Initial Japanese Multicenter Experience and Age-Related Outcomes Following Left Atrial Appendage Closure: The OCEAN-LAAC Registry

Current evidence and indications for left atrial appendage closure

Atrial fibrillation (AF) is the most common arrhythmia worldwide and its prevalence increases with age. The main and most severe complication of AF is ischemic stroke, yet an estimated 50 % of eligible patients cannot tolerate or are contraindicated to receive oral anticoagulation (OAC). In patients with AF, the left atrial appendage (LAA) is the main source of thrombus formation. Percutaneous LAA closure (LAAC) has emerged over the past two decades as a valuable alternative to OAC for reducing the risk of strokes and systemic embolisms in patients with AF who cannot tolerate long-term OAC. With newer generation devices such as the Watchman (Boston Scientific, Natick, MA, USA) and Amulet (Abbott, Abbott Park, IL, USA) gaining approval from the US Food and Drug Administration in recent years, the safety and efficacy of LAAC in specific populations intolerant to OAC have increased and more patients are being treated. This systematic review provides the indications for LAAC and the evidence for evaluating the use of the currently available device therapies. We also examine the current unsolved problems with patient selection and postprocedural antithrombotic regimens.

Impact of Angiographically Detected Residual Trabeculation After Left Atrial Appendage Closure Using the WATCHMAN Device: Insight From the OCEAN-LAAC Registry

BACKGROUND

Research on the impact of angiographically detected residual trabeculation after left atrial appendage closure (LAAC) is limited.

OBJECTIVES

To investigate the incidence, characteristics, and clinical implications of angiographically detected residual trabeculation after LAAC using the WATCHMAN device.

METHODS

We analyzed 1350 consecutive patients with atrial fibrillation undergoing LAAC using the WATCHMAN device from the OCEAN-LAAC registry, which is a prospective ongoing, multicenter Japanese registry. The inclusion criteria comprised patients who successfully underwent LAAC and whose presence or absence of residual trabeculation can be confirmed using a contrast medium. The clinical outcomes were compared between patients with and without angiographically detected residual trabeculation.

RESULTS

Residual trabeculation was angiographically detected in 5.6% (75/1350 patients). At the procedure, the proportion of peri-device leak (PDL) was significantly higher in the residual trabeculation group than in the non-residual trabeculation group (20% vs. 5.1%, p < 0.001). However, the PDL and device-related thrombosis at 45 days and 1 year were comparable between the two groups (37% vs. 23%, p = 0.24; 28% vs. 31%, p = 0.84; 2.1% vs. 1.4%, p = 0.50; 6.9% vs. 6.0%, p = 0.69, respectively). The 3-year cumulative incidence of ischemic stroke, all cardiovascular death, and all-cause death were comparable between the two groups (5.7% vs. 5.5%, log-rank p = 0.96; 7.7% vs. 8.9%, log-rank p = 0.34, 31.4% vs. 22.3%, log-rank p = 0.71, respectively).

CONCLUSION

The angiographically detected residual trabeculation rate was 5.6%, and this population had a significantly higher prevalence of PDL at the procedure. However, the presence of residual trabeculation did not contribute to PDL or device-related thrombosis at follow-up or affect the clinical outcomes.

Outcomes of Left Atrial Appendage Closure in Hemodialysis Patients With Atrial Fibrillation: The OCEAN-LAAC Registry

Background

Left atrial appendage closure (LAAC) has demonstrated favorable outcomes as an alternative to permanent anticoagulation in patients with nonvalvular atrial fibrillation (NVAF). In hemodialysis (HD) patients with NVAF, anticoagulation increases bleeding complications, with inconsistent benefits in stroke prevention.

Objectives

This study aimed to clarify the benefit of LAAC for HD patients.

Methods

Consecutive patients who underwent LAAC, as extracted from the Japanese multicenter registry, were eligible. When comparing HD and non-HD patients, perioperative events, including LAAC procedure success rates and the incidence of death, bleeding events, and ischemic stroke events, were analyzed.

Results

Among 1,464 patients (mean age 77.1 ± 7.6 years, mean CHA2DS2-VASc score 4.9 ± 1.5, mean HAS-BLED score 3.1 ± 1.0), 172 were HD patients. The HD group had higher HAS-BLED scores, whereas more patients in the non-HD group had a history of Bleeding Academic Research Consortium type 3 bleeding. Device implantation success was 97.3% (95% CI: 96.3%-98.0%) (HD group; 97.1% [167 of 172], non-HD group; 97.3% [1,257 of 1,292]; P = 0.88). There were no in-hospital deaths, and perioperative complications were rare and did not differ between the 2 groups. The median follow-up period was 367 days (Q1-Q3: 242-422 days). The ischemic stroke rate following LAAC in the HD group was 1.1% (95% CI: 0.3%-1.9%) per 100 patient-years, comparable to the non-HD group.

Conclusions

LAAC is feasible for HD patients and achieves results comparable to those in non-HD patients. Further research is necessary to determine the effectiveness of LAAC in preventing stroke in HD patients.

