Cryoballoon ablation vs. antiarrhythmic drugs: first-line therapy for patients with paroxysmal atrial fibrillation

AIMS

Treatment guidelines for patients with atrial fibrillation (AF) suggest that patients should be managed with an antiarrhythmic drug (AAD) before undergoing catheter ablation (CA). This study evaluated whether pulmonary vein isolation employing cryoballoon CA is superior to AAD therapy for the prevention of atrial arrhythmia (AA) recurrence in rhythm control naive patients with paroxysmal AF (PAF).

METHODS AND RESULTS

A total of 218 treatment naive patients with symptomatic PAF were randomized (1 : 1) to cryoballoon CA (Arctic Front Advance, Medtronic) or AAD (Class I or III) and followed for 12 months. The primary endpoint was ≥1 episode of recurrent AA (AF, atrial flutter, or atrial tachycardia) >30 s after a prespecified 90-day blanking period. Secondary endpoints included the rate of serious adverse events (SAEs) and recurrence of symptomatic palpitations (evaluated via patient diaries). Freedom from AA was achieved in 82.2% of subjects in the cryoballoon arm and 67.6% of subjects in the AAD arm (HR = 0.48, P = 0.01). There were no group differences in the time-to-first (HR = 0.76, P = 0.28) or overall incidence [incidence rate ratio (IRR)=0.79, P = 0.28] of SAEs. The incidence rate of symptomatic palpitations was lower in the cryoballoon (7.61 days/year) compared with the AAD arm (18.96 days/year; IRR = 0.40, P < 0.001).

CONCLUSIONS

Cryoballoon CA was superior to AAD therapy, significantly reducing AA recurrence in treatment naive patients with PAF. Additionally, cryoballoon CA was associated with lower symptom recurrence and a similar rate of SAEs compared with AAD therapy.

First-line therapy: insights from a real-world analysis of cryoablation in patients with atrial fibrillation

AIMS

Pulmonary vein isolation (PVI) using cryoballoon ablation (CBA) is mainly reserved for patients with drug-refractory or drug-intolerant symptomatic atrial fibrillation. We evaluated a large cohort of patients treated in a real-world setting and examined the safety and efficacy profile of CBA when applied as a first-line treatment for atrial fibrillation.

METHODS

In total, 249 patients (23% women; 56 ± 13 years; mean left atrial diameter 41 ± 7 mm; 73.5% paroxysmal atrial fibrillation; and 26.5% persistent atrial fibrillation) underwent an index PVI by CBA. Data were collected prospectively in the framework of the 1STOP ClinicalService project, involving 26 Italian cardiology centers.

RESULTS

Median procedure and fluoroscopy times were 90.0 and 21.0 min, respectively. Acute procedural success was 99.8%. Acute/periprocedural complications were observed in seven patients (2.8%), including: four transient diaphragmatic paralyses, one pericardial effusion (not requiring any intervention), one transient ischemic attack, and one minor vascular complication. The Kaplan--Meier freedom from atrial fibrillation recurrence was 86.3% at 12 months and 76% at 24 months. Seventeen patients (6.8%) had a repeat catheter ablation procedure during the follow-up period. At last follow-up, 10% of patients were on an anticoagulation therapy, whereas 6.8% were on an antiarrhythmic drug.

CONCLUSION

In our multicenter real-world experience, PVI by CBA in a first-line atrial fibrillation patient population was well tolerated, effective, and promising. CBA with a PVI strategy can be used to treat patients with paroxysmal and persistent atrial fibrillation with good acute procedural success, short procedure times, and acceptable safety.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov (NCT01007474).

Cryoballoon Ablation as Initial Therapy for Atrial Fibrillation

BACKGROUND

In patients with symptomatic paroxysmal atrial fibrillation that has not responded to medication, catheter ablation is more effective than antiarrhythmic drug therapy for maintaining sinus rhythm. However, the safety and efficacy of cryoballoon ablation as initial first-line therapy have not been established.

