What is the goal INR for patients on warfarin with documented chronic atrial fibrillation?

The goal International Normalized Ratio (INR) for patients on warfarin with documented chronic atrial fibrillation is typically set at 2.0 to 3.0. This target range is established to effectively reduce the risk of thromboembolic events, such as stroke, while minimizing the risk of bleeding complications.

Patients with chronic atrial fibrillation are at an increased risk for the formation of blood clots in the heart, which can lead to strokes. Warfarin is an anticoagulant used to manage this risk by inhibiting the vitamin K-dependent clotting factors in the blood. The INR is a standardized measure that assesses the blood's ability to clot; maintaining it within the appropriate range balances the benefits of preventing clots against the potential for excessive bleeding.

A target INR of 2.0 to 3.0 is considered effective for the majority of patients with atrial fibrillation to achieve this balance, ensuring adequate anticoagulation. Higher INR targets, such as those seen in the other options, increase the risk of bleeding complications without significantly improving thrombo-protection.