Impact of Catheter Ablation on Arrhythmia Burden in Patients With Shock-Resistant Persistent Atrial Fibrillation

Patterns of Postablation Recurrence and Adverse Cardiovascular Outcomes in Patients With Atrial Fibrillation

BACKGROUND

Atrial arrhythmia recurrence after atrial fibrillation (AF) catheter ablation is conventionally assessed as a binary end point. However, the prognostic value of recurrence patterns is less studied.

METHODS AND RESULTS

This study included patients undergoing catheter ablation from the multicenter China Atrial Fibrillation Registry study (2011-2022). Postablation AF patterns within 1 year were categorized as nonrecurrence, paroxysmal AF recurrence, or persistent AF (PersAF) recurrence. Cardiovascular outcomes included cardiovascular death, thromboembolism, and cardiovascular hospitalization. Cox proportional models with landmark analysis were used to assess the relationship between recurrence patterns and outcomes. Sensitivity analyses were conducted using Fine-Gray models, considering death unrelated to the outcomes as the competing risk and evaluating 2-year recurrence patterns. Among 13 811 patients (mean age, 60.5±10.8 years; 66.1% men), those with preablation PersAF, prior stroke/transient ischemic attack/systemic embolism, and increased left atrial diameter were more likely to develop PersAF postablation. Compared with nonrecurrence, PersAF recurrence was associated with higher risks of cardiovascular death (hazard ratio [HR], 2.03 [95% CI, 1.20-3.43]; P=0.009), thromboembolism (HR, 1.50 [95% CI, 1.09-2.06]; P=0.012), and cardiovascular hospitalization (HR, 1.74 [95% CI, 1.56-1.94]; P<0.001) during a median follow-up of 3.02 years (interquartile range, 1.44-5.03 years), while paroxysmal AF recurrence was only significantly associated with an increased risk of cardiovascular hospitalization (HR, 1.98 [95% CI, 1.83-2.14], P<0.001). Sensitivity analyses yielded consistent results.

CONCLUSIONS

Postablation PersAF recurrence was associated with significantly higher risks of cardiovascular death and thromboembolism, compared with paroxysmal AF recurrence and nonrecurrence, indicating the prognostic importance of recurrence patterns.

REGISTRATION

URL: www.chictr.org.cn/; unique identifier: ChiCTR-OCH-13003729.

One-Year Success Rates of a Stable, Low Pressure Cryoballoon for the Treatment of Paroxysmal Atrial Fibrillation: Results of the Prospective, International, Multicenter POLAR ICE Study

INTRODUCTION

Pulmonary vein isolation (PVI) using a cryoballoon is well-established for the treatment of paroxysmal atrial fibrillation (PAF). Compared to other available technologies, the usage of a stable, low-pressure cryoballoon (POLARx, Boston Scientific) has demonstrated lower nadir temperatures and longer thawing times. However, 1-year efficacy and safety still needs to be proven. The aim of the POLAR ICE Study was to evaluate 1-year efficacy and safety outcomes of cryoballoon ablation in patients with paroxysmal atrial fibrillation.

METHODS

POLAR ICE, a prospective, non-randomized, international, multicenter study to examine safety and efficacy of the novel cryoballoon for paroxysmal atrial fibrillation and de novo PVI, enrolled 399 patients across 19 centers, between August 2020 and May 2021, of which 11 were redo patients (previous treatment in the LA) and 10 were non-PAF patients.

RESULTS

This study treated 391 patients with the novel cryoballoon. After 12 months, freedom from atrial fibrillation could be demonstrated in 88.1% and freedom from any arrhythmia in 83.5%. Long-term primary composite safety events occurred in four (1.0%) patients, including one (0.26%) death (9.5 months post-index, cause unknown), one (0.26%) stroke, one (0.26%) myocardial infarction, and one (0.26%) persistent PNP (0.26%). AAD usage showed a significant decrease over the course of the study. Biophysical parameters nadir temperature (p = 0.008) and thaw time (p = 0.053) were predictive of 12-month freedom from recurrence.

CONCLUSION

In this prospective, non-randomized, international, multicenter study, isolation of the pulmonary veins using a stable, low pressure cryoballoon was highly effective and safe in patients treated for paroxysmal atrial fibrillation.

Atrial Fibrillation Ablation: Impact on Burden and Cardiovascular Outcomes

Atrial fibrillation [AF] is the most common sustained arrhythmia observed in clinical practice with considerable cardiovascular morbidity and mortality. AF burden provides a quantitative measurement of AF and is now more readily achievable utilizing wearable and implantable cardiac monitoring devices. This review summarizes the current literature on AF burden and cardiovascular outcomes and outlines the effect and role of catheter ablation in ameliorating AF burden.

