Pulmonary vein triggers play an important role in the initiation of atrial flutter: Initial results from the prospective randomized Atrial Fibrillation Ablation in Atrial Flutter (Triple A) trial

Incidence and patterns of atrial fibrillation after catheter ablation of typical atrial flutter-the FLUTFIB study

AIMS

In patients with atrial flutter (AFL), ablation of the cavotricuspid isthmus (CTI) is a highly effective procedure to prevent AFL recurrence, but atrial fibrillation (AF) may occur during follow-up. The presented FLUTFIB study was designed to identify the exact incidence, duration, timely occurrence, and associated symptoms of AF after CTI ablation using continuous cardiac monitoring via implantable loop recorders.

METHODS AND RESULTS

One hundred patients with AFL without prior AF diagnosis were included after CTI ablation (mean age 69.7 ± 9.7 years, 18% female) and received an implantable loop recorder for AF detection. After a median follow-up of 24 months 77 patients (77%) were diagnosed with AF episodes. Median time to first AF occurrence was 180 (43-298) days. Episodes lasted longer than 1 h in most patients (45/77, 58%). Forty patients (52%) had AF-associated symptoms.Patients with and without AF development showed similar baseline characteristics and neither HATCH- nor CHA2DS2-VASc scores were predictive of future AF episodes. Oral anticoagulation (OAC) was stopped during FU in 32 patients (32%) and was re-initiated after AF detection in 15 patients (15%). No strokes or transient ischaemic attack episodes were observed during follow-up.

CONCLUSION

This study represents the largest investigation using implantable loop recorders (ILRs) to detect AF after AFL ablation and shows a high incidence of AF episodes, most of them being asymptomatic and lasting longer than 1 h. In anticipation of trials determining the duration of AF episodes that should trigger OAC initiation, these results will help to guide anticoagulation management after CTI ablation.

[Isthmus-dependent right atrial flutter : Clinical course after isthmus ablation]

Ablation of the cavotricuspid isthmus (CTI) to create bidirectional isthmus blockade is the most effective way to achieve rhythm control in typical atrial flutter. Compared with drug therapy, ablation reduces cardiovascular mortality, all-cause mortality, stroke risk, and the risk of cardiac decompensation. Concomitant arrhythmia of atrial flutter is atrial fibrillation (AF); therefore the duration of oral anticoagulation should be adapted according to the risk of stroke and bleeding. A combined procedure of CTI ablation and pulmonary vein isolation (PVI) in patients with typical atrial flutter but without evidence of AF should be evaluated individually especially in patients aged > 54 years depending on (cardiac) comorbidities. The comprehensive diagnostic view should keep in mind not only arrhythmias but also possibly underlying coronary artery disease.

Cryoballoon Pulmonary Vein Isolation as First-Line Treatment for Typical Atrial Flutter

OBJECTIVE

We aimed to compare cryoballoon pulmonary vein isolation (PVI) with standard radiofrequency cavotricuspid isthmus (CTI) ablation as first-line treatment for typical atrial flutter (AFL).

METHODS

Cryoballoon Pulmonary Vein Isolation as First-Line Treatment for Typical Atrial Flutter was an international, multicentre, open with blinded assessment trial. Patients with CTI-dependent AFL and no documented atrial fibrillation (AF) were randomised to either cryoballoon PVI alone or radiofrequency CTI ablation. Primary efficacy outcome was time to first recurrence of sustained (>30 s) symptomatic atrial arrhythmia (AF/AFL/atrial tachycardia) at 12 months as assessed by continuous monitoring with an implantable loop recorder. Primary safety outcome was a composite of death, stroke, tamponade requiring drainage, atrio-oesophageal fistula, pacemaker implantation, serious vascular complications or persistent phrenic nerve palsy.

RESULTS

Trial recruitment was halted at 113 of the target 130 patients because of the SARS-CoV-2 pandemic (PVI, n=59; CTI ablation, n=54). Median age was 66 (IQR 61-71) years, with 98 (86.7%) men. At 12 months, the primary outcome occurred in 11 (18.6%) patients in the PVI group and 9 (16.7%) patients in the CTI group. There was no significant difference in the primary efficacy outcome between the groups (HR 1.11, 95% CI 0.46 to 2.67). AFL recurred in six (10.2%) patients in the PVI arm and one (1.9%) patient in the CTI arm (p=0.116). Time to occurrence of AF of ≥2 min was significantly reduced with cryoballoon PVI (HR 0.46, 95% CI 0.25 to 0.85). The composite safety outcome occurred in four patients in the PVI arm and three patients in the CTI arm (p=1.000).

CONCLUSION

Cryoballoon PVI as first-line treatment for AFL is equally effective compared with standard CTI ablation for preventing recurrence of atrial arrhythmia and better at preventing new-onset AF.