METHODS

We performed a multicenter trial in which patients 18 to 80 years of age who had paroxysmal atrial fibrillation for which they had not previously received rhythm-control therapy were randomly assigned (1:1) to receive treatment with antiarrhythmic drugs (class I or III agents) or pulmonary vein isolation with a cryoballoon. Arrhythmia monitoring included 12-lead electrocardiography conducted at baseline and at 1, 3, 6, and 12 months; patient-activated telephone monitoring conducted weekly and when symptoms were present during months 3 through 12; and 24-hour ambulatory monitoring conducted at 6 and 12 months. The primary efficacy end point was treatment success (defined as freedom from initial failure of the procedure or atrial arrhythmia recurrence after a 90-day blanking period to allow recovery from the procedure or drug dose adjustment, evaluated in a Kaplan-Meier analysis). The primary safety end point was assessed in the ablation group only and was a composite of several procedure-related and cryoballoon system-related serious adverse events.

RESULTS

Of the 203 participants who underwent randomization and received treatment, 104 underwent ablation, and 99 initially received drug therapy. In the ablation group, initial success of the procedure was achieved in 97% of patients. The Kaplan-Meier estimate of the percentage of patients with treatment success at 12 months was 74.6% (95% confidence interval [CI], 65.0 to 82.0) in the ablation group and 45.0% (95% CI, 34.6 to 54.7) in the drug-therapy group (P<0.001 by log-rank test). Two primary safety end-point events occurred in the ablation group (Kaplan-Meier estimate of the percentage of patients with an event within 12 months, 1.9%; 95% CI, 0.5 to 7.5).

CONCLUSIONS

Cryoballoon ablation as initial therapy was superior to drug therapy for the prevention of atrial arrhythmia recurrence in patients with paroxysmal atrial fibrillation. Serious procedure-related adverse events were uncommon. (Supported by Medtronic; STOP AF First ClinicalTrials.gov number, NCT03118518.).

Trends and predictors of early ablation for Atrial Fibrillation in a Nationwide population under age 65: a retrospective observational study

BACKGROUND

Catheter ablation (CA) has emerged as an effective treatment for symptomatic atrial fibrillation (AF). However practice patterns and patient factors associated with referral for CA within the first 12 months after diagnosis are poorly characterized. This study examined overall procedural trends and factors predictive of catheter ablation for newly-diagnosed atrial fibrillation in a young, commercially-insured population.

METHODS

A large nationally-representative sample of patients age 20 to 64 from years 2010 to 2016 was studied using the IBM MarketScan® Commercial Database. Patients were included with a new diagnosis of AF in the inpatient or outpatient setting with continuous enrollment for at least 1 year pre and post index visit. Patients were excluded if they had prior history of AF or had filled an anti-arrhythmic drug (AAD) in the pre-index period.

RESULTS

Early CA increased from 5.0% in 2010 to 10.5% in 2016. Patients were less likely to undergo CA if they were located in the Northeast (OR: 0.80, CI: 0.73-0.88) or North Central (OR: 0.91, CI: 0.83-0.99) regions (compared with the West), had higher CHA2DS2-VASc scores, or had Charlson Comorbidity Index (CCI) score of 3 or greater (OR: 0.61; CI: 0.51-0.72).

CONCLUSIONS

CA within 12 months for new-diagnosed AF increased significantly from 2010 to 2016, with most patients still trialed on an AAD prior to CA. Patients are less likely to be referred for early CA if they are located in the Northeast and North Central regions, have more comorbidities, or higher CHA2DS2-VASc scores.

Cryoballoon catheter ablation versus antiarrhythmic drugs as a first-line therapy for patients with paroxysmal atrial fibrillation: Rationale and design of the international Cryo-FIRST study

BACKGROUND

Radiofrequency current (RFC) catheter ablation for patients with paroxysmal atrial fibrillation (AF) has been shown to be safe and effective in first-line therapy. Recent data demonstrates that RFC ablation provides better clinical outcomes compared to antiarrhythmic drug (AAD) in the treatment of early AF disease. Furthermore, studies comparing RFC and cryoballoon have established comparable efficacy and safety of pulmonary vein isolation (PVI) for patients with symptomatic paroxysmal AF.

OBJECTIVES

The Cryo-FIRST trial was designed to compare AAD treatment against cryoballoon PVI as a first-line therapy in treatment naïve patients with AF. Efficacy and safety will be compared between the two cohorts and amongst subgroups.

