Electrical isolation of the left atrial appendage by Maze-like catheter substrate modification: A reproducible strategy for pulmonary vein isolation nonresponders?

Durable LAA isolation combining pulsed field ablation and radiofrequency linear lesions in a patient with a therapy refractory left atrial appendage tachycardia

BACKGROUND

Treating atrial tachycardia (AT) originating from left atrial appendage (LAA) needs sometimes electrical isolation of LAA. We report a case of AT originating from LAA successfully treated with electrical isolation using the novel lattice-tip pulsed-field/radiofrequency ablation (PFA/RFA) catheter. A 55-year-old female patient with a history of three focal ablative attempts for a highly symptomatic AT originating from the LAA in different centers was admitted to our department for the recurrence of the clinical tachycardia. Electrical isolation of the LAA (LAAEI) was successfully performed with a lattice-tip PFA/RFA ablation catheter. Six weeks after the procedure, an invasive re-mapping study indicated a durable electrical LAA isolation; therefore, a 24-mm-sized LAA occlusion device (WATCHMAN FLX device, Boston Scientific, Plymouth, MN, USA) was implanted.

DISCUSSION

In this case, we successfully treated an atrial tachycardia originating from LAA using the recently approved lattice-tip PFA/RFA ablation catheter. The combination between two energy sources during the same procedure could potentially improve lesions transmurality offering a new promising solution for the treatment of complex atrial tachycardias.

Repeat catheter ablation in patients with atrial arrhythmia recurrence despite durable pulmonary vein isolation

INTRODUCTION

Arrhythmia recurrence after pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) is common and often linked to pulmonary vein reconnection. In patients with arrhythmia recurrences despite durable PVI the optimal ablation approach is unclear. The purpose of the present study was to analyze efficacy of extended ablation maneuvers in these patients and predictors of procedural success.

METHODS

Consecutive patients with durable PVI undergoing repeat ablation procedures were prospectively enrolled. Patients underwent substrate modification with creation of linear lesions and/or mechanism-specific atrial tachycardia (AT) ablation. 3D-mapping images were analyzed for the presence of left atrial (LA) low-voltage areas according to published scoring systems.

RESULTS

Seventy-four patients were analyzed. Mode of recurrence after durable PVI was AF in 27 patients (36.5%) and AT in 47 patients (63.5%). Linear lesion ablation was performed in 60 patients (81.1%). Twenty-four patients (32.4%) were treated for focal AT mechanisms. Mean follow-up was 565±342 days. Estimated arrhythmia-free survival after 24 months was significantly higher in patients with AT than in patients with AF as mode of recurrence after durable PVI (42.9±8.2% vs. 24.7±8.5%, p=0.023) and in patients without compared to patients with marked LA low-voltage areas (40.5±9.2% vs. 22.8±8.5%, p=0.041). The mode of recurrence after durable PVI was the only independent predictor of further arrhythmia recurrence after repeat ablation.

CONCLUSION

Arrhythmia-free survival following repeat ablation procedures in patients with durable PVI highly depends on mode of arrhythmia recurrence and the presence of LA low-voltage areas. This article is protected by copyright. All rights reserved.

Hot or cold? Feasibility, safety, and outcome after radiofrequency-guided versus cryoballoon-guided left atrial appendage isolation

Background

Left atrial appendage (LAA) isolation (LAAI) has been described as an adjunctive ablation strategy for patients with recurrent atrial tachyarrhythmia (ATa).

Objectives

We compared the clinical impact of persistent durable LAAI between radiofrequency (RF)-guided wide-area LAAI and cryoballoon (CB)-guided ostial LAAI.

Methods

Consecutive patients who underwent RF- or CB-guided LAAI were retrospectively analyzed. RF-guided LAAI was performed by combining linear ablation. CB-guided LAAI was performed by LAA ostial ablation. Following LAAI, the patients underwent an invasive remapping study. LAA closure was conducted if persistent durability was confirmed. The procedural data, LAAI durability, and ATa recurrence were assessed.