TRIAL REGISTRATION NUMBER

NCT03401099.

Premature atrial contractions: A predictor of atrial fibrillation and a relevant marker of atrial cardiomyopathy

An increased burden of premature atrial contractions (PACs) has long been considered a benign phenomenon. However, strong evidence of their involvement in the occurrence of atrial fibrillation (AF), ischemic stroke, and excess mortality suggests the need for management. The central question to be resolved is whether increased ectopic atrial rhythm is only a predictor of AF or whether it is a marker of atrial cardiomyopathy and therefore of ischemic stroke. After reviewing the pathophysiology of PACs and its impact on patient prognosis, this mini-review proposes to 1) detail the physiological and clinical elements linking PACs and AF, 2) present the evidence in favor of supraventricular ectopic activity as a marker of cardiomyopathy, and 3) outline the current limitations of this concept and the potential future clinical implications.

Risk of New-Onset Atrial Fibrillation Post-cavotricuspid Isthmus Ablation in Typical Atrial Flutter Without History of Atrial Fibrillation

Aims: The aim was to describe the incidence of atrial fibrillation (AF) after cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL) without history of AF and to identify risk factors for new-onset AF after the procedure.

Methods: A total of 191 patients with typical AFL undergoing successful CTI ablation were enrolled. Patients who had history of AF, structural heart disease, cardiac surgery, or ablation or who received antiarrhythmic drug after procedure were excluded. Clinical and electrophysiological data were collected.

Results: There were 47 patients (24.6%) developing new AF during a follow-up of 3.3 ± 1.9 years after CTI ablation. Receiver operating characteristic (ROC) curves indicated that the cut-off values of left atrial diameter (LAD) and CHA₂DS₂-VASc score were 42 mm and 2, with area under the curve of 0.781 and 0.550, respectively. The multivariable Cox regression analysis revealed that obstructive sleep apnea (OSA) [hazard ratio (HR) 3.734, 95% confidence interval (CI) 1.470–9.484, P = 0.006], advanced interatrial block (aIAB) (HR 2.034, 95% CI 1.017–4.067, P = 0.045), LAD > 42 mm (HR 2.710, 95% CI 1.478–4.969, P = 0.001), and CHA₂DS₂-VASc score > 2 (HR 2.123, 95% CI 1.118–4.034, P = 0.021) were independent risk factors of new-onset AF.

Conclusion: A combination of OSA, aIAB, LAD > 42 mm, and CHA₂DS₂-VASc > 2 was a strongly high risk for new-onset AF after ablation for typical AFL, and it had significance in postablation management in clinical practice.

Rates of atrial flutter occurrence and cavotricuspid isthmus reconduction after prophylactic isthmus ablation performed during atrial fibrillation ablation: a clinical study, review, and comparison with previous findings

PURPOSE

Based on the high rate of coexisting atrial fibrillation (AF) and atrial flutter (AFL), prophylactic cavotricuspid isthmus ablation (CTIA) adjunctive to AF ablation has recently been attempted in patients with AF and without AFL. The present study aimed to determine the rates of AFL occurrence and CTI reconduction after performing CTI ablation adjunctive to AF ablation.

METHODS

We analyzed the data of 3833 consecutive patients with AF, who underwent prophylactic CTIA with AF ablation between 2009 and 2020.

RESULTS

In all patients, CTIA and AF ablations were successful. Clinical AFL occurred in seven patients (0.18%, 7/3,833), and the observed rate was lower than those reported for cases of AF ablation without CTIA and for those of CTIA for pure AFL. A second ablation was needed in 745 patients at a median of 253 days (25 and 75 percentiles, 116 and 775 days) after the first ablation. In 12.1% (90/745) of the patients, CTI reconduction was observed. The reconduction rate was lower than that previously reported for CTIA for pure AFL.

CONCLUSIONS

The present retrospective study found acceptably low rates of clinical AFL occurrence and CTI reconduction following prophylactic CTIA performed with AF ablation, which was supported by the findings obtained after performing a comparison of the rates with those of other ablations (AF ablation only and CTIA for pure AFL). Considering the high correlation between AF and AFL, the present study provided information regarding the efficacy of adjunctive CTIA.

Electrophysiological characteristics of atrial tachycardia recurrence: Relevance to catheter ablation strategies in adults with congenital heart disease

BACKGROUND

Catheter ablation outcomes for adults with congenital heart disease (ACHDs) are described, but recurrence mechanisms remain largely unknown.

OBJECTIVE

The purpose of this study was to identify the electrophysiological characteristics of atrial tachycardia (AT) recurrence in ACHD.

METHODS

ACHD AT procedures over a 10-year period were explored for AT or atrial fibrillation (AF) recurrence.