METHODS

The primary hypothesis is that cryoablation is superior to AAD therapy. To test this hypothesis, patients will be randomized in a 1:1 design. Using a 90-day blanking period, primary efficacy endpoint failure is defined as (at least) one episode of atrial arrhythmia with a duration >30 sec (documented by 7-day Holter or 12-lead ECG). Secondary endpoints (Quality-of-Life, rehospitalization, arrhythmia recurrence rate, healthcare utilization, and left atrial function) and adverse events will also be evaluated. Study enrollment will include 218 patients in up to 16 centers.

CONCLUSIONS

This study will be a multi-national randomized controlled trial comparing cryoablation against AAD as a first-line treatment in patients with paroxysmal AF. The results may help guide the selection of patients for early AF disease therapy via cryoballoon ablation.

PLAAF score as a novel predictor of long-term outcome after second-generation cryoballoon pulmonary vein isolation

Aims

Predictors of atrial arrhythmia recurrence have not been described in a long-term follow-up study of patients undergoing pulmonary vein isolation (PVI) using the cryoballoon technique. We aimed to evaluate the efficacy of a second-generation cryoballoon and identify pre-procedural predictors of 3-year outcome after PVI.

Methods and results

For this observational cohort study, we enrolled 440 patients ablated at our institution with a second-generation cryoballoon. The endpoint was the first documented recurrence (>30 s) of atrial fibrillation (AF), atrial flutter, or atrial tachycardia after a 3-month blanking period. The impact of several pre-existing variables on clinical outcome was evaluated by univariate and multivariate analyses using the Cox proportional hazards regression model. The PLAAF (persistent AF, left atrial area, abnormal PV anatomy, AF history, female gender) score was defined to predict outcome. After a median follow-up of 36 months (interquartile range 25/75-27/42), the endpoint was achieved in 95 of 440 (21.6%) patients. Cox regression analysis showed that persistent AF, left atrial (LA) area, abnormal PV anatomy, AF history, and female gender independently predicted recurrence. The calculated optimal cut-offs for LA area and AF history were 21 cm2 and 3 years, respectively. Patients with a PLAAF score of 0 showed the best outcome, with an arrhythmia-free survival of 86.7%.

Conclusion

PVI using the cryoballoon technique shows acceptable long-term results depending on predictors described by the new PLAAF score, which may facilitate patient selection for PVI.

A randomized clinical trial of early invasive intervention for atrial fibrillation (EARLY-AF) - methods and rationale

BACKGROUND

The ideal management of patients with newly diagnosed symptomatic atrial fibrillation (AF) remains unknown. Current practice guidelines recommend a trial of antiarrhythmic drugs (AAD) prior to considering an invasive ablation procedure. However, earlier ablation offers an opportunity to halt the progressive patho-anatomical changes associated with AF, as well as impart other important clinical benefits.

OBJECTIVE

The aim of this study is to determine the optimal initial management strategy for patients with newly diagnosed, symptomatic atrial fibrillation.

METHODS/DESIGN

The EARLY-AF study (ClinicalTrials.govNCT02825979) is a prospective, open label, multicenter, randomized trial with a blinded assessment of outcomes. A total of 298 patients will be randomized in a 1:1 fashion to first-line AAD therapy, or first-line cryoballoon-based pulmonary vein isolation. Patients with symptomatic treatment naïve AF will be included. Arrhythmia outcomes will be assessed by implantable cardiac monitor (ICM). The primary outcome is time to first recurrence of AF, atrial flutter, or atrial tachycardia (AF/AFL/AT) between days 91 and 365 following AAD initiation or AF ablation. Secondary outcomes include arrhythmia burden, quality of life, and healthcare utilization.

DISCUSSION

The EARLY-AF study is a randomized trial designed to evaluate the optimal first management approach for patients with AF. We hypothesize that catheter ablation will be superior to drug therapy in prevention of AF recurrence.

Second-generation cryoballoon ablation as a first-line treatment of symptomatic atrial fibrillation: Two-year outcome and predictors of recurrence after a single procedure

INTRODUCTION

Antiarrhythmic drug (AAD) therapy of patients with atrial fibrillation (AF) has limitations. We investigated the 2-year outcome and pre-procedural predictors of recurrence for first-line catheter ablation using the second-generation cryoballoon (CB-Adv) in a large cohort of patients with symptomatic AF.

