Is anticoagulation still recommended for a patient with atrial fibrillation (Afib) and a CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes, Stroke or transient ischemic attack, Vascular disease, Age 65-74 years, Sex category) score of 0?

Anticoagulation for Atrial Fibrillation with CHA₂DS₂-VASc Score of 0

Anticoagulation is NOT recommended for patients with atrial fibrillation and a CHA₂DS₂-VASc score of 0, as these patients are truly low-risk with an annual stroke rate of approximately 0% and do not benefit from anticoagulation therapy. 1

Risk Stratification Evidence

• Patients with a CHA₂DS₂-VASc score of 0 have an adjusted stroke rate of 0% per year, representing the lowest risk category. 2, 1

• In large cohorts of untreated patients with a CHA₂DS₂-VASc of 0, the annual risk of ischemic stroke was only 0.43%, while the bleeding risk was 1.08% and intracranial bleeding risk was 0.15%. 3

• The 2012 ESC Guidelines explicitly state that antithrombotic therapy is not recommended in patients with AF who are aged <65 years with lone AF (irrespective of gender), as these patients have very low absolute event rates. 2

Current Guideline Recommendations

• The most recent 2024 ESC Guidelines have moved away from the CHA₂DS₂-VASc score to the CHA₂DS₂-VA score (removing sex as a criterion), and recommend OAC only for scores ≥2, with consideration for score of 1. 2

• The 2014 AHA/ACC/HRS guidelines established that patients younger than 65 years with lone AF (CHA₂DS₂-VASc score of 0) should not receive anticoagulation. 2

• The 2018 CHEST guidelines strongly recommend that low-risk patients (age <65 with lone AF, including those with CHA₂DS₂-VASc score = 0 in males) should not be offered antithrombotic therapy. 1

Clinical Registry Data

• In the ORBIT-AF registry, patients with CHA₂DS₂-VASc score of 0 had a stroke rate of 0 per 100 patient-years, confirming the extremely low risk in this population. 4

• Despite the low risk, 60.3% of CHA₂DS₂-VASc score 0 patients in ORBIT-AF were still treated with oral anticoagulation, representing potential overtreatment. 4

Important Clinical Pitfalls

• Do not use antiplatelet therapy (aspirin) as an alternative to anticoagulation in AF patients with CHA₂DS₂-VASc score of 0, as it provides minimal stroke protection with similar bleeding risks. 1

• Female sex alone (resulting in a CHA₂DS₂-VASc score of 1 due solely to female sex) is not an indication for anticoagulation, as these patients are also considered low risk when they meet criteria for "age <65 and lone AF." 2

• Regular reassessment of thromboembolic risk is mandatory at periodic intervals, as patients may develop new risk factors (hypertension, diabetes, heart failure, or advancing age ≥65 years) that would increase their score and change management. 2, 1

Risk-Benefit Analysis

• The harm from anticoagulation (bleeding risk of 1.08% annually, including 0.15% intracranial bleeding) exceeds the benefit (stroke risk of 0.43% annually) in patients with CHA₂DS₂-VASc score of 0. 3

• Patients with a score of 0 do not require chronic anticoagulation because the absolute risk of stroke is lower than the risk of major bleeding from anticoagulation therapy. 3