Intracardiac Echocardiography-Guided Left Atrial Appendage Closure With a Novel Foam-Based Conformable Device: Safety and 1-Year Outcomes

Procedure Volume and Outcomes With WATCHMAN Left Atrial Appendage Occlusion

BACKGROUND

Procedure volumes are associated with outcomes for many cardiovascular procedures, leading to guidelines on minimum volume thresholds for certain procedures; however, the volume-outcome relationship with left atrial appendage occlusion is poorly understood. As such, we sought to determine the relationship between hospital and physician volume and WATCHMAN left atrial appendage occlusion procedural success overall and with the new generation WATCHMAN FLX device.

METHODS

We performed an analysis of WATCHMAN procedures (January 2019 to October 2021) from the National Cardiovascular Data Registry LAAO Registry. Three-level hierarchical generalized linear models were used to assess the adjusted relationship between procedure volume and procedural success (device released with peridevice leak <5 mm, no in-hospital major adverse events).

RESULTS

Among 87 480 patients (76.2±8.0 years; 58.8% men; mean CHA2DS2-VASc score, 4.8±1.5) from 693 hospitals, the procedural success rate was 94.2%. With hospital volume Q4 (greatest volume) as the reference, the likelihood of procedural success was significantly less among Q1 (odds ratio [OR], 0.66 [CI, 0.57-0.77]) and Q2 (OR, 0.78 [CI, 0.69-0.90]) but not Q3 (OR, 0.95 [CI, 0.84-1.07]). With physician volume Q4 (greatest volume) as the reference, the likelihood of procedural success was significantly less among Q1 (OR, 0.72 [CI, 0.63-0.82]), Q2 (OR, 0.79 [CI, 0.71-0.89]), and Q3 (OR, 0.88 [CI, 0.79-0.97]). Among WATCHMAN FLX procedures, there was attenuation of the volume-outcome relationships, with statistically significant but modest absolute differences of only ≈1% across volume quartiles.

CONCLUSIONS

In this contemporary national analysis, greater hospital and physician WATCHMAN volumes were associated with increased procedure success. The WATCHMAN FLX transition was associated with increased procedural success and less heterogeneity in outcomes across volume quartiles. These findings indicate the importance of understanding the volume-outcome relationship for individual left atrial appendage occlusion devices.

Left atrial appendage closure in patients with left atrial appendage thrombus guided by intracardiac echocardiography

BACKGROUND

Data regarding left atrial appendage closure (LAAC) in patients with left atrial appendage (LAA) thrombus are limited. Recently published cases have mostly been guided by transesophageal echocardiography. Intracardiac echocardiography (ICE) is now widely used during LAAC procedures.

OBJECTIVE

This is the first study to report the feasibility of LAAC in patients with LAA thrombus guided by ICE.

METHODS

Patients with persistent LAA thrombus despite anticoagulation or contraindications to anticoagulation who underwent a modified ICE-guided LAAC procedure between June 2021 and April 2023 were included. Periprocedural events and clinical outcomes during follow-up were recorded.

RESULTS

A total of 12 patients (mean age 65 ± 7 years; 92% male) were included: 10 with persistent LAA thrombus and 2 with contraindications to anticoagulation. Most of the thrombus was at the apex (n = 6), followed by the body (n = 3) and the ostium (n = 3). A LAmbre device was used and successfully implanted in all patients with the guidance of ICE. No thrombotic material was retrieved from patients with the protection of cerebral protection device (n = 11). No patient experienced severe periprocedural complications. All patients completed transesophageal echocardiography follow-up, and no device-related thrombus or peridevice leak > 3 mm was detected. None of the patients experienced stroke/transient ischemic attack, systemic embolism, or major bleeding events during a median follow-up of 147 days (interquartile range 80-306 days).

CONCLUSION

LAAC using the LAmbre device guided by ICE may be feasible in patients with LAA thrombus when performed by experienced operators.

Perioperative Treatment with Rivaroxaban and Dabigatran on Changes of Coagulation and Platelet Activation Biomarkers following Left Atrial Appendage Closure

Insufficient data exist regarding the investigation of the impact of novel oral anticoagulants (NOACs) on coagulation activation biomarkers in the context of left atrial appendage closure (LAAC) and device-related thrombosis (DRT). The study was designed to investigate the changes and presence of coagulation activation biomarkers between different antithrombotic strategies following LAAC. A total of 120 nonvalvular atrial fibrillation patients intolerant of long-term anticoagulants, who underwent successful WATCHMAN closure implantation, were enrolled (rivaroxaban, n = 82; dabigatran, n = 38). Blood samples were obtained from left atrium (LA) and left atrial appendage (LAA) during the operation and fasting blood samples on the same day of LAAC and 45 days after discharge. The biochemical indicators, thrombin-antithrombin complex (TAT), soluble P-selectin (sP-selectin), von Willebrand factor (vWF), and CD40 ligand (CD40L), were measured by enzyme-linked immunosorbent assay. The primary endpoints of this study were the efficacy and safety characteristics of different antithrombotic strategies, including DRT incidence, stroke or transient ischemic attack, systemic embolism, and clinical major and nonmajor bleeding complications during the follow-up of 180 days. The results revealed that TAT, vWF, sP-selectin, and CD40L levels in vein were significantly reduced by 2.4% (p = 0.043), 5.0% (p < 0.001), 8.7% (p < 0.001), and 2.5% (p = 0.043) from their baseline levels after rivaroxaban treatment. Conversely, no significant changes were detected in the dabigatran group. Furthermore, the plasma levels of platelet activation biomarkers (CD40L and sP-selectin) in both LA and LAA groups were significantly lower after anticoagulation with rivaroxaban, as compared to dabigatran treatment (CD40L: 554.62 ± 155.54 vs. 445.02 ± 130.04 for LA p = 0.0013, 578.51 ± 156.28 vs. 480.13 ± 164.37 for LAA p = 0.0052; sP-selectin: 2849.07 ± 846.69 vs. 2225.54 ± 799.96 for LA p = 0.0105, 2915.52 ± 1402.40 vs. 2203.41 ± 1061.67 for LAA p = 0.0022). Notably, the present study suggests that rivaroxaban may be more effective in the prevention of DRT for patients undergoing LAAC.

