Predictors of atrial fibrillation freedom postablation with the pentaspline pulsed field ablation catheter: Subanalysis of the ADVENT Study

BACKGROUND

Pulsed field ablation (PFA) has proven to be at least noninferior to thermal ablation for paroxysmal atrial fibrillation (AF). Predictors of AF freedom for PFA have not yet been described.

OBJECTIVE

The purpose of this study was to identify clinical and procedural predictors of treatment success in paroxysmal AF patients treated with the pentaspline PFA catheter.

METHODS

ADVENT (Randomized Controlled Trial for Pulsed Field Ablation versus Standard of Care Ablation for Paroxysmal Atrial Fibrillation) was a prospective randomized trial comparing PFA to thermal ablation with centers designated to randomize patients to either radiofrequency or cryoballoon ablation. Hazard ratios were estimated to evaluate clinical and procedural characteristics associated with ablation success. Subgroup analyses were performed by ablation modality and operator/center experience.

RESULTS

Of the 607 randomized patients (age 62.4 years, 34.6% female), treatment failure was documented in 26.7% of PFA and 28.7% of thermal ablation patients. The most common failure was arrhythmia recurrence (73.8% vs 76.5%) with no difference in subtype (non-AF arrhythmia: 12.1% PFA vs 14.6% thermal). Patients who previously failed Class I/III antiarrhythmic drugs (AADs) were more likely to benefit from PFA (hazard ratio [HR] 0.65, 95% confidence interval [CI] 0.44-0.96). Shorter left atrial dwell time was associated with higher success (HR 0.48, 95% CI 0.30-0.76), and a trend toward better outcomes was noted for patients enrolled during the second half of the trial (75.5% vs 69.9%, P = .17). PFA patients had similar success across radiofrequency and cryoballoon centers.

CONCLUSION

PFA with the pentaspline catheter is not associated with a higher incidence of postablation atypical flutters/tachycardias. Patients with previous Class I/III AAD failure are more likely to benefit from PFA and greater operator experience, irrespective of previous thermal modality, may be associated with better outcomes.

Safety of catheter ablation for atrial fibrillation in patients with liver cirrhosis

BACKGROUND AND AIMS

Atrial fibrillation is the most prevalent cardiac arrhythmia, and catheter ablation (CA) has emerged as a viable treatment option for selected patients. However, its safety profile in liver cirrhosis (LC) populations remains underexplored.

METHODS

This was an observational analysis of the National Inpatient Sample Database 2016-2020; we analyzed adult encounters undergoing CA for atrial fibrillation who had a concomitant diagnosis of LC. Using propensity scores, encounters were divided into two cohorts based on the presence or absence of LC and matched in a 1:1 fashion using LC as the dependent variable. In-hospital mortality and postprocedure total complications were compared using regression models.

RESULTS

93 830 procedures were identified for non-LC patients and 960 involving LC patients; after propensity score matching, each cohort included 910 hospitalizations. The mean age in the LC-matched cohort was 66.5 ± 9.1 years. In-hospital mortality did not differ between the groups (aOR = 1.01; 95% CI [0.06-16.1]; p = .99). However, the LC cohort exhibited higher odds of total complications (aOR = 1.98; 95% CI [1.42-2.75]; p < .001). Length of stay (LOS) was comparable, but total costs were higher in the LC cohort: LOS was 2 days (95% CI [1-3]) in the LC group versus 3 days (95% CI [1-4]) (p < .11) and LC: $202,000 (95% CI [$142 000-$261 000]) versus non-LC: $189 000, (95% CI [$153 000-$222 000]) (p < .0001).

CONCLUSION

In this national analysis of patients undergoing CA for AF, those with LC had similar in-hospital mortality, postprocedure complications, and LOS compared to noncirrhotic patients. Furthermore, longitudinal studies are needed to assess the safety profile of CA in this subpopulation.

Very high-power and short-duration radiofrequency ablation for atrial fibrillation in a Latin American low-volume private center

BACKGROUND

Center volume and operator experience/training are important factors impacting outcomes in AFib CA. Setting for RF delivery (power, duration, and contact force) associated with better outcomes remains to be determined.

METHODS

This is an observational, longitudinal, and retrospective study. All consecutive procedures performed between December 12, 2013, and March 9, 2023, in a low-volume private center in Latin America were analyzed. Procedure characteristics and outcomes were compared between STD and vHPSD.

RESULTS

Two hundred ten procedures were performed on 194 patients. Median annual number of procedures was 19 (7-29). Median age was 62 (52-68), and majority were male (71%). Median procedure duration was 155 (125-195) min, mean fluoroscopy time 32.8 ± 15 min and mean fluoroscopy dose 373.5 ± 208.9 mGray. Median follow-up was 27 months, significantly longer in STD compared with vHPSD group (43 [31-68] vs. 13 [8-19], respectively; P ≤ 0.001). The recurrence rate was 33.2% and major complications 8.6%. Compared with STD, vHPSD resulted in a significantly shorter procedure duration (125 vs. 180 min, P ≤ 0.001), shorter fluoroscopy time (22.7 ± 9.5 vs. 39.2 ± 14.3 min, P ≤ 0.001), and lower fluoroscopy dose (283.8 ± 161.1 vs. 438.3 ± 216.1 mGray, P ≤ 0.001). No long-term recurrence difference was observed when the follow-up periods were comparable. No difference in complication rate was observed (8.5% vs. 8.6%, P = 0.988).

