-month follow-up (p = 0.743).

CONCLUSIONS

Involving a small sample size of 100 AF patients, this study reveals a similar incidence of SCE in AF ablation procedures, comparing the HPSD strategy using the STSF catheter to the conventional approach with the ST catheter.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04408716. AF = Atrial fibrillation, DWI = Diffusion-weighted magnetic resonance imaging, HPSD = High-power short-duration, ST = Smart Touch, STSF = Smart Touch Surround Flow.

Catheter ablation and cognitive function in atrial fibrillation: A systematic review and meta-analysis

Background

Atrial fibrillation (AF) is a risk factor for cognitive dysfunction. Although catheter ablation (CA) is one of the main treatments for AF, whether it can improve cognitive function in patients with AF remains unclear. We conducted a systematic review and meta-analysis to evaluate the cognitive outcome post-CA procedure.

Methods

Two investigators independently searched the PubMed, EMBASE, Web of Science, CNKI, WanFang, and VIP databases from inception to September 2021 for all the potentially eligible studies. The outcomes of interest included dementia or cognitive disorder through scoring or recognized classification criteria. Heterogeneity was determined by using Cochrane's Q test and calculating the I². A random-effects model was used to incorporate the potential effects of heterogeneity. The Newcastle-Ottawa Scale (NOS) was used to assess the methodological quality of each included study, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method was adopted to evaluate the quality of evidence.

Result

Thirteen studies including 40,868 patients were included, among which 12,086 patients received AF ablation. Meta-analysis indicated that patients with AF ablation had a lower risk of dementia incidence in comparison to patients with AF without ablation [hazard ratio (HR): 0.60, 95% CI: 0.43 to 0.84, p = 0.003 I² = 40%]. Significant differences were observed in the incidence of new-onset dementia [risk ratio (RR): 0.43, 95% CI: 0.28 to 0.65, p < 0.0001 I² = 84%]; the changes in the Montreal Cognitive Assessment (MoCA) score [weighted mean difference (WMD): 1.00, 95% CI: 0.36 to 1.64, p < 0.005 I² = 0%] and Mini-Mental State Examination (MMSE) score (WMD: 0.98, 95% CI: 0.69 to 1.26, p < 0.00001 I² = 0%]. However, in subgroup analysis, we did not observe significant changes in MoCA score at < 3 months (WMD: 1.20, 95% CI: −0.19 to 2.58, p = 0.09 I² = 50%) and changes in cognitive function scores between the radiofrequency group and cryoballoon group [standard mean difference (SMD): 0.39, 95% CI: −0.47 to 1.24, p = 0.38 I² = 87%]. The NOS indicated that included studies were moderate to high quality, while the quality of evidence assessed by GRADE was low in 2 and very low in 2.

Conclusion

We analyzed the related cognitive outcomes after AF ablation. In the overall population, AF ablation had a positive trend for improving cognitive function at >3 months post-procedure. However, AF ablation might not be related to the improvement of cognitive function at < 3 months.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021285198.

Optimal Anticoagulant Strategy for Periprocedural Management of Atrial Fibrillation Ablation: A Systematic Review and Network Meta-Analysis

This network meta-analysis was performed to rank the safety and efficacy of periprocedural anticoagulant strategies in patients undergoing atrial fibrillation ablation. MEDLINE, EMBASE, CENTRAL, and Web of Science were searched to identify randomized controlled trials comparing anticoagulant regimens in patients undergoing atrial fibrillation ablation up to July 1, 2021. The primary efficacy and safety outcomes were thromboembolic and major bleeding events, respectively, and the net clinical benefit was investigated as the primary-outcome composite. Seventeen studies were included (n = 6950). The mean age ranged from 59 to 70 years; 74% of patients were men and 55% had paroxysmal atrial fibrillation. Compared with the uninterrupted vitamin-K antagonist strategy, the odds ratios for the composite of primary safety and efficacy outcomes were 0.61 (95%CI: 0.31–1.17) with uninterrupted direct oral anticoagulants, 0.63 (95%CI: 0.26–1.54) with interrupted direct oral anticoagulants, and 8.02 (95%CI: 2.35–27.45) with interrupted vitamin-K antagonists. Uninterrupted dabigatran significantly reduced the risk of the composite of primary safety and efficacy outcomes (odds ratio, 0.21; 95%CI, 0.08–0.55). Uninterrupted direct oral anticoagulants are preferred alternatives to uninterrupted vitamin-K antagonists. Interrupted direct oral anticoagulants may be feasible as alternatives. Our results support the use of uninterrupted direct oral anticoagulants as the optimal periprocedural anticoagulant strategy for patients undergoing atrial fibrillation ablation.

