Incidence of Asymptomatic Cerebral Microthromboembolism After Atrial Fibrillation Ablation Guided by Complex Fractionated Atrial Electrogram

Transseptal puncture: Review of anatomy, techniques, complications and challenges, a critical view

Transseptal puncture (TSP) was initially described to gain access to the left heart for hemodynamic assessment. Continuous evolution from its origins allows interventionists to perform a myriad of procedures that otherwise would be impossible to accomplish. In the recent years, the number of procedures in cardiology that require TSP has grown exponentially. Namely, transcatheter mitral valve repair and replacement, pulmonary vein isolation and left atrium appendage occlusion. In skilled hands, it is a safe and straightforward procedure; however, a lack of knowledge of the materials, anatomy of the interatrial septum and the technique can be met with life-threatening complications. Therefore, it is imperative that interventional cardiologists master this technique to successfully overcome these obstacles and ensure clinical outcomes in patients requiring TSP. The purpose of the following review is to critically analyze the available evidence regarding TSP, provide a step-by-step approach to the technique, the available materials and tips and tricks to overcome difficulties and manage complications.

Atrial Fibrillation Ablation Using Robotic Magnetic Navigation Reduces the Incidence of Silent Cerebral Embolism

Background: The incidence of silent cerebral embolisms (SCEs) has been documented after pulmonary vein isolation using different ablation technologies; however, it is unreported in patients undergoing with atrial fibrillation (AF) ablation using Robotic Magnetic Navigation (RMN). The purpose of this prospective study was to investigate the incidence, risk predictors and probable mechanisms of SCEs in patients with AF ablation and the potential impact of RMN on SCE rates.

Methods and Results: We performed a prospective study of 166 patients with paroxysmal or persistent AF who underwent pulmonary vein isolation. Patients were divided into RMN group (n = 104) and manual control (MC) group (n = 62), and analyzed for their demographic, medical, echocardiographic, and risk predictors of SCEs. All patients underwent cerebral magnetic resonance imaging within 48 h before and after the ablation procedure to assess cerebral embolism. The incidence and potential risk factors of SCEs were compared between the two groups. There were 26 total cases of SCEs in this study, including 6 cases in the RMN group and 20 cases in the MC group. The incidences of SCEs in the RMN group and the MC group were 5.77 and 32.26%, respectively (X² = 20.63 P < 0.05). Univariate logistic regression analysis demonstrated that ablation technology, CHA₂DS₂-VASc score, history of cerebrovascular accident/transient ischemic attack, and low ejection fraction were significantly associated with SCEs, and multivariate logistic regression analysis showed that MC ablation was the only independent risk factor of SCEs after an AF ablation procedure.

Conclusions: Ablation technology, CHA₂DS₂-VASc score, history of cerebrovascular accident/transient ischemic attack, and low ejection fraction are associated with SCEs. However, ablation technology is the only independent risk factor of SCEs and RMN can significantly reduce the incidence of SCEs resulting from AF ablation.

Clinical Trial Registration: ChiCTR2100046505.

Total atrial conduction time as a possible predictor of atrial fibrillation recurrence after catheter ablation for paroxysmal atrial fibrillation: relationship between electrical atrial remodeling and structural atrial remodeling time courses

PURPOSE

Recently, the estimated total atrial conduction time measured using tissue Doppler imaging (PA-TDI duration) has been reported as a more accurate predictor of atrial fibrillation (AF) recurrence after catheter ablation than left atrial volume index (LAVI). The PA-TDI duration is considered to reflect electrical and structural remodeling in the right atrium (RA) and left atrium (LA). We sought to investigate the association between AF recurrence and PA-TDI duration after AF ablation.

METHODS

We studied 209 patients who underwent radiofrequency ablation for paroxysmal AF and 75 patients who underwent second ablation for AF recurrence. We assessed the duration from the onset of the P wave on the surface electrocardiogram to the atrial electrogram in distal coronary sinus (CS) (PA-CSd duration) indicating electrical remodeling of the atrium, the PA-CS proximal duration (PA-CSp duration) representing electrical remodeling of RA, and the conduction time in CS (proximal to distal) (CSp-CSd duration) reflecting electrical remodeling of LA. We also measured LAVI as a marker of structural remodeling of LA.