Association between preprocedural thromboembolic and bleeding events under oral anticoagulation therapy and mid-term outcomes after percutaneous left atrial appendage closure

Currently, no consensus has been established on the most effective antithrombotic therapy to prevent thromboembolic and bleeding events in patients undergoing percutaneous left atrial appendage closure (LAAC) with preprocedural thromboembolic or bleeding events under oral anticoagulation (OAC) therapy. We retrospectively investigated the incidence of device-related thrombosis (DRT), thromboembolic events, and bleeding events in patients who underwent LAAC from September 2019 to October 2022. After categorizing patients into three groups based on preprocedural thromboembolic or bleeding events under OAC therapy, we compared the incidence of DRT and prognosis according to the postprocedural antithrombotic therapy. In patients who received the conventional antithrombotic therapy (OAC with and without single antiplatelet therapy for 45 days after LAAC and dual-antiplatelet therapy from 45 days to 6 months followed by single antiplatelet therapy), preprocedural thromboembolic events despite OAC were independently associated with DRT or postprocedural thromboembolic events at the 3 year follow-up (hazard ratio [HR] 4.55; 95% confidence interval [CI] 1.32-15.6; P = 0.016), whereas preprocedural bleeding events were independently associated with postprocedural bleeding events (HR 8.01, 95% CI 1.45-58.3; P = 0.036). Continuation of OAC for 12 months among patients who developed preprocedural thromboembolic events during OAC significantly decreased the incidence of DRT or postoperative thromboembolic events (P = 0.002) with no increase in the bleeding events (P = 0.522). Preprocedural thromboembolic and bleeding events can predict adverse events after LAAC with the conventional antiplatelet-based antithrombotic therapy. Patients who develop thromboembolic events under continuous OAC may benefit from continuous OAC for 1 year after LAAC.

Correlations Between Plasma BNP Level and Risk of Thrombotic-Hemorrhagic Events After Left Atrial Appendage Closure

Background: Percutaneous left atrial appendage closure (LAAC) reduces the incidence of stroke/bleeding events in patients with non-valvular atrial fibrillation, high risk of stroke, and contraindication in continuing anticoagulation therapy. Of them, patients with heart failure may remain at high risk of these events after LAAC. Method: Patients who underwent LAAC and were listed for the multi-center, prospectively collected OCEAN-LAAC registry, were eligible. Of them, individuals without baseline plasma B-type natriuretic peptide (BNP) levels and those dependent on hemodialysis were excluded. The prognostic impact of baseline plasma BNP levels on the incidence of death or stroke/bleeding events after LAAC was evaluated. Results: A total of 937 patients (median 78 years, 596 men) were included. The LAAC device was successfully implanted in 934 (98%) patients. Over the 366 (251, 436) days after the LAAC, 148 patients encountered a primary outcome. The common logarithm of baseline plasma BNP was independently associated with the primary outcome with an adjusted hazard ratio of 1.46 (95% confidence interval 1.06-2.18, p = 0.043). A calculated cutoff of 2.12 (equivalent to 133 pg/mL of plasma BNP level) significantly stratified the cumulative incidence of the primary outcome (29% vs. 21% for 2 years, p = 0.004). Conclusions: Using prospectively collected large-scale multi-center Japanese registry data, we demonstrated that a baseline higher plasma BNP level was independently associated with a higher incidence of stroke/bleeding events and mortality after LAAC. Further studies are warranted to understand the optimal therapeutic strategy for LAAC candidates with elevated baseline plasma BNP levels.

Prognostic impact of increase in left atrial volume following left atrial appendage closure: Insights from the OCEAN-LAAC registry

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) is an effective therapy to prevent thromboembolic events among patients with atrial fibrillation (AF). However, since the left atrial appendage (LAA) contributes to left atrial volume and serves as a buffer for increasing left atrial pressure, this procedure may impair left atrium (LA) compliance, enlarge LA, and deteriorate diastolic function. In this study, we sought to investigate the change in left atrial volume index (LAVI) following LAAC and its effect on prognosis.

METHODS AND RESULTS

We analyzed 225 patients from the OCEAN-LAAC registry, an ongoing, multicenter Japanese study. Comparing LAVI measurements at baseline and 6 months after LAAC, no significant increase was observed (55.0 [44.0, 70.0] ml/m2 vs. 55.0 [42.0, 75.6] ml/m2; P = 0.31). However, some patients underwent LAVI increase. Particularly, a smaller LAVI (odds ratio [OR]: 0.98 [95 % confidence interval (CI): 0.97-0.996]) and elevated tricuspid regurgitation pressure (TRPG) at baseline (OR: 1.04 [95 % CI: 1.00 - 1.08]) were significantly related to the increase in LAVI at 6-month follow-up. In addition, a 5 ml/m2 increase in LAVI was significantly associated with subsequent heart failure hospitalization (HFH) (hazard ratio: 3.37 [95 % CI: 1.18-9.65]). This association, however, was not observed in patients with lower baseline LAVI (≤55 ml/m2) but was only seen in those with a baseline LAVI over 55 ml/m2.

