# Blood thinners (oral anticoagulants) to prevent stroke in AF Intervention · id `cardio:oral-anticoagulation` · Cardiovascular Atlas · release `f6f6f1b6f50379ed` (public) > General information from published sources, not medical advice, and not reviewed by clinicians. Check the cited source before relying on anything here. The atlas's own text and curation may be reused under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/): credit the atlas, and do not use it commercially. See the atlas About page. Text quoted from a source stays under that source's own terms, given as the source's reuse\_basis. The atlas's reuse terms do not cover it. The downloads list each quotation with its source in third\_party\_quotations. Browse, organ or system: Heart Browse, condition area: Stroke; Heart rhythm problems ## In plain language People with atrial fibrillation may be offered a blood thinner to prevent the clots that can cause a stroke. NHLBI names warfarin and the direct-acting oral anticoagulants apixaban, dabigatran, rivaroxaban and edoxaban. Blood thinners can cause bleeding, and MedlinePlus calls bleeding their most common side effect. ## Technical summary Parent page for warfarin and the direct oral anticoagulants (DOACs) used in atrial fibrillation. The three DOAC substances with a page here (apixaban, dabigatran, rivaroxaban) were each compared with warfarin in a large randomized trial. Their results are on the substance pages. Edoxaban is named by NHLBI and has no page. Warfarin has no page. The text rests on NHLBI and MedlinePlus patient pages and gives no event rates. ## Claims, with the population each applies to ## Context: Patients with atrial fibrillation (ACC summary of the 2023 guideline) Recipient: Recipient not specified; 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: Not stated in the ACC summary; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (guideline context) ### An ACC summary of the 2023 ACC/AHA atrial fibrillation guideline says that, apart from patients who have mitral stenosis or a mechanical heart valve, direct oral anticoagulants rather than warfarin are the preferred choice. - Category: Recommendation - Evidence stage: Guidance - Certainty: Certainty not assessed - Applies to: Recipient: Recipient not specified; 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: Not stated in the ACC summary; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (guideline context) - Limitations: The source is the ACC key-perspectives summary of the guideline (ACC content, hash only), not the guideline text. The summary prints no class of recommendation for this statement and does not say what is preferred in the two exceptions. 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. - Last checked: 2026-10-15 - Source problem: a cited source is corrected. Check the sources before relying on this claim. - Sources: 1. Supports: 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 (Guideline, 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.) Locator: Key perspective 4, sentence 3. Retrieved 2026-10-15T13:52:56Z. Source state: Corrected. Snapshot hash: 351ef6a153a9922b720e0ea62e3c8ccb64abd9945012b3992bb58528d3446453. How it applies: Direct oral anticoagulants preferred over warfarin, with two exceptions. 2. Background: 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 (Guideline, 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.) Locator: CommentsCorrectionsList, three ErratumIn entries. Retrieved 2026-10-15T13:48:58Z. Source state: Corrected. Snapshot hash: 3ee3998a9178e8f21223e2388261924207d5e1f8fb19bf34e8355e11eb2c07a9. How it applies: Shows that corrections exist. What they change is unknown. ## Context: Adults with atrial fibrillation, in general terms (NHLBI and MedlinePlus patient pages) Recipient: Adult; Population: People with atrial fibrillation, described in general terms. NHLBI puts the number of US adults with atrial fibrillation above 2 million and says the chance of developing it grows with age. The pages do not describe a study population.; Care setting: Not applicable (patient information pages, not a study); Geography: Not stated in the pages for most statements; the prevalence sentence refers to the United States; Life stage: Adults in general. NHLBI describes atrial fibrillation as uncommon in children.; Follow-up: Not applicable (patient information pages) ### NHLBI names warfarin and the direct oral anticoagulants (apixaban, dabigatran, rivaroxaban and