CONCLUSIONS

Outcomes in AFib CA in a Latin American low-volume private center can be considered acceptable, with efficacy and safety similar to those reported in the literature. Compared with STD ablation, vHPSD showed higher efficiency with similar efficacy and safety.

Predictors of first pass isolation of the pulmonary veins in real world ablations: An analysis of 2671 patients from the REAL-AF registry

INTRODUCTION

During atrial fibrillation ablation (AFA), achievement of first pass isolation (FPI) reflects effective lesion formation and predicts long-term freedom from arrhythmia recurrence. We aim to determine the clinical and procedural predictors of pulmonary vein FPI.

METHODS

We reviewed AFA procedures in a multicenter prospective registry of AFA (REAL-AF). A multivariate ordinal logistic regression, weighted by inverse proceduralist volume, was used to determine predictors of FPI.

RESULTS

A total of 2671 patients were included with 1806 achieving FPI in both vein sides, 702 achieving FPI in one, and 163 having no FPI. Individually, age, left atrial (LA) scar, higher power usage (50 W), greater posterior contact force, ablation index >350 posteriorly, Vizigo™ sheath utilization, nonstandard ventilation, and high operator volume (>6 monthly cases) were all related to improved odds of FPI. Conversely sleep apnea, elevated body mass index (BMI), diabetes mellitus, LA enlargement, antiarrhythmic drug use, and center's higher fluoroscopy use were related to reduced odds of FPI. Multivariate analysis showed that BMI > 30 (OR 0.78 [0.64-0.96]) and LA volume (OR per mL increase = 1.00 [0.99-1.00]) predicted lower odds of achieving FPI, whereas significant left atrial scarring (>20%) was related to higher rates of FPI. Procedurally, the use of high power (50 W) (OR 1.32 [1.05-1.65]), increasing force posteriorly (OR 2.03 [1.19-3.46]), and nonstandard ventilation (OR 1.26 [1.00-1.59]) predicted higher FPI rates. At a site level, high procedural volume (OR 1.89 [1.48-2.41]) and low fluoroscopy centers (OR 0.72 [0.61-0.84]) had higher rates of FPI.

CONCLUSION

FPI rates are affected by operator experience, patient comorbidities, and procedural strategies. These factors may be postulated to impact acute lesion formation.

Risk factors for late reconnections after circumferential pulmonary vein isolation guided by lesion size index - Data from repeat invasive electrophysiology procedure

Background

Late reconnections (LR) of pulmonary veins (PVs) after wide antral circumferential ablation (WACA) using point-to-point radiofrequency (RF) ablation are common. Lesion size index (LSI) is a novel marker of lesion quality proposed by Ensite Precision mapping system, expected to improve PV isolation durability. This study aimed to assess the durability of LSI-guided PVI and the risk factors for LR of PVs.

Methods

The prospective study included 33 patients with paroxysmal atrial fibrillation (PAF) who underwent (1) the index LSI-guided WACA procedure (with target LSI of 5.5-6.0 for anterior and 5.0-5.5 for posterior WACA segments) and (2) the 3-month protocol-mandated re-mapping procedure in all patients, irrespective of AF recurrence after the index procedure. Ablation parameters reported by Ensite mapping system were collected retrospectively. The inter-lesion distance (ILD) between all adjacent WACA lesions was calculated off-line. Association between index ablation parameters and the LRs of PVs at 3 months was analyzed.

Results

The median patient age was 61 (IQR: 53-64) years and 55% of them were males. At index procedure, the first-pass WACA isolation rate was higher for the left PVs than the right PVs (64 vs. 33%, p = 0.014). In addition, a low acute reconnection rates were observed, as follows: in 12.1% of patients, in 6.1% of WACA circles, in 3.8% of WACA segments and in 4.5% of PVs. However, the 3-month remapping study revealed LR of PV in 63.6% of patients, 37.9% of WACA circles, 20.5% of WACA segments and 26.5% of PVs. The LRs were identified mostly along the left anterior WACA segment. Independent risk factors for the LR of WACA were left-sided WACA location (OR 3.216 [95%CI: 1.065-9.716], p = 0.038) and longer ILD (OR 1.256 [95%CI: 1.035-1.523] for each 1-mm increase, p = 0.021). The ILD of > 8.0 mm showed a predictive value for the LR of WACA, with the sensitivity of 84% and specificity of 46%. A single case of cardiac tamponade occurred following the re-mapping invasive procedure. No other complications were encountered.

Conclusion

Although the LSI-guided PVI ensures a consistent PVI during the index procedure, LRs of PVs are still common. Besides the LSI, the PVI durability requires an optimal ILD between adjacent lesions, especially along the anterior lateral ridge.

