2025 SCAI／HRS临床实践指南：经导管左心耳封堵术

ABSTRACT

BACKGROUND Left atrial appendage occlusion(LAAO) devices reduce the risk of atrial fibrillation-associated stroke relative to no oral anticoagulation. However, uncertainty and practice variation persist in the areas of patient selection, periprocedural im-aging,adjunctive antithrombotic therapy, and management of peridecle leaf(PDL) and device-related thrombus. The Society for Cardiovascular Angiography& Interventions and Heart Rhythm Society developed these evidence-based guidelines to sup-port clinicians, patients, and other stakeholders in management decisions regarding LAAO.

METHODS The Society for Cardiovascular Angiography& Interventions and Heart Rhythm Society convened a balanced, multi-disciplinary guideline panel with<50% of members reporting significant conflicts of interest with the industry. Evidence Foun-dation, a registered 501(c)(3) nonprofit organization, provided methodological support for guideline development. The guideline panel formulated and prioritized clinical questions following the Grading of Recording of Recommendations Assessment, Develop-ment, and Evaluation approach in a population, intervention, comparison, outcome form. A technical review team of clinical and methodological experts conducted systematic reviews of the published evidence, synthesized data, and graded the cer-tainty of evidence across outcomes. The guideline panel then developed recommendations and supporting statements informed by the technical review and using the Grading of Recommendations Assessment, Development, and Evaluation evidence-to-decision framework.

RESULTS The guideline panel developed 8 evidence-based recommendations to address variations in care related to LAAO.The panel also identified 2 knowledge gaps.

https://doi.org/10.1016/j.hrthm.2025.05.048

1547-5271/©2025 Published by Elsevier Inc. on behalf of Heart Rhythm Society.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

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CONCLUSIONS Key recommendations address patient selection for LAAO, periprocedural imaging, adjunctive antithrombotic therapy, and management of PDL and device-related thrombus. The panel also recommended necessary future research regarding the use of single antiplatelet therapy following LAAO and regarding the management of PDL.

KEYWORDS anticoagulation; antiplatelet therapy; atrial fibrillation; left atrial appendage occlusion; procedural imaging; stroke(Heart Rhythm 2025;■:1-16)© 2025 Published by Elsevier Inc. on behalf of Heart Rhythm Society.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/

ABBREVIATIONS DAPT= dual antiplatelet therapy; DRT=device device-related thrombus; GRADE= Grading of Recommen-dations Assessment, Development and Evaluation; ICE=intracardiac echocardiography; LAAO= left atrial appendage occlusion; NVAF= nonvalvular atrial fibrillation; OAC= oral

TABLE OF CONTENTS

anticoagulation; PDL= peridevice leak; SAP= single anti-platelet therapy; TEE= transesophageal echocardiography(Heart Rhythm 2025;■:1-16)

Summary of recommendations 3

Background 3

Methods 3

Interpretation of strong and conditional recommendations

Strong recommendation 3

Conditional recommendation 3

Recommendations 3

Introduction 4

Materials and methods 4

Organization, guideline panel composition, planning,and coordination

Guideline funding and management of conflicts of interest $\boxed{5}$

Formulating specific clinical questions and determining outcomes of interest 5

Evidence review and development of recommendations

Document review 5

How to use these guidelines 6

Updating guidelines

Recommendations 7

Recommendation 1.1

Summary of the evidence 7

Benefits, harms, and burden 7

Other considerations 7

Conclusions and future directions 7

Recommendation 2.18

Summary of the evidence 8

Benefits, harms, and burden 8

Other Considerations 8

Conclusions and future directions 8

Recommendation 3.1

Summary of the evidence 8

Benefits, harms, and burden 8

Other considerations 9

Conclusions and future directions 9

Recommendation 4.19

Summary of the evidence 9

Benefits, harms, and burden 9

Other considerations 9

Conclusions and future directions 10

Recommendation 5.110

Summary of the evidence 10

Benefits, harms, and burden.10

Other considerations 10

Conclusions and future directions 10

Recommendation 5.210

Summary of the evidence 10

Conclusions and Future Directions 11

Recommendation 6.111

Summary of the evidence 11

Benefits, harms, and burden 11

Other considerations 11

Conclusions and future directions 11

Recommendation 7.1111

Summary of the evidence 11

Benefits, harms, and burden 12

Other considerations 12

Conclusions and future directions 12

Recommendation 8.1225

Recommendation 8.2254

Summary of the evidence 12

Benefits, harms, and burden 12

Other considerations 13

Conclusions and future directions 13

Discussion 13

Acknowledgments 14

Declaration of competing interest 14

Funding sources 14

References 14

Other considerations 9

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Summary of recommendations

Background

A multisociety,multidisciplinary team conducted a systematic review to inform evidence-based left atrial appendage occlu-sion(LAAO) guidelines addressing variability in practice regarding indications, periprocedural imaging, adjunctive an-tithrombotic therapy, and management of peridevice leak(PDL) and device-related thrombus(DRT).

Methods

The Society for Cardiovascular Angiography& Interventions(SCAl)/Heart Rhythm Society(HRS) guidelines are based on an original systematic review conducted with support from the Evidence Foundation. The panel followed best practices for guideline development described by the Institute of Med-icine and the Guidelines International Network(GIN).1-3 The panel used the Grading of Recommendations Assessment,Development, and Evaluation(GRADE) methodology to assess the certainty of the evidence and formulate recommendations.

Interpretation of strong and conditional recommendations

The strength of a recommendation is expressed as either strong("the guideline panel recommends...") and has the following interpretation:

Strong recommendation

● For patients: Most patients in this situation would want the recommended course of action, and only a small proportion would not.

● For clinicians: Most patients should receive the recommen-ded treatment or test. Formal decision aids are likely not needed to assist individual patients in making decisions consistent with their values and preferences.

● For policymakers: The recommendation can be adopted as policy in most situations. Adherence to this recommenda-tion according to the guideline could be used as a quality metric or performance indicator.

Conditional recommendation

● For patients: The majority of individuals in this situation would want the suggested course of action, but a sizable minority would not.

● For clinicians: Recognize that different choices will be appropriate for individual patients and that patients should receive unbiased information to help them arrive at a man-agement decision consistent with their values and prefer-ences. Decision aids may be useful to help individuals make decisions consistent with their values and prefer-ences.

● For policymakers: Policymaking will require substantial debate and involvement of various stakeholders.Performance measures about the suggested course of

action should focus on documentation of an appropriate decision-making process.

Recommendations

1. In adults with nonvalvular atrial fibrillation(NVAF) and contraindication to oral anticoagulation(OAC), should LAAO be performed rather than no therapy?

1.1 For patients with NVAF and contraindication to OAC,the SCAI/HRS guideline panel suggests LAAO over no therapy(neither OAC nor LAAO)(conditional recom-mendation, very low certainty evidence).

Remarks: Many patients with contraindications to OAC(eg, bleeding history or bleeding risk) would reasonably choose to reduce their stroke risk by selecting LAAO over no therapy. Patients who value avoiding possible procedure-related adverse events more than a possible reduction in risk of stroke would reasonably choose no therapy. Clinicians should discuss with patients the pro-cedural risk of LAAO vs the ongoing risk of thromboem-bolic events associated with no treatment. LAAO may be inappropriate for patients with less than 1 year of quality life expectancy.

