Chest
Volume 141, Issue 2, Supplement, February 2012, Pages e531S-e575S
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Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physician Evidence-Based Clinical Practice Guidelines Online Only Articles
Antithrombotic Therapy for Atrial Fibrillation: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

https://doi.org/10.1378/chest.11-2304Get rights and content

Background

The risk of stroke varies considerably across different groups of patients with atrial fibrillation (AF). Antithrombotic prophylaxis for stroke is associated with an increased risk of bleeding. We provide recommendations for antithrombotic treatment based on net clinical benefit for patients with AF at varying levels of stroke risk and in a number of common clinical scenarios.

Methods

We used the methods described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement.

Results

For patients with nonrheumatic AF, including those with paroxysmal AF, who are (1) at low risk of stroke (eg, CHADS2 [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack] score of 0), we suggest no therapy rather than antithrombotic therapy, and for patients choosing antithrombotic therapy, we suggest aspirin rather than oral anticoagulation or combination therapy with aspirin and clopidogrel; (2) at intermediate risk of stroke (eg, CHADS2 score of 1), we recommend oral anticoagulation rather than no therapy, and we suggest oral anticoagulation rather than aspirin or combination therapy with aspirin and clopidogrel; and (3) at high risk of stroke (eg, CHADS2 score of ≥ 2), we recommend oral anticoagulation rather than no therapy, aspirin, or combination therapy with aspirin and clopidogrel. Where we recommend or suggest in favor of oral anticoagulation, we suggest dabigatran 150 mg bid rather than adjusted-dose vitamin K antagonist therapy.

Conclusions

Oral anticoagulation is the optimal choice of antithrombotic therapy for patients with AF at high risk of stroke (CHADS2 score of ≥ 2). At lower levels of stroke risk, antithrombotic treatment decisions will require a more individualized approach.

Section snippets

Summary of Recommendations

Note on Shaded Text: Throughout this guideline, shading is used within the summary of recommendations sections to indicate recommendations that are newly added or have been changed since the publication of Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Recommendations that remain unchanged are not shaded.

2.1.8. For patients with AF, including those with paroxysmal AF, who are at low risk of stroke (eg,

Methods

To inform our guideline development, we searched for relevant articles published since the last literature search performed for the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Specifically, for literature regarding the assessment of stroke risk in patients with AF, we searched Medline for articles published from January 1, 2005, to October 2009 using the search terms “atrial fibrillation,” “atrial

Antithrombotic Therapy for Patients With AF in General

Over the past 2 decades, numerous RCTs have investigated antithrombotic therapies to reduce the risk of thromboembolism, principally ischemic stroke, in patients with AF. In this section, we summarize the evidence and give treatment recommendations for VKA therapy, antiplatelet monotherapy (eg, aspirin), dual antiplatelet therapy with aspirin and clopidogrel, and new oral anticoagulants (eg, dabigatran) in patients with AF.

Patients With AF and Stable Coronary Artery Disease

Approximately one-third of patients with AF also have coronary artery disease.51 A recurring question is whether patients with AF for whom oral anticoagulation is indicated because of a high risk of stroke (eg, CHADS2 score of ≥ 2) and who have concomitant stable coronary artery disease should also use aspirin to prevent coronary heart disease events. In this article, we define stable coronary artery disease as the presence (or absence) of angina but no revascularization procedure (percutaneous

Antithrombotic Therapy for Patients With AF Undergoing Cardioversion

To minimize the risk of stroke and systemic embolism associated with cardioversion, therapeutic anticoagulation (eg, with adjusted-dose oral VKAs; INR 2.0-3.0) conventionally is recommended for a minimum of 3 weeks before, during, and for a minimum of 4 weeks after the procedure. For some patients with AF of documented short duration (eg, ≤ 48 h), a common practice is to cardiovert without prolonged precardioversion anticoagulation. For patients with AF duration of > 48 h or unknown duration, a

Optimal Target INR Range

For a full discussion of optimal target INR range with VKA therapy across a variety of indications, see Holbrook et al91 regarding evidence-based management of anticoagulation in this guideline. With respect to patients with AF specifically, several studies assessed oral anticoagulation at very-low INR targets or fixed low doses compared with adjusted-dose anticoagulation targeted at an INR of 2.0 to 3.0 and found that anticoagulation targeted at an INR of 2.0 to 3.0 was more effective in

Future Research

Approximately one in every three patients with AF also has coronary artery disease.51 However, the optimal approach to antithrombotic therapy in these patients is unclear. Research is needed to determine the effect of treatment with oral anticoagulation and aspirin compared with oral anticoagulation alone on patient-important outcomes of vascular death, nonfatal stroke, nonfatal MI, nonfatal major extracranial bleeding, and nonfatal systemic embolism. Research is also needed to inform

Conclusions

Stroke is a serious complication of AF, but its risk varies considerably across different groups of patients with AF. Antithrombotic prophylaxis for stroke is associated with an increased risk of bleeding. We provide recommendations for antithrombotic treatment based on net clinical benefit for patients with AF at varying levels of stroke risk. Oral anticoagulation is the optimal choice of antithrombotic therapy for patients with AF at high risk of stroke (eg, CHADS2 score ≥ 2). At lower levels

Acknowledgments

Author contributions: As Topic Editor, Dr You oversaw the development of this article, including the data analysis and subsequent development of the recommendations contained herein.

Dr You: contributed as Topic Editor.

Dr Singer: contributed as a panelist.

Dr Howard: contributed as a panelist.

Dr Lane: contributed as a panelist.

Dr Eckman: contributed as a resource consultant.

Dr Fang: contributed as a panelist.

Dr Hylek: contributed as a panelist.

Dr Schulman: contributed as a panelist.

Dr Go:

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    Funding/Support: The Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines received support from the National Heart, Lung, and Blood Institute [R13 HL104758] and Bayer Schering Pharma AG. Support in the form of educational grants was also provided by Bristol-Myers Squibb; Pfizer, Inc; Canyon Pharmaceuticals; and sanofi-aventis US.

    Disclaimer: American College of Chest Physician guidelines are intended for general information only, are not medical advice, and do not replace professional medical care and physician advice, which always should be sought for any medical condition. The complete disclaimer for this guideline can be accessed at http://chestjournal.chestpubs.org/content/141/2_suppl/1S.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (http://www.chestpubs.org/site/misc/reprints.xhtml).

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