Effects of uninterrupted dabigatran on the intensity of anticoagulation during atrial fibrillation ablation

Background

Uninterrupted dabigatran during atrial fibrillation (AF) ablation is now established as the standard therapy. However, there are few reports on the effects of uninterrupted dabigatran on the intensity of anticoagulation during AF ablation.

Methods

We retrospectively analyzed 247 consecutive patients who underwent AF ablation in our hospital from January 2017 to December 2018. Patients who took warfarin or uninterrupted direct oral anticoagulants (DOACs) except for dabigatran were excluded. 89 patients underwent ablation with uninterrupted dabigatran (uninterrupted group, male 71, mean age 59.6 ± 14.0) and 124 with interrupted DOACs (interrupted group, male 105, mean age 56.9 ± 12.9) during AF ablation. The initial ACT level, proportion of ACT levels of more than 300 s, and total amount of heparin were compared. Furthermore, the incidence of procedure complications was also evaluated.

Results

The initial ACT levels were significantly higher in the uninterrupted group, and the total number of ACTs of more than 300 s was significantly higher in the uninterrupted group (uninterrupted vs. interrupted; initial ACT level, 315.6 ± 59.8 vs. 264.5 ± 48.6, p < .001; total number of ACTs ≧300, n [%], 304/ 484 [62.8 %] vs. 372/745 [49.9%], p < .001). The total amount of heparin during procedure was significantly lower in the uninterrupted group (uninterrupted group vs. interrupted group; 12966 ± 4773 vs. 16371 ± 5212, p < .001). There was no significant difference in the incidence of complications between the two groups.

Conclusions

In the catheter ablation of AF, uninterrupted dabigatran would be useful to obtain a stable anticoagulation status during the entire procedure.

Symptomatic and asymptomatic intracerebral hemorrhages detected by magnetic resonance imaging after catheter ablation of atrial fibrillation

PURPOSE

Symptomatic intracerebral hemorrhages (ICHs) are a rare complication after atrial fibrillation (AF) catheter ablation, while the incidence of asymptomatic ICHs detected by magnetic resonance (MR) imaging remains unclear. This study aimed to investigate the incidence, characteristics, and predictors of new-onset ICHs on MR imaging after AF ablation.

METHODS

We retrospectively studied 1257 consecutive AF ablation procedures in 1201 patients who underwent MR imaging on the day after the procedure. Repeat MR imaging within 3 months post-ablation was available in 352 procedures.

RESULTS

Old ICHs on the initial MR imaging were observed in 28 procedures (2.2%). Post-ablation new ICHs were observed in 14 procedures (4.0%), including one symptomatic (0.3%) and 13 (3.7%) asymptomatic ICHs. One patient had a new ICH on the initial MR imaging, while the remaining 13 had such on the repeat MR imaging. A univariate analysis revealed that a previous ischemic stroke or transient ischemic attack (TIA) and the CHA₂DS₂-VASc score were positive predictors of new ICHs (odds ratios, 5.502 and 1.435; P = 0.004 and 0.044). The lesion diameter did not significantly differ between the old and new ICHs (median, 6.1 mm vs. 8.0 mm, P = 0.281), while the predominant location differed (lobar areas, 22.6% vs. 53.3%; cerebellum, 22.6% vs. 20.0%; others, 54.8% vs. 26.7%; P = 0.026).

CONCLUSIONS

A few asymptomatic ICHs may occur after AF ablation. Most of the post-ablation new ICHs occurred a few days or later after the procedure. A previous ischemic stroke/TIA and the CHA₂DS₂-VASc score may be risk factors for post-ablation ICHs.

Effect of preventing air intrusion on silent strokes during atrial fibrillation ablation using a mini-basket catheter

BACKGROUND

Air bubble intrusion through transseptal sheaths during left atrial (LA) catheter ablation can cause cerebral embolisms, especially when using complex-shape catheters. This study aimed to compare the incidence of silent cerebral events (SCEs) after atrial fibrillation (AF) catheter ablation using a mini-basket catheter (IntellaMap Orion; Boston Scientific) between the following groups: group SP, strict prevention of LA air intrusion and group CP, conventional air intrusion prevention.

METHODS

We enrolled 123 consecutive AF patients (group SP, n = 61 and group CP, n = 62) who underwent brain magnetic resonance imaging after a local-impedance-guided ablation using one mini-basket catheter and one circular mapping catheter. The preventive strategy in group SP included (a) the insertion of the mini-basket catheter into the transseptal sheaths in a container filled with heparinized saline and (b) no exchange of all catheters over the sheaths.

RESULTS

SCEs were detected in 67 patients (54.5%), and the incidence of SCEs did not significantly differ between groups SP and CP (55.7% vs 53.2%; P = .780). A multivariate analysis demonstrated that an older age, non-paroxysmal AF, and radiofrequency (RF) power output were independent positive predictors of SCEs (odds ratios: 1.079, 5.613, and 1.405; P = .005, <.001, and .012). On the follow-up MR imaging, 83.5% of the SCEs in group SP and 87.7% in group CP disappeared (P = .398).