2. In adults with NVAF, should LAAO be performed rather than OAC?

2.1 For patients with NVAF who have decided to pursue

stroke prevention treatment, the SCAI/HRS guideline panel suggests OAC or LAAO as treatment options.

Remarks: While most patients are offered stroke preven-tion with OAC, those with elevated bleeding risk, prior bleeding complications, or strong preferences to avoid long-term anticoagulation would reasonably choose LAAO over OAC. LAAO may be inappropriate for pa-tients with less than 1 year of quality life expectancy.

3. In adults with NVAF who are undergoing LAAO, should cardiac computed tomography(CT) or transesophageal echocardiogram(TEE) be performed prior to the day of the procedure vs no imaging prior to the day of the pro-cedure?

3.1 For patients with NVAF who are undergoing LAAO,the SCAI/HRS guideline panel suggests obtaining pre-procedural TEE or cardiac CT instead of omitting preprocedural TEE or CT(conditional recommenda-tion, very low certainty evidence).

4. In adults with NVAF who are undergoing LAAO, should intracardiac echocardiography(ICE) guidance be used rather than TEE during the procedure?

4.1 For patients with NVAF who have decided to undergo LAAO, the SCAI/HRS guideline panel suggests either ICE or TEE imaging during the procedure(conditional recommendation, low certainty evidence).

Remarks: Patients who prefer to avoid general anes-thesia and the invasiveness of TEE would reasonably choose ICE.

5. For adults with NVAF who have undergone LAAO, should clinicians prescribe postprocedural OAC vs antiplatelet therapy?

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5.1 The SCAI/HRS guideline panel suggests either post-procedural OAC or dual antiplatelet therapy(DAPT)for patients undergoing LAAO(conditional recom-mendation, low certainty of evidence).

Remarks: Patients with more significant contraindica-tions to OAC(eg, severe bleeding history or risk) would reasonably select DAPT.

5.2 The SCAI/HRS guideline panel makes no recommen-dation about the use of single antiplatelet therapy(SAPT) vs any other antithrombotic regimen post-LAAO(knowledge gap).

6. In adults with NVAF who have undergone LAAO, should follow-up TEE or CT imaging be performed vs no follow-up TEE or CT?

6.1 For patients with NVAF who have undergone LAAO,the SCAI/HRS guideline panel suggests postproce-dural TEE or CT over no postprocedural TEE or CT(conditional recommendation, very low certainty evi-dence).

7. In adults with NVAF who have a PDL of any size after undergoing LAAO, should OAC be prescribed over no OAC?

7.1 The SCAI/HRS guideline panel makes no recommen-dation regarding the use of OAC in adults with a PDL after LAAO(knowledge gap).

8. In adults with NVAF who have DRT after undergoing LAAO, should indefinite OAC be prescribed vs no OAC?

8.1 For adults with DRT following LAAO, the SCAI/HRS guideline panel suggests OAC rather than no OAC(conditional recommendation, very low certainty evi-dence).

8.2 The SCAI/HRS guideline panel makes no recommen-dation about the optimal duration of OAC and the timing of repeat imaging to assess for PDL and DRT(knowledge gap).

Introduction

Nonvalvular atrial fibrillation(NVAF) affects more than 12 million Americans,6 conferring a 5-fold increase in stroke risk7 due to thromboembolism from the left atrial appendage.8 Guidelines based on randomized controlled trial(RCT) data4 support the use of OAC to reduce the risk of stroke in NVAF. The well-established use of OAC in NVAF has been codified in previous multisociety guidelines.10 However, less than 2/3 of patients with NVAF are treated with OAC11 due to reasons including bleeding, fall risk,medication nonadherence, medication cost, and patient preference.12

Transchatter LAAO is a procedural alternative to OAC that similarly lowers the risk of NVAF-associated stroke.13-15649 More than 30,000 LAAO procedures are performed each year in the United States16 using 2 devices-WATCHMAN(and its subsequent iterations, WATCHMAN FLX and WATCHMAN FLX Pro; Boston Scientific) and Amplatzer Amulet(Abbott)-which are both approved by the US Food and Drug Administration for patients with contraindications to long-term OAC.17,18

As LAAO procedures are performed by both interventional cardiologists and cardiac electrophysiologists, SCAI and HRS previously collaborated on the SCAI/HRS Expert Consensus Statement on Transcatheter Left Atrial Appendage Closure.19,20 However, considerable variation in real-world clinical practice remains. Indications for LAAO(due to contra-indications to long-term OAC) are interpreted very differently by different physicians. Preprocedural imaging may be per-formed with CT or TEE or not at all. Intraprocedural imaging may be performed with TEE or ICE. Postprocedure surveil-lance imaging may be performed at different time points with CT or TEE or not at all. Patients undergoing LAAO may be treated postprocedurally with short-term OAC, DAPT, or SAPT. Peridevice leak(PDL) identified on postprocedure im-aging may be managed expectantly or with the resumption of anticoagulation. DRT may be managed with short-term or long-term OAC.

In the setting of an expanding evidence base, SCAl and HRS collaborated to conduct an original systematic review and formulate rigorous multisociety LAAO guidelines using the GRADE approach to evaluate and apply evidence sys-tematically.

Materials and methods

The joint SCAI/HRS guideline panel developed clinical ques-tions,assessed the certainty of the evidence, and graded the recommendations in these guidelines following the GRADE approach.5,21

All aspects of the guideline development process,including its funding, formation of the guideline panel, man-agement of conflicts of interest, internal and external reviews,and societal approval, have been guided by SCAl policies, as well as procedures derived from the GIN-McMaster Guideline Development Checklist.22 The guideline has been developed with the intent to meet standards for trustworthy guidelines from the National Academy of Medicine(formerly Institute of Medicine).23

Organization, guideline panel composition, planning,and coordination

The guideline panel was coordinated and sponsored jointly by SCAI and HRS. Oversight of the project was provided by the SCAI Standards and Guidelines Committee and the HRS Clinical Documents Committee, which report to the Executive Committee of their respective organizations. SCAI and HRS each vetted and appointed individuals to the guideline panel.Additionally,SCAI and HRS each appointed an equal number of researchers to conduct systematic reviews of evidence and contribute to the guideline development process as part of a separate technical review team, who are also listed as nonvoting authors of the guideline. The membership of the guideline panel and the technical review teams are listed in Supplemental Table S1.

The guideline panel included interventional cardiologists,cardiac electrophysiology, and cardiovascular imaging spe-cialists who have clinical and research expertise on the

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management of patients with NVAF, and methodologists with expertise in evidence appraisal and guideline development.The panel's work and deliberations were conducted via a se-ries of virtual meetings conducted between June 25 and July 16,2024.

