This focused update for the management of patients with atrial fibrillation (AF) includes revisions to anticoagulation therapy; the update also includes recommendations on interruption and bridging anticoagulation and nonpharmacological strategies for stroke prevention.

This focused update for the management of patients with atrial fibrillation (AF) by the AHA/ACC/HRS (American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society) covers recommendations for the prevention of thromboembolism.

Prevention of thromboembolism

Selecting an Anticoagulant Regimen—Balancing Risks and Benefits

1. For AF patients with an elevated CHA2DS2-VASc score (≥ 2 in men or ≥ 3 in women), oral anticoagulants such as warfarin, dabigatran, rivaroxaban, apixaban and edoxaban are recommended.
2. Due to the superior safety profile, the non–vitamin K oral anticoagulant or NOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) are recommended as firstline therapy over warfarin in patients with AF (except with moderate-to-severe mitral stenosis or a mechanical heart valve).
3. To assess the risk of stroke in patients with AF (except with moderate-to-severe mitral stenosis or a mechanical heart valve), the CHA2DS2-VASc score is recommended.
4. Warfarin is recommended in AF patients who have mechanical heart valves.
5. Before initiating NOAC, renal function and hepatic function should be evaluated; both functions should be re-evaluated at least once in a year. NOACs should not be used in patients with severe hepatic dysfunction.
6. NOAC is recommended in patients with AF (except with moderate-to-severe mitral stenosis or a mechanical heart valve) who are unable to maintain a therapeutic INR level with warfarin.
7. Anticoagulant therapy may be omitted in patients with AF (except with moderate-to-severe mitral stenosis or a mechanical heart valve) and a CHA2DS2-VASc score of 0 in men or 1 in women.
8. Warfarin (INR 2.0 to 3.0) or apixaban for oral anticoagulation is a reasonable option in AF patients who have a CHA2DS2-VASc score of ≥ 2 in men or 3 ≥ in women and who have end-stage chronic kidney disease (CKD) (creatinine clearance [CrCl] <15 mL/min) or are on dialysis.
9. In patients with AF (except with moderate-to-severe mitral stenosis or a mechanical heart valve) and moderate-to-severe CKD, with an elevated CHA2DS2-VASc score; treatment with reduced doses of direct thrombin or factor Xa inhibitors may be considered as below:
   • Serum creatinine ≥1.5 mg/dL - apixaban
   • CrCl 15 to 30 mL/min - dabigatran
   • CrCl ≤50 mL/min - rivaroxaban
   • CrCl 15 to 50 mL/min - edoxaban
10. An oral anticoagulant can be considered to reduce the risk of thromboembolic stroke in patients with AF (except with moderate-to-severe mitral stenosis or a mechanical heart valve) and a CHA2DS2-VASc score of 1 in men and 2 in women.
11. In patients with AF and end-stage CKD or on dialysis, the direct thrombin inhibitor dabigatran or the factor Xa inhibitors rivaroxaban or edoxaban are not recommended. This recommendation is based on the lack of evidence from clinical trials that benefit exceeds risk.
12. The direct thrombin inhibitor dabigatran should not be used in patients with AF and a mechanical heart valve. In clinical trials, dabigatran has demonstrated unacceptable thromboembolic and bleeding event rates when used in patients after heart valve replacement.

Anticoagulant Options

Non–Vitamin K Oral Anticoagulants

Overall, NOACs represent an advance in therapeutic safety when compared with warfarin for prevention of thromboembolism in patients with AF. Specific NOACs, such as apixaban, may have lower risks of bleeding (including intracranial hemorrhage) and improved efficacy for stroke prevention.

Studies show that uninterrupted dabigatran has a more favorable outcome than warfarin in ablation of AF. NOACs, especially dabigatran and rivaroxaban, may be associated with lower risks of adverse renal outcomes than warfarin in patients with AF.

In older patients with AF, dabigatran is associated with a lower risk of osteoporotic fracture than warfarin.

Interruption and Bridging Anticoagulation

1. The decision on bridging therapy should be based after considering the risks of stroke and bleeding; bridging anticoagulation may be appropriate only in patients (on warfarin) with a very high thromboembolic risk.
   1. Bridging therapy with unfractionated heparin or low-molecular-weight heparin is recommended for patients with AF and a mechanical heart valve undergoing procedures that require interruption of warfarin.
   2. The decision on bridging therapy in patients with AF without mechanical heart valves (who require interruption of warfarin for procedures) should balance the risks of stroke and bleeding and the duration of time a patient will not be anticoagulated.
2. In the event of life-threatening or uncontrolled bleeding,
   • Idarucizumab is recommended for the reversal of dabigatran
   • Andexanet alfa can be useful for the reversal of rivaroxaban and apixaban

Nonpharmacological Stroke Prevention

Percutaneous left atrial appendage (LAA) occlusion may be considered in patients with AF at increased risk of stroke who have contraindications to long-term anticoagulation. This recommendation was made based on the clinical trial data and FDA approval of the Watchman device.

Surgical occlusion of the LAA may be considered in patients with AF undergoing cardiac surgery.