Incidence of silent cerebral events detected by MRI in patients with atrial fibrillation undergoing pulsed field ablation vs thermal ablation: A systematic review and network meta-analysis

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and catheter ablation has been demonstrated to achieve superior success rates compared with antiarrhythmic drugs. However, this procedure entails certain risks, including silent cerebral events (SCEs), which may affect cognitive function. This network meta-analysis aimed to determine the global incidence of SCEs in patients with AF undergoing catheter ablation and to compare the incidence across energy sources and catheter types. Our analysis included 86 trials involving 10,456 patients with AF, with a pooled SCE incidence of 19.1%. For pulsed field ablation, the incidence of SCEs was 14.4%; thermal ablation techniques showed rates of 17.7% for radiofrequency ablation, 20.8% for cryoballoon ablation, and 32.7% for laser ablation. No significant differences were found between pulsed field ablation and thermal ablation in SCE incidence. The comparison of SCE incidence between different catheter types revealed variations. The HD Mesh Ablator demonstrated the lowest incidence rate (15.1%), whereas the PVAC catheter had the highest (36.2%). The Farawave catheter had an incidence rate of 18.5% and showed no significant differences compared with most thermal catheters, except for the HD Mesh Ablator (relative risk, 0.15; 95% credible interval, 0.03-0.89). Our findings indicate that a substantial proportion of patients experience SCEs after catheter ablation for AF, with an overall incidence of approximately 19.1% occurring within 1 week (mostly within 72 hours) after ablation. No significant differences were observed in SCE incidence between pulsed field ablation and thermal ablation or between the Farawave catheter and most thermal catheters.

Multielectrode Radiofrequency Balloon Catheter for Paroxysmal Atrial Fibrillation: Results From the Global, Multicenter, STELLAR Study

INTRODUCTION

The safety and efficacy of paroxysmal atrial fibrillation (PAF) ablation with the HELIOSTAR multielectrode radiofrequency (RF) balloon catheter have been demonstrated in European studies; data from elsewhere are lacking. This prospective, multicenter study conducted in the United States, Italy, and China investigated the safety and efficacy of pulmonary vein isolation (PVI) using HELIOSTAR in drug-refractory symptomatic PAF.

METHODS

The primary effectiveness endpoint (PEE) was 12-month freedom from documented atrial fibrillation/atrial flutter/atrial tachycardia plus freedom from acute procedural failure, nonstudy catheter failure, repeat ablation failure, direct current cardioversion (DCCV), and Class I/III antiarrhythmic drug (AAD) failure. The primary safety endpoint was the occurrence of early-onset primary adverse events (PAEs). Cerebral magnetic resonance imaging (MRI) and cardiac computed tomography were performed in a patient subset to assess silent cerebral lesions (SCLs) and severe pulmonary vein (PV) stenosis, respectively.

RESULTS

Across 36 centers, 257 eligible subjects in the main phase had the study catheter inserted. Acute PVI was achieved in all subjects, with the majority (94.1%) using the balloon catheter only. In 67.7% and 92.2% of subjects, respectively, PEE and freedom from repeat ablation were met; clinical success rate was 77.7%. The PAE rate was 5.1%. One of 15 (6.7%) subjects with MRI showed a new SCL at 1 month postablation, which resolved at 3 months. Clinically meaningful improvements in Atrial Fibrillation Effect on QualiTy-of-life scores were seen at 3 months and were sustained to 12 months postablation, and accompanied with reduction of Class I/III AAD use and DCCV.

CONCLUSION

STELLAR confirmed the safety and efficacy of the HELIOSTAR catheter for PVI, with clinically meaningful improvements in quality of life in patients with drug-refractory symptomatic PAF. Most PVIs were achieved without focal touch-up, and > 90% of patients were free from repeat ablation at 12 months.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03683030.