Results

A total of 260 patients (RF: n = 201; CB: n = 59) undergoing LAAI were identified. The acute rate of procedural LAAI was higher in the CB group (CB:94.9% vs. RF:82.6%, p = .02) with a lower pericardial effusion incidence (CB:0% vs. RF:7.5%, p = .03). The 6-week durable LAAI was similar between the two groups (RF:78.3% vs. CB:66.0%, p = .103). During follow-up, one gastrointestinal bleeding and four stroke events including one subsequent intracranial bleeding leading to death occurred in the RF group, while one gastrointestinal bleeding occurred in the CB group.The 1-year ATa recurrence-free rate was higher in patients with durable LAAI following RF-guided LAAI (RF:76.3% vs. CB:56.7%, p = .0017). Multivariate analysis revealed RF-guided LAAI as a predictor of freedom from ATa recurrence (HR: 0.478, 95%CI: 0.336-0.823, p = .017).

Conclusions

LAAI can be more readily and safely achieved by CB-guided ostial ablation. In patients with confirmed LAAI, however, the freedom from ATa recurrence was higher after RF-guided wide-area isolation.

Efficacy and safety of left atrial appendage electrical isolation during catheter ablation of atrial fibrillation: an updated meta-analysis

AIMS

Left atrial appendage electrical isolation (LAAEI) has been shown to improve freedom from all-atrial arrhythmia recurrence in patients with non-paroxysmal atrial fibrillation (AF). The aim of this study is to investigate the long-term efficacy and safety outcomes of LAAEI in patients with non-paroxysmal AF undergoing catheter ablation.

METHODS AND RESULTS

A systematic review of Medline, Cochrane, and Embase was performed for clinical studies evaluating the benefit of LAAEI in non-paroxysmal AF. Nine studies with a total of 2336 patients were included (mean age: 65 ± 9 years, 63% male). All studies included patients with persistent AF, long-standing persistent AF, or both. At a mean follow-up of 40.5 months, patients who underwent LAAEI had significantly higher freedom from all-atrial arrhythmia recurrence than patients who underwent standard ablation alone [69.3% vs. 46.4%; risk ratio (RR) 0.54; 95% confidence interval (CI) 0.42-0.69; P < 0.0001]. A 46% relative risk reduction and 22.9% absolute risk reduction in atrial-arrhythmia recurrence was noted with LAAEI. Rates of cerebral thromboembolism were not significantly different between the two groups (LAAEI 3% vs. standard ablation 1.6%, respectively; RR 1.76; 95% CI 0.61-5.04; P = 0.29). Furthermore, there was no significant difference in the acute procedural complication rates between the two groups (LAAEI 4% vs. standard ablation 3%, respectively; RR 1.29; 95% CI 0.83-2.02; P = 0.26).

CONCLUSION

At long-term follow-up, LAAEI led to a significantly higher improvement in freedom from all-atrial arrhythmia recurrence in patients with non-paroxysmal AF, when compared to standard ablation alone. Importantly, this benefit was achieved without an increased risk of acute procedural complications or cerebral thromboembolic events.

Long-term outcomes of cryoballoon-based left atrial appendage isolation in addition to pulmonary vein isolation in persistent atrial fibrillation

AIMS

Pulmonary vein isolation (PVI) alone in persistent atrial fibrillation (AF) is not as successful as in paroxysmal AF, and recent data indicate the key role of non-PV triggers. We aimed to assess the long-term safety and efficacy of left atrial appendage isolation (LAAi) as an adjunct to PVI using cryoballoon (CB) in persistent AF.

METHODS AND RESULTS

We compared 144 persistent AF patients (59 ± 10 years, 51% females) who underwent PVI combined with LAAi with a propensity-score matched cohort of 138 persistent AF patients (59 ± 6 years, 52% female) in whom PVI-only was performed. Baseline and follow-up data including electrocardiography (ECG), 24-h Holter ECG's, and echocardiography were recorded for all patients. Atrial tachyarrhythmia (ATa) recurrence was defined as detection of AF, atrial flutter, or atrial tachycardia (≥30 s) after a 3-month blanking period. At a mean of 30.5 ± 5.6 months follow-up, 85 (61.6%) patients in the PVI-only group and 109 (75.7%) patients in the PVI+LAAi group were free of ATa after the index procedure (P = 0.008). Ischaemic stroke/transient ischaemic attack was detected in 4 (2.9%) patients in PVI-only group and in 5 (3.5%) patients in the PVI+LAAi group (P = 0.784). Cox regression analysis revealed that the PVI-only strategy was found as a significant predictor for recurrence (hazard ratio 3.01, 95% confidence interval 1.81-5.03; P < 0.001).