RESULTS

At 299 procedures in 250 ACHD (mean age 39 ± 15 years; 52% male), 464 ATs (360 intra-atrial reentrant tachycardia, 104 focal AT; median 2 [IQR 1-3] ATs per procedure) were targeted. Complete (n = 256 [86%]) or partial (n = 37 [12%]) success was achieved in 98% of procedures. Over a median of 3.0 (IQR 1.4-5.3) years of follow-up, 67 patients (27%) developed AT/AF recurrence after the index procedure. Recurrent vs index tachycardias were more often focal AT (38% vs 19%; P < .001), demonstrated longer cycle length (325 ms vs 280 ms; P = .003), required isoproterenol (50% vs 32%; P = .03), and involved the pulmonary venous atrium (PVA)/septum (53% vs 27%; P < .001). AF history (hazard ratio [HR] 2.0; interquartile range [IQR] 1.2-3.4; P = .01), incomplete success (HR 3.6; IQR 2.1-6.4; P < .001), and PVA substrate (HR 2.1; IQR 1.2-3.5; P = .006) were independently associated with AT/AF recurrence. After complete index procedure success and no AF history, 5-year actuarial freedom from AT/AF and AT alone were 77% and 80%.

CONCLUSION

After catheter ablation in ACHD, repeat ATs were frequently focal, requiring isoproterenol administration, or involved intra-atrial reentrant tachycardia within the PVA or atrial septum. Negative factors were partial success, index PVA substrate, and remote history of AF. These data support aggressive pharmacological provocation to eliminate all inducible tachycardias and coexisting PVA substrates at index procedures for ACHD.

Pulmonary vein and left atrial posterior wall isolation for the treatment of atrial fibrillation: Comparable outcomes for adults with congenital heart disease

INTRODUCTION

Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF).

METHODS

A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period.

RESULTS

Three-hundred and sixteen patients (mean: 63 ± 12 years, [63% male]) underwent CB PVI ± PWI during the study, including 31 (10%) ACHD (simple 35%, moderate 39% complex 26%; nonparoxysmal AF in 52%). ACHD was younger (51 vs. 64 years; p < .001) with a lower CHADS₂ DS₂ -VASc score (1.2 vs. 2.1; p = .001) but had a greater LA diameter (4.9 vs. 4.0 cm; p < .001) and a number of prior cardioversions (0.9 vs. 0.4; p < .001) versus controls. 12-month freedom from recurrent AF was similar for ACHD and controls (76% vs. 80%; p = .6) and remained nonsignificant in multivariate analysis (hazard ratio: 1.8, 95% confidence interval: 0.7-5.1; p = .22). At 12-months postablation, 75% of ACHD versus 93% of control patients were off antiarrhythmic drug therapy (p = .07).

CONCLUSION

This study demonstrates younger age and lower conventional stroke risk, yet clinically advanced AF for ACHD relative to controls. CB PVI ± PWI was an effective strategy for the treatment of AF among all forms of ACHD with similar 12-month outcomes as compared to controls.

Cavotricuspid isthmus line in patients undergoing catheter ablation of atrial fibrillation with or without history of typical atrial flutter: A meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is the mainstay of catheter ablation (CA) for paroxysmal atrial fibrillation (AF). However, for persistent and long-standing persistent AF, there are no established strategies to improve the success rate of CA. Despite studies indicating that prophylactic cavotricuspid isthmus (CTI) ablation provides no or limited incremental benefit in patients with AF, it is still routinely performed worldwide.

OBJECTIVE

We sought to examine whether CTI ablation for AF is associated with improvement in recurrence of all-atrial arrhythmias, compared with PVI alone in patients with and without typical atrial flutter (AFL).

METHODS

A systematic review of PubMed, Cochrane, and Embase was performed for clinical studies including AF patients, reporting outcomes of CTI + PVI versus PVI alone. The primary efficacy endpoint was recurrence of all-atrial arrhythmias.

RESULTS

Five studies comprising 1400 patients undergoing CTI + PVI versus PVI alone were included; 1110 patients had AF without AFL, and 290 patients had coexistent AF and AFL. After a mean follow-up of 14.4 ± 4.8 months, CTI + PVI was not associated with improvement in recurrence of all-atrial arrhythmias when compared with PVI alone (risk ratio [RR]: 1.29; 95% confidence interval [CI]: 0.93-1.79;p = .13). In the subgroup analysis, there were no differences between both groups in patients with AF without AFL (RR: 1.55; 95% CI: 0.96-2.48; p = .07), and in patients with AF and AFL (RR: 0.91; 95% CI: 0.6-1.39; p = .68).

CONCLUSION

In AF patients, irrespective of the presence of typical AFL, additional CTI ablation is not associated with improvement in recurrence of all-atrial arrhythmias, compared with PVI alone.

