Stroke risk in atrial fibrillation patients on warfarin. Predictive ability of risk stratification schemes for...

Area of Science:

• Cardiology
• Neurology
• Pharmacology

Background:

• Atrial fibrillation (AF) patients exhibit heterogeneous ischemic stroke risks.
• Existing risk stratification schemes aim to guide anticoagulant therapy.
• The agreement and predictive accuracy of these schemes require evaluation.

Purpose of the Study:

• To assess the agreement among different risk stratification schemes in AF patients.
• To evaluate the correlation of these schemes with adverse events during follow-up.
• To determine optimal management strategies for AF patients, particularly those on secondary prevention.

Main Methods:

• Prospective study of 662 AF patients on long-term oral anticoagulant therapy (OAT).
• Comparison of risk distribution across CHADS(2), NICE, and ACCP scores.
• Analysis of adverse events (bleeding and thrombotic) during follow-up.
• Separate analysis for patients on secondary prevention.

Main Results:

• CHADS(2) and NICE scores demonstrated better predictive accuracy compared to ACCP.
• Significant discrepancies observed in moderate and high-risk patient classification among schemes.
• Patients on secondary prevention were generally classified as high-risk, with some exceptions by CHADS(2).
• Adverse events, including major bleeding and thrombotic events, were predominantly observed in high-risk patients on secondary prevention.

Conclusions:

• CHADS(2) and NICE scores are reliable for risk stratification in AF patients on OAT.
• AF patients on secondary prevention are at high risk, warranting specific management considerations.
• Warfarin is the recommended treatment of choice for secondary prevention in AF patients, obviating the need for further risk stratification.