Shortened radiofrequency delivery time to optimize efficiency and safety of pulmonary vein isolation with the radiofrequency balloon: insights from the COLLABORATE registry

AIMS

Previous clinical studies on pulmonary vein isolation (PVI) with a radiofrequency balloon (RFB) reported safe and effective procedures using conventional ablation settings with 20/60 s RF delivery via posterior/anterior (PST/ANT) electrodes. The latest evidence suggests that reducing the application time to 15 s (s) on the posterior wall when facing the oesophageal region is as effective as applying 20 s. To prospectively assess whether reducing RF time on PST/ANT segments to 15/45 s can ensure sufficient quality of lesion metrics and compare the new shortened ablation settings with the conventional one in terms of safety, and effectiveness at 1-year.

METHODS AND RESULTS

A total of 641 patients from seven European centres were enrolled in a collaborative registry, with 374 in the conventional RF delivery group and 267 in the shortened RF delivery group. Procedural outcomes, lesion metrics, and safety profiles were assessed and compared between the groups. Freedom of any atrial tachycarrythmias at one year was 85.4% and 88.2% in the SHRT and CONV groups, respectively. The shortened RF delivery strategy was associated with significantly shorter procedure times (median 63.5 vs. 96.5 min, P < 0.001) and shortened fluoroscopy exposure (median 10.0 vs. 14.0 min, P < 0.001) compared to conventional delivery. Efficacy metrics, including first-pass isolation rates and time to isolation, were comparable between groups. Shortened RF delivery was associated with a lower incidence of procedural complications (1.4% vs. 5.3%, P = 0.04) and optimized thermal characteristics.

CONCLUSION

Analyses from the COLLABORATE registry demonstrate that shortening RF energy delivery times to 15/45 s (PST/ANT) during PVI with the RFB resulted in comparable freedom from recurrent atrial tachyarrhythmia compared to conventional delivery times with comparable efficiency and safety.

Early atrial fibrillation recurrence post catheter ablation: Analysis from insertable cardiac monitor in the era of optimized radiofrequency ablation

BACKGROUND

Early recurrence of atrial tachyarrhythmia (ERAT) is associated with ablation-induced proarrhythmogenic inflammation; however, existing studies used intermittent monitoring or nonoptimized radiofrequency (RF) applications (noncontiguous or without ablation index target value).

OBJECTIVE

The purpose of this study was to investigate the relationship between ERAT and late recurrence based on insertable cardiac monitor (ICM) data.

METHODS

We compiled data from Close-To-Cure and Close Maze studies, which enrolled patients who underwent RF ablation for paroxysmal or persistent atrial fibrillation (AF). All patients were implanted with an ICM 2-3 months before ablation.

RESULTS

We studied 165 patients (104 with paroxysmal AF, 61 with persistent AF). Over the 1-year follow-up period, 41 of the patients experienced late recurrence. The risk of late recurrence was higher in patients experiencing ERAT (hazard ratio [HR] 6.2; 95% confidence interval [CI] 3.0-13.0), with negative and positive predictive values of 90.5% and 45.7%, respectively. Median burden of AF during the blanking period was significantly higher in patients with late recurrence (7.9% [0.0%-99.6%]) compared to those without recurrence (0.0% [0.0%-6.0]; P <.001). For each 1% increase in AF burden during the blanking period, late recurrence increased by 4.6% (HR 1.046; 95% CI 1.035-1.059). The best tradeoff for predicting AF from ERAT occurrence was AF burden of 0.6% and last ERAT at 64 days.

CONCLUSION

In patients ablated for paroxysmal and persistent AF with a durable RF lesion set and implanted with a continuous monitoring device, postablation early AF recurrence and burden significantly predict late recurrence. The post-AF ablation blanking period should be reduced to 2 months.

Vein of Marshall Ethanol Infusion for AF Ablation; A Review

The outcomes of persistent atrial fibrillation (AF) ablation are modest with various adjunctive strategies beyond pulmonary vein isolation (PVI) yielding largely disappointing results in randomised controlled trials. Linear ablation is a commonly employed adjunct strategy but is limited by difficulty in achieving durable bidirectional block, particularly at the mitral isthmus. Epicardial connections play a role in AF initiation and perpetuation. The ligament of Marshall has been implicated as a source of AF triggers and is known to harbour sympathetic and parasympathetic nerve fibres that contribute to AF perpetuation. Ethanol infusion into the Vein of Marshall, a remnant of the superior vena cava and key component of the ligament of Marshall, may eliminate these AF triggers and can facilitate the ease of obtaining durable mitral isthmus block. While early trials have demonstrated the potential of Vein of Marshall 'ethanolisation' to reduce arrhythmia recurrence after persistent AF ablation, further randomised trials are needed to fully determine the potential long-term outcome benefits afforded by this technique.