Left Atrial Appendage Occlusion and Post-procedural Antithrombotic Management

Left atrial appendage occlusion (LAAO) is an established alternative to oral anticoagulation for stroke prevention in atrial fibrillation. Antithrombotic therapy is used in the post-procedural period to prevent device-related thrombosis (DRT). The risk of DRT is considered highest in the first 45-90 days after device implantation, based on animal studies of the device healing process. Clinically applied antithrombotic regimens vary greatly across studies, continents, and centers. This article gives an overview of the evidence behind current antithrombotic regimens, ongoing randomized trials, and future post-procedural management.

Left atrial appendage closure: the journey today and tomorrow

PURPOSE OF REVIEW

This review aims to discuss the rationale behind the development of percutaneous LAAC devices as a treatment option for atrial fibrillation patients ineligible for long-term anticoagulation. The evolution of LAAC, from early experiences and challenges to risk mitigation and improved devices and techniques, will be examined. Furthermore, the review will explore our current understanding of the potential and limitations of LAAC in stroke prevention.

RECENT FINDINGS

Multiple trials confirm LAAC device safety and efficacy for stroke prevention, but peri-device leak and thrombus remain concerns postimplantation. Even small leaks pose increased stroke risk. While guidelines suggest short-term anticoagulation postimplant; real-world data show equivalent efficacy with dual antiplatelet regimen.

SUMMARY

LAAC device design has evolved and now serve as a viable option for stroke prevention in high-risk atrial fibrillation patients, offering protection in the absence of anticoagulation.

Left atrial appendage closure for stroke prevention in atrial fibrillation patients: A promise that came true

Anticoagulation therapy plays a crucial role in the management of atrial fibrillation (AF), considering the high morbidity and mortality of AF-related ischemic strokes. With the plausible hypothesis that left atrial appendage is the main source of thrombus in AF patients, left atrial appendage closure (LAAC) has been regarded as a potential substitute to oral anticoagulation in order to meet the unmet needs for stroke prevention, particularly in patients with high bleeding risk. Notable advancements in safety, efficacy, and device innovation have been made in recent years, albeit concerns still remain regarding the insufficient efficacy data, device-related complications, and the need for procedural optimization. We aim to review current knowledge about LAAC and provide potential future directions for the remaining key issues.

A comparable efficacy and safety between intracardiac echocardiography and transesophageal echocardiography for percutaneous left atrial appendage occlusion

Background

Accumulated clinical studies utilized intracardiac echocardiography (ICE) to guide percutaneous left atrial appendage occlusion (LAAO). However, its procedural success and safety compared to traditional transesophageal echocardiography (TEE) remained elusive. Therefore, we performed a meta-analysis to compare efficacy and safety of ICE and TEE for LAAO.

Methods

We screened studies from four online databases (including the Cochrane Library, Embase, PubMed, and Web of Science) from their inception to 1 December 2022. We used a random or fixed-effect model to synthesize the clinical outcomes and conducted a subgroup analysis to identify the potential confounding factors.

Results

A total of twenty eligible studies with 3,610 atrial fibrillation (AF) patients (1,564 patients for ICE and 2,046 patients for TEE) were enrolled. Compared with TEE group, there was no significant difference in procedural success rate [risk ratio (RR) = 1.01; P = 0.171], total procedural time [weighted mean difference (WMD) = -5.58; P = 0.292], contrast volume (WMD = -2.61; P = 0.595), fluoroscopic time (WMD = -0.34; P = 0.705; I² = 82.80%), procedural complications (RR = 0.82; P = 0.261), and long-term adverse events (RR = 0.86; P = 0.329) in the ICE group. Subgroup analysis revealed that ICE group might be associated with the reduction of contrast use and fluoroscopic time in the hypertension proportion <90 subgroup, with lower total procedure time, contrast volume, and the fluoroscopic time in device type subgroup with multi-seal mechanism, and with the lower contrast use in paroxysmal AF (PAF) proportion ≤50 subgroup. Whereas, ICE group might increase the total procedure time in PAF proportion >50 subgroup and contrast use in multi-center subgroup, respectively.

Conclusion

Our study suggests that ICE may have comparable efficacy and safety compared to TEE for LAAO.

Transcatheter Left Atrial Appendage Closure

Atrial fibrillation is the most common arrhythmia worldwide, placing a large population at risk for potentially disabling ischemic strokes, yet an estimated 50% of eligible patients cannot tolerate or are contraindicated to receive oral anticoagulation. Within the last 15 years, transcatheter options for left atrial appendage closure (LAAC) have provided a valuable alternative to chronic oral anticoagulation for reducing risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. With newer generation devices such as Watchman FLX and Amulet gaining approval from the US Food and Drug Administration in recent years, several large clinical trials have demonstrated the safety and efficacy of transcatheter LAAC in a population intolerant to systemic anticoagulation. In this contemporary review, we discuss the indications for transcatheter LAAC and the evidence evaluating the use of various device therapies currently available or in development. We also examine current unmet challenges in intraprocedural imaging and controversies in postimplantation antithrombotic regimens. Several ongoing seminal trials are hoping to clarify the role of transcatheter LAAC as a safe, first-line option for all patients with nonvalvular atrial fibrillation.