Left Atrial Appendage Electrical Isolation Research Articles

Durability of cryoballoon left atrial appendage isolation: Acute and invasive remapping electrophysiological findings.

The left atrial appendage (LAA) has been identified as a potential source of atrial fibrillation (AF) and has been described as the "fifth" pulmonary vein (PV). We report our initial experience in LAA isolation (LAAI) using the cryoballoon (CB) and data on durability of CB-LAAI. Patients treated with a CB-LAAI were retrospectively identified. Six weeks after electrical LAAI, patients were scheduled for staged percutaneous LAA closure. During the second procedure, a subset of patients underwent invasive remapping of the LAA. A total of 32 patients (21 males, 68±10 years old) were treated with CB-LAAI. Acute LAAI was achieved in 29 of 32 (91%) patients: single-shot LAAI was observed in 18 of 32 (56%) patients. Acute procedural sustained LAAI was related with a significantly shorter time to LAAI (sustained LAAI: 84±50s vs nonsustained LAAI: 166±76s, P=0.004). Mean procedure and fluoroscopy time were 61±29 and 8±6min, respectively. One left-sided phrenic nerve palsy occurred. In 25 of 32 (78%) patients, a second procedure for percutaneous LAA closure device implantation was performed. In 22 patients, persistency of LAAI was tested: durable LAAI was documented in 16/22 patients (73%). In the present report, CB LAA isolation followed by staged LAA closure appeared to be safe and feasible but more data are required. Time to LAAI played a role in predicting acute sustained LAAI rate. CB LAA ablation leads to 73% of durable LAA isolation.

Left Atrial Appendage Electrical Isolation as a Target in Atrial Fibrillation.

Although the benefit of catheter ablation of the pulmonary veins is well established in paroxysmal atrial fibrillation (AF), the optimal ablation strategy for persistent AF is yet to be determined. Pulmonary vein isolation in persistent AF often results in AF recurrence and the success rate may be low even after multiple procedures. Recurrent AF risk may besecondary to non-pulmonary vein triggers, and adjunctive therapies to better control persistent AF are under investigation. The left atrial appendage (LAA) is a complex structure with distinct physiological and electrical properties, and multiple studies have implicated the LAA as a potential contributor to persistence of AF. Therapies targeting the LAA for electrical isolation have demonstrated potential efficacy in freedom from AF. The overarching concept of this therapy is to isolate the atria electrically from the LAA via catheter ablation, surgical excision or ligation, or percutaneous ligation. LAA electrical isolation has already demonstrated benefit in reducing AF recurrence and AF burden. LAA electrical isolation has the potential to form a foundational piece in the optimal rhythm control management of AF and thereforewarrants further study and is the focus of this review.

RISK OF THROMBOEMBOLIC EVENTS IN PATIENTS WITH HIGH CHA2DS2-VASC SCORE UNDERGOING CATHETER ABLATION OF NON-PAROXYSMAL ATRIAL FIBRILLATION WITH/WITHOUT LEFT ATRIAL APPENDAGE ELECTRICAL ISOLATION: A PROPENSITY SCORE MATCHED COMPARISON

We sought to investigate the arrhythmia-free survival and incidence of thromboembolic (TE) events after radiofrequency catheter ablation (RFCA) with/without left atrial appendage electrical isolation (LAAEI) in patients at high stroke risk (CHA2DS2-VASc score≥3) on long-term oral anticoagulation (

Evidence of relevant electrical connection between the left atrial appendage and the great cardiac vein during catheter ablation of atrial fibrillation

Atrial fibrillation (AF) triggers within the coronary sinus (CS)/great cardiac vein (GCV) and the left atrial appendage (LAA) have been recognized as nonpulmonary vein triggers of AF. The aim of this study was to describe an electrical connection between the LAA and CS/GCV and its importance in achieving LAA electrical isolation (LAAEI). A total of 488 consecutive patients undergoing catheter ablation for persistent or long-standing persistent AF who showed firing from the LAA and/or from the CS/GCV were enrolled in this multicenter prospective study. In all patients, potential defragmentation of the CS/GCV to achieve isolation and LAAEI was attempted with both endocardial and epicardial ablation. In 7% (n = 34) of these patients, after attempting endocardial LAAEI, the LAA was isolated during epicardial ablation in the GCV. In 8% (n = 39) of patients after attempting endocardial LAA isolation, the LAA was isolated during ablation along the endocardial aspect of the GCV. The presence of a venous branch connecting the GCV with the LAA was found in all these patients. In 23% (n = 112) of patients, the isolation of the LAA also isolated the GCV. In all these patients, LAA dissociated firing was present together with the CS/GCV recordings. These findings suggest the presence of a distinct electrical connection between the GCV and the LAA. The clinical relevance of our results requires further investigation. Ablation in the CS/GCV can result in inadvertent isolation of the LAA. Ablation of the GCV is relevant to achieve LAAEI. Considering the potential long-term implications, ablation in the distal CS/GCV should prompt assessment of LAA conduction.