Safety and effectiveness of a novel dielectric mapping system: one-year, two chinese centers experiences

BACKGROUND

The KODEX-EPD system is a novel, dielectric three-dimensional mapping system. We aim to illustrate the feasibility, safety, and outcomes of ablation using the KODEX-EPD system.

METHODS

A total of 272 patients with supraventricular arrhythmias were enrolled and underwent catheter ablation using the KODEX-EPD system from October 2020 to July 2021. The feasibility, safety, and ablation outcomes were analyzed.

RESULTS

Of the enrolled patients, 15 (5.4%) had atrial tachycardia (AT), 88 (31.4%) had atrioventricular reentrant tachycardia (AVRT), 141 (50.4%) had atrioventricular nodal reentrant tachycardia (AVNRT), 34 (12.1%) had atrial fibrillation (AF), and 9 (3.2%) had atrial flutter (AFL). All AF patients included were first-do-pulmonary vein isolation (PVI); there were 26 paroxysmal AF and 8 persistent AF. All patients achieved immediate success of ablation. The mean follow-up duration was 11.8 ± 2.4 months. One patient (1.1%) in the AVRT subgroup and two patients (1.4%) in the AVNRT subgroup experienced recurrence. When considering a three-month blanking time, the estimated freedom of AF at one-year post-ablation with and without AADs was 75.7% and 70.4%, respectively. The Kaplan-Meier analysis showed no significant difference in the overall AF recurrence (log-rank; P = 0.931) or AAD-free AF recurrence (log-rank; P = 0.841) between RFCA and cryoablation. One patient had mild pulmonary embolism. None of the patients died or had a cerebrovascular event in the periprocedural period.

CONCLUSIONS

This retrospective, two-center study demonstrated that catheter ablation of supraventricular arrhythmias using the KODEX-EPD system is feasible, safe, and effective. Trial registration Retrospectively registered.

Performance of the ablation index during pulmonary vein isolation: periprocedural data from a multicenter registry

PURPOSE

Our study aimed to assess the achievement of target ablation index (AI) values and their impact on first-pass pulmonary vein isolation (FPI) as well as to identify FPI predictors.

METHODS

Atrial fibrillation (AF) ablation was performed according to the local practice, and target AIs were evaluated. The actual AI was calculated as the median value of all ablation points for the anterior and posterior left atrial (LA) walls.

RESULTS

A total of 450 patients from nine centers were enrolled. Patients with first-time ablation (n = 408) were divided into the FPI and non-FPI groups. In the FPI group, a higher median target AI was reported for both the anterior and posterior LA walls than those in the non-FPI group. A higher actual AI was observed for the anterior LA wall in the FPI group. The actual AI was equal to or higher than the target AI for the posterior, anterior, and both LA walls in 54%, 47%, and 35% (n = 158) cases, respectively. Parameters such as hypertension, stroke, ablation power, actual AI value on the anterior wall, target AI values on both LA walls, AI achievement on the posterior wall, carina ablation, and operator experience were all associated with FPI in a univariate logistic regression model; only carina ablation was an independent predictor of FPI.

CONCLUSIONS

According to our multicenter study, FPI and a target AI were not achieved in a significant proportion of AF ablation procedures. Higher actual and target AI values were associated with FPI, but only carina ablation can independently predict FPI.

Relationship between procedural volume and complication rates for catheter ablation of atrial fibrillation: a systematic review and meta-analysis

AIMS

There are conflicting data as to the impact of procedural volume on outcomes with specific reference to the incidence of major complications after catheter ablation for atrial fibrillation. Questions regarding minimum volume requirements and whether these should be per centre or per operator remain unclear. Studies have reported divergent results. We performed a systematic review and meta-analysis of studies reporting the relationship between either operator or hospital atrial fibrillation (AF) ablation volumes and incidence of complications.

METHODS AND RESULTS

Databases were searched for studies describing the relationship between operator or hospital AF ablation volumes and incidence of complications which were published prior to 12 June 2020. Of 1593 articles identified, 14 (315 120 patients) were included in the meta-analysis. Almost two-thirds of the procedures were performed in low-volume centres. Both hospital volume of ≥50 and ≥100 procedures/year were associated with a significantly lower incidence of complications compared to <50/year (4.2% vs. 5.5%, OR = 0.58, 95% CI 0.50-0.66, P < 0.001) or <100/year (5.5% vs. 6.2%, OR = 0.62, 95% CI 0.53-0.73, P < 0.001), respectively. Hospitals performing ≥50 procedures/year demonstrated significantly lower mortality compared with those performing <50 procedures/year (0.16% vs. 0.55%, OR = 0.33, 95% CI 0.26-0.43, P < 0.001). A similar relationship existed between proceduralist volume of <50/year and incidence of complications [3.75% vs. 12.73%, P < 0.001; OR = 0.27 (0.23-0.32)].

CONCLUSION

There is an inverse relationship between both hospital and proceduralist AF ablation volume and the incidence of complications. Implementation of minimum hospital and operator AF ablation volume standards should be considered in the context of a broader strategy to identify AF ablation Centers of Excellence.