CONCLUSIONS

Strict prevention of LA air intrusion may have no additional effect for reducing the incidence of SCEs after local impedance-guided AF ablation using a mini-basket catheter. An older age, non-paroxysmal AF, and high-power RF applications may increase the risk of SCEs.

Incidence and characteristics of silent cerebral embolisms after radiofrequency-based atrial fibrillation ablation: A propensity score-matched analysis between different mapping catheters and indices for guiding ablation

INTRODUCTION

The difference in the incidence and characteristics of silent cerebral events (SCEs) after radiofrequency-based atrial fibrillation (AF) ablation between the different mapping catheters and indices used for guiding radiofrequency ablation remains unclear. This study aimed to compare the incidence and characteristics of postablation SCEs between the following two groups: Group C, Ablation Index-guided ablation using two circular mapping catheters with CARTO (Biosense Webster); Group R, local impedance-guided ablation using one mini-basket catheter and one circular mapping with Rhythmia (Boston Scientific).

METHODS AND RESULTS

Of 211 consecutive patients who underwent an AF ablation and brain magnetic resonance (MR) imaging after the ablation, 120 patients (each group, n = 60) were selected by propensity score matching. SCEs were detected in 37 patients (30.8%). Group R had a higher incidence of SCEs (51.7% vs. 10.0%; p < .001) and more SCEs per patient (median, 3 vs. 1, p = .028) than Group C. A multivariate analysis demonstrated that nonparoxysmal AF and being Group R were independent positive predictors of SCEs (odds ratios, 6.930 and 15.464; both p < .001). On the follow-up MR imaging, all SCEs in Group C and 87.9% of the SCEs in Group R disappeared (p = .537).

CONCLUSIONS

Group R had a significantly higher incidence of SCEs than Group C. Most probably the use of a complexly designed basket mapping catheter is the reason for the difference in the incidence of SCEs but further validation is needed. A nonparoxysmal form of AF may also increase the risk of SCEs during these ablation procedures.

Meta-analysis of efficacy and safety of new oral anticoagulants compared with warfarin in Japanese patients undergoing catheter ablation for atrial fibrillation

OBJECTIVES

This meta-analysis was designed to evaluate the efficacy and safety of new oral anticoagulants (NOACs) for perioperative anticoagulation of atrial fibrillation (AF) catheter ablation (CA) in Japanese patients with non-valvular atrial fibrillation (NVAF).

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for articles published up to June 30, 2019. Two reviewers independently screened literature, extracted data, and assessed the methodological quality of the included studies according to the inclusion and exclusion criteria. Then, meta-analysis was performed using RevMan 5.3 software.

RESULTS

Nineteen studies with a total of 6827 patients were included in this meta-analysis. The experimental group received dabigatran, rivaroxaban, apixaban, or edoxaban; the control group received warfarin. The safety endpoints were bleeding complications; the efficacy endpoints were thromboembolic complications. Results were as follows: Patients with NOACs had a lower risk of overall bleeding complications (OR = 0.69, 95% CI (0.54, 0.87), P = 0.002), including major bleeding complications (OR = 0.52, 95% CI (0.32, 0.84), P = 0.007) and minor bleeding complications (OR = 0.73, 95% CI (0.56, 0.94), P = 0.02). There was no significant difference in thromboembolic complications between NOACs and warfarin after CA (OR = 0.39, 95% CI (0.14, 1.10), P = 0.08).

CONCLUSIONS

In Japanese NVAF patients undergoing CA, NOACs have similar effects to warfarin in the prevention of stroke and systemic embolism. Moreover, NOACs were associated with a lower incidence of bleeding complications.

Cerebral thromboembolic risk in atrial fibrillation ablation: a direct comparison of vitamin K antagonists versus non-vitamin K-dependent oral anticoagulants

PURPOSE

Cerebral thromboembolic events are well-known complications of pulmonary vein isolation (PVI) and can manifest as stroke or silent cerebral embolic lesions. The aim of this study was to compare the incidence of cerebral embolic lesions (including silent cerebral embolism and stroke) after AF ablation in patients on vitamin K antagonists versus patients on non-vitamin K-dependent oral anticoagulants, and to identify corresponding clinical and procedural risk factors.

METHODS

A total of 421 patients undergoing PVI were prospectively included into the study. Of these, 43.7% were on VKA and 56.3% on NOAC treatment (dabigatran, rivaroxaban, apixaban, and edoxaban). In the NOAC group, 38% of patients had an interruption of anticoagulation for 24-36 h. All patients underwent pre- and postprocedural cerebral magnetic resonance imaging.