Guideline funding and management of conflicts of interest

Development of these guidelines was wholly funded by SCAI and HRS, nonprofit medical specialty societies that represent interventional cardiologists and cardiac electrophysiologists,respectively. Each society was represented by half the mem-bers of the guideline panel. SCAI and HRS staff provided logistical support for the technical review, management of conflicts of interest, the guideline development process,and manuscript preparation but had no role in selecting the guideline questions or determining the recommendations.

Physician members of the guideline panel were not compensated for their participation in this effort. Methodo logical support for the guideline was provided by Evidence Foundation, a registered 501(c)(3) nonprofit organization.

Conflicts of interest were managed according to SCAI pol-icies, which are based on recommendations of the National Academy of Medicine and the Guidelines International Network. ${}^{1,24}$

Before appointment to the guideline panel, individuals dis-closed financial and nonfinancial interests. Members of the SCAI Standards and Guidelines Committee reviewed the dis-closures and defined which relationships represented con-flicts requiring management. A complete summary of the"Disclosure of Interest" forms for the guideline panel and technical review team is available in Supplemental Table S1.At the time of appointment, a majority of the guideline panel,including the chair and the vice-chair, had no conflicts of inter-est as defined and judged by the SCAI Standards and Guide-lines Committee. None of the Evidence Foundation-affiliated researchers who contributed to the technical review or who supported the guideline development process had any cur-rent material interest in a commercial entity with any product that could be affected by the guidelines.

Panel members whose disclosures indicated a conflict of interest were reused from panel deliberations relevant to their financial interests in any commercial entity with any prod-uct that could be affected by the guidelines. The panel mem-bers who participated in judgments about each recommendation were recorded.

Formulating specific clinical questions and determining outcomes of interest

The SCAI/HRS guideline panel, with support from the meth-odologists, formulated each clinical question and prioritized outcomes a priori using the GRADE approach. ${}^{25}$ Each question identified a specific population, intervention,comparator, and outcomes(PICO). Outcomes were rated numerically for their relative importance to clinical decision-making on a scale of 1-9. Outcomes receiving a score of 7-9

were considered critical, whereas scores of 4-6 were consid-ered important, and scores of 1-3 were considered less impor-tant for clinical decision-making. Only critical outcomes(7-9)were included in the final list of PICO questions. PICO ques-tions were further reviewed by the technical review team(Supplemental Table S2).

Evidence review and development of recommendations

Each PICO question was addressed by a rigorous, high-quality systematic review, and findings were summarized in GRADE evidence profiles(Supplemental Table S3).5,26 A companion technical review manuscript reports these results in greater detail and should be referred to for more in-depth analysis of the recommendations contained herein.27 The certainty of the evidence(also known as the level or qual-ity of the evidence) relevant to each outcome was assessed using the GRADE approach based on the risk of bias, inconsis-tency, indirectness, imprecision, likelihood of publication bias, magnitude of effect, and dose-response relationship.4 Interpretations of certainty of evidence and the implications of strong and conditional recommendations can be found in Supplemental Table S3, Supplemental Table S4 and Supplemental Table S5.

The panel developed recommendations during 4, 2-hour virtual meetings. Recommendations were informed by data presented in the evidence profiles, the certainty of evidence ratings, patient values and preferences, the balance of bene-fits and harms of the intervention and comparator, resource use, health equity, acceptability by key stakeholders, and feasibility considerations. The panel agreed on each recom-mendation statement including the direction of the recom-mendation(for or against), strength of recommendation,and, if deemed appropriate, accompanying remarks by consensus. If a quorum of 75% of voting authors was present on the calls, consensus required unanimity. A formal vote could be called at any time and was required if a quorum was not present. In a formal vote, strong recommendations required 75% agreement. For conditional recommendations,a majority was needed, with a maximum of 20% preferring not to make a recommendation. The panel also discussed accom-panying text for the narrative, including implementation con-siderations and future research, during these meetings. The final manuscript has been reviewed and approved by all mem-bers of the panel.

Document review

The draft manuscript was reviewed by the guideline panel and then made available online on January 6,2025, for external re-view by SCAI and HRS members, as well as other stake-holders. The document was then revised to address relevant feedback, although the recommendations were unchanged.In March 2025, the SCAI Standards and Guidelines Commit-tee and HRS Clinical Guidelines Committee approved the manuscript; in May 2025, the officers of the SCAI Executive Committee and the members of the HRS Clinical Guidelines Committee, on authority delegated by the HRS Board of 697

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Trustees, approved submission of the guidelines for publica-tion under the imprimatur of SCAl and HRS.

How to use these guidelines

These guidelines are intended to help clinicians and patients make decisions about LAAO, including pre-, intra-, and post-procedural interventions and their alternatives. In addition,these guidelines should also serve to guide policy, education,and advocacy while highlighting knowledge gaps for future research. These guidelines should not be construed as a stan-dard of care. Clinicians should tailor decisions according to the unique circumstances of each patient, ideally through a collaborative approach that considers the patient's values and preferences. The decision-making process may be influ-enced by clinical settings, local resources, institutional pol-icies, and availability of treatments, technologies, or providers. A treatment algorithm to help clinicians and pa-tients assess these factors is included(Figure 1). These guide-lines may not encompass all appropriate approaches for the

clinical scenarios described. As new evidence becomes avail-able, these recommendations may become outdated. Adher-ence to these guidelines cannot guarantee successful outcomes.

The underlying values, preferences, and qualifying re-marks accompanying each recommendation are integral to implementation. These elements should always be included when citing or translating recommendations from these guidelines.

Updating guidelines

A document update may be initiated any time between 2 and 5 years after publication. Updates are prioritized according to the criteria described in the topic identification and prioritiza-tion section of the SCAI Publications Committee Manual of Standard Operating Procedures: 2022 Update.

If an update is warranted but not initiated after 5 years, the document is considered retired. If an update is not warranted after conducting a literature search, the date of the most


Figure 1

A decision pathway for treatment with LAAO. CT= computed tomography; DRT= device-related thrombus; ICE= intracardiac echocardiography; LAAO= left atrial appendage occlusion; NVAF= nonvalvular atrial fibrillation; OAC= oral anticoagulation; PDL= perideide leak; TEE= transesophageal echocardiography.

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recent assessment will be included in the document, and a no-tation that the recommendations should still be considered current.

Recommendations

1. In adults with NVAF, should LAAO be performed rather than no therapy?

Recommendation 1.1

For patients with NVAF and contraindication to OAC, the SCAI/HRS guideline panel suggests LAAO over no therapy(neither OAC nor LAAO)(conditional recommendation,very low certainty evidence).

Remarks: Many patients with contraindications to OAC(eg,bleeding history or bleeding risk) would reasonably choose to reduce their stroke risk by selecting LAAO over no therapy.Patients who value avoiding possible procedure-related adverse events more than a possible reduction in risk of stroke would reasonably choose no therapy. Clinicians should discuss with patients the procedural risk of LAAO vs the ongoing risk of thromboembolic events associated with no treatment. LAAO may be inappropriate for patients with less than 1 year of quality life expectancy.

