Year 2021
October 2021


Abstract Title
Should the optimal international normalized ratio (INR) range of 2.0 – 3.0 for non-valvular atrial fibrillation be lowered for the elderly?



National Healthcare Group Polyclinics1

Background & Hypothesis

There has been much controversy regarding the option of using a lowered INR target for the elderly, as there’s conflicting evidence whether lowering the target may truly have similar stroke risk reduction and at the same time confers a lesser risk of major bleeding. The study aims to determine if a lowered INR range from the standard INR 2.0 – 3.0 will be optimal for the elderly in terms of reduction of risks of thromboembolic events versus major bleeding events


A systematic literature review was carried out and studies were retrieved from searches of computerized databases or from hand-searches. The findings were synthesized and analyzed to determine a more effective and safer therapeutic INR window is present for the elderly on warfarin.


A total of 8 articles were retrieved from the literature. An INR of less than or equal to 1.6 has significantly higher risk of thromboembolic event. When the INR exceeds 2.5, there is considerable risk of major bleeding

Discussion & Conclusion

The optimal intensity of anticoagulation therapy for elderly patients with non-valvular atrial fibrillation is when the INR is between 1.7 and 2.5