CONCLUSIONS

Our findings indicated that CB-based LAAi+PVI was associated with a favourable efficacy compared to PVI-only strategy in patients with persistent AF. Although ischaemic event rates were similar between the groups, rigorous adherence to anticoagulation regime is paramount in order to prevent thrombo-embolic complications.

Long-Term Outcomes of Left Atrial Appendage Electrical Isolation in Patients With Nonparoxysmal Atrial Fibrillation

Background:

Left atrial appendage electrical isolation (LAAEI) has been proposed for the treatment of nonparoxysmal atrial fibrillation (AF). The long-term clinical outcomes of this approach remain unclear. The objective of our study was to investigate the incremental benefit and safety of LAAEI in patients undergoing catheter ablation for nonparoxysmal AF.

Methods:

Propensity score-matched analysis was performed using a prospective registry database from 2010 to 2014. All patients in the LAAEI group were matched based on baseline characteristics, echocardiographic parameters, and procedural ablation techniques.

Results:

We identified 1842 patients who underwent catheter ablation for nonparoxysmal AF. Propensity score matching yielded 1092 patients, 546 patients with LAAEI, and 546 patients without LAAEI. At 5-year follow-up, overall freedom from all-atrial arrhythmia recurrence, off-antiarrhythmic drugs, in patients who underwent LAAEI was 68.9% versus 50.2% in those who underwent standard ablation alone ( P <0.001). Acute complication rates were similar between groups (LAAEI 1.3% versus non-LAAEI 0.73%, P =0.36). At 5-year follow-up, 382 (70%) patients in the LAAEI group remained on oral anticoagulation versus 217 (39.7%) in the non-LAAEI group. At 5-year follow-up, thromboembolic events occurred in 15/546 (2.75%) in the LAAEI group and 4/546 (0.73%) in the non-LAAEI group ( P =0.01). No thromboembolic events occurred in either group on-oral anticoagulation. In patients who were off-oral anticoagulation, at 5-year follow-up, thromboembolic events occurred in 15/164 (9.1%) in the LAAEI group and 4/329 (1.2%) in the non-LAAEI group ( P <0.001).

Conclusions:

At 5-year follow-up, LAAEI was associated with significantly higher freedom from all-atrial arrhythmia recurrence in patients with persistent and long-standing persistent AF without increasing acute procedural complication rate. In patients off-oral anticoagulation, there appears to be a higher risk of thromboembolic events in the LAAEI group.

Thromboembolism after electrical isolation of the left atrial appendage: a new indication for interventional closure?

AIMS

Left atrial appendage electrical isolation (LAAI) may improve the rhythm outcome in selected patients with atrial fibrillation (AF). Controversy exists if LAAI is associated with an increased rate of thromboembolic complications. We sought to assess the feasibility, efficacy, and safety of interventional left atrial appendage closure (LAAC) in comparison to oral anticoagulation (OAC) after electrical LAAI.

METHODS AND RESULTS

Weeks after index LAAI using the cryoballoon or a linear maze like ablation strategy patients' left atrial appendage was invasively remapped. In case of persistent LAAI, LAAC was performed. Patients who refused invasive remapping continued OAC. The primary endpoint was composed of any stroke or systemic embolism (SE) and the occurrence of intracardiac thrombus. Secondary endpoints included stroke/SE, major bleeding, and all-cause death. Of 166 patients (51% female; mean age 70 ± 8 years; mean CHAD2S2VASc score 3.4 ± 1.8) after LAAI, 94 patients received LAAC (LAAC group) and 72 continued OAC (no LAAC). After LAAC, 83% of patients received dual antiplatelet therapy for 6 weeks and aspirin thereafter. During a mean follow-up of 778 ± 630 days, 5 and 11 primary endpoint events were observed in the LAAC and no LAAC group, respectively [hazard ratio (HR) 0.27, 95% confidence interval (CI) 0.10-0.75; P = 0.010]. The calculated annual thromboembolic event rates were 6.9% (no LAAC) and 2.3% (LAAC), respectively. Left atrial appendage closure significantly reduced the incidence of stroke and SE (HR 0.31, CI 0.1-0.98; P = 0.04).