edoxaban) as medicines that stop clots from forming and so reduce the chance of stroke. It says a person at risk of stroke may need one, and that all of them carry a bleeding risk. MedlinePlus lists atrial fibrillation among the conditions in which a person may need a blood thinner and calls bleeding the most common side effect of blood thinners. Neither page gives a number. - Category: Description - Evidence stage: Evidence synthesis - Certainty: Certainty not assessed - Applies to: Recipient: Adult; Population: People with atrial fibrillation, described in general terms. NHLBI puts the number of US adults with atrial fibrillation above 2 million and says the chance of developing it grows with age. The pages do not describe a study population.; Care setting: Not applicable (patient information pages, not a study); Geography: Not stated in the pages for most statements; the prevalence sentence refers to the United States; Life stage: Adults in general. NHLBI describes atrial fibrillation as uncommon in children.; Follow-up: Not applicable (patient information pages) - Limitations: Patient information pages. They name edoxaban, which has no page in this atlas. The trial results behind apixaban, dabigatran and rivaroxaban are recorded on their own claims, and the pages give no event rates. - Last checked: 2026-10-14 - Sources: 1. Supports: Atrial Fibrillation Treatment (NHLBI) (Webpage, edition Page as fetched on 2026-10-14, with the line Last updated on November 30, 2022.) Locator: Page body, Medicines, Blood thinners (fragment 1). Retrieved 2026-10-14T18:19:49Z. Source state: Current. Snapshot hash: 4717eb3d282d9c95f17fc4755692af9a8db61d4e8e2283bbb993b25abde06989. How it applies: NHLBI: blood thinners and DOACs, first part of the sentence. 2. Supports: Atrial Fibrillation Treatment (NHLBI) (Webpage, edition Page as fetched on 2026-10-14, with the line Last updated on November 30, 2022.) Locator: Page body, Medicines, Blood thinners (fragment 2). Retrieved 2026-10-14T18:19:49Z. Source state: Current. Snapshot hash: 4717eb3d282d9c95f17fc4755692af9a8db61d4e8e2283bbb993b25abde06989. How it applies: NHLBI: these medicines stop clots forming and reduce stroke risk. 3. Supports: Atrial Fibrillation Treatment (NHLBI) (Webpage, edition Page as fetched on 2026-10-14, with the line Last updated on November 30, 2022.) Locator: Page body, Medicines, Blood thinners. Retrieved 2026-10-14T18:19:49Z. Source state: Current. Snapshot hash: 4717eb3d282d9c95f17fc4755692af9a8db61d4e8e2283bbb993b25abde06989. How it applies: NHLBI: who may need them. 4. Supports: Atrial Fibrillation Treatment (NHLBI) (Webpage, edition Page as fetched on 2026-10-14, with the line Last updated on November 30, 2022.) Locator: Page body, Medicines, Blood thinners (passage 2). Retrieved 2026-10-14T18:19:49Z. Source state: Current. Snapshot hash: 4717eb3d282d9c95f17fc4755692af9a8db61d4e8e2283bbb993b25abde06989. How it applies: NHLBI: bleeding risk. 5. Supports: Blood Thinners | Anticoagulants (MedlinePlus) (Webpage, edition Page as fetched on 2026-10-14.) Locator: Summary, Who needs blood thinners?. Retrieved 2026-10-14T18:19:51Z. Source state: Current. Snapshot hash: 2b4141ab8f60f42c97c4cc1dc5da568cf7c4073464f1e0fdfe75043f57d8e4c7. How it applies: MedlinePlus lists atrial fibrillation among conditions that may need a blood thinner. 6. Supports: Blood Thinners | Anticoagulants (MedlinePlus) (Webpage, edition Page as fetched on 2026-10-14.) Locator: Summary, What are the side effects of blood thinners?. Retrieved 2026-10-14T18:19:51Z. Source state: Current. Snapshot hash: 2b4141ab8f60f42c97c4cc1dc5da568cf7c4073464f1e0fdfe75043f57d8e4c7. How it applies: MedlinePlus: bleeding is the most common side effect. ## Connected pages - Blood thinners lower stroke risk in AF and carry a bleeding risk (NHLBI): Atrial fibrillation (AF) (`cardio:atrial-fibrillation`) [a claim, not a settled fact; see claim `cardio:claim-oral-anticoagulation-prevents-stroke-in-af` and its context] - Filed under this front: Medicines (`cardio:front-medicines`) - Related to: MedlinePlus (`core:medlineplus`) - Related to: Apixaban (`cardio:apixaban`) - Related to: Dabigatran (`cardio:dabigatran`) - Related to: Rivaroxaban (`cardio:rivaroxaban`) - Related to: Left atrial appendage occlusion (`cardio:left-atrial-appendage-occlusion`) ## Provenance Content hash: c2392467abed96eb127b1421849f0b649357ac7d757b6cb3b223387fc6010b36 Last substantive edit: 2026-10-15 Evidence last checked: 2026-10-14