RESULTS

The PA-TDI duration had a positive correlation with PA-CSd duration. In the patients with AF recurrence, PA-TDI duration, PA-CSd duration, and CSp-CSd duration in the second ablation were significantly longer than those in the first (p < 0.01, respectively), whereas there was no significant difference in LAVI and PA-CSp duration between the first and second ablation sessions.

CONCLUSION

A prolonged PA-TDI duration after AF ablation may indicate advanced electrical remodeling of LA, and may predict AF recurrence after ablation in patients with paroxysmal AF.

Factors associated with silent cerebral events during atrial fibrillation ablation in patients on uninterrupted oral anticoagulation

INTRODUCTION

Silent cerebral events (SCEs) are related to the potential thromboembolic risk in atrial fibrillation (AF) ablation. Periprocedural uninterrupted oral anticoagulation (OAC) reportedly reduced the risk of SCEs, but the incidence still remains.

METHODS AND RESULTS

AF patients undergoing catheter ablation were eligible. All patients took non-vitamin K antagonist oral anticoagulants (NOACs; n = 248) or vitamin K antagonist (VKA; n = 37) for periprocedural OAC (>4 weeks) without interruption during the procedure. Brain magnetic resonance imaging was performed within 2 days after the procedure to detect SCEs. Clinical characteristics and procedure-related parameters were compared between patients with and without SCEs. SCEs were detected in 66 patients (23.1%; SCE[+]) but were not detected in 219 patients (SCE[-]). Age was higher in SCE[+] than in SCE[-] (66 ± 10 vs. 62 ± 12 years; p < .05). Persistent AF prevalence, CHADS₂ /CHA₂ DS₂ -VASc scores, serum NT-ProBNP levels, left atrial dimension (LAD), and spontaneous echo contrast prevalence in transesophageal echocardiography significantly increased in SCE[+] versus SCE[-]. SCE[+] had lower baseline activated clotting time (ACT) before heparin injection and longer time to reach optimal ACT (>300 s) than SCE[-] (146 ± 27 vs. 156 ± 29 s and 44 ± 30 vs. 35 ± 25 min; p < .05, respectively). In multivariate analysis, age, LAD, baseline ACT, and time to reach the optimal ACT were predictors for SCEs. The average values of the ACT parameters were significantly different among NOACs/VKA.

CONCLUSION

Age, LAD, and intraprocedural ACT kinetics significantly affect SCEs during AF ablation. Different anticoagulants have different impacts on ACT during the procedure, which should be considered when estimating the risk of SCEs.

A randomized comparison of two direct oral anticoagulants for patients undergoing cardiac ablation with a contemporary warfarin control arm

BACKGROUND

The safety and efficacy of periprocedural use of direct oral anticoagulants (DOACs) for atrial fibrillation (AF) remain unclear. We compared the incidence of asymptomatic cerebral micro-thromboembolism and hemopericardium following AF ablation among patients receiving edoxaban, rivaroxaban, and warfarin and between normal- and low-dose use of edoxaban and rivaroxaban.

METHODS

This prospective randomized study included 170 consecutive AF patients. Patients taking DOACs upon admission to our hospital were randomly assigned to an edoxaban group or to a rivaroxaban group. Warfarin was continued in patients receiving warfarin at admission. All patients underwent AF ablation, and cerebral MRI was performed to evaluate asymptomatic cerebral micro-thromboembolism the day after the procedure.

RESULTS

Sixty-one patients were assigned to edoxaban and 63 to rivaroxaban. Warfarin was continued in 46 patients. Although asymptomatic cerebral micro-thromboembolism was detected in 25 patients (16.3%), there were no significant differences among the groups. Hemopericardium occurred in 2 patients (one each in the rivaroxaban and warfarin groups). The incidence of asymptomatic cerebral micro-thromboembolism was higher in the low-dose group (9 patients, 25.7%) than in the normal-dose group (8 patients, 10.0%) for patients prescribed either edoxaban or rivaroxaban (p < 0.05). The proportion of males (88.0%, 69.5%, p < 0.05), history of prior AF ablation (64.0%, 42.2%, p < 0.05), and hypertension (68.0%, 46.1%, p < 0.05) were significantly higher in patients with cerebral thromboembolism.