METHODS AND RESULTS

For this prospective observational study, we enrolled 457 patients with symptomatic AF (278 paroxysmal, 179 persistent) who had no history of AAD use and who underwent pulmonary vein isolation (PVI) with the CB-Adv at our institution. Follow-up data, including Holter-ECGs, were collected during outpatient clinic visits. The impact of several variables on outcome was evaluated in univariate and multivariate analyses and Cox proportional hazards regression models. Median follow-up duration was 28 (interquartile range 15/42) months. PVI was sufficient in restoring and maintaining sinus rhythm in 79.2% (n=362) of patients. The median procedure and fluoroscopy times were 90 (72/120) and 16 (12/21) min, respectively. Phrenic nerve injury occurred in 16 (3.5%) patients, persisting until hospital discharge in 6 (1.3%) patients; phrenic nerve function recovered in all patients during follow-up. Seven patients developed groin hematomas (1.5%). Cox regression analysis showed that left atrial area >21cm² independently predicted recurrence.

CONCLUSION

This is the first demonstration that PVI with CB-Adv is safe and effective as a first-line treatment of symptomatic AF. Sinus rhythm persisted in 79.2% of patients even 2years after ablation. The success rate was lower in patients with enlarged left atria.

Catheter Ablation as First-Line Therapy for Atrial Fibrillation: Ready for Prime-Time?

Current guidelines include atrial fibrillation (AF) catheter ablation as part of the management strategy in patients that have failed at least one oral antiarrhythmic drug treatment course. However, growing evidence derived from both randomized and non-randomized studies demonstrate lower rates of AF recurrence and AF burden in patients with paroxysmal AF that are naïve to antiarrhythmic drug treatment. Furthermore, progression from paroxysmal AF to persistent AF appears to be delayed by early catheter ablation of AF. The current review addresses the question of the best timing for ablation in patients with paroxysmal AF and provides the rationale for offering AF ablation as first-line therapy based on the most updated evidence available.

Catheter Ablation of Atrial Fibrillation: An Overview for Clinicians

Catheter ablation (CA) of atrial fibrillation (AF) is currently one of the most commonly performed electrophysiology procedures. Ablation of paroxysmal AF is based on the elimination of triggers by pulmonary vein isolation (PVI), while different strategies for additional AF substrate modification on top of PVI have been proposed for ablation of persistent AF. Nowadays, various technologies for AF ablation are available. The radiofrequency point-by-point ablation navigated by electro-anatomical mapping system and cryo-balloon technology are comparable in terms of the efficacy and safety of the PVI procedure. Long-term success of AF ablation including multiple procedures varies from 50 to 80%. Arrhythmia recurrences commonly occur, mostly due to PV reconnection. The recurrences are particularly common in patients with non-paroxysmal AF, dilated left atrium and the "early recurrence" of AF within the first 2-3 post-procedural months. In addition, this complex procedure can be accompanied by serious complications, such as cardiac tamponade, stroke, atrio-esophageal fistula and PV stenosis. Therefore, CA represents a second-line treatment option after a trial of antiarrhythmic drug(s). Good candidates for the procedure are relatively younger patients with symptomatic and frequent episodes of AF, with no significant structural heart disease and no significant left atrial enlargement. Randomized trials demonstrated the superiority of ablation compared to antiarrhythmic drugs in terms of improving the quality of life and symptoms in AF patients. However, nonrandomized studies reported additional clinical benefits from ablation over drug therapy in selected AF patients, such as the reduction of the mortality and stroke rates and the recovery of tachyarrhythmia-induced cardiomyopathy. Future research should enable the creation of more durable ablative lesions and the selection of the optimal lesion set in each patient according to the degree of atrial remodeling. This could provide better long-term CA success and expand indications for the procedure, especially among the patients with non-paroxysmal AF.

Ablation as First-Line Therapy for Atrial Fibrillation: Yes

This article addresses the use of catheter ablation (CA) as first-line therapy for atrial fibrillation (AF). CA increases long-term freedom from AF, reduces hospitalizations, and improves quality of life compared with antiarrhythmic drug (AAD) therapy in patients with symptomatic AF who have already failed one AAD. The role of CA as first-line therapy for AF, however, is still controversial. Evidence from randomized controlled trials shows that CA is definitely superior to AADs as first-line therapy for relatively young patients with paroxysmal AF, with comparable complication rates and results consistently reproducible across different institutions, operators, and types of ablation approaches.