CONCLUSION

After electrical LAAI for rhythm control in AF patients, interventional LAAC was associated with fewer thromboembolic complications when compared with OAC.

Electrophysiological findings in patients with isolated veins after cryoablation for paroxysmal atrial fibrillation

AIMS

The main cause of atrial fibrillation recurrence after catheter ablation is pulmonary vein reconnection. The purpose of this retrospective study was to analyse the electophysiological findings in patients undergoing repeat procedures after an index cryoballoon ablation (CB-A) and presenting with permanency of pulmonary vein isolation (PVI) in all veins. In addition, we sought to compare the latter with a similar group of patients with reconnected veins at the redo procedure.

METHODS

A total of 132 patients (81 men, 60.7 ± 12.4 years) who underwent CB-A for paroxysmal atrial fibrillation (PAF) were enrolled. Indication for the redo procedure was symptomatic PAF in 83 (63%), persistent atrial fibrillation (PerAF) in 32 (24%) or persistent regular atrial tachycardia (RAT) in 17 (13%) patients.

RESULTS

Seventy-five (57%) patients presented a pulmonary vein reconnection (pulmonary vein group) during the redo procedure, whereas 57 (43%) had no pulmonary vein reconnection (non-pulmonary vein group). The non-pulmonary vein group exhibited significantly more non-pulmonary vein foci and atrial flutters than the pulmonary vein group after induction protocol (51 vs. 24%, P = 0.002 and 67 vs. 36%, P = 0.003, respectively). Twenty-two (29.3%) patients of the pulmonary vein group and 20 (35%) patients of the non-pulmonary vein group had atrial fibrillation/RAT recurrence after a mean follow-up of 12.5 ± 8 months. The survival analysis demonstrated no statistical significance in recurrence between both groups (log rank P = 0.358).

CONCLUSION

Atrial fibrillation/RAT recurrence in patients after CB-A with durable PVI is significantly associated with non-pulmonary vein foci and atrial flutters. No statistically different success rate regarding atrial fibrillation/RAT freedom was detected between the pulmonary vein and non-pulmonary vein groups after redoing RF-CA.

Management of thrombus formation after electrical isolation of the left atrial appendage in patients with atrial fibrillation

Aims

Left atrial appendage (LAA) electrical isolation (LAAEI) in addition to pulmonary vein isolation is an emerging catheter-based therapy to treat symptomatic atrial fibrillation. Previous studies found high incidences of LAA thrombus formation after LAAEI. This study sought to analyse therapeutic strategies aiming at the resolution of LAA thrombi and prevention of thromboembolism.

Methods and results

Left atrial appendage electrical isolation was conducted via creation of left atrial linear lesions or cryoballoon ablation. Follow-up including transoesophageal echocardiography was conducted. In patients with LAA thrombus, oral anticoagulation (OAC) was adjusted until thrombus resolution was documented. Percutaneous LAA closure (LAAC) under use of a cerebral protection device was conducted in case of medically refractory LAA thrombi. Left atrial appendage thrombus was documented in 54 of 239 analysed patients who had undergone LAAEI. Thrombus resolution was documented in 39/51 patients (72.2%) with available follow-up after adjustment of OAC. Twenty-nine patients underwent LAAC and 10 patients were kept on OAC after LAAEI. No thromboembolic events or further LAA thrombi were documented after 553 ± 443 days of follow-up in these patients. Persistent LAA thrombi despite adaption of OAC was documented in 12/51 patients. One patient remained on OAC until the end of follow-up, while LAAC with a cerebral protection device was performed in 11 patients in the presence of LAA thrombus without complications.

Conclusion

Left atrial appendage thrombus formation is common after LAAEI. Adjustment of OAC leads to LAA thrombus resolution in most patients. Left atrial appendage closure in the presence of LAA thrombi might be a feasible option in case of failed medical treatment.