Impact of centre volume on atrial fibrillation ablation outcomes in Europe: a report from the ESC EHRA EORP Atrial Fibrillation Ablation Long-Term (AFA LT) Registry

AIMS

The aim of the study was to investigate differences in clinical outcomes and complication rates among European atrial fibrillation (AF) ablation centres related to the volume of AF ablations performed.

METHODS AND RESULTS

Data for this analysis were extracted from the ESC EHRA EORP European AF Ablation Long-Term Study Registry. Based on 33rd and 67th percentiles of number of AF ablations performed, the participating centres were classified into high volume (HV) (≥ 180 procedures/year), medium volume (MV) (<180 and ≥74/year), and low volume (LV) (<74/year). A total of 91 centres in 26 European countries enrolled in 3368 patients. There was a significantly higher reporting of cardiovascular complications and stroke incidence in LV centres compared with HV and MV (P = 0.039 and 0.008, respectively) and a lower success rate after AF ablation (55.3% in HV vs. 57.2% in LV vs. 67.4% in MV centres, P < 0.001), despite lower CHA2DS2-VASc score of patients, enrolled in LVs and less complex ablation techniques used. Adjustments of confounding factors (including type of AF ablation) led to elimination of these differences.

CONCLUSION

Low-volume centres tended to present slightly higher cardiovascular complications' and stroke incidence and a lower unadjusted success rate after AF ablation, despite the fact that ablation procedures and patients were of lower risk compared with MV and HV centres. On the other hand, adjusted overall complication and recurrence rates were non-significantly different among different volume centres, a fact reflecting the heterogeneity of patient and procedural profiles, and a counterbalance between expertise and risk level among participating centres.

Effect of Outcome Measures on the Apparent Efficacy of Ablation for Atrial Fibrillation: Why "Success" is an Inappropriate Term

INTRODUCTION

Different endpoint criteria, different durations of follow-up and the completeness of follow-up can dramatically affect the perceived benefits of atrial fibrillation (AF) ablation.

METHODS

We defined three endpoints for recurrence of AF post ablation in a cohort of 200 patients with symptomatic AF, refractory to antiarrhythmic drugs (AADs). A 'Strict Endpoint' where patients were considered to have a recurrence with any symptomatic or documented recurrence for ≥30 seconds with no blanking period, and off their AADs, a 'Liberal Endpoint' where only documented recurrences after the blanking period, either on or off AADs were counted, and a 'Patient-defined Outcome endpoint' which was the same as the Liberal endpoint but allowed for up to two recurrences and one repeat ablation or DCCV during follow-up. We also surveyed 50 patients on the waiting list for an AF ablation and asked them key questions regarding what they would consider to be a successful result for them.

RESULTS

Freedom from recurrence of atrial tachyarrhythmias (AT) at 5 years was 62% for the Strict Endpoint, 73% for the Liberal Endpoint, and 80% for the Patient-defined Outcome endpoint (p<0.001). Of the 50 patients surveyed awaiting AF ablation, 70% said they would still consider the procedure a success if it required one repeat ablation or one DCCV (p=0.004), and 76% would be accepting of one or two recurrences during follow-up (p<0.001).

CONCLUSION

In this study, the majority of patients still considered AF ablation a successful treatment if they had up to two recurrences of AF, one repeat procedure or one DCCV. Furthermore, a 'Patient-defined' definition of success lead to significantly different results in this AF ablation cohort when compared to conventionally used/guideline directed measures of success.

Safety and complications of catheter ablation for atrial fibrillation: Predictors of complications from an updated analysis the National Inpatient Database

BACKGROUND

Catheter ablation is increasingly employed in the management of atrial fibrillation (AF). Data regarding safety of ablation of AF is largely derived from controlled clinical trials.

OBJECTIVES

The aim of this study was to analyze safety and complications of AF ablation performed in a "real world" setting outside of clinical trials, and obtain insights on predictors of complications.

METHODS

We utilized the National Inpatient Sample database, to identify all patients who underwent AF ablations between 2015 and 2017 using International Classification of Disease-Tenth revision codes. Complications were defined as per the Agency for Health Care Research and Quality Guidelines. Statistical tests including multivariate logistic regression were performed to determine predictors of complications.

RESULTS

Among 14,875 cases of AF ablation between 2015 and 2017, a total of 1884 complications were identified among 1080 (7.2%) patients. Patients with complications were likely to be older and female with a higher burden of comorbidities. A 27% increase in complications was observed from 2015 to 2017, driven by an increase in pericardial complications. Multivariate regression analysis revealed that pulmonary hypertension (adjusted odds ratio [aOR]: 1.99, p = .041) and chronic kidney disease (CKD; aOR: 1.67, p = .024), were independent predictors of complications. Centers with higher procedural volumes were associated with lower complication rates.

CONCLUSIONS

Complication rates related to AF ablations remain substantially high. Presence of pulmonary hypertension and CKD are predictive of higher procedural complications. Furthermore, hospital procedure volume is an important factor that correlates with complication rates.

