Anticoagulation Guidelines for Atrial Fibrillation and Venous Thromboembolism

Introduction to Anticoagulation Therapy

The European Society of Cardiology recommends direct oral anticoagulants (DOACs) over warfarin for patients with non-valvular atrial fibrillation at elevated stroke risk, with apixaban 5 mg twice daily as the preferred agent due to superior efficacy and safety 1, 2

The American College of Cardiology recommends using the CHA₂DS₂-VASc score to determine anticoagulation need, with a score of ≥2 in men or ≥3 in women indicating high stroke risk requiring oral anticoagulation 1, 3
For patients with a CHA₂DS₂-VASc score of 0 in men or 1 in women, no anticoagulation is recommended 1, 3
The CHA₂DS₂-VASc scoring system includes congestive heart failure, hypertension, age ≥75 years, diabetes, prior stroke/TIA, vascular disease, age 65-74 years, and female sex 3

The European Heart Journal recommends apixaban 5 mg twice daily as the first-line choice for most patients with non-valvular atrial fibrillation 1, 2
For patients with prior gastrointestinal bleeding, apixaban 5 mg twice daily or dabigatran 110 mg twice daily are preferable as they do not increase GI bleeding risk compared to warfarin 4, 5

The American College of Chest Physicians recommends a target INR of 2.0-3.0 with time in therapeutic range (TTR) ideally ≥70% when using vitamin K antagonists (VKAs) 4, 5
For patients with suboptimal INR control, measures such as increasing frequency of INR monitoring, reviewing medication adherence, and addressing factors affecting INR control should be implemented 4, 5, 6

The American College of Cardiology recommends anticoagulation for at least 3 weeks before cardioversion using either well-managed VKA (INR 2.0-3.0) or DOAC (dabigatran, rivaroxaban, edoxaban, or apixaban) 4, 7, 6
After successful cardioversion, continue therapeutic anticoagulation for at least 4 weeks regardless of baseline stroke risk 4, 7, 6

The European Society of Cardiology recommends never using aspirin alone or aspirin plus clopidogrel for stroke prevention in atrial fibrillation, as they are inferior to oral anticoagulation and are not recommended 1, 2
The American College of Cardiology recommends not adding antiplatelet therapy to anticoagulation for stroke prevention in atrial fibrillation, as this increases bleeding without reducing stroke 1

The European Heart Journal recommends reassessing stroke and bleeding risks at every patient contact to ensure appropriate ongoing anticoagulation 1, 3, 2
The American College of Cardiology recommends checking INR at least weekly during initiation and at least monthly when stable for patients on warfarin 3
Modifiable bleeding risk factors, including uncontrolled hypertension, concomitant antiplatelet use, excessive alcohol intake, and labile INRs, must be addressed at each visit 1, 2