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

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). This is a retrospective two-center study of patients who underwent percutaneous LAAO following LAAI. Patients with at least 3-monthfollow-up were included in the study. The antithrombotic therapy and TE events at the time of the last follow-up were noted. 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. Up to 98% of patients with LAAI could safely discontinue OAC after undergoing the appendage closure procedure.

Left atrial appendage isolation in atrial fibrillation catheter ablation: A meta-analysis.

A significant proportion of patients’ experience recurrence of atrial fibrillation (AF) despite pulmonary venous isolation (PVI), especially those with persistent AF. Isolation of the left atrial appendage (LAA) may reduce AF recurrence. The aim of this study was to assess the efficacy of LAA isolation in addition to PVI compared with PVI alone. We conducted a comprehensive search of electronic databases, up to April 21st, 2017, for all studies comparing the effect LAA electrical isolation or ligation in addition to PVI, as opposed to PVI alone, on the recurrence of atrial fibrillation after catheter ablation. We used random‐effects meta‐analysis models to summarize the studies. One RCT and four observational studies enrolling 781 patients were retained. Four studies assessed the added effect of LAA catheter ablation, and one study evaluated the effect of LAA ligation with the aim of LAA electrical isolation. Four studies exclusively enrolled patients with persistent atrial fibrillation and one study predominantly enrolled patients with persistent atrial fibrillation. Follow‐up ranged from 12 to 15 months. The addition of LAA isolation to PVI reduced AF recurrence compared with the latter alone (odds ratio (OR) = 0.19; 95% confidence intervals (CI) = 0.10‐0.37; P < 0.00001). Left atrial appendage isolation was also associated with a reduction in AF recurrence after repeat ablation (OR = 0.40; CI = 0.25‐0.65; P = 0.0003). The addition of LAA isolation to PVI was associated with a decrease in AF recurrence in patients with persistent AF. Further studies are needed to assess the effect on long‐term risk of stroke.

How to perform left atrial appendage electrical isolation using radiofrequency ablation

How to perform left atrial appendage electrical isolation using radiofrequency ablation

Benefit of left atrial appendage electrical isolation for persistent and long-standing persistent atrial fibrillation: a systematic review and meta-analysis.

The long-term outcomes of left atrial appendage electrical isolation (LAAEI) in patients with non-paroxysmal atrial fibrillation (AF) have corroborated the significant role of the LAA in this arrhythmia. We sought to investigate the incremental benefit of LAAEI in patients undergoing catheter ablation for persistent AF or long-standing persistent AF (LSPAF). A systematic review of Medline, Cochrane, and Embase for all the clinical studies in which assessment LAAEI in non-paroxysmal AF patients was performed. The benefit of LAAEI in patients with AF was analysed from seven studies that enrolled a total of 930 patients [mean age 63 ± 5 years; male: 69%]. All studies included patients with either persistent AF or LSPAF or the combination of them. The overall freedom from all-arrhythmia recurrence at 12 months of follow-up off antiarrhythmic medications in patients who underwent LAAEI was 75.5% vs. 43.9% in those in whom only standard ablation was performed [56% relative reduction and 31.6% absolute reduction; risk ratio (RR) 0.44, 95% confidence interval (95% CI) 0.31-0.64; P < 0.0001]. The rate of ischaemic stroke in the LAAEI group was 0.4% and in the control group 2.1% at 12 months follow-up (RR 0.40, 95% CI 0.12-1.30; P = 0.13). Acute complications rates were identical between groups [LAAEI 5.5%, control 5.5% (RR 0.99, 95% CI 0.46-2.16; P = 0.99)]. Left atrial appendage electrical isolation in addition to standard ablation appears to have a substantial incremental benefit to achieve freedom from ALL atrial arrhythmias in patients with persistent AF and LSPAF without increasing acute procedural complications and without raising the risk of ischaemic stroke.

