What are the best choices for anticoagulant therapy in Atrial Fibrillation (AF)?

From the Guidelines

The best choices for anticoagulant therapy in atrial fibrillation are direct oral anticoagulants (DOACs) including apixaban, dabigatran, edoxaban, and rivaroxaban, which are preferred over vitamin K antagonists (VKAs) such as warfarin, except in patients with mechanical heart valves and mitral stenosis. According to the 2024 ESC guidelines for the management of atrial fibrillation 1, DOACs are recommended for all eligible patients, except those at low risk of incident stroke or thromboembolism. The decision to start anticoagulation should be based on stroke risk assessment using the CHA₂DS₂-VASc score, with therapy recommended for scores ≥2 in men or ≥3 in women.

Some key points to consider when choosing an anticoagulant include:

• The use of full standard doses for DOACs unless the patient meets specific dose-reduction criteria
• The preference for DOACs over VKAs due to their fixed dosing, fewer drug interactions, and reduced need for monitoring
• The importance of managing modifiable bleeding risk factors to improve safety
• The need to avoid combining anticoagulants and antiplatelet agents, unless necessary for acute vascular events or procedures

In terms of specific dosing, the following adjustments are necessary for patients with renal impairment:

• Apixaban 2.5mg twice daily if two of the following are present: age ≥80, weight ≤60kg, or serum creatinine ≥1.5mg/dL
• Rivaroxaban 15mg daily for CrCl 15-50mL/min
• Dabigatran 75mg twice daily for CrCl 15-30mL/min
• Edoxaban 30mg daily for CrCl 15-50mL/min

It's also important to note that anticoagulants work by preventing thrombus formation in the left atrial appendage, which is the source of most cardioembolic strokes in atrial fibrillation patients. The 2020 update to the 2016 ACC/AHA clinical performance and quality measures for adults with atrial fibrillation or atrial flutter also supports the use of DOACs over VKAs in eligible patients 1.

From the FDA Drug Label

Oral anticoagulation therapy with warfarin is recommended in patients with persistent or paroxysmal AF (PAF) (intermittent AF) at high risk of stroke (i.e., having any of the following features: prior ischemic stroke, transient ischemic attack, or systemic embolism, age >75 years, moderately or severely impaired left ventricular systolic function and/or congestive heart failure, history of hypertension, or diabetes mellitus) In patients with persistent AF or PAF, age 65 to 75 years, in the absence of other risk factors, but who are at intermediate risk of stroke, antithrombotic therapy with either oral warfarin or aspirin, 325 mg/day, is recommended.

The best choices for anticoagulant therapy in atrial fibrillation include:

• Warfarin for patients at high risk of stroke
• Warfarin or aspirin for patients at intermediate risk of stroke, aged 65 to 75 years, with no other risk factors The target INR for warfarin therapy in atrial fibrillation is 2.0-3.0 2

From the Research

Anticoagulant Therapy Options

The choice of anticoagulant therapy for atrial fibrillation depends on various factors, including patient characteristics and the risk of stroke and bleeding. The following are some of the best choices for anticoagulant therapy in atrial fibrillation:

• Direct oral anticoagulants (DOACs) such as dabigatran, rivaroxaban, and apixaban, which have been shown to be non-inferior or superior to warfarin in preventing stroke and systemic embolism, with a lower risk of major hemorrhage 3, 4, 5
• Novel oral anticoagulants (NOACs) such as dabigatran, rivaroxaban, and apixaban, which are easier to use and manage than warfarin, and have a more favorable bleeding risk profile 3, 6, 7

Patient Characteristics to Consider

When choosing an anticoagulant therapy, the following patient characteristics should be considered:

• Age: patients aged 75 years or older may require a reduced dose of anticoagulant therapy 3
• Renal dysfunction: patients with renal dysfunction may require a reduced dose of anticoagulant therapy 3
• Coronary artery disease: patients with coronary artery disease may require a different anticoagulant therapy regimen 3
• Risk of bleeding: patients with a high risk of bleeding may require a more cautious approach to anticoagulant therapy 3, 6

Comparison of Anticoagulant Therapies

Studies have compared the effectiveness and safety of different anticoagulant therapies in atrial fibrillation, including:

• Apixaban, dabigatran, and rivaroxaban: a study found that apixaban and dabigatran had a lower risk of major bleeding than rivaroxaban, while dabigatran had the lowest all-cause mortality in reduced dose 5
• Apixaban and acenocumarol: a study found that apixaban had a lower rate of stroke and psychiatric illness compared to acenocumarol, and a lower rate of thromboembolic events 7