Summary of the evidence

The panel found 1 nonrandomized study(NRS) that addresses LAAO compared with neither OAC nor LAAO treatment among patients with a contraindication to OAC.28 The pa-tients in this analysis were all undergoing renal replacement therapy, which led to serious concerns for indirectness of ev-idence. Additionally, the panel rated the risk of bias as serious due to uncontrolled confounding, selection bias, and missing outcomes. Procedure-related adverse event rates were taken from the treatment arms of 3 RCTs,13-15 as we can assume a rate of 0 events in a comparative population that did not undergo LAAO(Supplemental Table S3).

Benefits, harms, and burden

Left atrial appendage occlusion may reduce mortality compared with no treatment at 5 years of follow-up in the above trial(hazard ratio[HR], 0.52; 95% CI, 0.34-0.78).LAAO also may reduce thromboembolic events(HR, 0.16;95% CI, 0.04-0.66) and major bleeding(HR, 0.51; 95% CI,0.23-1.12).28 As this study's results were exclusive to patients undergoing renal replacement therapy, the panel had very low certainty in these outcomes. Indeed, follow-up data are scarce regarding patients with NVAF and contraindications to anticoagulation who did not undergo LAAO; however,the EWOLUTION Registry compared stroke rates among LAAO patients with the validated CHA2DS-VASc risk model,29 reporting that LAAO was associated with an 83%reduction in observed ischemic stroke compared with pre-dicted risk at the 2-year follow-up. ${}^{30}$

Data on adverse events attributable to LAAO are comparatively more robust. As taken from 3 RCTs, the rates

of pericardial effusion(2.7%), device embolization(0.6%),and procedure-related stroke(0.6%) are low13-15 and even lower from recent NRS with newer-generation LAAO de-vices.31,32 These data led the panel to consider the undesir-able effects of treatment to be small.

Other considerations

Left atrial appendage occlusion is an advanced service offered in the United States, only at centers with cardiac sur-gery capability as mandated by the Centers for Medicare and Medicaid Services. Disparities in access to care and out-comes may be associated with race and socioeconomic sta-tus.33 Most LAAO patients are≥65 years of age, and the risks and benefits of the procedure may not be generalizable to a younger population. Insurance status is important because a recent analysis of 11,240 adult patients undergoing LAAO in the United States between 2016 and 2019 showed that the average cost for an LAAO hospital admission totaled$24,719.70(range:$18,992.60-$31,193.00).34

Contraindications to OAC are common, affecting at least one-third of patients with NVAF.6,7 Such contraindications also vary widely in severity from life-threatening to mere an-noyances, and subgroup data regarding LAAO for specific OAC contraindications are not available. The panel agrees that procedural complications are reduced with current LAAO devices compared with those used in earlier pivotal tri-als. Additionally, the risk of NVAF-related stroke accumulates over time: patients with comorbidities affording a prognosis of<1 year of quality lifetime are unlikely to benefit from LAAO.

The dearth of randomized data led the panel to condition-ally recommend LAAO with a very low certainty of evidence.Other American and European guidelines have similarly rec-ommended LAAO in high-risk AF patients with a contraindica-tion to OAC therapy, giving LAAO a weak recommendation(American Heart Association/American College of Cardiology and European Society of Cardiology recommendation level llb).10,35

In light of ongoing clinical trials that will potentially provide more meaningful guidance in the future, the decision to perform LAAO vs no treatment for patients with NVAF and no contraindications to OAC falls outside of the scope of this guideline.

Conclusions and future directions

Future RCTs in this space are unlikely because of ethical con-cems about randomizing patients with NVAF to no treatment.For example, the ASAP-TOO(Assessment of the WATCHMAN Device in Patients Unsuitable for Oral Anticoa-gulation, NCT02928497) trial was terminated due to slow enrollment. Guidelines and clinical practice may have to rely on nonrandomized and indirect evidence. Based on current,albeit limited, evidence that LAAO reduces the risk of mortal-ity and thromboembolic events compared with no antithrom-botic treatment, the SCAI/HRS guideline panel agrees that LAAO is suggested in patients with NVAF and contraindica-tions for OAC.

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2. In adults with NVAF, should LAAO be performed rather than OAC?

Recommendation 2.1

For patients with NVAF who have decided to pursue stroke prevention treatment, the SCAI/HRS guideline panel sug-gests OAC or LAAO as treatment options.

Remarks: Although most patients are offered stroke pre-vention with OAC, those with elevated bleeding risk, prior bleeding complications, or strong preferences to avoid long-term anticoagulation would reasonably choose LAAO over OAC. LAAO may be inappropriate for patients with less than 1 year of quality life expectancy.

Summary of the evidence

The panel identified 3 RCTs that compared LAAO vs OAC in adults with NVAF including 1516 patients.13-15 Two RCTs were funded by the device manufacturer, and 1 was funded by the Czech Ministry of Health. The outcomes of interest were all-cause mortality, stroke(both ischemic and hemor-hagic), major bleeding, and procedure-related adverse events(Supplemental Table S3). The panel rated the risk of bias, indirectness, and inconsistency as not serious, although there were concerns about imprecision related to the small number of events. The exclusion of patients who could not tolerate short-term anticoagulation did not lead to downgrad-ing the level of evidence because, at present, some type of antithrombotic therapy is recommended after all LAAO pro-cedures. The overall level of certainty is moderate.

Benefits, harms, and burden

In patients with NVAF, LAAO may reduce the risk of all-cause mortality(HR, 0.76; 95% CI, 0.59-0.96), although there was no statistically significant difference in either stroke(HR, 1.05;95% CI, 0.62-1.77) or major bleeding(HR, 0.88; 95% CI,0.65-1.20). LAAO reduced the risk of hemorrhagic stroke(HR,0.24;95% CI,0.09-0.61), without a statistically significant increase in the rate of ischemic stroke(HR, 1.52; 95% CI, 0.93-2.50).13-15

The panel considered the risk of procedure-related adverse events as small. Although there are clearly risks asso-ciated with long-term use of OAC, in this instance, the panel was primarily interested in the risks of LAAO device implanta-tion itself. In aggregate, the 3 RCTs reported pericardial effu-1008 sion in 2.7% of LAAO patients, and the rate of device embolization and procedure-related strokes were both 0.6%. The total adverse event rate was 6.9%, including bleeding outcomes.

Other Considerations

The relative costs of LAAO compared with long-term OAC vary by geographic region and the type of OAC, but the panel considered the up-front cost of LAAO to be moderately more cost effective. A systematic review of cost-effectiveness studies found that LAAO was probably the more cost effective

option in 6 of 9 evaluations compared with warfarin, 6 of 8 evaluations when compared with dibagtran, in 3 of 5 evalu-ations against apixaban, and in 2 of 3 studies compared with rivaroxaban. ${}^{36}$ Most studies concluded that LAAO is the more cost effective strategy for stroke prevention in AF;however, shortcomings in methodological quality raise con-cems about the reliability and validity of results.

Conclusions and future directions

In light of ongoing clinical trials that will potentially provide more meaningful guidance in the future, LAAO for patients with NVAF and no contraindications to OAC falls outside of the scope of this guideline.