Symptoms and quality of life in patients with coexistent atrial fibrillation and atrial flutter

Aims

Atrial fibrillation (AF) and atrial flutter (AFL) are two of the most common atrial arrhythmias and often coexist. Many patients with AF or AFL are symptomatic, which impacts their quality of life (QoL). The purpose of this study was to determine whether coexistent AFL represents an added burden for AF patients.

Methods

We combined baseline data from two large prospective, observational, multicenter cohort studies (BEAT-AF and Swiss-AF). All 3931 patients included in this analysis had documented AF. We obtained information on comorbidities, medication, and lifestyle factors. All participants had a clinical examination and a resting ECG. Symptom burden and QoL at the baseline examination were compared between patients with and without coexistent AFL using multivariable adjusted regression models.

Results

Overall, 809 (20.6%) patients had a history of AFL. Patients with coexistent AFL more often had history of heart failure (28% vs 23%, p = 0.01), coronary artery disease (30% vs 26%, p = 0.007), failed therapy with antiarrhythmic drugs (44% vs 29%, p < 0.001), and more often underwent AF-related interventions (36% vs 17%, p < 0.001). They were more often symptomatic (70% vs 66%, p = 0.04) and effort intolerant (OR: 1.14; 95% CI: 1.01-1.28; p = 0.04). Documented AFL on the baseline ECG was associated with more symptoms (OR: 2.30; 95% CI: 1.26-4.20; p = 0.007).

Conclusion

Our data indicates that patients with coexistent AF and AFL are more often symptomatic and report poorer quality of life compared to patients suffering from AF only.

CHA2DS2-VASc Score as a Predictor of New-Onset Atrial Fibrillation After Catheter Ablation of Typical Atrial Flutter

Purpose

Cavotricuspid isthmus (CTI) ablation is an effective procedure for typical atrial flutter (AFL), but patients remain at an elevated risk for developing new atrial fibrillation (AF). Currently, there are limited data on the utility of CHA₂DS₂-VASc score to predict new-onset AF after typical AFL ablation. In this study, we assessed whether the CHA₂DS₂-VASc score is a useful predictor of new-onset AF after CTI ablation in typical AFL patients without a prior history of AF.

Methods

This was a retrospective study of 103 typical AFL patients with no prior history of AF, who underwent successful CTI ablation. The endpoint was occurrence of new-onset AF during follow-up.

Results

During a mean follow-up period of 24.6 ± 16.9 months, at least one episode of AF occurred in 33 (32%) patients. Multivariate Cox regression analysis revealed that CHA₂DS₂-VASc score (hazard ratio = 1.736; 95% confidence interval = 1.370–2.201; P < 0.001) was significantly associated with postablation new-onset AF (area under the curve = 0.797). A cutoff value of three stratified these patients into two groups with different incidences of postablation new-onset AF (67.9 vs. 18.7%, P < 0.001).

Conclusion

The CHA₂DS₂-VASc score is a useful tool for the prediction of new-onset AF after ablation of typical AFL. Patients with CHA₂DS₂-VASc score ≥3 are more likely to develop new-onset AF and should be monitored more closely.

Prophylactic pulmonary vein isolation in typical atrial flutter patients without atrial fibrillation: a systematic review and meta-analysis of randomized trials

BACKGROUND

New-onset atrial fibrillation (AF) is common after cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) ablation. The meta-analysis was conducted to evaluate the benefit of prophylactic pulmonary vein isolation (PVI) in typical AFL patients.

METHODS

Randomized controlled trials (RCT) comparing prophylactic PVI to CTI ablation alone in typical AFL patients without prior documentation of AF were identified in the MEDLINE, EMBASE, and Cochrane databases.

RESULTS

Four RCTs met the inclusion criteria. A total of 357 patients with follow-up of 20 ± 9 months were included. More patients in prophylactic PVI group were free from atrial arrhythmias (AA) compared with those in CTI group (69% versus 50%, OR = 2.36, 95% CI: 1.51 to 3.68; P = 0.0001). In the subgroup of age > 55, prophylactic PVI showed even higher incidence of freedom from AA. There is a lower occurrence of AF in prophylactic PVI group (27% versus 46%, OR = 0.45, 95% CI: 0.28 to 0.73; P = 0.001) and no difference of complications between prophylactic PVI group and CTI group (4% versus 2%; P = 0.33).

CONCLUSION

Our study indicated the efficacy and safety of prophylactic PVI during CTI ablation in typical AFL patients without AF history, especially for elder patients. Large prospective RCTs are warranted to confirm the benefit of prophylactic PVI in typical AFL.

Cryoballoon pulmonary vein isolation as first line treatment for typical atrial flutter (CRAFT): study protocol for a randomised controlled trial

Purpose

Treatment of typical atrial flutter (AFL) with cavo-tricuspid isthmus (CTI) ablation is associated with a high occurrence rate of new onset atrial fibrillation (AF) during follow-up. There are data to support the addition of pulmonary vein isolation (PVI) to CTI ablation in patients with both AF and AFL, but the role of cryoballoon PVI only, with no CTI ablation, in AFL patients with no prior documentation of AF has not been studied.