CONCLUSIONS

The incidence of asymptomatic cerebral micro-thromboembolism and hemopericardium in AF ablation was similar among patients using edoxaban, rivaroxaban, and warfarin. However, low doses of DOACs may increase the risk of asymptomatic stroke.

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.

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.

REduction of THRomboembolic EVents during Ablation using the laserballoon: The RETHREVA registry

INTRODUCTION

Cerebral events (CEs), including silent (SCEs), are a known complication of left atrial catheter ablation (LACA) in patients with atrial fibrillation. The aim of this prospective registry was to gain more information about CEs during laserballoon LACA and to reduce the risk of their occurrence.

METHODS AND RESULTS

We enrolled 74 patients (age 61 ± 11 years; 74% male; CHA₂ DS₂ -VASc 1.9 ± 1.4). Cerebral MRI (1.5 Tesla) was performed to detect CEs. ASPItest identified aspirin-resistant patients (ARPs). All bleeding complications were recorded. Due to an initial high CE rate, we evolved our clinical procedure step-by-step arriving at an optimized protocol: -Group 1: heparin after single transseptal puncture (TP), activated clotting time (ACT) > 300 seconds (CE: 64.3%). -Group 2: heparin after double TP, ACT > 300 seconds; 2a without (CE: 45.5%, RRR: -29.2%) and 2b with additional intravenous aspirin (CE: 36.4%, RRR: -43.4%; excluding ARP: 30%, RRR: -53.3%). -Group 3: heparin before double TP, ACT > 350 seconds; 3a without (CE: 54.5%, RRR: -15.2%) and 3b with aspirin (CE: 18.5%, RRR: -71.2%; excluding ARP: 8.7%, RRR: -86.5%). Larger LA diameter > 44 mm (OR: 1.149, P  =  0.005) and no aspirin use (OR: 4.308, P  =  0.008) were CE risk factors in multivariate logistic regression. In those patients receiving aspirin, aspirin resistance (OR: 22.4, P  =  0.011) was an exceptionally strong risk factor.

CONCLUSION

These data support the use of intravenous aspirin including monitoring of aspirin resistance in addition to ACT-guided heparin. An optimized protocol of heparin before TP, double TP, and intravenous aspirin in non-ARP resulted in a significantly lowered CE incidence and severity.

Transseptal Techniques for Emerging Structural Heart Interventions

The development of new transseptal transcatheter interventions for patients with structural heart disease is fueling increasing interest in transseptal puncture techniques. The authors review contemporary transseptal puncture indications and techniques and provide a step-by-step approach to challenging transseptal access and procedural complications.

Atrial Fibrillation Ablation and Stroke

Catheter ablation has become a widely available and accepted treatment to restore sinus rhythm in atrial fibrillation patients who fail antiarrhythmic drug therapy. Although generally safe, the procedure carries a non-negligible risk of complications, including periprocedural cerebral insults. Uninterrupted anticoagulation, maintenance of an adequate ACT during the procedure, and measures to avoid and detect thrombus build-up on sheaths and atheters during the procedure, appears useful to reduce the risk of embolic events. This is a review of the incidence, mechanisms, impact, and methods to reduce catheter ablation related cerebral insults.

A Patient With Asymptomatic Cerebral Lesions During AF Ablation: How Much Should We Worry?

Silent brain lesions due to thrombogenicity of the procedure represent recognized side effects of atrial fibrillation (AF) catheter ablation. Embolic risk is higher if anticoagulation is inadequate and recent studies suggest that uninterrupted anticoagulation, ACT levels above 300 seconds and administration of a pre-transeptal bolus of heparin might significantly reduce the incidence of silent cerebral ischemia (SCI) to 2%. Asymptomatic new lesions during AF ablation should suggest worse neuropsychological outcome as a result of the association between silent cerebral infarcts and increased long-term risk of dementia in non-ablated AF patients. However, the available data are discordant. To date, no study has definitely linked post-operative asymptomatic cerebral events to a decline in neuropsychological performance. Larger volumes of cerebral lesions have been associated with cognitive decline but are uncommon findings acutely in post-ablation AF patients. Of note, the majority of acute lesions have a small or medium size and often regress at a medium-term follow-up. Successful AF ablation has the potential to reduce the risk of larger SCI that may be considered as part of the natural course of AF. Although the long-term implications of SCI remain unclear, it is conceivable that strategies to reduce the risk of SCI may be beneficial.