Anatomical targets and expected outcomes of catheter-based ablation of atrial fibrillation in 2020

Anatomical-based approaches, targeting either pulmonary vein isolation (PVI) or additional extra PV regions, represent the most commonly used ablation treatments in symptomatic patients with atrial fibrillation (AF) recurrences despite antiarrhythmic drug therapy. PVI remains the main anatomical target during catheter-based AF ablation, with the aid of new technological advances as contact force monitoring to increase safety and effective radiofrequency (RF) lesions. Nowadays, cryoballoon ablation has also achieved the same level of scientific evidence in patients with paroxysmal AF undergoing PVI. In parallel, electrical isolation of extra PV targets has progressively increased, which is associated with a steady increase in complex cases undergoing ablation. Several atrial regions as the left atrial posterior wall, the vein of Marshall, the left atrial appendage, or the coronary sinus have been described in different series as locations potentially involved in AF initiation and maintenance. Targeting these regions may be challenging using conventional point-by-point RF delivery, which has opened new opportunities for coadjuvant alternatives as balloon ablation or selective ethanol injection. Although more extensive ablation may increase intraprocedural AF termination and freedom from arrhythmias during the follow-up, some of the targets to achieve such outcomes are not exempt of potential severe complications. Here, we review and discuss current anatomical approaches and the main ablation technologies to target atrial regions associated with AF initiation and maintenance.

Outcomes of cryoballoon or radiofrequency ablation in symptomatic paroxysmal or persistent atrial fibrillation

Aims

To evaluate the effectiveness and safety of cryoballoon ablation (CBA) compared with radiofrequency ablation (RFA) for symptomatic paroxysmal or drug-refractory persistent atrial fibrillation (AF).

Methods and results

Prospective cluster cohort study in experienced CBA and RFA centres. Primary endpoint was ‘atrial arrhythmia recurrence’, secondary endpoints were as follows: procedural results, safety, and clinical course. A total of 4189 patients were included: CBA 2329 (55.6%) and RFA 1860 (44.4%). Cryoballoon ablation population was younger, with fewer comorbidities. Procedure time was longer in the RFA group (P = 0.01). Radiation exposure was 2487 (CBA) and 1792 cGycm² (RFA) (P < 0.001). Follow-up duration was 441 (CBA) and 511 days (RFA) (P < 0.0001). Primary endpoint occurred in 30.7% (CBA) and 39.4% patients (RFA) [adjusted hazard ratio (adjHR) 0.85, 95% confidence interval (CI) 0.70–1.04; P = 0.12). In paroxysmal AF, CBA resulted in a lower risk of recurrence (adjHR 0.80, 95% CI 0.64–0.99; P = 0.047). In persistent AF, the primary outcome was not different between groups. Major adverse cardiovascular and cerebrovascular event rates were 1.0% (CBA) and 2.8% (RFA) (adjHR 0.53, 95% CI 0.26–1.10; P = 0.088). Re-ablations (adjHR 0.46, 95% CI 0.34–0.61; P < 0.0001) and adverse events during follow-up (adjHR 0.64, 95% CI 0.48–0.88; P = 0.005) were less common after CBA. Higher rehospitalization rates with RFA were caused by re-ablations.

Conclusions

The primary endpoint did not differ between CBA and RFA. Cryoballoon ablation was completed rapidly; the radiation exposure was greater. Rehospitalization due to re-ablations and adverse events during follow-up were observed significantly less frequently after CBA than after RFA. Subgroup analysis suggested a lower risk of recurrence after CBA in paroxysmal AF.

Trial Registration

ClinicalTrials.gov (NCT01360008), https://clinicaltrials.gov/ct2/show/NCT01360008.

Catheter ablation for atrial fibrillation in a low-volume center using contemporary technology

BACKGROUND

Catheter ablation is increasingly being performed worldwide for atrial fibrillation (AF). However, there are concerns of lower success rates and higher complications of AF ablations performed in low-volume centers. Thus, we sought to evaluate the safety and efficacy of AF catheter ablation in a low-volume center using contemporary technologies.

METHODS AND RESULTS

71 consecutive patients (50 paroxysmal AF [pAF] vs 21 persistent AF) who underwent first catheter ablation were studied. Primary outcome was AF recurrence rate. Secondary outcomes included periprocedural complications, hospitalization for symptomatic tachy-arrhythmias post-ablation and number of repeat ablations. Mean age of our cohort was 59.1 ± 9.7 years, of which 56 (78.9%) were males. 1-year AF recurrence was 19.5% in pAF and 23.8% in persistent AF (p = 0.694). Ablation in persistent AF group required longer procedural (197.76 ± 48.60 min [pAF] vs 238.67 ± 70.50 min [persistent AF], p = 0.006) and ablation duration (35.08 ± 15.84 min [pAF] vs 52.65 ± 28.46 min [persistent AF], p = 0.001). There were no significant differences in secondary outcomes. Major periprocedural complication rate was 2.8%.Subset analysis on (i) cryoablation vs radiofrequency, (ii) Ensite vs CARTO navigational system and (iii) circular vs high density mapping catheter did not yield significant differences in primary or secondary outcomes.

CONCLUSIONS

The AF ablation complication and recurrence free rates in both paroxysmal and persistent AF at one year were comparable to high-volume centers. Long-term follow up is needed. In addition, first AF catheter ablation in a low-volume center is realistic with comparable efficacy and safety outcomes to high-volume centers using contemporary ablation technologies.