Fourth-Generation Cryoablation Based Left Atrial Appendage Isolation for the Treatment of Persistent Atrial Fibrillation: First Case Report

BACKGROUND Pulmonary vein isolation (PVI) is an effective treatment strategy for patients with paroxysmal atrial fibrillation (AF), yet it is associated with limited success rates in patients with persistent AF (PersAF). The left atrial appendage (LAA) was recently identified as a target of catheter ablation especially in PVI non-responders and LAA-isolation (LAAI) by cryoballoon or radiofrequency was shown to be effective. Recently the fourth-generation cryoballoon (CB4) was introduced to clinical practice. Here we are demonstrating the first case report of CB4-based LAAI followed by LAA-closure in a patient with PersAF. CASE REPORT A 67-year-old male patient presented with symptomatic PersAF and thromboembolism due to LAA-thrombus. After resolving the LAA-thrombus cryoballoon based PVI and empirical LAAI was successfully performed. To prevent further thromboembolism LAA-closure was successfully performed after 6 weeks. On short-term follow-up (12 weeks) the patients stayed in stable sinus rhythm. CONCLUSIONS Fourth-generation cryoballoon based ablation seems to be an effective treatment strategy for LAAI.

Percutaneous left atrial appendage closure in the presence of thrombus: A feasibility report

BACKGROUND

Patients with a left atrial appendage thrombus (LAAT) despite oral anticoagulation (OAC) are at high risk of thromboembolism (TE) and a relevant proportion of LAAT do not resolve under continued OAC. Left atrial appendage closure (LAAC) in the presence of LAAT was anecdotally described as a therapeutic option to prevent TE in the patients.

OBJECTIVE

To describe the feasibility of LAAC despite LAAT in consecutive patients.

METHODS

We searched the LAAC database of our center to identify patients in whom a LAAC was performed despite evidence of a thrombus in the LAA. All procedures were performed under transesophageal echocardiography guidance, no angiographies were performed to avoid LAAT dislocation. An Amulet Occluder device was preferred to allow proximal implantation and sealing of the LAA.

RESULTS

Nine patients were identified. The mean age was 68.1 ± 10.7 years, four were female, mean CHADSVASC and HASBLED were 3.6 ± 1.7 and 3.0 ± 1.0. Eight of nine patients were on OAC, one patient was under lone aspirin therapy because of bleeding. The mean distance between the LAAT and the estimated landing zone was 18 ± 6 mm, the minimal distance was 11 mm. The mean landing zone was 21 ± 3 mm, devices with a mean size of 25 ± 4 mm were chosen for implantation. All implantation succeeded, only two patients required an intraprocedural replacement. No procedural complication nor short term thromboembolic complication during a follow up of 138 ± 149 days were recorded.

CONCLUSION

In the presented series a percutaneous LAAC despite a LAAT resulted to be feasible and safe.

Thromboembolic events and need for anticoagulation therapy following left atrial appendage occlusion in patients with electrical isolation of the appendage

INTRODUCTION

Electrical isolation of the left atrial appendage (LAA) is an important adjunctive ablation strategy in patients with nonparoxysmal atrial fibrillation (AF). Patients who have impaired LAA contractility following isolation may require long-term oral anticoagulant (OAC) therapy irrespective of their CHADS₂ -VASc score. Percutaneous LAA occlusion (LAAO) is a potential alternative to life-long OAC therapy. We aimed to assess the rate of OAC discontinuation and thromboembolic (TE) events following percutaneous LAAO in patients who underwent LAA electrical isolation (LAAI).

METHODS

This is a retrospective two-center study of patients who underwent percutaneous LAAO following LAAI. Patients with at least 3-month follow-up were included in the study. The antithrombotic therapy and TE events at the time of the last follow-up were noted.

RESULTS

The LAA was successfully occluded in 162 (with Watchman device in 140 [86.4%] and Lariat in 22 [13.6%]). A total of 32 patients had leaks detected on the 45-day transesophageal echocardiogram (TEE); 21 (15%) Watchman and 11 (50%) Lariat cases (P = 0.0001). Two (one Watchman and one Lariat) of the 32 leaks were more than 5 mm. After the 45-day TEE, 150 (92.6%) patients were off-OAC. No TE events were reported in the 150 patients who stopped the anticoagulants. Four (2.47%) patients experienced stroke following the LAAO (three Watchman and one Lariat) procedure while on-OAC, two of which were fatal. At the median follow-up of 18.5 months, 159 (98.15%) patients were off-anticoagulant.

CONCLUSION

Up to 98% of patients with LAAI could safely discontinue OAC after undergoing the appendage closure procedure.