• Assessment of thromboembolic stroke risk in patients with non-valvular Atrial Fibrillation (AF).
• Guidance for initiating oral anticoagulation (OAC) therapy.
• Identifying truly low-risk patients who do not require anticoagulation.

• Valvular AF: Patients with moderate-to-severe mitral stenosis or mechanical heart valves require Warfarin regardless of score.
• Hypertrophic Cardiomyopathy: These patients are high-risk for stroke regardless of AF and typically require OAC.

• Superior to CHADS2 in identifying "truly low-risk" patients; a score of 0 in males is associated with nearly 0% annual stroke risk.
• The "Female" point (Sc) should not be considered in isolation. A female with no other risk factors (Score 1) does not require anticoagulation.
• Vascular disease (V) increases risk even without other factors, particularly in the presence of carotid atherosclerosis.

• Overestimates risk in some younger populations (Age < 65) with low-risk comorbidities.
• Does not account for AF burden (paroxysmal vs. permanent); however, current guidelines treat all AF patterns with the same risk thresholds.
• Kidney disease is not a variable, despite CKD being a known independent risk factor for both stroke and bleeding.

The score quantifies factors that contribute to Virchow’s Triad in the left atrium: stasis (HF), endothelial injury (HTN, Diabetes), and hypercoagulability (Age, Vascular disease).

• Score 0 (Males) / 1 (Females): Omit anticoagulation.
• Score 1 (Males) / 2 (Females): "Consider" OAC. Shared decision-making is vital; individualize based on bleeding risk.
• Score ≥ 2 (Males) / ≥ 3 (Females): Oral anticoagulation is strongly recommended (Class I).

The CHA2DS2-VASc score was developed as an evolution of the simpler CHADS2 score. The original CHADS2 left many patients in a "grey zone" of intermediate risk. By refining the age brackets and adding vascular/sex variables, Gregory Lip and colleagues aimed to clarify who truly benefits from OAC.

A world-renowned expert in AF from the University of Liverpool. His research has moved AF management toward a "risk-based" approach, emphasizing the importance of stroke prevention as the cornerstone of care.