Keeping it Simple: Balloon Devices for Atrial Fibrillation Ablation Therapy

Atrial fibrillation is a common disease of increasing prevalence. Catheter ablation has evolved into an established therapeutic option that mainly aims to electrically isolate the pulmonary veins from atrial myocardium. The traditional method comprises point-by-point radiofrequency current ablation guided by electroanatomical mapping and has proven to be effective and safe in experienced hands. However, this approach is technically highly demanding and associated with a long learning curve, limiting its widespread utilization. To address these shortcomings, simplified ablation tools for pulmonary vein isolation are needed. In this context, balloon devices promise to ease the procedure by approaching the entire orifice of a targeted pulmonary vein in a single maneuver. This requires less catheter manipulation in the left atrium and often allows ablation of a large volume of tissue with a single application of ablative energy. Two balloon devices-one using cryoenergy, the other laser energy-have already been established in clinical routine and have demonstrated noninferiority when compared with radiofrequency ablation in large randomized trials. More balloon devices are on the verge of being introduced into clinical practice and bear the potential to expand the interventional electrophysiologist's armamentarium when treating atrial fibrillation. The authors review the use of the established balloon devices available for atrial fibrillation ablation and provide a detailed outlook on upcoming balloon technologies, including 3 different balloons utilizing radiofrequency energy as well as a novel cryoballoon.

A Prospective Registry of Atrial Fibrillation Ablation with the Ablation Index Technology: Rationale and Study Design

This is a prospective multicenter registry of atrial fibrillation (AF) ablation with the Ablation Index (AI) technology, which has been introduced as a marker predicting ablation lesion depth. The index incorporates the main parameters of radiofrequency point-by-point ablation: power, contact force, and time of ablation. The AI is calculated for every operator depending on personal skills, and there are no strict indications on the range of the parameter considering its safety and efficacy during pulmonary vein isolation. The registry aims to evaluate AI values used in different centers by different operators and to evaluate the optimal limits associated with better acute and long-term AF ablation results.

Electroanatomic guidance versus conventional fluoroscopy during transseptal puncture for atrial fibrillation ablation

INTRODUCTION

Technological advancement in the setting of atrial fibrillation (AF) ablation has decreased radiation exposure and complications associated with the procedure. Yet, transseptal puncture (TSP) remains a challenging step that necessitates accurate guidance. We describe our experience performing TSP under electroanatomic (EA) guidance.

METHODS AND RESULTS

The analysis included 145 consecutive EA-guided ablation procedures performed between June 2018 and April 2019 and 145 consecutive standard ablations performed before June 2018. EA guidance utilized the CARTO 3 three-dimensional mapping system to reconstruct anatomic and electrical characteristics of the right atrium and fossa ovalis. Patients with a history of previous cardiac surgery were excluded. For EA-guided procedures, the mean patient age was 60 ± 10 years, 75.2% were male, and 69.0% had paroxysmal AF. Similarly, the mean age for conventional procedures was 60 ± 11 years, 71.0% were male, and 71.7% had paroxysmal AF. The fossa ovalis was detected as a region of low voltage, <0.75 mV. EA guidance yielded shorter fluoroscopy times (EA vs. conventional, 3.6 ± 2.5 vs. 13.5 ± 10.5 min; p < .001) and a lower dose area product than conventional guidance (13 ± 11 Gy* cm² vs. 28 ± 27  Gy* cm² ; p < .001). The total procedure duration was similar between groups (146 ± 48 vs. 148 ± 54 min). There were no significant complications related to TSP.

CONCLUSION

During AF ablation, TSP with EA guidance facilitated safe access to the left atrium while reducing radiation risk to both patients and operators.

Comparison of Outcomes Using the First and Second Generation Cryoballoon to Treat Atrial Fibrillation

BACKGROUND

Pulmonary vein isolation using cryoballoon ablation is an effective treatment for patients with atrial fibrillation. We sought to compare outcomes with the first and second generation cryoballoon, with the second generation balloon incorporating the Achieve Lasso catheter, in terms of freedom from symptomatic recurrence and major complications.

METHODS

The first 200 patients who underwent cryoballoon ablation with the first generation balloon were compared with the first 200 patients using the second-generation balloon. All patients had symptomatic atrial fibrillation and had failed at least one antiarrhythmic drug. The primary efficacy endpoint was freedom from symptomatic recurrence of atrial fibrillation (AF) after a single pulmonary vein isolation (PVI) procedure using the cryoballoon. The primary safety endpoint was major procedural complications.

RESULTS

At 12 months, freedom from symptomatic AF after a single procedure in the first generation cohort was 64.3% compared with 78.6% in the second-generation cohort (p = 0.002). At 24 months, freedom from symptomatic AF in the first generation cohort was 51.3% compared with 72.6% in the second-generation cohort (p < 0.001). Procedural time (150 min vs 101 min; p < 0.001) and fluoroscopy time (32.5 min vs 21.4 min; p < 0.001) was lower in the second-generation group. The rate of major complications was comparably low in both groups.

