Correlates of Arrhythmia Recurrence After Hybrid Epi- and Endocardial Radiofrequency Ablation for Persistent Atrial Fibrillation

Adjunctive posterior wall isolation for patients with persistent atrial fibrillation: A systematic review and meta-analysis

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Its effectiveness for persistent atrial fibrillation (PeAF) is limited, and the benefits of adjunctive posterior wall ablation are uncertain.

Objective

The purpose of this study was to perform a systematic review and meta-analysis of PVI with/without adjunctive PWI in patients with PeAF.

Methods

We systematically searched PubMed, Embase, Cochrane, and ClinicalTrials.gov databases for randomized controlled trials (RCTs) comparing PVI with/without PWI in patients with PeAF. Random-effects model was used for the meta-analysis. Atrial tachyarrhythmia (ATA) was a composite of AF, atrial flutter, or atrial tachycardia.

Results

Our meta-analysis included eight RCTs with 1104 patients (546 PVI, 558 PVI plus PWI). Compared with PVI alone, adjunctive PWI significantly increased freedom from ATA recurrence (relative risk [RR] 1.13, 95% confidence interval [CI] 1.01-1.27, P = .036). A subanalysis of patients with long-standing PeAF showed a greater effect of PWI (RR 1.76, 95% CI 1.02-3.04, P = .04). A subgroup analysis of PWI techniques indicated no significant difference for ATA recurrence with box isolation alone (RR 1.13, 95% CI 0.97-1.33, P = .12), whereas a pooled analysis using only studies with direct posterior wall ablation favored the adjunctive PWI group (RR 1.39, 95% CI 1.11-1.74, P <.01). Adverse events did not significantly differ between groups.

Conclusion

Our findings support that adjunctive PWI to PVI is an effective strategy compared with PVI alone for reducing ATA recurrence in patients with PeAF without compromising safety. Notably, patients with long-standing PeAF may benefit more from PWI.

Lesion durability found during mandated percutaneous catheter ablation after surgical cryo-ablation for treatment of non-paroxysmal atrial fibrillation

OBJECTIVES

Current recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation.

METHODS

Patients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol.

RESULTS

We analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation (P < 0.05). Cryo-ablation using nitrous oxide (N20) or argon (Ar) gas as cooling agents was similarly effective (P = NS).

CONCLUSIONS

The effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.

Electrical Posterior Box Isolation in Repeat Ablation for Atrial Fibrillation: A Prospective Randomized Clinical Study

OBJECTIVES

This study investigated whether additional electrical posterior box isolation (POBI) may improve the rhythm outcome of repeat ablation in atrial fibrillation (AF).

BACKGROUND

Although electrically reconnected pulmonary veins (PVs) are the main mechanism of AF recurrence, it is unclear whether linear ablation in addition to circumferential PV isolation (CPVI) improves rhythm outcomes after repeat ablation.

METHODS

The authors prospectively randomized 150 patients with PV reconnection undergoing redo procedures to either a CPVI-alone group (n = 75) or an additional POBI group (n = 75). The primary endpoint was AF recurrence after a single procedure, and the secondary endpoints were recurrence pattern, cardioversion rate, and response to antiarrhythmic drugs.

RESULTS

After a median follow-up of 17 months, the clinical recurrence rate did not significantly differ between the CPVI-alone and additional-POBI groups (30.7% vs 30.7%; log-rank P =0.828). Of the 46 patients with clinical recurrence, the recurrences as atrial tachycardia (8.7% vs 30.4%; P =0.137) and cardioversion rates (21.7% vs 47.8%; P =0.122) were not significantly different between the CPVI-alone and additional-POBI groups. Major complication rates did not differ between the 2 groups (1.3% vs 5.3%; P = 0.363), but the total ablation time was significantly longer in the additional-POBI group than in the CPVI-alone group (median: 1,084 [IQR: 704-1,664] vs 1,595 [IQR: 1,244-2,302] seconds; P < 0.001).

CONCLUSIONS

Among patients undergoing redo AF ablation with reconnected PVs, the addition of POBI to CPVI did not improve rhythm outcomes or influence overall safety, whereas leading to a longer ablation time than that with CPVI alone. (Comparison of Circumferential Pulmonary Vein Isolation and Complex Pulmonary Vein Isolation Additional Linear Ablation for Recurred Atrial Fibrillation After Previous Catheter Ablation: Prospective Randomized Trial [RILI Trial]; NCT02747498).

Simultaneous hybrid maze procedure for long-standing persistent atrial fibrillation with dilated atrium

Background

The efficacy of catheter-based or thoracoscopic ablation for treating long-standing persistent atrial fibrillation (AF) with a dilated atrium remains suboptimal. This study aimed to assess the feasibility and initial results of simultaneous hybrid ablation with a new biatrial lesion set in these patients.

