{ "release_id": "f6f6f1b6f50379ed", "id": "cardio:left-atrial-appendage-occlusion", "owner": "cardio", "kind": "technology", "slug": "left-atrial-appendage-occlusion", "name": "Left atrial appendage occlusion", "aliases": [ "LAA closure", "Left atrial appendage closure", "LAAO" ], "atlases": [ "cardio" ], "summary_plain": "The left atrial appendage is a small pouch off the heart's upper left chamber. Closing it off is meant to stop clots from forming there and causing a stroke. A US government patient page describes this for people who cannot take blood thinners. In the PROTECT AF trial, which enrolled people who were eligible for warfarin, percutaneous closure with a device did not do worse than warfarin for the trial's main outcome, but it had more serious safety events, mostly linked to the procedure. The same page also cautions that complete closure is hard to achieve and that a leak leaves some clotting risk.", "summary_technical": "MeSH descriptor D000097546 (Left Atrial Appendage Closure). Percutaneous closure was tested in PROTECT AF with one closure device. A US government patient page says surgeons may also deal with the appendage during surgical ablation or other heart surgery. The US approval of the closure device (PMA P130013) is for people who are suitable for warfarin and have a rationale to seek a non-drug alternative; the patient population that page describes (people who cannot take blood thinners) and the population approved in the US label wording are not the same, and the sources read do not reconcile them.", "editorial_state": "draft", "last_substantive_edit": "2026-10-15", "last_evidence_check": "2026-10-14", "next_review_due": null, "identifiers": [ { "scheme": "mesh", "value": "D000097546", "normalized_value": "D000097546", "match": "exact", "version": "id.nlm.nih.gov linked data, retrieved 2026-10-14", "label": null, "from_source": false } ], "navigation": { "cardio": { "system": [ "heart" ], "condition-area": [ "arrhythmias", "stroke" ] } }, "payload": { "principle": "A device or a surgical closure blocks off the left atrial appendage so that clots cannot form there and cause a stroke (a US government patient page). Percutaneous closure places a device without open surgery (PROTECT AF).", "strengths": [ "In PROTECT AF, closure with the WATCHMAN device and discontinuation of warfarin was non-inferior to warfarin for a composite of stroke, cardiovascular death and systemic embolism (probability of non-inferiority more than 99.9%).", "It gives people who cannot take blood thinners an option, according to NHLBI." ], "limitations": [ "Primary safety events were more frequent with the device than with warfarin in PROTECT AF (7.4 compared with 4.4 per 100 patient-years; rate ratio 1.69, credible interval 1.01 to 3.19), mainly from periprocedural complications according to the authors.", "NHLBI cautions that complete closure is hard to achieve and that a leak leaves some clotting risk.", "The efficacy rate ratio in PROTECT AF (0.62, credible interval 0.35 to 1.25) includes 1." ], "required_infrastructure": [ "A procedure by a provider: percutaneous placement of a device (PROTECT AF), or closure of the appendage during surgical ablation or other heart surgery (NHLBI)." ] }, "content_digest": "d711d8cc22ca8037a1684fe0aaa48e0c2914bfb29d2a2c1c15c86069080bb701", "review": { "content_digest": "d711d8cc22ca8037a1684fe0aaa48e0c2914bfb29d2a2c1c15c86069080bb701", "current": [], "conflicting": [], "stale": [], "inactive": [] }, "claims": [ { "release_id": "f6f6f1b6f50379ed", "id": "cardio:claim-acc-aha-2023-af-laao", "owner": "cardio", "subject_entity_id": "cardio:left-atrial-appendage-occlusion", "category": "recommendation", "statement": "An ACC summary of the 2023 ACC/AHA atrial fibrillation guideline says percutaneous left atrial appendage occlusion is reasonable (class 2a) for patients with a CHA2DS2-VASc score of 2 or more who have a medical reason not to take anticoagulants over the long term, and might reasonably be used instead of anticoagulation (class 2b) for patients at moderate or high stroke risk who also face a high chance of serious bleeding while taking anticoagulants.", "context": { "id": "cardio:ctx-acc-aha-2023-patients-with-af", "label": "Patients with atrial fibrillation (ACC summary of the 2023 guideline)", "recipient": "unknown", "population": "Patients with atrial fibrillation. The ACC summary gives no age limits and, apart from the exceptions each claim names, no exclusions.", "care_setting": "Not stated in the ACC summary.", "geography": "Not stated in the ACC summary (issued by American societies; jurisdiction not verified)", "life_stage_note": "Not stated in the ACC summary", "life_stage_terms": null, "gestational_age_min_days": null, "gestational_age_max_days": null, "gestational_age_basis": null, "postnatal_age_min_days": null, "postnatal_age_max_days": null, "gestational_age_status": null, "postnatal_age_status": null, "followup_description": "Not applicable (guideline context)", "eligibility": { "inclusion": [ "Patients diagnosed with atrial fibrillation" ], "exclusion": [] } }, "evidence_stage": "guidance", "certainty": "not_assessed", "certainty_method": null, "limitations": "The