Atrial Fibrillation When Vitamin K Antagonist Therapy Has Not Achieved Adequate INR Control

In atrial fibrillation, oral anticoagulation is central to stroke prevention. When a vitamin K antagonist is used and the patient does not maintain adequate time within the target INR range, this constitutes a failure of the initial anticoagulation strategy — and a defined next step applies.

Why the Previous Treatment Was Not Sufficient

Goal not achieved

The prior approach used a vitamin K antagonist with a target INR of 2.0–3.0. The failure condition triggering escalation is the inability to maintain adequate time in therapeutic range on this agent — specifically, a time in therapeutic range below 70%.

Consistent INR control within the 2.0–3.0 range is the defined goal for this therapy; falling short of it signals that a different anticoagulation strategy is warranted.

The Next Anticoagulation Step

For eligible patients who have not maintained adequate INR control on a vitamin K antagonist, a switch to a different class of oral anticoagulant is the approach this protocol outlines — aimed at preventing thromboembolism and reducing the risk of intracranial haemorrhage.

Eligibility criteria, the specific agents involved, and full clinical guidance are available in the complete protocol below.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1093/eurheartj/ehae176

Switching to a DOAC is recommended for eligible patients that have failed to maintain an adequate time in therapeutic range on a VKA (TTR <70%) to prevent thromboembolism and intracranial haemorrhage.

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