Left Atrial Appendage Electrical Isolation for Treatment ofRecurrent Atrial Fibrillation: A Meta-Analysis.

In this study, the authors sought to perform a meta-analysis of controlled studies assessing the relationship between left atrial appendage (LAA) electrical isolation (EI) and recurrent atrial fibrillation (AF). LAA triggers could play an important role in AF and can be treated with complete EI of the LAA via surgical or percutaneous approaches. We conducted a meta-analysis of all controlled studies published as of November 21, 2016, assessing therelationship between left atrial appendage electrical isolation (LAAEI) and recurrent AF. The primary endpoint was atrial tachycardia (AT) or AF recurrence after the post-procedure blanking period. The association between LAAEI and AT/AF was estimated using random-effects modeling. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the DerSimonian and Laird method. We identified 7 studies including 1,037 patients; LAAEI was performed in 566 patients (55%). LAAEI was associated with a significantly lower rate of AT/AF recurrence in the primary analysis (OR: 0.38; 95% CI: 0.16 to 0.90; p= 0.02). The association between LAAEI and recurrent AT/AF was strongest in a sensitivity analysis restricted to studies of percutaneous LAAEI (OR: 0.22; 95% CI: 0.11 to 0.46; p< 0.001; 5 studies, n= 623). LAAEI was not associated with thromboembolism (OR: 0.50; 95% CI: 0.18 to 1.39; p= 0.18; 5 studies, n= 767), although these studies either incorporated LAA occlusion (3 studies, n= 552 patients) or follow-up echocardiography to assess LAA function (2 studies, n= 215 patients) to inform antithrombotic strategies. LAAEI is associated with a significant reduction in recurrent AT/AF. Randomized trials are required to confirm the efficacy and long-term safety of LAAEI and to determine the optimal concomitant antithrombotic strategy.

Ablation of Advanced Subtypes of Atrial Fibrillation: Highlighting the Art of When and When Not to Perform Additional Ablation

The purpose of this review is to determine the role of pulmonary vein (PV) triggers in different types of atrial fibrillation (AF) as well as to determine based on prospective randomized data which other approaches may increase the success rate of radiofrequency ablation of persistent AF. Special attention must be paid to detect, diagnose, and optimize management of reversible or treatable causes of persistent AF such as obesity, obstructive sleep apnea, hypertension, hypo- or hyperthyroidism, inflammatory and infectious diseases, and stress. Though the role of PVs is more pronounced in paroxysmal AF than in persistent AF, performing an adequate PV isolation is still a key part in treating persistent AF. There are now numerous techniques to obtain long-lasting pulmonary vein isolation and avoid esophageal damage. Patients with persistent AF will frequently require a more aggressive mapping and ablative approach. Ablation of sites associated with non-PV triggers such as the entire posterior wall, the roof, the anterior part of the left atrial (LA) septum, the left atrial appendage (LAA), the coronary sinus, and the superior vena cava has been shown to improve the freedom from AF at follow-up when combined with PV isolation. We do not encourage the use of empiric lines or complex fractionated atrial electrograms. Several studies have shown the role of empirical LAA electrical isolation in persistent AF. When focal ectopic atrial activity is observed after PV isolation, its activation sequence is compared to that of sinus rhythm, allowing quick identification of its origin. For significant non-PV triggers (repetitive isolated beats, focal atrial tachycardias or beats triggering AF/atrial flutter), a more detailed activation mapping is performed in the area of origin. They are subsequently targeted with focal ablation, except for triggers originating from the superior vena cava (SVC), LAA, or coronary sinus, for which complete isolation of these structures is the ablation strategy of choice. We truly believe the LAA and the posterior LA wall deserve special consideration when managing patients with persistent AF.