Methods

CRAFT is an international, prospective, randomised, open with blinded assessment, multicentre superiority study comparing radiofrequency CTI ablation and cryoballoon PVI in patients with typical AFL. Participants with typical AFL are randomised in a 1:1 ratio to either treatment arm, with patients randomised to PVI not receiving CTI ablation. Post-procedural cardiac monitoring is performed using an implantable loop recorder. The primary endpoint is time to first recurrence of sustained symptomatic atrial arrhythmia. Key secondary endpoints include (1) total arrhythmia burden at 12 months, (2) time to first episode of AF lasting ≥ 2 min, (3) time to recurrence of AFL or AT and (4) procedural and fluoroscopy times. The primary safety endpoint is the composite of death, stroke/transient ischaemic attack, cardiac tamponade requiring drainage, atrio-oesophageal fistula, requirement for a permanent pacemaker, serious vascular complications requiring intervention or delaying discharge and persistent phrenic nerve palsy lasting > 24 h.

Conclusion

This study compares the outcomes of 2 different approaches to typical AFL—the conventional ‘substrate’-based strategy of radiofrequency CTI ablation versus a novel ‘trigger’-based strategy of cryoballoon PVI.

Trial registration

(ClinicalTrials.gov ID: NCT03401099)

Electronic supplementary material

The online version of this article (10.1007/s10840-020-00746-6) contains supplementary material, which is available to authorized users.

Cardiac magnetic resonance-derived right atrial functional analysis in patients with atrial fibrillation and typical atrial flutter

BACKGROUND

Typical atrial flutter (AFL) often occurs in patients with atrial fibrillation (AF). Decision-making tools for application of prophylactic cavo-tricuspid isthmus (CTI) ablation at the time of AF ablation may improve outcomes. In this study, we sought to define the right atrial (RA) functional characteristics of AF patients with documented typical AFL.

METHODS

Consecutive patients that underwent cardiac magnetic resonance (CMR) prior to initial AF ablation in the Johns Hopkins Hospital were enrolled. The AF database was reviewed to identify prevalent and incident documented typical AFL. Feature tracking CMR analysis during sinus rhythm was utilized to quantify RA longitudinal strain and strain rate, as well as RA passive and active emptying fractions derived from phasic RA volumes.

RESULTS

A total of 115 patients were analyzed (mean age 59.1 ± 11.4 years, 78.3% male, 74.8% paroxysmal AF). Of all patients, 30 (26.1%) had typical AFL. Clinical characteristics and AF type did not differ among groups defined by the absence or presence of typical AFL. In contrast, RA longitudinal strain (41.6 ± 16.8% vs. 55.8 ± 17.1%, p ≤ 0.001), systolic strain rate (1.71 ± 0.85 s^-1 vs. 2.33 ± 0.93 s^-1, p = 0.002), and late diastolic strain rate (1.78 ± 1.02 s^-1 vs. 2.50 ± 0.91 s^-1 p ≤ 0.001) were significantly lower in patients with typical AFL. Although RA passive emptying fraction was similar among groups (18.9 ± 8.1 vs. 19.5 ± 8.0, p = 0.75), RA active emptying fraction was lower in patients with typical AFL (34.8 ± 12.3 vs. 40.8 ± 12.1, p = 0.02).

CONCLUSIONS

The reservoir and pump function of the RA is significantly reduced in patients with typical AFL. Prophylactic CTI ablation warrants further study as adjunctive therapy to AF catheter ablation in selected patients with RA dysfunction.

Additional cavotricuspid isthmus block ablation may not improve the outcome of atrial fibrillation ablation

AIMS

Pulmonary vein isolation (PVI) is an effective procedure for atrial fibrillation (AF). The role of additional cavotricuspid isthmus (CTI) block ablation remains controversial in AF patients without atrial flutter (AFL). Therefore, this study aimed to explore the clinical outcome of additional CTI block ablation in patients without AFL.

METHODS

Between January 2013 and December 2017, a total of 139 patients who did not have documented AFL and who underwent catheter ablation for AF were recruited. Fifty-seven patients were classified in additional CTI block ablation group and 82 patients were classified in without CTI group. The incidence of early-onset and late-onset atrial arrhythmia recurrence was compared between the two groups.

RESULTS

The additional CTI group had a higher prevalence of persistent or long-standing AF and larger left atrial volume. The additional CTI group had a higher incidence of late-onset atrial arrhythmia recurrence (38.6% vs 12.2%; P < .001). When compared to without CTI group, additional CTI therapy did not have a better outcome in terms of freedom of atrial arrhythmia in subgroup analysis. The incidence of early-onset and late-onset atrial arrhythmia recurrence did not differ between additional CTI group and without CTI group in paroxysmal AF patients and nonparoxysmal AF patients after propensity scoring matching.