Silent cerebral lesions after catheter ablation for atrial fibrillation using cryoballoon, hotballoon, laserballoon and radiofrequency catheters: a Bayesian network meta-analysis

Background

Catheter ablation (CA) is an effective therapeutic option for patients with symptomatic atrial fibrillation (AF). Previous studies have reported silent cerebral lesions (SCLs) detected by magnetic resonance imaging (MRI) after different CA techniques; however, the results were controversial. Therefore, we performed this network meta-analysis (NMA) to assess the incidence of SCLs after cryoballoon, hotballoon, laserballoon, and radiofrequency ablation (RFA).

Methods

Databases such as PubMed, Embase, and the Cochrane Library were searched systematically. Both pairwise meta-analysis (PMA) and NMA were conducted. The primary outcome was the incidence of new SCLs on MRI after CA procedures.

Results

Nine studies were analyzed and 1,057 patients were enrolled. Laserballoon ablation (LBA) had a higher incidence of SCLs than cryoballoon ablation (CBA) [odds ratio [OR] = 1.86, 95% confidence interval [CI] 1.06-3.27, p = 0.032] in the PMA, while no significant difference was detected between the CA techniques according to the NMA. The surface under the cumulative ranking curve (SUCRA) values indicated that CBA may be the best therapeutic option (SUCRA = 81.1%). The NMA results demonstrated similar procedure-related complication rates and mean activated clotting time between CBA (SUCRA = 53.7%, 66.3%), hotballoon ablation (HBA) (SUCRA = 81.5%, 43.6%), LBA (SUCRA = 3.39%, 42.8%) and RFA (SUCRA = 61.3%, 47.3%). LBA therapy required significantly more procedure time than CBA [weighted mean difference (WMD) = 24.36 min, 95% CI 12.51-36.21 min, p = 0.00].

Conclusions

CBA treatment had lower incidence of post-procedural SCLs and took less procedure time compared with LBA for patients with AF. The procedure-related complications were comparable between CBA, LBA, HBA and RFA.

Systematic Review Registration

PROSPERO, identifier (CRD42024511110).

VARIPULSE: A step-by-step guide to pulmonary vein isolation

INTRODUCTION

The VARIPULSE™ variable-loop circular catheter (VLCC) is a bidirectional, multielectrode catheter that can perform electrophysiological mapping and deliver pulsed field energy through the TRUPULSE™ Generator for the treatment of atrial fibrillation. This ablation system, including the CARTO 3™ three-dimensional electroanatomical mapping system, represents a fully integrated system.

METHODS

Pulsed field ablation (PFA) is a novel, primarily cardiac tissue-selective ablation technology with a minimal thermal effect, potentially eliminating the collateral tissue damage associated with radiofrequency ablation or cryoablation. Integration of a mapping system may lead to shorter fluoroscopy times and improve the usability of the system, allowing tracking of energy density and placement to confirm no areas around the vein are left untreated.

RESULTS

This step-by-step review covers patient selection, mapping, the step-by-step ablation workflow, details on catheter repositioning and ensuring contact, considerations for ablation of specific anatomical variations, and discussion of ablation without fluoroscopy based on our initial clinical experience.

CONCLUSIONS

The VLCC is part of the fully integrated PFA system designed for pulmonary vein isolation, using mapping to guide catheter placement and lesion set creation. The current workflow, which is based on our initial clinical experience, may be further refined as the PFA system is used in real-world settings.

Silent Brain Infarction, Delirium, and Cognition in Three Invasive Cardiovascular Procedures: a Systematic Review

Silent brain infarctions (SBIs) are brain lesions noted on neuroimaging that are not associated with clinical symptoms. SBIs are associated with a number of vascular risk factors and are common following invasive cardiovascular procedures such as atrial fibrillation (AF) ablation, coronary artery bypass graft (CABG), and transcatheter aortic valve replacement (TAVR). Although not eliciting signs of clinical stroke, SBIs are associated with increased frailty, and motor and mood features. Less is known, however, about the relationship between SBI, cognition, and delirium following invasive cardiac procedures and most investigations into these relationships have been reported in large-scale epidemiological studies. In the current paper, we conducted a systematic review to evaluate evidence of a relationship between SBI, delirium, and cognitive decline following CABG, AF ablation, and TAVR. Twenty studies met inclusion criteria. In general, our review identified conflicting results for each cardiac procedure, with some studies suggesting a relationship between SBI, cognitive impairment, and delirium, whereas others showed no relationship between SBI, cognitive impairment, and delirium. Potential reasons for this discrepancy as well as suggestions for future research are discussed.