RESULTS

Periprocedural cerebral lesions occurred in 13.1% overall. Of these, three (0.7%) resulted in symptomatic cerebrovascular accidents and 52 (12.4%) in silent cerebral embolic lesions. Incidence of cerebral lesions was significantly higher in patients on NOAC compared with VKA (16% vs. 9.2%, respectively, p = 0.04), and in patients who had intraprocedural cardioversions compared with no cardivoersions (19.5% vs. 10.4%, respectively, p = 0.03). In multivariate analysis, both parameters were found to be independent risk factors for cerebral embolism. No significant difference between interrupted and uninterrupted NOAC administration could be detected.

CONCLUSIONS

In patients undergoing AF ablation, we identified the use of NOAC and intraprocedural cardioversion as independent risk factors for the occurrence of periprocedural cerebral embolic lesions.

Perioperative Safety and Efficacy of Different Anticoagulation Strategies With Direct Oral Anticoagulants in Pulmonary Vein Isolation: A Meta-Analysis

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of uninterrupted and interrupted direct oral anticoagulant (DOAC) administration in patients undergoing pulmonary vein isolation (PVI).

BACKGROUND

The optimal periprocedural management of DOACs in patients undergoing PVI is not well defined, and different strategies are used.

METHODS

A systematic search of PubMed/MEDLINE, Ovid/MEDLINE, and EMBASE was performed. Three strategies for periprocedural DOAC administration were considered: uninterrupted, mildly interrupted (<12 h), and interrupted (≥12 h). Primary endpoints were major bleeding (MB) and thromboembolic (TE) complications; pooled weighted mean incidence (WMI) was calculated using a random-effects model. A secondary endpoint was the WMI of overall bleeding (OB).

RESULTS

The analysis included 43 studies for a total of 8,362 patients. DOACs showed similar safety and efficacy in the 3 subgroups. The WMI of MB was 1.02%, 1.49%, and 1.17% for the uninterrupted, mildly interrupted, and interrupted strategy, respectively; the WMI of TE complications was 0.16%, 0.46%, and 0.49% for the uninterrupted, mildly interrupted, and interrupted strategy, respectively, with no heterogeneity. OB appeared to be higher in uninterrupted (6.33%) and mildly interrupted (8.62%) groups compared with the interrupted (3.53%), with substantial heterogeneity among studies. No interaction was found between the incidence of MB and TE complications and different DOACs.

CONCLUSIONS

In patients undergoing PVI, these 3 anticoagulation strategies may have similar safety and efficacy in terms of MB and TE complications. OB appears to be higher in uninterrupted and mildly interrupted strategies compared with the interrupted strategy. No substantial differences were observed among DOACs regarding the incidence of MB and TE complications.

Impact of the type of electroanatomic mapping system on the incidence of cerebral embolism after radiofrequency catheter ablation of left atrial tachycardias

BACKGROUND

Left atrial tachycardias (ATs) often occur after left atrial ablation. The incidence of symptomatic and silent cerebral embolism after radiofrequency catheter ablation of left ATs and the impact of the type of 3-dimensional electroanatomic mapping (3D-EAM) system on the incidence of cerebral embolism remain unclear.

OBJECTIVES

This study aimed to investigate the incidence of cerebral embolism after a 3D-EAM system-guided left AT ablation procedure and compare that between the different 3D-EAM systems.

METHODS

We prospectively enrolled 59 patients who underwent left AT ablation and brain magnetic resonance imaging after the procedure: 30 were guided by the Rhythmia system (Boston Scientific, Marlborough, MA) and 29 by the CARTO system (Biosense Webster, Diamond Bar, CA) (groups R and C, respectively).

RESULTS

One transient ischemic attack occurred in group R, and no symptomatic embolism occurred in group C. Silent cerebral ischemic lesions (SCILs) were observed in 35 patients (59.3%), and group R had a significantly higher incidence of SCILs than did group C (86.2% vs 33.3%; P < .001). In multivariate analysis, group R and left atrial linear ablation were independent positive predictors of SCILs (odds ratio 12.822 and 8.668; P = .001 and P = .005). The incidence of bleeding complications was comparable between groups R and C (0% vs 3.3%; P = .508).

CONCLUSION

Group R exhibited a higher incidence of postablation cerebral embolism than did group C. The use of the high-resolution 3D-EAM system with a mini-basket catheter to guide radiofrequency ablation of left atrial macroreentrant tachycardias may markedly increase the risk of silent cerebral embolism. The present results require further validation in a randomized study.