CONCLUSIONS

The second-generation cryoballoon was associated with improved freedom from symptomatic AF with reduction in procedure and fluoroscopy time, with a similar low rate of major complications.

Cryoballoon pulmonary vein ablation and left atrial appendage closure combined procedure: A long-term follow-up analysis

BACKGROUND

The combined left atrial appendage closure (LAAC) and cryoenergy pulmonary vein isolation (PVI) procedure has been proven safe and effective in managing stroke in patients with nonvalvular atrial fibrillation (AF), although most data refer to procedures performed using radiofrequency as the main energy source.

OBJECTIVE

The purpose of this study was to evaluate long-term follow-up of patients with AF undergoing concomitant LAAC and cryoenergy PVI.

METHODS

Patients undergoing LAAC and cryoballoon PVI at our institution were enrolled. At 3, 6, and 24 months from the index procedure, we determined the atrial arrhythmia recurrence rate, the extent of LAAC, and the rate of cerebrovascular/bleeding events.

RESULTS

Forty-nine patients (mean age 69 ± 8 years; 32/49 (67%) men; CHA₂DS₂-VASc score 2.8 ± 1.2; HAS-BLED score 3 ± 1) with a guideline-recommended LAAC indication were included. Acute PVI and complete LAAC were achieved in 100% of patients. All patients completed at least 24 months of follow-up. At 8 weeks and 6 months, complete or satisfactory (<5 mm leak) LAAC rates were achieved in 40 (82%) and 9 (18%) and in 42 (86%) and 7 (14%) of patients, respectively. The overall freedom from atrial arrhythmia rate at 24 months was 29 (60%), and 45 (92%) of patients were off antithrombotic drugs. The observed annualized stroke and bleeding rates were 1% and 2%, respectively, a 71% and 60% risk reduction in comparison to event rates predicted from CHA₂DS₂-VASc and HAS-BLED scores.

CONCLUSION

Concomitant cryoballoon ablation and LAAC procedures appear safe and effective at long-term follow-up, with high antithrombotic drug withdrawal rates at 24 months.

Combining Watchman left atrial appendage closure and catheter ablation for atrial fibrillation: multicentre registry results of feasibility and safety during implant and 30 days follow-up

Aims

Long-term results from catheter ablation therapy for atrial fibrillation (AF) remain uncertain and clinical practice guidelines recommend continuation of long-term oral anticoagulation in patients with a high stroke risk. Left atrial appendage closure (LAAC) with Watchman has emerged as an alternative to long-term anticoagulation for patients accepting of the procedural risks. We report on the initial results of combining catheter ablation procedures for AF and LAAC in a multicentre registry.

Methods and results

Data were pooled from two prospective, real-world Watchman LAAC registries running in parallel in Europe/Middle-East/Russia (EWOLUTION) and Asia/Australia (WASP) between 2013 and 2015. Of the 1140 patients, 139 subjects at 10 centres underwent a concomitant AF ablation and LAAC procedure. The mean CHA2DS2-VASc score was 3.4 ± 1.4 and HAS-BLED score 1.5 ± 0.9. Successful Watchman implantation was achieved in 100% of patients. The overall 30-day serious adverse event (SAE) rate was 8.7%, with the device and/or procedure-related SAE rate of 1.4%. One pericardial effusion required percutaneous drainage, but there were no strokes, device embolization, or deaths at 30 days. The 30-day bleeding SAE rate was 2.9% with 55% of patients prescribed NOAC and 38% taking warfarin post-procedure.

Conclusion

The outcomes from these international, multicentre registries support the feasibility and safety of performing combined procedures of ablation and Watchman LAAC for patients with non-valvular AF and high stroke risk. Further data are needed on long-term outcomes for the hybrid technique on all-cause stroke and mortality.

The quest for durable lesions in catheter ablation of atrial fibrillation - technological advances in radiofrequency catheters and balloon devices

INTRODUCTION

Atrial fibrillation is the most common cardiac arrhythmia and represents a growing clinical, social and economic challenge. Catheter ablation for symptomatic atrial fibrillation has evolved from an experimental procedure into a widespread therapy and offers a safe and effective treatment option. A prerequisite for durable PVI are transmural and contiguous circumferential lesions around the pulmonary veins. However, electrical reconnection of initially isolated pulmonary veins remains a primary concern and is a dominant factor for arrhythmia recurrence during long-term follow up. Areas covered: This article discusses the physiology of lesion formation using radiofrequency-, cryo- or laser- energy for pulmonary vein isolation and provides a detailed review of recent technological advancements in the field of radiofrequency catheters and balloon devices. Finally, future directions and upcoming developments for the interventional treatment of atrial fibrillation are discussed. Expert commentary: Durable conduction block across deployed myocardial lesions is mandatory not only for PVI but for any other cardiac ablation strategy as well. A major improvement urgently expected is the intraprocedural real-time distinction of durable lesions from interposed gaps with only transiently impaired electrical conduction. Furthermore, a simplification of ablation tools used for PVI is required to reduce the high technical complexity of the procedure.