Left Atrial Appendage Isolation in Patients With Longstanding Persistent AF Undergoing Catheter Ablation: BELIEF Trial

BackgroundLongstanding persistent (LSP) atrial fibrillation (AF) is the most challenging type of AF. In addition to pulmonary vein isolation, substrate modification and triggers ablation have been reported to improve freedom from AF in patients with LSPAF. ObjectivesThis study sought to assess whether the empirical electrical isolation of the left atrial appendage (LAA) could improve success at follow-up. MethodsThis was an open-label, randomized study assessing the effectiveness of empirical electrical left atrial appendage isolation for the treatment of LSPAF. Patients were randomly assigned to undergo empirical electrical left atrial appendage isolation along with extensive ablation (group 1; n = 85) or extensive ablation alone (group 2; n = 88). Recurrence of atrial arrhythmias was the primary endpoint. Secondary endpoints included cardiac-related hospitalization, all-cause mortality, and stroke at follow-up. ResultsMajor clinical characteristics were not different between the 2 groups. At 12-month follow-up, 48 (56%) patients in group 1 and 25 (28%) in group 2 were recurrence free after a single procedure (unadjusted hazard ratio [HR] for recurrence with standard ablation: 1.92; 95% confidence interval [CI]: 1.3 to 2.9; log-rank p = 0.001). After adjusting for age, sex, and left atrial size, standard ablation was predictive of recurrence (HR: 2.22; 95% CI: 1.29 to 3.81; p = 0.004). During repeat procedures, empirical electrical left atrial appendage isolation was performed in all patients. After an average of 1.3 procedures, cumulative success at 24-month follow-up was reported in 65 (76%) in group 1 and in 49 (56%) in group 2 (unadjusted HR: 2.24; 95% CI: 1.3 to 3.8; log-rank p = 0.003). ConclusionsThis randomized study showed that both after a single procedure and after redo procedures in patients with LSPAF, empirical electrical isolation of the LAA improved long-term freedom from atrial arrhythmias without increasing complications. (Effect of Empirical Left Atrial Appendage Isolation on Long-term Procedure Outcome in Patients With Persistent or Longstanding Persistent Atrial Fibrillation Undergoing Catheter Ablation [BELIEF]; NCT01362738)

Left Atrial Appendage Electrical Isolation and Concomitant Device Occlusion to Treat Persistent Atrial Fibrillation: A First-in-Human Safety, Feasibility, and Efficacy Study.

Left atrial appendage (LAA) electric isolation is reported to improve persistent atrial fibrillation (AF) ablation outcomes. However, loss of LAA mechanical function may increase thromboembolic risk. Concomitant LAA electric isolation and occlusion as part of conventional AF ablation has never been tested in humans. We therefore evaluated the feasibility, safety, and efficacy of LAA electric isolation and occlusion in patients undergoing long-standing persistent AF ablation. Patients with long-standing persistent AF (age, 68±7 years; left atrium diameter, 46±3 mm; and AF duration, 25±15 months) underwent AF ablation, LAA electric isolation, and occlusion. Outcomes were compared with a balanced (1:2 ratio) control group who had AF ablation alone. Among 22 patients who underwent ablation, LAA electric isolation was possible in 20. Intraprocedural LAA reconnection occurred in 17 of 20 (85%) patients, predominantly at anterior and superior locations. All were reisolated. LAA occlusion was successful in all 20 patients. There were no major periprocedural complications. Imaging at 45 days and 9 months confirmed satisfactory device position and excluded pericardial effusion. One of twenty (5%) patients had a gap of ≥5 mm requiring anticoagulation. Nineteen of twenty (95%) patients stopped warfarin at 3 months. Without antiarrhythmic drugs, freedom from AF at 12 months after a single procedure was significantly higher in the study group (19/20, 95%) than in the control group (25/40, 63%), P=0.036. Freedom from atrial arrhythmias was demonstrated in 12 of 20 (60%) and 18 of 20 (90%) patients after 1 and ≤2 procedures (mean, 1.3), respectively. Persistent AF ablation, LAA electric isolation, and mechanical occlusion can be performed concomitantly. This technique may improve the success of persistent AF ablation while obviating the need for chronic anticoagulation. URL: https://clinicaltrials.gov. Unique identifier: NCT02028130.