CONCLUSION

CTI block ablation in addition to PVI for AF patients without a history of AFL or inducible AFL during ablation may not improve the clinical outcome of AF ablation in the patients with larger LA volume, nonparoxysmal AF, or post-PVI inducible AF.

A Retrospective Study of Atrial Fibrillation Following Cavotricuspid Isthmus Ablation for Atrial Flutter

Background

Catheter radiofrequency ablation for typical atrial flutter is considered to be safe and effective. However, atrial fibrillation (AF) following cavotricuspid isthmus ablation for atrial flutter has been reported in patients without a previous history of AF, which has implications for the decision to use oral anticoagulation. This retrospective study at a single center aimed to evaluate the occurrence of AF in patients after successful cavotricuspid isthmus ablation of typical atrial flutter and to determine the incidence and associations with AF during follow-up.

Material/Methods

Between January 2011 and July 2017, of 110 consecutive patients who underwent cavotricuspid isthmus ablation for typical atrial flutter, 67 patients had no previous history of AF, of which 40 patients underwent follow-up. The 40 patients included in this retrospective clinical study included 34 men and 6 women, with a mean age of 67±10 years.

Results

Forty patients underwent post-ablation follow-up for 46±23 months, and 12 patients (30%) developed AF; six patients (15%) experienced recurrent of atrial flutter. More than half of the patients with post-ablation AF were asymptomatic with a European Heart Rhythm Association (EHRA) score of 1, and univariate analysis showed the absence of variables associated with the prevalence of AF.

Conclusions

Following cavotricuspid isthmus ablation for atrial flutter, recurrence of atrial flutter was found in 15% of cases, and asymptomatic AF occurred in 30%. These findings have implications for the use of post-ablation oral anticoagulation treatment, which is often discontinued following ablation therapy and before patient follow-up.

Prophylactic Atrial Fibrillation Ablation in Atrial Flutter Patients without Atrial Fibrillation: A Meta-Analysis with Trial Sequential Analysis

Background

New-onset atrial fibrillation (AF) is common after atrial flutter (AFL) ablation, but it was unclear whether AF ablation could reduce the incidence of AF in AFL patients without AF history. The present meta-analysis was conducted to evaluate the benefit of prophylactic AF ablation in reducing the occurrence of AF in typical AFL patients.

Material/Methods

We systematically searched PubMed, EMBASE, and the Cochrane Library from inception to December 2017 for randomized controlled trials (RCTs) that assessed the efficacy of AF ablation in reducing the occurrence of AF in AFL patients without AF. Trial sequential analysis (TSA) was used to control random errors and calculate the required information size.

Results

Four trials (n=357 patients) met the inclusion criteria and were included in our meta-analysis. The incidence of AF after AFL ablation was 46.4%. We observed that prophylactic AF ablation reduced the AF incidence compared with simple AFL ablation (26.1% versus 46.4%, RR: 0.57, 95% CIs: 0.42–0.76, P=0.0002) with a prolonged procedure duration (P<0.00001) and fluoroscopy time (P=0.004). Further TSA indicated that more RCTs were needed to reach more conclusive results. There was no significant difference in clinical complications (P=0.33) between the 2 groups.

Conclusions

This meta-analysis provides evidence that prophylactic AF ablation may be more effective than simple AFL ablation in reducing AF incidence after AFL ablation. Large prospective RCTs are warranted to confirm the benefit of prophylactic AF ablation in AFL patients without AF history.

Incidence of new-onset atrial fibrillation after cavotricuspid isthmus ablation for atrial flutter

Aims

In patients with cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL), the decision to hold oral anticoagulation (OAC) often becomes an issue. The purpose of this study was to describe the incidence of the development of atrial fibrillation (AF) after CTI ablation in patients with documented AFL with and without a previous history of AF and to identify risk predictors for the occurrence of AF after CTI.

Methods and results

We included 364 consecutive patients undergoing successful CTI ablation. Thereof, 230 patients (170 male; age 66 ± 11 years) had AFL only (AFL group) and 134 patients (94 male; age 65 ± 11 years) had AFL and previously documented AF (AFL and AF group). Over a mean follow-up of 22 ± 20 months, 163 (71%) patients in the AFL group and 67 (50%) patients in the AFL and AF groups had no documentation of a recurrent atrial arrhythmia (P < 0.001). AF developed in 51 patients (22%) in the AFL group and in 57 (43%) patients in the AFL and AF groups (P < 0.001). In patients without history of AF, left atrial diameter was the only predictor of development of AF (HR 1.058 [95%CI 1.011-1.108], P = 0.016). Multivariate analysis of the total population identified history of AF (HR 1.918 [95%CI 1.301-2.830], P = 0.001) and BMI as predictors for AF development (HR 1.052 [95%CI 1.012-1.093], P = 0.011).