source is the ACC key-perspectives summary of the guideline (ACC content, hash only), not the guideline text. The classes of recommendation are as printed on the ACC page. These are weaker recommendations than a plain recommendation, so no recommendation record is written for them. PubMed lists three corrections to the guideline (2024-01-02, 2024-02-27 and 2024-06-11); their text was not read, so it is not known whether they change anything stated here.", "editorial_state": "draft", "checked_at": "2026-10-15", "next_review_due": null, "valid_from": null, "valid_to": null, "citations": [ { "evidence_role": "supports", "locator": "Key perspective 7, sentence 2", "applicability_note": "Class 2a for a contraindication to long-term anticoagulation.", "snapshot": { "id": "cardio:acc-af2023-key-perspectives-2026-10-15", "retrieved_at": "2026-10-15T13:52:56Z", "content_hash": "351ef6a153a9922b720e0ea62e3c8ccb64abd9945012b3992bb58528d3446453", "source_effective_date": null, "public_archive_url": null, "source_state": "corrected" }, "source": { "id": "cardio:acc-aha-2023-af", "source_type": "guideline", "title": "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines", "canonical_url": "https://doi.org/10.1161/CIR.0000000000001193", "identifiers": [ { "scheme": "doi", "value": "10.1161/CIR.0000000000001193", "normalized_value": "10.1161/cir.0000000000001193", "match": "exact", "version": null, "label": null, "from_source": false }, { "scheme": "pmid", "value": "38033089", "normalized_value": "38033089", "match": "exact", "version": null, "label": null, "from_source": false }, { "scheme": "pmcid", "value": "PMC11095842", "normalized_value": "PMC11095842", "match": "exact", "version": null, "label": null, "from_source": false } ], "publication_date": "2024-01-02", "publisher": "Circulation", "edition": "Published in Circulation 149(1):e1-e156 (issue date 2024-01-02; electronic publication 2023-11-30). PubMed abstract and bibliographic data only. PMC lists an author manuscript (PMC11095842) that is not in the PMC Open Access subset, so it was not fetched. The guideline text was not read. PubMed lists 3 corrections to the guideline; their text was not read. The same source also holds a snapshot of the ACC key-perspectives summary page (dated Nov 30, 2023), an ACC summary and not the guideline text. In the page markup some less-than symbols hide the text that follows them, so only passages free of such symbols are quoted. The publisher field is the journal title as PubMed gives it.", "reuse_basis": "PubMed record and ACC page. PubMed record fetched through NCBI E-utilities on 2026-10-15. Only the hash of the bytes is kept; nothing is committed. Bibliographic metadata and short quotations from the PubMed abstract, under 25 words each. The full text was not redistributed and the societies' reuse terms were not reviewed. ACC web page fetched with a plain Mozilla/5.0 user agent on 2026-10-15. Only the hash of the bytes is kept; nothing is committed. The ACC's reuse terms were not read, so public text is cite_only: public pages state the summary in the atlas's own words, with a citation and a link, and use no ACC wording. Quote rows are short evidence fragments for the reviewer.", "public_text": "cite_only" } }, { "evidence_role": "supports", "locator": "Key perspective 7, sentence 3, fragments 1 and 2", "applicability_note": "Class 2b for a high bleeding risk on anticoagulation.", "snapshot": { "id": "cardio:acc-af2023-key-perspectives-2026-10-15", "retrieved_at": "2026-10-15T13:52:56Z", "content_hash": "351ef6a153a9922b720e0ea62e3c8ccb64abd9945012b3992bb58528d3446453", "source_effective_date": null, "public_archive_url": null, "source_state": "corrected" }, "source": { "id": "cardio:acc-aha-2023-af", "source_type": "guideline", "title": "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines", "canonical_url": "https://doi.org/10.1161/CIR.0000000000001193", "identifiers": [ { "scheme": "doi", "value": "10.1161/CIR.0000000000001193", "normalized_value": "10.1161/cir.0000000000001193", "match": "exact", "version": null, "label": null, "from_source": false }, { "scheme": "pmid", "value": "38033089", "normalized_value": "38033089", "match": "exact", "version": null, "label": null, "from_source": false }, { "scheme": "pmcid", "value": "PMC11095842", "normalized_value": "PMC11095842", "match": "exact", "version": null, "label": null, "from_source": false } ], "publication_date": "2024-01-02", "publisher": "Circulation", "edition": "Published in Circulation 149(1):e1-e156 (issue date 2024-01-02; electronic publication 2023-11-30). PubMed abstract and bibliographic data only. PMC lists an author manuscript (PMC11095842) that is not in the PMC Open Access subset, so it was not fetched. The guideline text was not read. PubMed lists 3 corrections to the guideline; their text was not read. The same source also holds a snapshot of the ACC key-perspectives summary page (dated Nov 30, 2023), an ACC summary and not the guideline text. In the page markup some less-than symbols hide the text that follows them, so only passages free of such symbols are quoted. The publisher field is the journal title as PubMed gives it.", "reuse_basis": "PubMed record