Influence of cardioversion on asymptomatic cerebral lesions following atrial fibrillation ablation

PURPOSE

Asymptomatic cerebral lesions detected by diffusion-weighted magnetic resonance imaging (MRI) following atrial fibrillation (AF) ablation were reported in recent years. It was reported that cardioversion during the procedure of AF ablation was one independent risk factor of asymptomatic cerebral lesions. However, in some studies, the similar association between asymptomatic cerebral lesions and intraprocedural cardioversion was not observed. Given the inconsistent results, we did a meta-analysis to explore the influence of intraprocedural cardioversion on the asymptomatic cerebral lesions detected by MRI following AF ablation.

METHODS

Studies exploring the association between cardioversion during AF ablation and asymptomatic cerebral lesions following AF ablation were systematically searched in PubMed, Web of Science and the Cochrane Library Databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled. Subgroup and sensitivity analyses were performed to explore the source of heterogeneity.

RESULTS

Nine studies involving 813 participants were included in the present meta-analysis. When we pooled data from nine studies using fixed-effects model, we found cardioversion during the procedure significantly increased the risk of asymptomatic cerebral lesions detected by MRI following AF ablation (pooled OR = 1.793, 95% CI 1.201-2.678, I (2) = 38.8%, P heterogeneity = 0.109).

CONCLUSIONS

Cardioversion during AF ablation significantly increased the risk of asymptomatic cerebral lesions on MRI following the procedure. Additional studies are required to further verify the association.

The optimal setting of complex fractionated atrial electrogram software in substrate ablation for atrial fibrillation

BACKGROUND

Complex fractionated atrial electrogram (CFAE)-targeted catheter ablation (CFAE ablation) requires a high rate of atrial fibrillation (AF) termination to provide good outcomes. We determined the optimal settings of CFAE software.

METHODS

In our 430 consecutive patients, AF was terminated in 97 (234/242) and 79% (149/188) of patients with paroxysmal and persistent AF, respectively, by CFAE ablation combined with (31%) or without (69%) pulmonary vein isolation, occasionally with nifekalant infusion. We analyzed 109 consecutive patients who underwent CFAE ablation to determine the optimal settings for comparing subjective versus objective decisions by the CFAE software on CARTO3. We compared three settings: the default setting (0.05-0.15 mV, 50-120 ms) and two modified settings (#1: 0.05-0.30 mV, 40-70 ms, #2: 0.05-0.13 mV, 10-20 ms). We retrospectively analyzed 11,425 points during left atrial mapping before ablation and 10,306 points that were subjectively detected and ablated as CFAE points. An interval confidence level ≥6 denoted a site with CFAE.

RESULTS

With the default setting, the accuracy, sensitivity, specificity, positive productive value, and negative productive values were 67, 42, 77, 48, and 73%, respectively. With modified setting #1, the values were 78, 55, 87, 74, and 77%, respectively, versus 64, 82, 60, 53, and 91%, respectively, for modified setting #2.

CONCLUSION

These data suggest that setting #1 was generally superior to the default setting, whereas setting #2 was optimal for excluding areas not requiring ablation. The optimal CFAE software setting was a voltage of 0.05-0.30 mV and an interval parameter of 40-70 ms.

Association between ablation technology and asymptomatic cerebral injury following atrial fibrillation ablation

BACKGROUND

Asymptomatic cerebral injury (ACI) detected by diffusion-weighted magnetic resonance imaging (MRI) following atrial fibrillation (AF) ablation has been reported recently. The purpose of this study was to provide an overview of the incidence of ACI detected by MRI following AF ablation and to explore the association between ablation technology and ACI by systematically reviewing published trials.