Cognitive dysfunction in atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in adults, and its incidence and prevalence increase with age. The risk of cognitive impairment and dementia also increases with age, and both AF and cognitive impairment or dementia share important risk factors. In meta-analyses of published studies, AF is associated with a 2.4-fold and 1.4-fold increase in the risk of dementia in patients with or without a history of stroke, respectively. This association is independent of shared risk factors such as hypertension and diabetes mellitus. Neuroimaging has illustrated several potential mechanisms of cognitive decline in patients with AF. AF is associated with increased prevalence of silent cerebral infarcts, and more recent data also suggest an increased prevalence of cerebral microbleeds with AF. AF is also associated with a pro-inflammatory state, and the relationship between AF-induced systemic inflammation and dementia remains to be investigated. Preliminary reports indicate that anticoagulation medication including warfarin can reduce the risk of cognitive impairment in patients with AF. Catheter ablation, increasingly used to maintain sinus rhythm in patients with AF, is associated with the formation of new silent cerebral lesions. The majority of these lesions are not detectable after 1 year, and insufficient data are available to evaluate their effect on cognition. Large prospective studies are urgently needed to confirm the association between AF and dementia, to elucidate the associated mechanisms, and to investigate the effect of anticoagulation and rhythm control on cognition.

Prevalence and Characteristics of Venous Thrombosis after Catheter Ablation of Atrial Fibrillation in Patients Receiving Periprocedural Direct Oral Anticoagulants

Background

Periprocedural venous thromboembolisms (VTEs) area rare occurrence but a critical complication after catheter ablation of atrial fibrillation (AF).The aim of this study was to investigate the incidence of symptomatic deep vein thromboses (DVTs) and pulmonary thromboembolisms (PTEs) in patients who underwent AF catheter ablation and received periprocedural oral anticoagulation with direct oral anticoagulants (DOACs).

Methods and Results

A total of 2,193 consecutive patients undergoing AF catheter ablation with periprocedural DOACs were retrospectively analyzed.Two patients (0.091%) experienced symptomatic DVTs after the ablation, and no patients had any PTEs. One patient was a 72-year-old female who underwent cryoballoon ablation with periprocedural apixaban at a dose of 2.5 mg twice daily. The other patient was a 74-year-old male who underwent a Hot Balloon ablation and thereafter radiofrequency catheter ablation for recurrent AF with edoxaban at30 mg once daily. Both DVT patients underwent AF ablation by the right femoral vein approach, and after discharge had right leg pain and swelling on post-procedural days 4 and 8, respectively. TheDVT was treated by increasing the dose of apixaban and changing it from 30 mg/day of edoxaban to 15-30 mg/day of rivaroxaban, and the thrombi completely disappeared in both patients without any thromboembolic and hemorrhagic complications.

Conclusions

AF catheter ablation with periprocedural DOAC treatment revealed anextremely low incidence of symptomatic VTEs, which may be successfully treated by increasing the DOAC dose or changing the DOAC type.

Postablation cerebral embolisms in balloon-based atrial fibrillation ablation with periprocedural direct oral anticoagulants: A comparison between cryoballoon and HotBalloon ablation

INTRODUCTION

This prospective observational study aimed to investigate the incidence of symptomatic and silent cerebral embolisms after balloon-based ablation of atrial fibrillation (AF) in patients receiving periprocedural anticoagulation with direct oral anticoagulants (DOACs), and compare that between cryoballoon and HotBalloon ablation (CBA and HBA).

METHODS AND RESULTS

We enrolled 123 consecutive AF patients who underwent a balloon-based pulmonary vein isolation (PVI) and brain magnetic resonance (MR) imaging after the ablation procedure (CBA, n = 65; HBA, n = 58). The DOACs were continued in 62 patients throughout the periprocedural period and discontinued in 61 on the procedural day. Intravenous heparin was infused to maintain an activated clotting time of 300 to 400 seconds during the procedure. No symptomatic embolisms occurred in this series. Silent cerebral ischemic lesions (SCILs) were observed on MR imaging in 22 patients (17.9%), and the incidence of SCILs did not significantly differ between the CBA and HBA groups (21.5 vs 13.8%; P = 0.263). According to a multivariate logistic regression analysis, an older age was an independent positive predictor of SCILs (odds ratio, 1.062; 95% CI, 1.001-1.126; P = 0.046), but neither the balloon catheter type nor periprocedural continuation or discontinuation of the DOACs were significant predictors. The incidence of major and minor bleeding complications was comparable between the CBA and HBA groups (1.5 vs 0%, P = 0.528; 7.7 vs 5.2%, P = 0.424).

CONCLUSIONS

Both CBA and HBA of AF revealed a similar incidence of postablation cerebral embolisms. Elderly patients may be at a risk of SCILs after a balloon-based PVI with periprocedural DOAC treatment.