The burden of proof: The current state of atrial fibrillation prevention and treatment trials

Atrial fibrillation (AF) is an age-related arrhythmia of enormous socioeconomic significance. In recent years, our understanding of the basic mechanisms that initiate and perpetuate AF has evolved rapidly, catheter ablation of AF has progressed from concept to reality, and recent studies suggest lifestyle modification may help prevent AF recurrence. Emerging developments in genetics, imaging, and informatics also present new opportunities for personalized care. However, considerable challenges remain. These include a paucity of studies examining AF prevention, modest efficacy of existing antiarrhythmic therapies, diverse ablation technologies and practice, and limited evidence to guide management of high-risk patients with multiple comorbidities. Studies examining the long-term effects of AF catheter ablation on morbidity and mortality outcomes are not yet completed. In many ways, further progress in the field is heavily contingent on the feasibility, capacity, and efficiency of clinical trials to incorporate the rapidly evolving knowledge base and to provide substantive evidence for novel AF therapeutic strategies. This review outlines the current state of AF prevention and treatment trials, including the foreseeable challenges, as discussed by a unique forum of clinical trialists, scientists, and regulatory representatives in a session endorsed by the Heart Rhythm Society at the 12th Global CardioVascular Clinical Trialists Forum in Washington, DC, December 3-5, 2015.

Long term outcomes from catheter ablation of very longstanding persistent atrial fibrillation

INTRODUCTION

Success rates for catheter ablation of longstanding persistent atrial fibrillation (AF) are significantly poorer than for recently persistent or paroxysmal forms. We report on single centre long term outcomes from ablation of very longstanding (> 2years) persistent AF.

MATERIAL AND METHODS

A retrospective analysis of outcomes for patients undergoing catheter ablation for symptomatic very longstanding persistent AF between 2008 and 2013 was performed.

RESULTS

Twenty-nine patients were followed for a mean of 61±15months following the index ablation procedure. The mean duration of persistent AF prior was 64±51months (range 24-200), mean age 61±6years and mean CHA₂DS₂-VASc score 1.1±1.2. Antral pulmonary vein electrical isolation only was performed in 14 (48%) with the remainder having additional lines and/or CFAE ablation also. At last follow-up 24 (83%) were in sinus rhythm but only 9 (31%) remained free of detectable arrhythmia, 25 (86%) were taking antiarrhythmic therapy and 18 (62%) required intermittent DC cardioversions. The mean time to first AF recurrence was 14±14months (range 2-48). Redo ablation was required in 13 (45%) at a mean follow-up time of 15±12months. The mean EHRA score improved from 3.5±0.5 to 1.4±0.4 (p<0.0001).

CONCLUSIONS

The vast majority (83%) of very longstanding persistent AF patients maintained sinus rhythm at a mean follow-up time of 5years following catheter ablation, associated with a significant improvement in symptom scores. Adjunctive therapies including antiarrhythmics, DC cardioversions and redo ablation were required in most patients.

Rhythm control in atrial fibrillation

Many patients with atrial fibrillation have substantial symptoms despite ventricular rate control and require restoration of sinus rhythm to improve their quality of life. Acute restoration (ie, cardioversion) and maintenance of sinus rhythm in patients with atrial fibrillation are referred to as rhythm control. The decision to pursue rhythm control is based on symptoms, the type of atrial fibrillation (paroxysmal, persistent, or long-standing persistent), patient comorbidities, general health status, and anticoagulation status. Many patients have recurrent atrial fibrillation and require further intervention to maintain long term sinus rhythm. Antiarrhythmic drug therapy is generally recommended as a first-line therapy and drug selection is on the basis of the presence or absence of structural heart disease or heart failure, electrocardiographical variables, renal function, and other comorbidities. In patients who continue to have recurrent atrial fibrillation despite medical therapy, catheter ablation has been shown to substantially reduce recurrent atrial fibrillation, decrease symptoms, and improve quality of life, although recurrence is common despite continued advancement in ablation techniques.

Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study

Background. There are little comparative data on catheter ablation of paroxysmal atrial fibrillation (AF) using the contact force radiofrequency (CF-RF) catheter versus the second-generation cryoballoon (CB2). Methods and results. This is a single center, retrospective, nonrandomized study of 98 patients with symptomatic, drug-refractory paroxysmal AF who underwent their first PVI ablation using either the CB2 (n = 40) or CF-RF (n = 58). The mean age was 60 years with 63% men, a mean LA size of 42 mm. The procedure duration (74 ± 17 versus 120 ± 49 minutes p < 0.05) was shorter for CB2 group; the fluoroscopy time (14 ± 17 versus 16 ± 5 minutes, p = 0.45) was similar. Complete PVI was achieved in 96% of patients with RF-CF and 98% with CB2. Phrenic nerve palsies (2 transient and 1 persistent) occurred exclusively in the CB2 group and 1 severe, nonlethal complication (pericardial tamponade) occurred in the CF-RF group. At 24-month follow-up, the success rate, defined as freedom from AF/atrial tachycardia (AT) after a single procedure without antiarrhythmic drug, was comparable in CF-RF group and CB2 group (65.5% versus 67%, resp., log rank p = 0.54). Conclusion. Both the CB2 and the RF-CF ablation appeared safe; the success rate at 2 years was comparable between both technologies.