METHODS AND RESULTS

PubMed, Web of Science, and the Cochrane Library Databases were systematically searched for studies exploring ACI detected by MRI following AF ablation. Incidence of ACI, odds ratios, and 95% confidence intervals (CIs) were pooled. We identified 21 eligible studies. The combined ACI incidence across all studies was 15.9% (95% CI: 0.124-0.202). We also did a subgroup analysis stratified by different technologies. The incidence of ACI stratified by ablation technology was 13.0%, 27.6%, 12.5%, 17.3%, and 32.6% of the irrigated radiofrequency (RF), multielectrode-phased RF pulmonary vein ablation catheter (PVAC), cryoballoon, laser balloon, and nMARQTM groups, respectively.

CONCLUSIONS

The incidence of ACI following AF ablation with PVAC was higher than with other technologies. Uninterrupted oral anticoagulant (OAC) during the procedure could lower the incidence of ACI. It seems prudent not to interrupt OACs during the procedure. In addition, intraprocedural activated clotting time was associated with ACI. Different MRI diagnostic criteria for ACI also influenced the results. To facilitate the future research, a generally accepted definition for silent cerebrovascular ischemia suitable to different kinds of MRI is needed.

Atrial Fibrillation and Stroke: Increasing Stroke Risk with Intervention

This article focuses on the important newly recognized appreciation for the paradoxic increase in stroke and transient ischemic attack as a result of intervention meant to treat atrial fibrillation (AF) with the hope of decreasing stroke risk in the long term. The impact of silent cerebral lesions has recently been identified as a potentially major limitation, and the risks with AF ablation, as well as the present understanding of how risk can be minimized, are explained. This article provides a platform for newer study, changes in the way procedures are done, and possibly vascular-based stroke-reduction strategies.

Cerebrovascular Complications Related to Atrial Fibrillation Ablation and Strategies for Periprocedural Stroke Prevention

Transcatheter treatment of atrial fibrillation (AF) is a complex intervention performed in patients who are at inherently increased risk of a thromboembolic complication, including stroke. It is therefore not surprising that cerebrovascular accidents have been among the most feared complications since the inception of AF ablation. While improvements have been made to limit the incidence of thromboembolic events during catheter ablation of AF, the optimal strategy to minimize such complications has yet to be determined. It is hoped that larger trials using periprocedural anticoagulation strategies can be undertaken to definitively address these important concerns.

Silent Cerebral Embolism during Atrial Fibrillation Ablation:Pathophysiology, Prevention and Management

Although many efforts have been directed to improve atrial fibrillation transcatheter ablation safety, thromboembolism to the brain remains one of the major complications. In fact several studies have confirmed occurrence of silent cerebral embolic lesions by post-procedure magnetic resonance imaging. The present review will focus on the possible mechanisms leading to silent cerebral embolism in an attempt to provide recommendations holding the potential to reduce the incidence of this clinically relevant complication.

Predictors of asymptomatic cerebral infarction associated with radiofrequency catheter ablation for atrial fibrillation using an irrigated-tip catheter

AIMS

Catheter ablation is a potentially curative treatment for atrial fibrillation (AF). However, complications such as ischaemic stroke are more frequent and more severe compared with ablation procedures for other arrhythmias. Irrigated-tip catheters have been reported to reduce the risk of stroke. The present study aimed to evaluate predictors of asymptomatic cerebral infarction (CI) after AF ablation using an irrigated-tip catheter.

METHODS AND RESULTS

A total of 70 consecutive AF patients who underwent catheter ablation were subjected to brain magnetic resonance imaging (MRI) 1 day after the procedure. In 10 (14.3%) of 70 patients, MRI revealed acute CI, but neither symptoms nor abnormal neurological findings were present in these patients. In univariate analysis, a history of persistent AF, left atrial dimension, presence of spontaneous echo contrast (SEC), procedure duration prior to heparin injection, and electrical cardioversion during the procedure differed significantly between the two groups, those with and without CI (P = 0.02, 0.05, 0.01, 0.01, and 0.05, respectively). Multivariate logistic regression analysis identified SEC [odds ratio (OR), 9.39; 1.60-55.2; P = 0.01] and procedure duration prior to heparin injection (OR, 1.19; 1.04-1.36; P = 0.01) as predictive of acute asymptomatic CI after AF ablation.

CONCLUSION

The presence of SEC and procedure duration prior to heparin injection are determinants of asymptomatic CI during AF ablation despite the use of an irrigated-tip catheter.