Methods

Twenty-seven consecutive patients with long-standing persistent AF and dilated atrium underwent simultaneous hybrid ablation with a new biatrial lesion set consistent with the principle of the Cox maze procedure at our institution. Patients were followed up at 3, 6, and 12 months after the procedure and annually thereafter.

Results

After thoracoscopic epicardial ablation, endocardial mapping confirmed complete bilateral pulmonary vein isolation in 25 patients (96.2%). All patients were followed for a mean of 18.7 ± 8.9 months. Freedom from atrial tachyarrhythmia at 1 year after the single hybrid procedure was 64% with antiarrhythmic drugs and 60% without antiarrhythmic drugs. Freedom from atrial tachyarrhythmia at latest follow-up after the hybrid procedure and redo catheter ablation was 77.8% with antiarrhythmic drugs and 74.1% without antiarrhythmic drugs. In patients with sinus rhythm restoration, mean left atrial diameter decreased from 54.4 ± 4.3 mm to 45.2 ± 4.1 mm (P < .001), and mean right atrial diameter decreased from 59.4 ± 3.9 mm to 54.9 ± 4.4 mm (P < .001). Postoperative pleural effusion was observed in 3 patients (11.1%), and no adverse events occurred during follow-up.

Conclusions

In patients with long-standing persistent AF and a dilated atrium, simultaneous hybrid ablation with the new biatrial lesion set, in combination with touch-up catheter ablation when necessary, can achieve promising results. More studies are needed to confirm these findings.

Subxiphoid Hybrid Epicardial-Endocardial Atrial Fibrillation Ablation and LAA Ligation: Initial Sub-X Hybrid MAZE Registry Results

OBJECTIVES

The aim of this study was to assess the safety and efficacy of a new subxiphoid hybrid epicardial-endocardial atrial fibrillation (AF) ablation and left atrial appendage (LAA) ligation approach for the treatment of persistent AF.

BACKGROUND

Surgical hybrid ablation procedures have shown promise for maintaining sinus rhythm versus catheter ablation but are associated with increased periprocedural adverse events.

METHODS

Patients with symptomatic persistent AF (n = 33, mean age 64 ± 9 years, 25 men) who had antiarrhythmic drug therapy or prior catheter ablation was unsuccessful were referred for hybrid epicardial-endocardial AF ablation and LAA exclusion. LAA closure was confirmed by transesophageal echocardiographic Doppler flow and/or computed tomographic angiography 1 to 3 months post-ligation. The incidence of atrial tachycardia or AF recurrence, LAA closure, thromboembolic events, and post-operative complications were assessed.

RESULTS

All 33 patients underwent successful LAA ligation with epicardial ablation of the posterior left atrial wall, as well as endocardial pulmonary vein isolation and cavotricuspid isthmus ablation. Freedom from atrial tachycardia or AF was 91% (20 of 22 patients) at 6 months, 90% (18 of 20 patients) at 12 months, 92% (11 of 12 patients) at 18 months, and 92% (11 of 12) at 24 months. There were no acute periprocedural complications (<7 days). Thirty-day adverse events included 2 patients with pericardial effusion requiring pericardiocentesis and 1 incisional hernia repair. There were no long-term complications, strokes, or deaths. LAA ligation was complete in 27 of 33 subjects (82%), with 6 subjects having leaks of <5 mm.

CONCLUSIONS

Subxiphoid hybrid epicardial-endocardial ablation with LAA ligation is feasible, safe, and effective. Future prospective studies are needed to validate these initial findings.

Electrical Posterior Box Isolation in Persistent Atrial Fibrillation Changed to Paroxysmal Atrial Fibrillation: A Multicenter, Prospective, Randomized Study

BACKGROUND

Persistent atrial fibrillation (AF) can change to paroxysmal AF after antiarrhythmic drug medication and cardioversion. We investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in those patient groups.

METHODS

We prospectively randomized 114 patients with persistent AF to paroxysmal AF (men, 75%; 59.8±9.9 years old) to circumferential pulmonary vein isolation (CPVI) alone group (n=57) and additional POBI group (n=57). Primary end point was AF recurrence after a single procedure, and secondary end points were recurrence pattern, cardioversion rate, and response to antiarrhythmic drugs.

RESULTS

After a mean follow-up of 23.8±10.2 months, the clinical recurrence rate did not significantly differ between the CPVI alone and additional POBI group (31.6% versus 28.1%; P=0.682; log-rank P=0.729). The recurrences as atrial tachycardias (5.3% versus 12.3%; P=0.134) and cardioversion rates (5.3% versus 10.5%; P=0.250) were not significantly different between the CPVI and POBI groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 52.6% of CPVI group and 59.6% of POBI group (P=0.450). No significant difference was found in major complication rates between the two groups (5.3% versus 1.8%; P=0.618), but the total ablation time was significantly longer in the POBI group (4187±952 versus 5337±1517 s; P<0.001).