CONCLUSION

Our study demonstrated an increase in LAVI after LAAC was related to smaller LAVI or elevated TRPG at baseline. The LAVI increase was significantly associated with subsequent HFH.

Safety and feasibility of atrial fibrillation ablation after left atrial appendage closure: A single-center experience of the left atrial appendage closure first strategy

BACKGROUND

Patients with atrial fibrillation (AF) who are not suitable for long-term anticoagulant therapy undergo percutaneous left atrial appendage closure (LAAC). The safety and feasibility of left atrial catheter ablation (CA) procedures after LAAC remain unclear. This study aimed to clarify the feasibility and safety of CA after LAAC, including in the early phase within 180 days.

METHODS

Characteristics and clinical outcomes of 46 patients with AF who had undergone both CA and LAAC within 2 years (mean age, 72 years; 29 men) were compared between those who had undergone CA-first (31 patients) and LAAC-first (15 patients).

RESULTS

The mean CHA₂DS₂-VASc and HAS-BLED scores were 4.8 and 3.3 points, respectively. The LAAC-first strategy was often used in patients with prior major bleeding and LAA thrombosis or sludge. In the LAAC-first group, the mean duration between both procedures was 212 days, and all LAAC-first patients, including seven patients in the early phase, could undergo CA without LAAC device-related complications; moreover, no cardiovascular adverse events were reported after both procedures (mean periods: 420 days). After CA post-LAAC, no device-related adverse events (device-related thrombosis, new peri-device leak appearance, peri-device leak increase, or device dislodgement) were observed, whereas, after LAAC post-CA, 3 new peri-device leak appearance events and 1 peri-device leak increase event were observed, especially patients who underwent LAAC in the early phase post-CA.

CONCLUSION

Based on single-center experience, left atrial CA in the presence of an LAAC device implanted including the early phase was safe and feasible.

Comparative Data of Procedural and Midterm Outcomes in Patients Who Underwent Percutaneous Left Atrial Appendage Closure Between the WATCHMAN FLX and WATCHMAN 2.5 Devices - Insight From the OCEAN-LAAC Registry

BACKGROUND

Limited data are available regarding clinical outcomes after percutaneous left atrial appendage closure using WATCHMAN FLX (WM-FLX) and WATCHMAN-2.5 (WM2.5) devices in Asian patients.

METHODS AND RESULTS

Data of 1,464 consecutive patients (WM-FLX, n=909; WM2.5, n=555) were extracted from a Japanese multicenter registry, and clinical data were compared between the 2 groups. No in-hospital deaths, periprocedural stroke, or device embolization occurred. Procedural success was significantly higher in the WM-FLX than WM2.5 group (95.8% vs. 91.9%; P=0.002) owing to the lower incidence of periprocedural pericardial effusion (0.55% vs. 1.8%; P=0.021). No significant differences in all-cause death, postprocedural stroke, and device-related thrombus were observed between the 2 groups. However, the cumulative bleeding rate at 1 year was substantially lower in the WM-FLX group (7.8% vs. 16.4%; P<0.001). Landmark analysis of bleeding events highlighted lower bleeding rates in the WM-FLX than WM2.5 group within the first 6 months (6.4% vs. 14.8%; P<0.001), with comparable bleeding rates over the 6- to 12-month period (1.5% vs. 3.2%, respectively; P=0.065).

CONCLUSIONS

This study demonstrated higher early safety and lower 1-year bleeding rates in the WM-FLX than WM2.5 group. The lower bleeding events with WM-FLX are likely due to multiple factors other than purely difference in devices, such as postprocedural drug regimen.

Zero-Contrast Left Atrial Appendage Closure in Patients With Chronic Kidney Disease

BACKGROUND

Left atrial appendage closure (LAAC) usually requires contrast medium during the procedure. However, patients with chronic kidney disease (CKD) are at high risk of developing contrast nephropathy. This study aimed to assess the safety and feasibility of zero-contrast LAAC in patients with CKD.

METHODS AND RESULTS

Zero-contrast LAAC was attempted in 15 patients with CKD Stages 3b-5 who were not on hemodialysis. All procedures were performed successfully, without any periprocedural complications. At the 45-day follow-up, no device-related complications or acute kidney disease were observed.

CONCLUSIONS

The strategy of zero-contrast LAAC in patients with CKD can be an acceptable option.

Choosing Appropriate Candidates for Left Atrial Appendage Occlusion

Atrial fibrillation (AF) is one the most prevalent arrhythmias globally and is associated with a significantly higher risk of morbidity and mortality, including an up to five-fold increase in risk of stroke. While oral anticoagulation therapy remains the standard approach for stroke prevention in nonvalvular AF, left atrial appendage occlusion (LAAO) has emerged as a viable alternative for patients who are intolerant to long-term oral anticoagulation therapy. However, selecting appropriate candidates for LAAO requires a comprehensive evaluation that considers various clinical factors, although this presents a challenge in clinical practice. This review aims to provide an overview of the current recommendations for patient selection in LAAO procedures and the key factors that need to be considered both before and after the procedure, as well as the ongoing advancements in this field that may facilitate the selection of patients for LAAO.