Conclusion

Our results indicate that new-onset AF develops in a significant proportion of patients undergoing CTI for AFL. One should therefore be careful to withhold OAC. Furthermore, pulmonary vein isolation should be considered in conjunction with CTI, particularly in patients with previously documented AF.

Efficacy and safety of ablation for people with non-paroxysmal atrial fibrillation

BACKGROUND

The optimal rhythm management strategy for people with non-paroxysmal (persistent or long-standing persistent) atrial fibrilation is currently not well defined. Antiarrhythmic drugs have been the mainstay of therapy. But recently, in people who have not responded to antiarrhythmic drugs, the use of ablation (catheter and surgical) has emerged as an alternative to maintain sinus rhythm to avoid long-term atrial fibrillation complications. However, evidence from randomised trials about the efficacy and safety of ablation in non-paroxysmal atrial fibrillation is limited.

OBJECTIVES

To determine the efficacy and safety of ablation (catheter and surgical) in people with non-paroxysmal (persistent or long-standing persistent) atrial fibrillation compared to antiarrhythmic drugs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, conference abstracts, clinical trial registries, and Health Technology Assessment Database. We searched these databases from their inception to 1 April 2016. We used no language restrictions.

SELECTION CRITERIA

We included randomised trials evaluating the effect of radiofrequency catheter ablation (RFCA) or surgical ablation compared with antiarrhythmic drugs in adults with non-paroxysmal atrial fibrillation, regardless of any concomitant underlying heart disease, with at least 12 months of follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We evaluated risk of bias using the Cochrane 'Risk of bias' tool. We calculated risk ratios (RRs) for dichotomous data with 95% confidence intervals (CIs) a using fixed-effect model when heterogeneity was low (I² <= 40%) and a random-effects model when heterogeneity was moderate or substantial (I² > 40%). Using the GRADE approach, we evaluated the quality of the evidence and used the GRADE profiler (GRADEpro) to import data from Review Manager 5 to create 'Summary of findings' tables.

MAIN RESULTS

We included three randomised trials with 261 participants (mean age: 60 years) comparing RFCA (159 participants) to antiarrhythmic drugs (102) for non-paroxysmal atrial fibrillation. We generally assessed the included studies as having low or unclear risk of bias across multiple domains, with reported outcomes generally lacking precision due to low event rates. Evidence showed that RFCA was superior to antiarrhythmic drugs in achieving freedom from atrial arrhythmias (RR 1.84, 95% CI 1.17 to 2.88; 3 studies, 261 participants; low-quality evidence), reducing the need for cardioversion (RR 0.62, 95% CI 0.47 to 0.82; 3 studies, 261 participants; moderate-quality evidence), and reducing cardiac-related hospitalisation (RR 0.27, 95% CI 0.10 to 0.72; 2 studies, 216 participants; low-quality evidence) at 12 months follow-up. There was substantial uncertainty surrounding the effect of RFCA regarding significant bradycardia (or need for a pacemaker) (RR 0.20, 95% CI 0.02 to 1.63; 3 studies, 261 participants; low-quality evidence), periprocedural complications, and other safety outcomes (RR 0.94, 95% CI 0.16 to 5.68; 3 studies, 261 participants; very low-quality evidence).

AUTHORS' CONCLUSIONS

In people with non-paroxysmal atrial fibrillation, evidence suggests a superiority of RFCA to antiarrhythmic drugs in achieving freedom from atrial arrhythmias, reducing the need for cardioversion, and reducing cardiac-related hospitalisations. There was uncertainty surrounding the effect of RFCA with significant bradycardia (or need for a pacemaker), periprocedural complications, and other safety outcomes. Evidence should be interpreted with caution, as event rates were low and quality of evidence ranged from moderate to very low.

Crucial role of pulmonary vein firing as an initiator of typical atrial flutter: Evidence of a close relationship between atrial fibrillation and typical atrial flutter

Background

Several studies reported that cavotricuspid isthmus-dependent atrial flutter (typical AFL) frequently coexists with atrial fibrillation (AF); however, the underlying mechanisms have not been fully investigated. This study aimed to reveal the mechanisms of the initiation of typical AFL and the association between typical AFL and AF.

Methods

Among 154 consecutive patients undergoing a first catheter ablation of AF, we investigated the appearance and mechanism of spontaneous initiation of typical AFL during catheter ablation. Then, we retrospectively investigated 67 consecutive patients without a previous AF episode who underwent typical AFL ablation. The occurrence and predictors of AF after catheter ablation were evaluated.