Hippocampal silent infarct leads to subtle cognitive decline that is associated with inflammation and gliosis at twenty-four hours after injury in a rat model

Silent infarcts (SI) are subcortical cerebral infarcts that occur in the absence of clinical symptoms commonly associated with ischemia and are linked to dementia development. Little is known about the pathophysiology underlying the cognitive dysfunction associated with SI, and few studies have examined the early cellular responses and neurobiological underpinnings. We induced SI in adult male Sprague-Dawley rats using an infusion of endothelin-1 in the CA1 dorsal hippocampus. Twenty-four hours later, we assessed cognition using the hippocampal-dependent object place recognition task. We also examined whether the resulting cognitive effects were associated with common markers of ischemia, specifically cell and synapse loss, gliosis, and inflammation, using histology and immunohistochemistry. Hippocampal SI led to subtle cognitive impairment on the object place recognition task 24 -hs post-injury. This was characterized by a significant difference in exploration proportion relative to a pre-injury baseline and a positive association between time spent with both the moved and unmoved objects. SI did not result in any detectable cell or synaptophysin loss, but did increase apoptosis, gliosis and inflammation in the CA1. Principal component analysis indicated the main variables associated with hippocampal SI included increased time spent with the unmoved object, gliosis, apoptosis and inflammation as well as decreased exploration proportion and CA1 cells. Our data demonstrate that hippocampal SI can lead to cognitive dysfunction 24 -hs after injury. Further, this appears to be driven by early degenerative processes including apoptosis, gliosis and inflammation, suggesting that these may be targets for early interventions treating hippocampal SI and its cognitive consequences.

Comparative efficacy and safety of catheter ablation interventions for atrial fibrillation: comprehensive network meta-analysis of randomized controlled trials

PURPOSE

Point-by-point radiofrequency (RF) ablation has been the cornerstone of pulmonary vein isolation (PVI) for patients with atrial fibrillation (AF); however, it remains a complex and time-consuming procedure. Many novel AF catheter ablation (CA) techniques have been introduced, but whether they represent valuable alternatives remains controversial. Thus, we conducted a network meta-analysis to comprehensively evaluate the efficacy and safety of different CA interventions.

METHODS

We systematically searched several databases (Embase, PubMed, the Cochrane Library, and ClinicalTrials.gov ) from inception to March, 2020. The primary outcomes of interest were freedom from atrial tachyarrhythmia (AT) and procedure-related complications; secondary outcomes included procedure time and fluoroscopy time.

RESULTS

Finally, 33 randomized controlled trials (RCTs) with a total of 4801 patients were enrolled. No significant differences were found among the different interventions in terms of primary efficacy or safety outcomes. PVAC was most likely to have the shortest procedure time (Prbest = 61.5%) and nMARQ the shortest fluoroscopy time (Prbest = 60.6%); compared with conventional irrigated RF (IRF) ablation, cryoballoon ablation (CBA) showed comparable clinical efficacy and safety; CBA with second-generation CB (CB2) had a significantly shorter procedure time than IRF with contact force technology (CF-IRF) (WMD = - 20.75; p = 0.00).

CONCLUSION

There is insufficient evidence to suggest that one CA technique is superior to another. However, PVAC may be associated with a shorter procedural duration, and the CB2 catheters also seemed to reduce the procedure time compared with that of CF-IRF. Further large-scale studies are warranted to compare the available CA techniques and provide an up-to-date optimum recommendation.