CHEST 2018 guideline: antithrombotic therapy for atrial fibrillation

Official guidelineAntithrombotic Therapy for Atrial Fibrillation: CHEST Guideline and Expert Panel Report. CHEST, 2018.
Read the official guideline · Checked for a newer edition on 2026-10-20
We do not reproduce the guideline text — this page is an independent summary.

Who it applies to

Adults with atrial fibrillation, including paroxysmal, persistent, and permanent forms, being considered for stroke prevention therapy.

Key recommendations

Stroke risk should be estimated using a validated clinical prediction tool such as CHA2DS2-VASc rather than relying on AF pattern alone.
Patients with AF and a high stroke risk score should receive oral anticoagulation rather than no therapy, aspirin, or combination antiplatelet therapy.
For patients with nonvalvular AF who are candidates for anticoagulation, a direct oral anticoagulant is suggested in preference to a vitamin K antagonist.
Patients with AF and mitral stenosis or a mechanical heart valve should be treated with a vitamin K antagonist rather than a direct oral anticoagulant.
In patients with a low stroke risk score, withholding antithrombotic therapy is suggested rather than using anticoagulation or antiplatelet therapy.
Routine addition of antiplatelet therapy to anticoagulation is not recommended for stroke prevention in AF unless there is a separate indication such as recent coronary stenting.
Bleeding risk assessment should be incorporated into the decision to anticoagulate, but a high bleeding risk score alone should not be used to withhold anticoagulation in patients who otherwise warrant it.
For patients already stable on long-term vitamin K antagonist therapy with good INR control, continuing the vitamin K antagonist rather than switching to a direct oral anticoagulant is a reasonable option.

What is new in this edition

Increased emphasis on direct oral anticoagulants as preferred first-line therapy over vitamin K antagonists in eligible nonvalvular AF patients, reflecting accumulated trial evidence since the prior edition.

Practice points for students

CHA2DS2-VASc is the preferred tool for estimating stroke risk and guiding the anticoagulation decision.
Mechanical valves and significant mitral stenosis are key exceptions where DOACs should be avoided in favor of warfarin.
Combining anticoagulation with antiplatelet therapy increases bleeding risk without added stroke protection benefit in most AF patients.
A high bleeding risk score should prompt closer monitoring and risk factor modification rather than withholding indicated anticoagulation.

Condition

Atrial fibrillation