Both LAAO and OAC are in flux. Novel LAAO devices that may reduce procedural complications and risks are undergo-ing clinical trials. Emerging data may curtail periprocedural antithrombotic regimes that potentiate bleeding complica-tions. Simultaneously, many direct oral anticoagulants(DOACs) are becoming available as generic medications,reducing costs. Increased competition in the LAAO device market may decrease costs. As LAAO procedures are per-formed more quickly, a future revised National Coverage Determination from Centers for Medicare and Medicaid Ser-vices may also reduce LAAO reimbursement.

3. In adults with NVAF who are undergoing LAAO, should cardiac CT or TEE be performed prior to the procedure vs no imaging prior to the procedure?

Recommendation 3.1

For patients with NVAF who are undergoing LAAO, the SCAI/HRS guideline panel suggests obtaining preprocedural TEE or CT(Con-ditional recommendation, very low certainty evidence).

Summary of the evidence

Precedural imaging throughout this document is consid-ered that which is performed prior to the day of the proced-ure. Evidence of very low certainty to address this issue is available from 2 NRS that are complicated by risk of bias,indirectness, and imprecision(Supplemental Table S3).37,38

Benefits, harms, and burden

Only 1 of the 2 NRS, a subanalysis of the 219-patient random-ized SWISS-APERO trial, compared the rate of procedural suc-cess, defined as complete LAAO without major complications, between imaging strategies. Ninety-two pro-cedures were performed by operators with access to prepro-cedural CT imaging(protocol version 2), and 127 procedures were performed by operators blinded to preprocedural CT imaging(protocol version 1). Access to preprocedural CT im-aging was associated with a significantly higher rate of proce-dural success(RR, 0.87; 95% CI, 0.79-0.96).37 Both the aforementioned study and the SOLO-CLOSE study of single-operator TEE-guided LAAO, together including a total

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of 364 patients, reported the rate of PDL after the use or omis-sion of preprocedural imaging. Preprocedural imaging may have no effect on the rate of PDL assessed by TEE at 45 days postprocedure(RR,1.17;95% CI,0.65-2.13).37,38

Other considerations

Preprocedural imaging facilitates case planning, including se-lection of the most appropriate LAAO device and delivery sheath, location and orientation of transeptal puncture,39 and ICE vs TEE intraoprecu imaging. Preprocedural imag-ing may reduce the rate of procedures canceled or aborted due to unfavorable anatomy or the presence of an LAA thrombus. In the NCDR LAAO Registry, 2.6% of procedures were aborted for anatomy not conducive to implantation,and 1.4% of procedures were canceled due to the thrombus detected.40 Whether the cost savings of fewer aborted pro-cedures offsets the cost of universal preprocedural imaging is unknown. Moreover, due to a somewhat more limited view of the LAA with current ICE techniques, most patients in a published series of ICE-guided LAAO underwent prepro-cedural imaging.41,42

Conversely, scheduling preprocedural imaging may cause patient inconvenience, especially in underserved and rural communities, and may delay the actual LAAO procedure or impede access to care. Preprocedural imaging also entails modest risks. TEE carries the risks of patient discomfort, anes-thesia, aspiration, and esophageal injury. CT exposes patients to radiation and contrast, although modem CT technology has reduced the magnitude of both exposures significantly compared with prior technology.

Conclusions and future directions

At present, preprocedural imaging remains appropriate for most patients undergoing LAAO, especially those with ICE-guided procedures. CT has gained popularity compared with TEE for this purpose due to the noninvasive nature of CT, although data comparing outcomes between the 2 mo-dalities remain limited. ${}^{43}$ Preprocedural imaging is particularly important in patients who are not taking OAC and are at high-est risk for thrombus and in patients planning to undergo ICE-guided LAAO. If patients have had prior cardiac imaging, such as a TEE cardioversion or transcatheter aortic valve replacement-protocol CT, these studies may frequently suf-fice for preprocedural planning. In the future, newer, more universally applicable LAAO devices as well as steerable de-livery sheaths may render preprocedural imaging less impor-tant, but substantial research will be required in these areas.

4. In adults with NVAF who are undergoing LAAO, should ICE guidance be used rather than TEE during the proced-ure?

Recommendation 4.1

For patients with NVAF who have decided to undergo LAAO, the SCAI/HRS guideline panel suggests either ICE

or TEE imaging during the procedure(conditional recom-mendation, low certainty evidence).

Remark: Patients who prefer to avoid general anesthesia and the invasiveness of TEE would reasonably choose ICE.

Summary of the evidence

The panel identified 6 NRS that compared clinical outcomes between intraprocedural guidance with ICE vs TEE.41,44-48 Reported outcomes included all-cause mortality, stroke, ma-jor bleeding, PDL of>5 mm, and procedural success, here defined as complete LAAO. The panel rated the risk of bias as very serious for all outcomes due to concerns about un-known and uncontrolled confounding, selection bias of pa-tients with contraindications to TEE, and varying levels of operator experience with ICE; however, the patient popula-tions were appropriate, and the studies were not rated down for imprecision or inconsistency(Supplemental Table S3). Overall certainty in the evidence is low.

Benefits, harms, and burden

Mortality due to any cause may be higher in patients who receive ICE guidance compared with TEE(RR, 1.65; 95% CI,1.02-2.08). In absolute terms, this could amount to 5 addi-tional deaths per 1000 patients(95% CI, 0-9 more), which fell below the a priori threshold for meaningful difference set at 10 per 1000 patients. The panel had low certainty about the clinical impact of this finding.

No differences were reported in the rates of stroke(RR,0.96;95% CI,0.55-1.68),bleeding(RR,1.06;95% CI,0.89-1.29),PDL(RR,1.10;95% CI,0.63-1.92), or procedural success(RR,1.01;95% CI,1.00-1.01) between the 2 imaging modalities.

Other considerations

Imaging protocols can differ greatly between institutions, and some institutions may not have both ICE and TEE available.Factors that may influence the decision include local expertise,costs, procedure time, and number of personnel required.

These studies comparing ICE and TEE were conducted early in the era of ICE-guided LAAO by operators with signif-icant TEE-guided LAAO experience. Patients were likely selected for ICE guidance because they had contraindications to TEE such as high-risk esophageal varices or contraindica-tions to general anesthesia such as advanced pulmonary dis-ease.Thus, the ICE cohort included patients with more severe comorbidities than the TEE cohort. Furthermore, these studies were conducted with 2-dimensional(2D) ICE cathe-ters. The subsequent development of 3-dimensional(3D)ICE imaging, with capabilities similar but not identical to TEE, along with increased operator familiarity with ICE-guided LAAO may change the safety and efficacy of ICE imag-ing for procedural guidance.

Operators must select an imaging modality based upon in-dividual patient characteristics and operator experience. 49 ICE may be most appropriate in patients with a low risk for LAA thrombus(preprocedure anticoagulation), noncomplex LAA anatomy, adequate renal function for more adjunctive

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contrast angiography, and tolerance of moderate sedation.Precedural imaging to define anatomy may be especially important for patients scheduled for ICE-guided LAAO. ICE imaging quality may also vary substantially depending upon patient anatomy, operator experience, and ICE technology(2D vs 3D).