Asymptomatic Cerebral Infarction During Catheter Ablation for Atrial Fibrillation: Comparing Uninterrupted Rivaroxaban and Warfarin (ASCERTAIN)

OBJECTIVES

This randomized study compared uninterrupted rivaroxaban therapy with warfarin therapy as prophylaxis against catheter ablation (CA)-induced asymptomatic cerebral infarction (ACI) and identified the risk factors of rivaroxaban.

BACKGROUND

The reported incidence of ACI during CA for atrial fibrillation (AF) remains at 10% to 30%, and periprocedural oral anticoagulation could affect this incidence.

METHODS

Patients with nonvalvular AF undergoing radiofrequency CA were randomly assigned to receive either uninterrupted rivaroxaban or warfarin as periprocedural anticoagulation therapy. CA was performed after at least 1 month of adequate anticoagulation. Cerebral magnetic resonance imaging (MRI) was performed within 2 weeks before and 1 day after CA to detect ACI.

RESULTS

A total 132 patients were enrolled; 127 (median: 60.0 years of age; 83.5% males; 64.6% incidence of paroxysmal AF) complied with the study protocol and were analyzed; 64 patients received rivaroxaban, and 63 patients received warfarin. The rates of CA-induced ACI in the rivaroxaban group (15.6% [10 of 64 patients]) were similar to those in the warfarin group (15.9% [10 of 63 patients]; p = 1.000). No thromboembolic events developed; no differences in major or nonmajor bleeding rates were observed between the 2 drug groups (3.1% vs. 1.6%, respectively, or 18.8% vs. 19.0%, respectively). Multiple regression analysis indicated that the presence of deep and subcortical white matter hyperintensity (p = 0.002; odds ratio [OR]: 5.323) and the frequency of cardioversions (p = 0.016; OR: 1.250) were associated with the incidence of ACI.

CONCLUSIONS

No notable differences were found between the incidence of CA-induced ACI in the rivaroxaban group and that in the warfarin group in this randomized study.

Serum neuron-specific enolase, a marker of neuronal injury, increases after catheter ablation of atrial fibrillation

Objective

Catheter ablation of atrial fibrillation (AF) can lead to thromboembolic complications, especially stroke. We measured the periprocedural serum neuron-specific enolase (NSE) level, which is a biomarker of neuronal injury, after ablation of AF.

Methods

Forty-three patients with paroxysmal AF were prospectively enrolled before radiofrequency ablation. A neurological examination was performed before and after the procedure. The serum NSE level was determined before and at the end of the procedure and at 2, 24, and 48 h after the procedure.

Results

No patients developed new neurological deficits. However, the median (interquartile range) NSE level increased after ablation from 6.7 (3.87) ng/mL at baseline to 11.48 (5.3) ng/mL at 24 h postoperatively. The NSE level exceed the upper reference limit of normal (17 ng/mL) in 14 patients (33%), and these patients were found to have a larger left atrium.

Conclusions

Serum NSE increased in most of the patients undergoing ablation for AF, and it exceeded the normal limit in one-third of the patients. Although NSE is a biomarker of neuronal injury, the clinical importance of this increase after AF ablation and its relationship with the left atrial diameter should be evaluated in a longitudinal study.

Meta-Analysis of Effectiveness and Safety of Oral Anticoagulants in Atrial Fibrillation With Focus on Apixaban

We performed a meta-analysis of data on the effectiveness and safety of apixaban compared with other oral anticoagulants (warfarin or rivaroxaban or dabigatran or edoxaban) for stroke prevention in atrial fibrillation (AF) in different settings of randomized controlled trials, real-world studies, and radiofrequency ablation (RFA). Thirty studies were searched in PubMed, the Cochrane Library, and Clinicaltrials.gov databases reporting comparative effectiveness and safety of apixaban with warfarin (n = 23), rivaroxaban (n = 12), dabigatran (n = 13), or edoxaban (n = 2) for stroke prevention in AF. In real-world estimates, apixaban was similar to warfarin for the prevention of stroke or systematic thromboembolism (hazard ratio 0.93, 95% CI 0.71 to 1.14, I² = 82.9%, N = 7), and safer than warfarin in the risks of major bleeding (hazard ratio 0.62, 95% CI 0.54 to 0.70, I² = 18.7%, N = 9) in patients with AF. The risk of stroke or thromboembolism with apixaban was similar to rivaroxaban, dabigatran, and edoxaban in the settings of real-world studies and RFA. Major bleeding with apixaban was generally lower than rivaroxaban (relative risks 0.45, 95% CI 0.38 to 0.53, I² = 0%, N = 5) and similar to dabigatran in real-world studies (relative risks 1.44, 95% CI 0.33 to 6.30, I² = 97.7%, N = 5), but similar to rivaroxaban, dabigatran, and edoxaban in RFA. In conclusion, our meta-analysis provides a comprehensive estimate of the effectiveness and safety of apixaban compared with other oral anticoagulants (warfarin, rivaroxaban, dabigatran, and edoxaban) in patients with AF in different settings of randomized controlled trial, real-world studies, and RFA.