Results

During AF ablation, spontaneous initiation of typical AFL occurred during sinus rhythm in eight (5.2%) patients. The initiations of typical AFL were pulmonary vein (PV) firings except in one patient, in whom paroxysmal AF following superior vena cava firing initiated reverse typical AFL after PV isolation. After typical AFL ablation, AF occurred in 23 (34.3%) patients (mean follow up, 28.2±20.3 months). Kaplan-Meier analysis showed the occurrence of AF after typical AFL ablation to be significantly higher in the patients with a larger left atrial diameter over 40 mm (log-rank test, P=0.046).

Conclusions

PV firing through AF played an important role in initiating typical AFL. The occurrence of AF after typical AFL ablation was high, and a dilated left atrium was associated with increased occurrence of AF. These findings disclosed the close relationship between typical AFL and AF, especially PV firing.

The feasibility of a Box isolation strategy for non-paroxysmal atrial fibrillation in elderly patients

BACKGROUND

Catheter ablation of non-paroxysmal atrial fibrillation (non-PAF) is a therapeutic challenge especially in elderly patients. This study describes the feasibility of a posterior left atrium isolation as a substrate modification in addition to pulmonary vein isolation, the so-called Box isolation, for elderly patients with non-PAF.

METHODS

Two hundred twenty-nine consecutive patients who underwent Box isolations for drug-refractory non-PAF were divided into two groups according to their age; younger group comprising 175 patients aged <75 years and elderly group comprising 54 patients aged ≥75 years.

RESULTS

During 23.7±12.0 months of follow-up, the arrhythmia-free rates after one procedure were 53.1% in younger group versus 48.1% in elderly group (p=0.50). Following the second procedure, all patients had electrical conduction recoveries along the initial Box lesion. However, a complete Box re-isolation was highly established in both age groups (87.1% vs. 92.9%, respectively; p=1.00). Recurrence of macro-reentrant atrial tachycardia was mainly associated with the gaps through the initial Box lesion in both age groups (25.8% vs. 21.4%, p=1.00), but typical cavo-tricuspid isthmus (CTI) dependent atrial flutter was significantly observed in the elderly patients' group only (all events were observed within 6 months after the initial procedure; 3.2% vs. 28.6%, p=0.009). After two procedures, the arrhythmia-free rates increased to 73.1% in younger group versus 66.7% in elderly group (p=0.38). The occurrence rate of procedural-related complications did not differ between the two age groups, and there were no life-threatening complications even in elderly patients.

CONCLUSIONS

Box isolation of non-PAF is effective and safe even in elderly patients. A prophylactic CTI ablation combined with Box isolation might be feasible to improve the long-term outcome.

Obstructive Sleep Apnea Treatment and Atrial Fibrillation: A Need for Definitive Evidence

Prevalence rates of atrial fibrillation (AF) and obstructive sleep apnea (OSA) are rising on a global scale. Epidemiological data have consistently demonstrated an independent association between the 2 conditions. Investigators pose that pathophysiologic features of OSA enable progression of the AF substrate; these features include abnormalities of gas exchange, autonomic remodeling, atrial stretch, and inflammation. Furthermore, many of the mechanistic perturbations that impact the AF substrate in OSA can be substantially attenuated by effective treatment with continuous positive airway pressure (CPAP). Clear associations of OSA treatment and improved AF control have been observed across multiple clinical contexts. However, the precision and generalizability of these findings are unclear in view of the data's observational nature. Although risk factor management has emerged as a critical component of AF treatment, effective control of many AF risk factors can be challenging in the longer term. In view of the efficacy and sustainability of CPAP therapy, OSA raises its profile as a prime candidate for intervention. However, translation of this strategy to the broader framework for AF management requires robust data from randomized controlled trials.

[Typical atrial flutter: Diagnosis and therapy]

Typical, cavotricuspid-dependent atrial flutter is the most common atrial macroreentry tachycardia. The incidence of atrial flutter (typical and atypical forms) is age-dependent with 5/100,000 in patients less than 50 years and approximately 600/100,000 in subjects > 80 years of age. Concomitant heart failure or pulmonary disease further increases the risk of typical atrial flutter.Patients with atrial flutter may present with symptoms of palpitations, reduced exercise capacity, chest pain, or dyspnea. The risk of thromboembolism is probably similar to atrial fibrillation; therefore, the same antithrombotic prophylaxis is required in atrial flutter patients. Acutely symptomatic cases may be subjected to cardioversion or pharmacologic rate control to relieve symptoms. Catheter ablation of the cavotricuspid isthmus represents the primary choice in long-term therapy, associated with high procedural success (> 97 %) and low complication rates (0.5 %).This article represents the third part of a manuscript series designed to improve professional education in the field of cardiac electrophysiology. Mechanistic and clinical characteristics as well as management of isthmus-dependent atrial flutter are described in detail. Electrophysiological findings and catheter ablation of the arrhythmia are highlighted.