As LAAO procedural volumes continue to grow, LAAO has followed the paradigm of percutaneous coronary interven-tion, becoming a conscious sedation, same-day-discharge procedure.50 ICE imaging facilitates minimally invasive LAAO by eliminating the need for an anesthesiologist, a noninvasive cardiologist, intubation, and postesthesia re-covery. In addition, ICE is associated with shorter LAAO pro-cedure times.51 These factors may render ICE-guided LAAO more economically effective, especially considering the ex-penses associated with additional structural heart disease pro-cedural time.52

Conclusions and future directions

In the era of 3D ICE and LAAO operators with substantial ICE experience, either ICE or TEE may be appropriate to guide LAAO. The decision may depend on both patient and institu-tional factors. Comparative data between these 2 modalities does not include recent advances in 3D ICE, and further studies with more contemporary technology may provide further clarity toward a preferred approach for intraprocedural imaging guidance.

5. For adults with NVAF who have undergone LAAO, should clinicians prescribe postcorcedural OAC vs antiplatelet therapy?

Recommendation 5.1

The SCAI/HRS guideline panel suggests either postproce-rundual OAC or DAPT for patients undergoing LAAO(condi-tional recommendation, low certainty of evidence).

Remarks: Patients with more significant contraindications to OAC(eg, severe bleeding history or risk) would reasonably select DAPT.

Summary of the evidence

Five NRS compared DAPT vs OAC in patients undergoing LAAO.53-57 These studies comprised data from national registries and included a total of more than 34,000 patients for each selected outcome of interest, although most patients received OAC. The panel rated the studies as having a serious risk of bias due to the potential for unmeasured and residual confounding, although there were no concerns regarding indirectness and inconsistency(Supplemental Table S3). Overall certainty in the evidence is low.

Benefits, harms, and burden

Rates of major bleeding were comparable for patients who received DAPT vs OAC(RR,1.07;95% CI,0.93-1.07), despite the assumption that OAC, may convey a greater antithrom-

robotic effect. The risks of DRT for patients who received DAPT(RR, 1.40; 95% CI, 1.00-1.96) as well as embolic stroke at 6 months(RR, 1.33; 95% CI, 0.97-1.81) were also not signif-icantly different from those who received OAC. In absolute terms, this may amount to 1 more DRT with DAPT per 1000 patients(95% CI, 0-3 more) and 2 additional embolic strokes per 1000 patients(95% CI, 0-3 more), which the panel consid-ered to fall below a threshold for clinical relevance.

Other considerations

Initial trials of LAAO used 45 days of OAC therapy before switching to DAPT. Patients with more serious contraindica-tions to OAC(eg, intracranial bleeding, life-threatening bleeding, and severe thrombocytopenia) are often consid-ered for LAAO using DAPT or even SAPT with no postproce-dure OAC. In addition, as LAAO devices have improved,newer devices may require less aggressive periprocedural an-tithrombotic therapy. Although current evidence does not suggest OAC is more effective than DAPT in preventing thromboembolic events or DRT, the perception that DAPT might increase these risks will likely persist in the absence of randomized data. Reduced-dose apixaban has been the sub-ject of preliminary research and may be associated with lower rates of adverse events than DAPT.58 In addition to consider-ation of contraindications for OAC, clinicians should consider patient preference. Furthermore, the optimal duration of OAC or DAPT following LAAO remains uncertain. The initial trials used 6 months of therapy.13,14,59 whereas the CHAMPION-AF study is studying 3 months of DAPT.60

Conclusions and future directions

Available data suggest that DAPT following LAAO does not significantly affect the risk of either thrombotic or major bleeding events compared with OAC so either regimen is reasonable. Less aggressive periprocedural antithrombotic regimens, including DAPT, may be appropriate with newer LAAO devices that are designed to improve proximal posi-tioning and contain less exposed metal to reduce the risk of DRT compared with first-generation devices. Future random-ized trials should compare DAPT vs OAC as well as reduced-dose regimens for the current generation of LAAO devices with sufficient sample sizes to clarify the safety of DAPT begin-ning immediately postprocedure.

Recommendation 5.2

The SCAI/HRS guideline panel makes no recommendation about the use of SAPT vs any other antithrombotic regimen post-LAAO(knowledge gap).

Summary of the evidence

Three NRS compared use of SAPT vs OAC,56,61,62 and 4 NRS compared SAPT vs DAPT.61,63-65 In contrast to the comparisons of DAPT vs OAC(Recommendation 5.1,above), these outcomes were not derived from national registry data and included relatively few patients. Serious

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concerns with the indirectness and imprecision of the results precluded the panel from making any recommendations regarding the use of SAPT. Overall certainty in the level of evidence is very low.

Conclusions and Future Directions

In the absence of higher certainty evidence, the SCAI/HRS panel makes no recommendation about the use of SAPT vs either OAC or DAPT post-LAAO. Ideally, RCTs such as the ongoing SIMPLAAFY trial(NCT06521463) will support a future recommendation about the use of SAPT post-LAAO.

6. In adults with NVAF who have undergone LAAO, should follow-up TEE or CT imaging be performed vs no follow-up TEE or CT?

Recommendation 6.1

For patients with NVAF who have undergone LAAO, the SCAI/HRS guideline panel suggests postprocedural TEE or CT over no postprocedural TEE or CT(conditional recom-mendation, very low certainty evidence).

Summary of the evidence

The panel identified 5 relevant NRS that primarily served to provide data on baseline risk of DRT and PDL as detected by use of follow-up imaging.66-70 The panel rated the risk of bias as very serious, with serious concerns about indirectness, leading to very low certainty(Supplemental Table S3).

Benefits, harms, and burden

The panel was unable to determine the extent to which post-LAAO follow-up imaging is beneficial. The baseline risk for DRT as assessed by TEE may be clinically important(4.1% at a median of 54 days for a single nitinol plug device, 1.7% at 1 year for a lobe-and-disk device). An analysis of the NCDR LAAO Registry found a PDL rate of 26.5%,71>11,000 patients in this cohort had missing TEE data, some of whom may have had CT rather than TEE imaging. No studies compared LAAO outcomes with any postprocedure imaging vs no postproce-dure imaging at all.

Other considerations

While the desire to monitor for these potentially severe adverse events would likely be favored by most patients,some may be willing to forgo follow-up imaging to reduce the inconvenience of multiple follow-up visits, the discomfort of TEE, and the exposure to radiation and contrast with CT.Posteprocedure imaging is frequently used to determine whether a procedure was successful, which may assuage some patients' anxieties about undergoing the procedure.Additionally,imaging provides a baseline record of device im-plantation appearance for future comparison. Should con-cems like stroke or bacteremia arise in the future, new imaging can be compared with baseline imaging.

The panel deemed the cost of follow-up imaging as negli-gible amid the costs of the entire LAAO procedural pathway.Anesthesia services for TEE may increase this cost.