229-06: Left Atrial Appendage Electrical Isolation for Long-Standing Persistent Atrial Fibrillation: Computational Three-Dimensional Left Atrial Appendage Wall Thickness Maps and Histological Analysis to Guide Ablation

Purpose of the study: Left atrial appendage (LAA) electrical isolation may improve the efficacy of persistent atrial fibrillation (AF) ablation. We have previously demonstrated substantial acute LAA reconnection rates in both canines and humans following electrical isolation. We sought to establish whether LAA ostial thickness variations could be evaluated by a novel computational algorithm applied to a pre-procedure CT. Methods used: LAA wall thickness was calculated by solving the Laplace equation between the boundary conditions assigned to the endo- and epi-cardial surfaces from CT scans of 20 patients. Comparison was made with acute LAA reconnection sites in 20 patients with longstanding persistent AF undergoing LAA isolation following conventional AF ablation and with ostial LAA thicknesses from a group of cadaveric human hearts without previous ablation matched with the ablation group. Summary of the results: The anterior (2.5 ± 0.8 mm) and superior (2.4 ± 1.2 mm) LAA margins were thickest histologically. This correlated with recorded sites of acute reconnection. The algorithm calculated thicker tissue at the same ostial sites. The thickest region was at the anterior wall; the inferior wall was the thinnest (2.4 ± 1.5 mm vs 1.8 ± 0.8 mm, p = 0.039).

The clinical efficacy of left atrial appendage isolation caused by extensive left atrial anterior wall ablation in patients with atrial fibrillation.

The left atrial appendage (LAA) can be a source of atrial fibrillation (AF) triggering or a part of reentry. We sought to determine the characteristics and clinical outcomes of patients with LAA potential delay including electrical isolation (LAAEI) following LA anterior wall (LAAW) ablation for AF. LAAW ablation cases were collected from among 846 patients who underwent catheter ablation (CA). A total of 89 patients were enrolled; they were divided into three groups according to the extent of LAA potential injury. The ejection fractions (EFs) of the LAA and LA were measured by means of LA angiograms. The mean age of all patients was 56.2 ± 10.7years (74 males, 83%). In 47 of the 89 patients, an LAA potential delay was identified after LAAW ablation (group 2). LAAEI was seen in 18 patients (group 3). In the remaining 24 patients, there was no LAA potential delay or LAAEI (group 1). The mean EF decreased significantly after CA in group 3 (P < 0.001). At 21-month follow-up, three patients (17%) in group 3 had recurrence compared with 11 (42%) in group 2 and 12 (46%) in group 3 (P = 0.028). In multivariate analysis, diabetes mellitus and LAA potential delay were independent predictors of AF recurrence (P = 0.021, P = 0.008, respectively). Ablation of the LA anterior wall near the insertion of Bachmann's bundle and the neck of the LAA resulting in LAA potential delay or electrical isolation is effective in preventing recurrence of atrial fibrillation.

Abstract 14764: Left Atrial Appendage Function and Risk of Stroke After Left Atrial Appendage Electrical Isolation in Patients With Long-Standing Persistent AF: Results From the BELIEF Randomized Trial

Introduction: The Belief Randomized trial sought to assess whether the empirical isolation of the left atrial appendage (LAA) in addition to an extensive ablation could improve success at follow up in patients with long standing persistent (LSP) atrial fibrillation (AF). The aim of this sub-analysis of the trial aimed to evaluate the LAA contraction at the 6 month repeat Trans-esophageal echocardiogram (TEE). Methods: Patients with LSP AF undergoing ablation were enrolled and randomly assigned to undergo empirical LAA isolation along with an extensive ablation or extensive ablation alone. All patients undergoing LAA isolation received a TEE at the 6 months follow up, irrespective of their underlying rhythm. We evaluated TEE parameters and compared thromboembolic complication between groups. Results: We enrolled 173 pts with average age of 63.8 ± 8.5 years and 85.5% male pts. LAA isolation was performed in 101 pts. LAA was not isolated in 72 pts. Follow-up TEE was performed in all pts with LAA isolation. The peak flow velocity in the appendage was low (&lt;0.4 m/s) in 56.4% (57/101) patients. The doppler across the mitral valve demonstrated E-wave to A-wave ratio (E/A) of 2.64 ± 1.4. All patients had E/A &gt;1, out of which 55.4 %( 56/101) had E/A &gt; 2 (p=0.16). One (1.2%) LAA thrombus [Oral anticoagulant warfarin INR subtherapeutic] and 1 (1.2%) LAA smoke [Oral anticoagulant warfarin, INR : 2.24] were detected in the LAA isolation group as an incidental finding at TEE before redo ablation procedure. One patient (0.99%) had stroke in the LAA isolation group after warfarin discontinuation due to a surgical procedure, while 3 (4.2%) stoke/TIA occurred (p=0.31) in the no LAA isolation group (2 pts on warfarin, 1 pt on aspirin). Conclusion: The results of this study show that LAA isolation does not increase the risk of tia/stroke at follow up. This risk appears to be related to the compliance to oral anticoagulation.