The Impact of Left Atrial Surface Area and the Second Generation Cryoballoon on Clinical Outcome of Atrial Fibrillation Cryoablation

AIMS

In this observational study, we examine the significance of the left atrial (LA) surface area and compare the clinical usage of the Arctic Front Advance (CBA) versus Arctic Front (CB) cryoballoon with the intent to investigate the impact of each in terms of long-term freedom from atrial fibrillation (AF) for patients with nonvalvular AF.

METHODS

Pulmonary vein isolation (PVI) was performed while using a cryoballoon ablation catheter in conjunction with an intraluminal circular diagnostic mapping catheter, Achieve. The consecutive patients ablated with CBA were matched with patients previously ablated with CB, using propensity score matching. The primary endpoint of this observational single-center retrospective study was the first observation of electrocardiogram-documented recurrence of atrial arrhythmias lasting >30 seconds.

RESULTS

The patient demographic data were similar in the CBA- and CB-group (N = 188 patients each group). In all patients in the CBA-group and in 95% of the patients in the CB group, acute procedural PVI of all veins was achieved with the single usage of a 28-mm cryoballoon. The one-year freedom from atrial arrhythmias was significantly better in the CBA- versus the CB-group of patients, 90% versus 64%, respectively. During 15-month clinical follow-up in CBA group, patients with LA area above 23 cm(2) were more likely to experience recurrence of AF (23%) than patients with LA area below 23 cm(2) (7%).

CONCLUSIONS

Comparing one-year outcomes, the CBA is superior to the CB with regards to maintenance of normal sinus rhythm. When using the CBA catheter, an enlarged LA is associated with a higher recurrence of arrhythmia.

Cryoballoon ablation in young patients with lone paroxysmal atrial fibrillation

INTRODUCTION AND OBJECTIVES

Long-term efficacy following cryoballoon ablation of lone paroxysmal atrial fibrillation remains unknown. We describe long-term follow-up results of the single cryoballoon ablation procedure.

METHODS

Pulmonary vein isolation was performed in 103 patients (72 male; median age 52 years) with symptomatic lone paroxysmal atrial fibrillation. The end-point of this observational cohort study was first electrocardiogram-documented recurrence of arrhythmia (atrial fibrillation, atrial tachycardia, or atrial flutter) during the 5-year follow-up, in the absence of anti-arrhythmic treatment.

RESULTS

Acute complete pulmonary vein isolation was achieved in 86% of the patients with a single cryoballoon. The 6-month, 1-year, and 5-year success rate after a single procedure was 94%, 91%, and 77%, respectively. Arrhythmia recurrence was observed in 24 cases at a median of 14.8 months [range, 8.0-16.8 months]. Thirteen symptomatic patients were well controlled on beta-blockers only. Seven symptomatic patients had anti-arrhythmic treatment (class IC in 5 patients; dronedarone in 2 patients) introduced during the blanking period. Two of them had early arrhythmia recurrence within the blanking period only; they were arrhythmia-free in further follow-up on dronedarone. The rate of complications was relatively low and included a 4.8% incidence of transient phrenic nerve palsy.

CONCLUSIONS

A single cryoballoon ablation procedure for lone paroxysmal atrial fibrillation resulted in high rates of acute, medium-term, and long-term efficacy. The rate of complications is relatively low and includes a 4.8% incidence of transient phrenic nerve palsy.

Ablation of atrial fibrillation with cryoballoon or duty-cycled radiofrequency pulmonary vein ablation catheter: a randomized controlled study comparing the clinical outcome and safety; the AF-COR study

AIMS

The urge to facilitate the atrial fibrillation (AF) ablation procedure has led to the development of new ablation catheters specifically designed as 'one-shot tools' for pulmonary vein isolation (PVI). The purpose of this study was to compare the efficacy, safety, and procedure times for two such catheters using different energy sources.