Some DRTs and PDLs require intervention, such as antico-agulation for DRT and for PDL deemed sufficiently large to pose a risk for stroke; however, the size at which PDL should be considered clinically relevant is still debated, and consensus remains elusive. A meta-analysis of 37 studies using TEE and 5 studies using CT compared outcomes of TEE: vs-ct identified PDL: PDL>0 mm found on TEE was associated with thromboembolism, whereas CT-identified PDL was not associated with thromboembolism.72 CT likely has greater sensitivity for detecting very small leaks around or through the LAAO device; however, the prognostic rele-vance of these very small leaks both on CT and TEE is still un-der investigation. Also, owing to this increased sensitivity with CT, the optimal timing of post-LAAO CT imaging remains un-certain: early CT imaging(ie, at 45 days) may show small, clin-ically insignificant leaks, whereas delayed CT imaging may allow for closure of such leaks.

While follow-up imaging imposes a minor burden on the patient and health care system, this burden can be reduced by limiting imaging procedural time, abbreviating acquisition protocols, and optimizing patient comfort with anesthesia.432222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222

Conclusions and future directions

The guideline panel suggests postprocedural follow-up imag-ing rather than no imaging to identify PDL and DRT. Further research on the timing and clinical significance of these find-ings is necessary to determine the necessity and timing of follow-up imaging.

7. In adults with NVAF who have a PDL after undergoing LAAO, should OAC be prescribed over no OAC?

Recommendation 7.1

The SCAI/HRS guideline panel makes no recommendation regarding the use of OAC in adults with a PDL after LAAO(knowledge gap).

Summary of the evidence

One NRS analyzed TEE results obtained at 45 days, 6 months,and 12 months following LAAO with the first-generation com-mercial WATCHMAN device(Supplemental Table S3). ${}^{73}$ All patients received OAC until 45 days postimplantation unless there was a leak>5 mm or DRT on 45-day TEE.This study was not designed to test the effect of warfarin in patients with PDL but to look for a correlation of outcome with a size of PDL. Rare clinical end points and small study sizes affect the applicability of this study. Notably, all patients with leaks>5 mm were kept on OAC. Given the paucity of evidence,

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the guideline panel was unable to make a recommendation on the appropriateness of OAC in the management of PDL.

Benefits, harms, and burden

The rate of PDL of any size at 45 days was 41%, which decreased to 32% at 1 year. This study demonstrated no dif-ference in clinical outcomes associated with the presence or severity of PDL. A composite outcome of stroke(ischemic or hemorrhagic), systemic embolism, and cardiovascular or un-explained death did not differ in patients treated with OAC(warfarin) or no OAC(DAPT, SAPT, or no therapy)(HR, 0.85;95% CI, 0.45-1.51).

Other considerations

The association of any PDL with increased risk for transient ischemic attack(TIA) or cerebrovascular accident(CVA) is sup-ported by subgroup analyses of large RCTs and multiple large observational registries. ${}^{71,74}$ Patients with PDL>5 mm typi-cally were maintained on anticoagulation in accordance with the original RCT protocols.8,9 Risk factors for PDL included permanent atrial fibrillation, larger LAA diameter, lower de-vice compression, and off-axis device position.75

Whether antithrombotic treatment for PDL between 1 and 5 mm is protective against TIA/CVA after LAAO is not known.71,74 The 2 studies that have addressed this question failed to demonstrate an effect of OAC in these patients. A combined analysis of 3 RCTs demonstrated an increased risk of stroke in patients with leaks<5 mm, but the effect of OAC could not be determined.76 Another analysis also demonstrated PDL 1-5 mm was significantly associated with CVA or TIA but could not determine the effect of post-LAAO OAC in the setting of PDL.77 Similarly, evidence from surgical studies correlates postsurgical LAAO(S-LAAO) leaks with thromboembolic complications35 but without data on the effect of OAC in these patients.

The PDL rate remains significant(>10% in all RCTs), and OAC may be harmful in the high-bleeding-risk LAAO popula-tion. Device-based plug or coil closure of PDL as an alterna-tive to OAC has been reported but not subjected to comparative studies to report either efficacy or safety out-comes. ${}^{78-80}$ Follow-up imaging may also be considered to assess for the closure of PDL, but data are not available to sup-port specific recommendations regarding when and how such imaging should be performed.

Conclusions and future directions

Observational evidence suggests a trend toward increased thromboembolic events with 1-5 mm PDL; however, a protec-tive effect of OAC, although logical, has not been demon-strated. Clinicians should balance the risks of stroke with the risks of bleeding with OAC treatment. Future studies with larger sample sizes are needed to define which patients may benefit from OAC to reduce adverse events in the setting of PDL.

8. In adults with NVAF who have DRT after undergoing LAAO, should indefinite OAC be prescribed vs no OAC?

Recommendation 8.1

For adults with device-related thrombus following LAAO,the SCAI/HRS guideline panel suggests OAC rather than no OAC(conditional recommendation, very low certainty ev-idence).

Remarks: The optimal duration of OAC and timing of repeat imaging are knowledge gaps requiring further research. Shared decision-making should take into account an individual patient's risks of stroke and bleeding.

Recommendation 8.2

The SCAI/HRS guideline panel makes no recommendation about the optimal duration of OAC and the timing of repeat imaging to assess for PDL and DRT(knowledge gap).

Summary of the evidence

The panel identified 5 NRS that provided follow-up data on DRT30,81-84 comparing OAC vs no OAC in as secondary outcomes in small samples. The group not receiving OAC was particularly small, and the studies were at high-risk of bias due to uncontrolled and residual confounding as well as selection bias. All 5 studies reported DRT resolution as as-sessed by TEE, with a duration of follow-up ranging from 35 days to 21 months. Two of the studies provided data on the rate of major bleeding among those who received OAC compared with those who did not(Supplemental Table S3).Overall certainty of evidence was very low.

Benefits, harms, and burden

Device-related thrombus resolution was not significantly improved with the use of OAC vs no OAC(RR, 1.13; 95%Cl,0.90-1.41).The rate of major bleeding in patients who un-derwent treatment with OAC was likewise not significantly different(RR, 1.73; 95% CI, 0.32-9.27); however, due to the small sample size and the presence of confounding variables,the panel had very low certainty in these results.

The primary purpose of LAAO is elimination of the need for long-term OAC; however, the development of DRT under-mines this purpose, as DRT not only negates the protective ef-fect of LAAO but also introduces a heightened risk of thromboembolic stroke. DRT resolution can be considered a surrogate for reduction of stroke risk, and in general, patients may be more willing to tolerate bleeding risk than stroke risk because blood may be replaced or transfused, but brain injury is permanent.

The management of DRT in patients undergoing LAAO due to an inability to tolerate OAC, often as a result of prior bleeding, presents a substantial clinical challenge. The risks and benefits of OAC treatment must be considered with

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respect to each individual patient's thromboembolic risk(ie.thrombus size and mobility) and bleeding risks.

Although DRT resolution was not significantly improved in patients who received OAC compared with those who did not, data from 2 meta-analyses suggest a high rate of com-plete DRT resolution with reinitiation of anticoagulation:100% with low molecular weight heparin and 89.5% with OAC in 1 study85 and 97% resolution in another.86 However,these data come from small, nonrandomized case series.