Sequential Percutaneous LAA Ligation and Pulmonary Vein Isolation in Patients with Persistent AF: Initial Results of a Feasibility Study.

Left atrial appendage (LAA) ligation results in LAA electrical isolation and a decrease in atrial fibrillation (AF) burden. This study assessed the feasibility of combined percutaneous LAA ligation and pulmonary vein isolation (PVI) in patients with persistent AF. A total of 22 patients with persistent AF underwent LAA ligation with the LARIAT device followed by PVI. PVI was confirmed with the demonstration of both entrance and exit block. Patients (n = 10) in sinus rhythm pre- and post-LAA ligation underwent P-wave analysis. Monitoring for AF was performed at 1, 3, and 6 months postablation. LAA ligation was successful in 21 of 22 (95%) patients. The procedure was aborted in one patient due to pericardial adhesions. PVI was performed in 20 of 21 patients. One patient converted to atrial flutter with a controlled ventricular response after LAA ligation and refused subsequent PVI. Demonstration of entrance and exit block was achieved in 19 of 20 patients. At 3 months, 13 of 19 (68.4%) patients were in sinus rhythm. Four patients underwent a second PVI. At 6 months, 15 of 20 (75%) patients were in sinus rhythm. There was a significant decrease in P-wave duration and P-wave dispersion after LAA ligation. Complications with LAA ligation included pericarditis, a delayed pleural effusion, and a late pericardial effusion. Staged LAA ligation and PVI is feasible and decreases P-wave dispersion. Randomized studies are needed to assess the efficacy of LAA ligation as adjunctive therapy to PVI for maintaining sinus rhythm in patients with persistent AF.

Left atrial appendage electrical isolation and concomitant device occlusion: A safety and feasibility study with histologic characterization.

Left atrial appendage (LAA) electrical isolation is reported to improve atrial fibrillation ablation outcomes. However, loss of mechanical function may increase thromboembolic risk. The aim of this study was to evaluate the feasibility and safety of LAA occlusion after electrical isolation in a canine model. Nine canines underwent LAA isolation with irrigated radiofrequency ablation after pulmonary vein (PV) isolation. Entrance and exit block were confirmed with intravenous adenosine after 30 minutes. The LAA was then occluded with a Watchman device. Device position was assessed at 10 days by using transthoracic echocardiography. At 45 days, LAA isolation was assessed epicardially. Hearts were then examined macroscopically and histologically. All 36 PVs and 8 of 9 LAAs (89%) were electrically isolated. Acute LAA reconnection occurred in 4 of 8 LAAs (50%). All were reisolated. The mean ablation time was 51 ± 19 minutes, including 24 ± 18 minutes for LAA isolation. LAA occlusion was successful in all cases. One animal died of a primary intracranial bleed due to anticoagulant hypersensitivity 36 hours after the procedure. Transthoracic echocardiography at 10 days confirmed satisfactory device positions and no pericardial effusion. At 45 days, 7 of 8 (88%) had persistent LAA electrical isolation. All devices were stable without evidence of erosion. Microscopy revealed complete device-tissue apposition and a mature connective tissue layer overlying the device surface in all cases. LAA electrical isolation and mechanical occlusion can be performed concomitantly in this animal model, with no displacement or mechanical erosion of the appendage at 45 days. This technique can potentially improve success rates and obviate the need for chronic anticoagulation. Future studies should address efficacy, safety, and feasibility in humans.

WATCHMAN for Concomitant Left Atrial Appendage Electrical Isolation and Occlusion to Treat Persistent Atrial Fibrillation Rhythm

WATCHMAN for Concomitant Left Atrial Appendage Electrical Isolation and Occlusion to Treat Persistent Atrial Fibrillation Rhythm