METHODS AND RESULTS

One hundred and ten patients, referred for ablation of paroxysmal or persistent AF, were randomized to treatment with either the cryoballoon or the circular multipolar duty-cycled radiofrequency-based pulmonary vein ablation catheter (PVAC). Complete PVI was achieved in 98 vs. 93% patients in the cryoballoon and PVAC group, respectively, with complication rates of 8 vs. 2% (P = 0.2). Complete freedom from AF, without antiarrhythmic drugs, after one single ablation procedure was seen in 46% in the cryoballoon vs. 34% after 12 months (P = 0.2). Procedure times were comparable, but fluoroscopy time was shorter for the cryoballoon (32 ± 16 min) than for the PVAC procedures (47 ± 17 min) (P < 0.001). A significant improvement of quality of life (QoL) and arrhythmia-related symptoms was seen in both groups after ablation.

CONCLUSION

Both catheters proved comparably effective and safe in achieving acute PVI, apart from the shorter fluoroscopy times achieved with the cryoballoon. At follow-up, there was no statistically significant difference between the groups regarding freedom from AF and clinical success. The QoL increased to the same levels as for the general Swedish population in both groups.

Cryoballoon ablation of paroxysmal atrial fibrillation: 5-year outcome after single procedure and predictors of success

AIMS

Long-term efficacy following cryoballoon (CB) ablation of atrial fibrillation (AF) remains unknown. This study describes 5 years follow-up results and predictors of success of CB ablation in patients with paroxysmal atrial fibrillation (PAF).

METHODS AND RESULTS

In total, 163 patients were enrolled with symptomatic, drug refractory PAF. Pulmonary vein isolation (PVI) with CB technique was performed. Primary endpoint of this consecutive single-centre study was first electrocardiogram-documented recurrence of AF, atrial tachycardia or atrial flutter (AFLAT). Five years success rate after single CB ablation was 53%. In 70% of the patients acute complete PVI was achieved with a single 28 mm balloon. The univariate predictors of AFLAT recurrence were (1) size of left atrium, with normalized left atrium (NLA) ≥10.25 [hazard ratios (HR) of 1.81, 95% confidence interval (CI): 1.28-2.56] when compared with NLA <10.25 (35% vs. 53%, P = 0.0001) and (2) renal function, with impaired glomerular filtration rate (GFR) <80 ml/min (HR of 1.26, 95% CI: 1.02-1.57) when compared with GFR ≥80 ml/min (45% vs. 53%, P = 0.041). Normalized left atrium ≥10.25 was the sole independent predictor for outcome (HR 2.11; 95% CI: 1.34-3.31; P = 0.0001).

CONCLUSIONS

Sinus rhythm can be maintained in a substantial proportion of patients with PAF even 5 years after circumferential PVI using CB ablation. The rate of decline in freedom from AFLAT was highest within the first 12 months after the index procedure. The patients with enlarged left atrium and/or impaired renal function have lower outcome.

Treating Atrial Fibrillation With Cryoballoon Technology

Cryoballoon ablation has emerged as a novel tool to perform pulmonary vein isolation. The aim of this paper is to review the advantages, drawbacks as well as possible complications and clinical outcomes of this technology and to discuss some important technical issues.

Outcome of Patients Discharged after their First Detected Episode of Atrial Fibrillation

Atrial fibrillation (AF) is the most frequent supraventricular arrhythmia with an approximative prevalence of 1 % in the general population and above 6 % in the elderly. After a first AF diagnosis, the hospitalization rate is markedly increased. Management of a first AF episode is different depending on the clinical status of patients. Practical guidelines developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society are available for the management of these patients. A four-step decisional scheme must be followed in the management of a first recent AF episode: need for a short- and long-term anticoagulation, define a rythmologic strategy (rhythm or rate control), select the weapon (drug, device or ablation) and reconsider the strategy if needed. After a first uncomplicated paroxysmal AF episode, guidelines recommend that prescription of antiarrhythmics must be avoided and anticoagulation is optional. After a first persistent AF episode, guidelines recommend to either respect or reduce the arrhythmia. Prescription of antiarrhythmics and anticoagulation is also optional depending on the patient?s condition. In case of the AF reduction decision, anticoagulation must be tailored preliminary to this reduction. AF recurrence rate varies depending on the patient?s condition, and the risk of stroke assessed by the CHA₂DS₂-VASc score might be similarly considered for both paroxysmal and persistent AF.