Other considerations

The stroke risk associated with DRT may vary by thrombus size and mobility, although data are absent in this regard. In cases of DRT recurrence or where a large or mobile DRT is present,surgical extraction ${}^{87-89}$ and percutaneous aspiration of thrombus ${}^{90}$ have been reported as potential treatment op-tions.

Conclusions and future directions

Device-related thrombus remains an important concern following LAAO. Treatment of DRT with OAC may result in resolution in most patients but depends greatly on the under-lying pathophysiology and clinical presentation for any indi-vidual patient. Future data may guide classification of DRT-associated stroke risk based upon anatomic and clinical char-acteristics. Future trials will be necessary to determine the optimal duration of OAC for patients with prior DRT.

Discussion

SCAI and HRS have jointly published these multisociety LAAO guidelines based upon a comprehensive systematic review in order to guide and standardize evidence-based practice in LAAO. The societies and authors hope that these guidelines will lead to improved patient outcomes by optimizing LAAO for appropriate indications, with optimal perprocedural imag-ing and adjunctive antithrombotic therapy, and with consider-ation for management of PDL and DRT. These guidelines should guide and support the decisions of physicians, pa-tients, administrators, regulators, and payers.

Left atrial appendage occlusion procedural volumes will continue to grow, and many questions remain regarding indi-cations, antithrombotic therapy, and complication manage-ment. Presently, LAAO is Food and Drug Administration-approved for patients in whom long-term OAC is contraindi-cated; however, the severity of such contraindications varies substantially, and many patients seek to avoid OAC due to reasons of personal preference. The OPTION trial reported that, in patients undergoing AF ablation procedures, LAAO was associated with less clinically significant bleeding and similar rates of death or stroke compared with OAC.91 The safety and effectiveness of LAAO in broader populations of patients with NVAF and without contraindications to OAC is currently under investigation in 2 RCTs: the CHAMPION-AF(WATCHMAN FLX versus NOAC for embolic Protection in the management of patients with NVAF) trial(NCT04394546) and the CATALYST(Clinical trial of atrial

fibrillation patients comparing LAAO therapy to nonvitaminier K antagonist oral anticoagulants) trial(NCT04226547).Furthermore, the possibility of LAAO for patients merely at risk for NVAF may be on the distant horizon: a meta-analysis of 6 small studies showed lower stroke rates among cardiac surgical patients treated with surgical LAAO than those not treated with LAAO,92 and 3 large surgical RCTs are underway(LeAAPS[Left Atrial Appendage Exclusion for Prophylactic Stroke Reduction, NCT05478304], LAA-CLOSURE,93 and LAAO-294). These results could be extrapolated to patients undergoing other cardiac interventions to support combina-tion procedures, for example with transcatheter aortic valve replacement, where new-onset NVAF occurs at a rate of approximately 10%.96 Clinical trials should be conducted so as to minimize the risk of industry bias. As procedural volumes grow, communal experience increases, and complications become increasingly rare, the possibility of performing LAAO in hospitals without cardiac surgical capabilities and in ambulatory surgical centers must be considered.

Antithrombotic therapy is important following LAAO to reduce the risk of DRT, with platelets adhering to the LAAO device and activating the coagulation cascade. LAAO device fabric is covered in endothelization by 6 weeks after implanta-tion,97 but tissue coverage of exposed metal may require many months. The initial RCTs of the WATCHMAN device8,9 used 45 days of warfarin(international normalized ratio goal:2.0-3.0) plus aspirin 325 mg daily, then de-escalating to clopi-dogrel 75 mg daily plus aspirin until 6 months postimplant,followed by destination aspirin toophairmenta sublimation. Subsequent studies replaced warfarin with DOACs10 and then eliminated postprocedural anticoagulation altogether, moving directly to DAPT with aspirin plus clopidogrel for 6 months.59 The CHAMPION-AF study used only 3 months of DAPT with re-sults pending. The ongoing SIMLAFAY trial compares an aspirin-only regimen to 6 months of DAPT or reduced-dose DOAC. Future data will allow clinicians to tailor antithrom-botic therapy to a patient's individual risks of thrombosis and bleeding.

The optimal management of LAAO complications of PDL and DRT remains unresolved. Even PDL<5 mm is definitively associated with an increased risk of thromboembolic events,with a hazard ratio of 1.152 reported from the NCDR LAAO Registry, which includes all commercial LAAO procedures performed in the United States.71 Long-term anticoagulation could potentially mitigate this thromboembolic risk at the cost of substantial bleeding risk in the population of patients who underwent LAAO because of contraindications to long-term anticoagulation. Percutaneous closure of LAAO with vascular plugs or coils has been described in many case reports,98 but the stroke prevention efficacy of this procedure remains un-known.

Novel devices under development may also change the future LAAO landscape. These devices specifically designed to reduce the risks of PDL and DRT are the subjects of ongoing RCTs vs the commercially available devices, including the CONFORM Pivalitor(NCT05147792) and the Laminar LAAX Pivotal IDE trial(NCT06168942).

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Heart Rhythm, Vol.No,■2025

1769 Because LAAO may frequently be characterized as an$$\text{elective procedure, the standard for quality must be high,}$$with low rates of complications. A national registry such as the NCR LAAO Registry allows for robust outcomes research to improve quality standards at the national level.Additionally, national registry participation allows individual programs to compare their risk-adjusted performance to na-tional benchmarks for the purpose of local quality improve-ment. The national registry is an extremely valuable resource for research and quality improvement. Therefore,the SCA/HRS Guideline Panel encourages operators and fa-cilities to participate actively and to submit high-quality data to the registry.

Left atrial appendage occlusion will undibitably grow as a critical component in the future of NVAF management. These SCAI/HRS joint guidelines recommend optimal evidence-based strategies for the use of LAAO in 2024. Nevertheless,LAAO is an evolving field, with novel devices, techniques,and data expected rapidly. Future updates will be necessary to ensure that the guidelines keep pace with the evidence.

Acknowledgments

The authors thank Karim Al-Aziz, MD,FSCIan, Jonathan P.Pic-cini, MD,MHS,FHS,MRich,Jinali MD,FSCAI,Vincent Y. See, MD, MS, and Triston B.B.J.S. MD, and FSCIAM for serving as peer reviewers for the document.

Appendix

Supplementary data

Supplementary data associated with this article can be found in the online version at https://doi.org/10.1016/j.hrthm.2025.05.048.

Declaration of competing interest: All relevant relationships with industry are listed below. Conflicts of interest were defined according to SCAI and HRS policy as outlined in Supplemental Table S1. Michael Gikson has received hono-raria and has served as a speaker and consultant for Boston Scientific. Jacqukey Joza has received honoraria and has served as a speaker and consultant for Boston Scientific. Dr.Bhanunya Jalkireddy has received honoraria and has served as a speaker and consulting for Abbott, and as a speaker for Boston Scientific. Devi G. Nair has received hon-aria or has served as a speaker and consulting for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and Bott, and as a speaker and consultant for Abbott, and as a speaker for Boston Scientific. Jecine Jstric and

Funding sources: This work was not supported by funding agencies in the public, commercial, or not-for-profit sectors.

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