and ACC page. PubMed record fetched through NCBI E-utilities on 2026-10-15. Only the hash of the bytes is kept; nothing is committed. Bibliographic metadata and short quotations from the PubMed abstract, under 25 words each. The full text was not redistributed and the societies' reuse terms were not reviewed. ACC web page fetched with a plain Mozilla/5.0 user agent on 2026-10-15. Only the hash of the bytes is kept; nothing is committed. The ACC's reuse terms were not read, so public text is cite_only: public pages state the summary in the atlas's own words, with a citation and a link, and use no ACC wording. Quote rows are short evidence fragments for the reviewer.", "public_text": "cite_only" } }, { "evidence_role": "context", "locator": "CommentsCorrectionsList, three ErratumIn entries", "applicability_note": "Shows that corrections exist. What they change is unknown.", "snapshot": { "id": "cardio:pubmed-38033089-2026-10-15", "retrieved_at": "2026-10-15T13:48:58Z", "content_hash": "3ee3998a9178e8f21223e2388261924207d5e1f8fb19bf34e8355e11eb2c07a9", "source_effective_date": null, "public_archive_url": null, "source_state": "corrected" }, "source": { "id": "cardio:acc-aha-2023-af", "source_type": "guideline", "title": "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines", "canonical_url": "https://doi.org/10.1161/CIR.0000000000001193", "identifiers": [ { "scheme": "doi", "value": "10.1161/CIR.0000000000001193", "normalized_value": "10.1161/cir.0000000000001193", "match": "exact", "version": null, "label": null, "from_source": false }, { "scheme": "pmid", "value": "38033089", "normalized_value": "38033089", "match": "exact", "version": null, "label": null, "from_source": false }, { "scheme": "pmcid", "value": "PMC11095842", "normalized_value": "PMC11095842", "match": "exact", "version": null, "label": null, "from_source": false } ], "publication_date": "2024-01-02", "publisher": "Circulation", "edition": "Published in Circulation 149(1):e1-e156 (issue date 2024-01-02; electronic publication 2023-11-30). PubMed abstract and bibliographic data only. PMC lists an author manuscript (PMC11095842) that is not in the PMC Open Access subset, so it was not fetched. The guideline text was not read. PubMed lists 3 corrections to the guideline; their text was not read. The same source also holds a snapshot of the ACC key-perspectives summary page (dated Nov 30, 2023), an ACC summary and not the guideline text. In the page markup some less-than symbols hide the text that follows them, so only passages free of such symbols are quoted. The publisher field is the journal title as PubMed gives it.", "reuse_basis": "PubMed record and ACC page. PubMed record fetched through NCBI E-utilities on 2026-10-15. Only the hash of the bytes is kept; nothing is committed. Bibliographic metadata and short quotations from the PubMed abstract, under 25 words each. The full text was not redistributed and the societies' reuse terms were not reviewed. ACC web page fetched with a plain Mozilla/5.0 user agent on 2026-10-15. Only the hash of the bytes is kept; nothing is committed. The ACC's reuse terms were not read, so public text is cite_only: public pages state the summary in the atlas's own words, with a citation and a link, and use no ACC wording. Quote rows are short evidence fragments for the reviewer.", "public_text": "cite_only" } } ], "review": { "content_digest": "f78bbfee0de4cb06b869fb1f25b0c79827c80ff3abf02d954ef366ba708f7076", "current": [], "conflicting": [], "stale": [], "inactive": [] }, "api_path": "api/v1/claims/cardio--claim-acc-aha-2023-af-laao.json" } ], "decisions": [], "milestones": [], "relationships": { "outgoing": [ { "predicate": "related_to", "label": "A device alternative to long-term blood thinners for some people", "clinical_claim_not_fact": false, "family": "navigation", "other_entity_id": "cardio:oral-anticoagulation", "other_entity_in_atlas": true, "claim_id": null, "evidence": null, "primary": false, "role": null, "valid_from": null, "valid_to": null }, { "predicate": "part_of", "label": "Filed under this front", "clinical_claim_not_fact": false, "family": "navigation", "other_entity_id": "cardio:front-procedures-and-surgery", "other_entity_in_atlas": true, "claim_id": null, "evidence": null, "primary": true, "role": null, "valid_from": null, "valid_to": null } ], "incoming": [ { "predicate": "uses_technology", "label": "Used by", "clinical_claim_not_fact": false, "family": "navigation", "other_entity_id": "cardio:watchman", "other_entity_in_atlas": true, "claim_id": null, "evidence": null, "primary": false, "role": null, "valid_from": null, "valid_to": null }, { "predicate": "investigates", "label": "Investigated in", "clinical_claim_not_fact": false, "family": "sourced", "other_entity_id": "cardio:protect-af", "other_entity_in_atlas": true, "claim_id": null, "evidence": { "snapshot_id": "cardio:ctgov-nct00129545-2026-10-14", "locator": "protocolSection.armsInterventionsModule.interventions[0].name" }, "primary": false, "role": null, "valid_from": null, "valid_to": null } ] }, "page_path": "technologies/left-atrial-appendage-occlusion/", "context_path": "api/v1/context/cardio--left-atrial-appendage-occlusion.md" }