CONCLUSIONS

In patients with persistent AF converted to paroxysmal AF by antiarrhythmic drug, the addition of POBI to CPVI did not improve the rhythm outcome of catheter ablation or influence overall safety, while leading to longer ablation time. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02176616.

Clamping versus nonclamping thoracoscopic box ablation in long-standing persistent atrial fibrillation

OBJECTIVE

To compare clinical outcomes of clamping devices and linear nonclamping devices for isolation of the posterior left atrium (box) in thoracoscopic ablation of long-standing persistent atrial fibrillation.

METHODS

Eighty patients who underwent thoracoscopic pulmonary vein and box isolation using a bipolar clamping device (42 patients) or bipolar nonclamping device (38 patients) to create the roof/inferior lesions for box isolation were included from 2 centers. Follow-up consisted of 24-hour Holter at regular intervals. Freedom from AF during 1-year follow-up and catheter repeat interventions were compared between groups.

RESULTS

Acute intraoperative electrical isolation of the box compartment was significantly higher in the clamping group than in the nonclamping group (100% and 79%, respectively, P < .01). At 1-year follow-up, 91% of the clamping group and 79% of the nonclamping group were in sinus rhythm. During 1-year follow-up, recurrence rates did not significantly differ between the 2 groups (P = .08). Repeat catheter interventions were required in 10% of the clamping group and 21% of the nonclamping group (P = .15). Conduction gaps in the roof or inferior lesions were found in 1 patient (2%) in the clamping group versus 4 patients (11%) in the nonclamping group (P = .13).

CONCLUSIONS

Thoracoscopic pulmonary vein and box isolation are highly effective in restoring sinus rhythm in long-standing persistent atrial fibrillation on short-term follow-up. Comparison of clamping and nonclamping devices revealed lower rates of intraoperative exit block of the box in the nonclamping group. However, this did not translate into a significant difference in atrial fibrillation freedom at short-term (1-year) follow-up.

Midterm outcomes of mini-invasive surgical and hybrid ablation of atrial fibrillation

BACKGROUND

We evaluated the feasibility and effectiveness of thoracoscopic and a staged surgical and transcatheter ablation technique to treat stand-alone atrial fibrillation (AF).

METHODS

. Between 2009 and 2016, a cohort of 65 patients underwent bilateral totally thoracoscopic ablation of symptomatic paroxysmal AF (n=30; 46%), persistent AF (n=18; 28%) or long-standing persistent AF (n=17; 26%) followed by catheter ablation in case of AF recurrence. Surgical box lesion procedure included bilateral pulmonary vein and left atrial posterior wall ablation using irrigated bipolar radiofrequency with documentation of conduction block.

RESULTS

There were no intra- or peri-operative ablation-related complications. There was no operative mortality, no myocardial infarction, and no stroke. Skin-to-skin procedure time was 120.5 ± 22.0 min and the postoperative average length of stay was 8.1 ± 3.0 days. At discharge, 60 patients (92%) were in sinus rhythm. Median follow-up time was 866 days (IQR, 612-1185 days). One-year success rate after surgical procedure was 78% (off antiarrhythmic drugs). Eleven patients (17%) underwent catheter re-ablation. Sixty (92%) patients were free of atrial fibrillation after hybrid ablation (on demand) at 1 year follow up after the last ablation. The success at 24-months was achieved in 96% (paroxysmal) and 78% (persistent) patients. At the last follow-up control, 69% patients discontinued oral anticoagulant therapy.

CONCLUSIONS

. Combination of mini-invasive surgical and endocardial treatment (two-stage hybrid procedure) is a safe and effective method for the treatment of isolated (lone) AF. This procedure provided good midterm outcomes.

Hybrid and surgical procedures for the treatment of persistent and longstanding persistent atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common cardiac arrhythmia. The incidence of AF increases with age and is associated with increased stroke, heart failure and mortality. Persistent and long standing persistent AF is difficult to treat and often refractory to medical therapy and catheter ablation. Areas covered: This article reviews the historical development of the surgical Cox-MAZE procedure and current hybrid and minimally invasive surgical approaches for the treatment of persistent and long standing persistent AF. The role of concomitant pulmonary vein isolation and left atrial appendage (LAA) exclusion will also be reviewed. Expert commentary: An ablation pattern emulating the Cox-Maze surgical procedure is commonly needed to obtain maintenance of sinus rhythm in patients with persistent and long standing persistent atrial fibrillation. Minimally invasive bilateral thorascopic surgical procedures can achieve a similar Cox-Maze lesion set, but are associated with increased adverse events compared to catheter ablation. Future prospective randomized studies are required to confirm whether the recently developed hybrid subxyphoid epicardial/endocardial procedure and percutaneous LAA ligation and catheter ablation are indeed as effective as surgical options with less adverse events.