The influence of residual apixaban on bleeding complications during and after catheter ablation of atrial fibrillation

Background

The periprocedural protocol for atrial fibrillation (AF) ablation commonly includes anticoagulation therapy. Apixaban, a direct oral anticoagulant, is currently approved for clinical use; however, little is known about the effects of residual apixaban concentration on bleeding complications during/after AF ablation. Therefore, we measured residual apixaban concentration by using mass spectrometry and examined the anticoagulant's residual effects on bleeding complications.

Methods

Fifty-eight patients (Mean age of 64.7±12.5 years; 31 males, 27 females) were enrolled and administered apixaban twice daily. We analyzed trough apixaban concentration, activated clotting time (ACT), heparin dose, and bleeding complications during/after AF ablation. Apixaban concentrations were directly measured using mass spectrometry.

Results

Bleeding complications were observed in 19 patients (delayed hemostasis at the puncture site, 16; hematuria, 3; hemosputum, 1). No patient required blood transfusion. The mean trough apixaban concentration was significantly lower in patients with bleeding complications than without (152.4±73.1 vs. 206.8±98.8 ng/mL respectively, P=0.037), while the heparin dose to achieve ACT>300 s was significantly higher in patients with bleeding complications (9368.4±2929.0 vs. 7987.2±2135.2 U/body respectively, P=0.046). Interestingly, a negative correlation was found between the trough apixaban concentration and the heparin dose to achieve ACT>300 s (P=0.033, R=-0.281).

Conclusions

Low residual plasma apixaban is associated with a higher incidence of bleeding complications during/after AF ablation, potentially because of a greater heparin requirement during AF ablation.

Efficacy and Safety of Uninterrupted Low-Intensity Warfarin for Radiofrequency Catheter Ablation of Atrial Fibrillation in the Elderly

Background: No previous studies exist investigating the optimal intensity of uninterrupted anticoagulation with warfarin during radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in the elderly. Objective: Evaluate the efficacy and safety of continuous low-intensity warfarin therapy throughout the periprocedural period of RFCA for AF in the elderly. Methods: This is a prospective randomized study. We enrolled AF patients (age ≥ 70 years) who underwent first-time RFCA for AF. Enrolled patients were randomized to group A and group B. The international normalized ratios before ablation were maintained at 1.5 to 2.0 and 2.0 to 2.5 in group A and B, respectively. Primary end points were periprocedural thromboembolic complications and major bleeding. Secondary end points included periprocedural asymptomatic cerebral emboli (ACE) and minor bleeding. Results: A total of 101 patients were enrolled in our study (group A: 52; group B: 49). Baseline characteristics were well balanced between the 2 groups. Only 1 patient suffered from stroke in group B. No major bleeding events occurred in either group. The incidence of new ACE lesions was comparable between the 2 groups (11.5% vs 8.2%, P = 0.82). Minor bleeding occurred in 1 of 52 (1.9%) patients in group A and in 5 of 49 (10.2%) patients in group B ( P = 0.10). Conclusions: Uninterrupted low-intensity warfarin for RFCA of AF might be as effective as standard-intensity warfarin in preventing periprocedural thromboembolic complications and might be associated with fewer bleeding events in the elderly.

Incidence and predictors of silent cerebral thromboembolic lesions after catheter ablation for atrial fibrillation in patients treated with direct oral anticoagulants

There are few reports about the incidence and predictors of silent cerebral thromboembolic lesions (SCLs) after atrial fibrillation (AF) ablation in patients treated with direct oral anticoagulants (DOACs). The purpose of this study is to evaluate the incidence and predictors of SCLs after AF ablation with cerebral magnetic resonance imaging (C-MRI) in patients treated with DOACs. We enrolled 117 consecutive patients who underwent first AF ablation and received DOACs, including apixaban, dabigatran, edoxaban, and rivaroxaban. DOACs were discontinued after administration 24 h before the procedure, and restarted 6 h after the procedure. During the procedure, activated clotting time (ACT) was measured every 15 min, and intravenous heparin infusion was performed to maintain ACT at 300-350 s. All patients underwent C-MRI the day after the procedure. SCLs were detected in 28 patients (24%) after AF ablation. Age, female sex, the presence of persistent AF, left atrial volume, procedure time, radiofrequency energy, electrical cardioversion, and mean ACT showed no correlations with the incidence of SCLs. Multivariate analysis revealed independent predictors of SCLs were CHA₂DS₂VASc scores ≥3, left atrial appendage (LAA) emptying velocity ≤39 cm/s, and minimum ACT ≤260 s. Patients with both CHA₂DS₂VASc scores ≥3 and LAA flow velocity ≤39 cm/s had the highest incidence of SCLs 15 of 26 patients (58%). In patients treated with DOACs, CHA₂DS₂VASc score ≥3, minimum ACT ≤260 s, and LAA emptying velocity ≤39 cm/s were independent risk factors for the SCLs after AF ablation.

Predictors of chronic pulmonary vein reconnections after contact force-guided ablation: importance of completing electrical isolation with circumferential lines and creating sufficient ablation lesion densities

PURPOSE

We aimed to identify the predictors of chronic pulmonary vein reconnections (CPVRs) after contact force (CF)-guided circumferential PV isolation (CPVI) of atrial fibrillation (AF).

METHODS

Forty-nine consecutive patients undergoing second ablation procedures for recurrent AF after CF-guided ablation were retrospectively studied. The CPVI was performed by point-by-point ablation with a target CF of 15-20 g. The incidence of CPVRs was evaluated along the right- and left-sided anterior and posterior CPVI regions (Ant-RPVs, Post-RPVs, Ant-LPVs, and Post-LPVs).

RESULTS

CPVRs were observed in 30.6, 22.4, 20.4, and 32.7 % of patients along the Ant-RPVs, Post-RPVs, Ant-LPVs, and Post-LPVs, respectively (P = 0.436). In the multivariate logistic analyses, completing a left atrium-PV conduction block with touch-up ablation inside the initially estimated CPVI lines (Ant-RPVs, Post-RPVs, Ant-LPVs, Post-LPVs; odds ratio [OR] 5.747, 15.000, 207.619, 7.940; P = 0.032, 0.004, 0.034, 0.021) and region length (Post-LPVs; OR 3.183, P = 0.027) were positive predictors of CPVRs, while the mean CF (Ant-RPVs; OR 0.861, P = 0.045) and number of radiofrequency applications per unit length (Ant-LPVs, Post-LPVs; OR 0.038, 0.122; P = 0.034, 0.029) were negative predictors. At optimal cutoffs of 5.8 cm for the region length, 14.2 g for the mean CF, and 1.97/cm (Ant-LPVs) and 2.01/cm (Post-LPVs) for the radiofrequency application density, the sensitivity and specificity were 93.8 and 63.6 %, 60.0 and 76.5 %, 90.0 and 64.1 %, and 75.0 and 63.6 %, respectively.

CONCLUSIONS

Completing PVI with circumferential lines without touch-up ablation and creating a sufficient density of radiofrequency ablation lesions on the lines with a sufficient CF may be necessary to prevent CPVRs after a CF-guided CPVI.

Efficacy and Safety of Novel Oral Anticoagulants for Atrial Fibrillation Ablation: An Updated Meta-Analysis

INTRODUCTION

Novel oral anticoagulants (NOACs) have been approved for prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF). A large number of patients are on NOACs when they present for AF ablation. We intended to evaluate the safety and efficacy of NOACs for AF ablation during the periprocedural period by performing a meta-analysis of trials comparing NOACs with warfarin.

METHODS

Studies comparing NOACs (dabigatran and rivaroxaban) with warfarin as periprocedural anticoagulants for AF ablation were identified using an electronic search. Primary outcomes were: (1) a composite endpoint of stroke, transient ischemic attack (TIA), peripheral arterial embolism, or silent cerebral lesions on magnetic resonance imaging (MRI) and (2) major bleeding complications. A random effects model was used to pool the safety and efficacy data across all included trials.

RESULTS

When compared to warfarin, there was an increased risk of the composite endpoint of stroke, TIA, peripheral arterial embolism, or silent cerebral lesions on MRI with NOACs as periprocedural anticoagulants for AF ablation [odds ratio (OR): 1.69, 95% confidence interval (CI): 1.06-2.68]. Sub-group analysis revealed a higher risk of composite endpoint with dabigatran as a periprocedural anticoagulant for AF ablation (OR: 2.01, 95% CI: 1.19-3.39) whereas the risk was similar with rivaroxaban (OR: 0.90, 95% CI: 0.34-2.41). Sensitivity analysis after excluding silent cerebral lesions on MRI showed there was no increased risk of thromboembolic events with either dabigatran (OR: 1.69, 95% CI: 0.81-3.51) or rivaroxaban (OR: 0.70, 95% CI: 0.12-4.04). Risk of bleeding with NOACs was similar to warfarin (OR: 0.91, 95% CI: 0.62-1.34).

CONCLUSION

NOACs are comparable to warfarin in terms of bleeding complications. However, dabigatran therapy is potentially associated with a higher risk of silent cerebral lesions on MRI. The results of this study should be considered as hypothesis-generating and assessed further in prospective randomized clinical studies.