The association between antithrombotic drug regimen changes and clinical outcomes after stroke in atrial fibrillation

The impact of post-stroke antithrombotic regimen in atrial fibrillation is uncertain.

This study aimed to describe antithrombotic therapy prescribing patterns after ischemic stroke and the impact on outcomes.

A total of 23,165 patients with atrial fibrillation experiencing ischemic stroke were identified. Subsequent post-stroke events included recurrent ischemic stroke, intracranial hemorrhage, major bleeding, mortality, and composite outcomes.

Of those who were nonanticoagulated before a stroke, 33.5% remained nonanticoagulated and 39.2% were prescribed only antiplatelet agents (APs) after a stroke. Compared with non-vitamin K antagonist oral anticoagulants (NOACs) after stroke, there was a significant increase in ischemic stroke and mortality in nonanticoagulated patients (adjusted hazard ratio [aHR], 2.09 and 3.92) and AP users (aHR, 1.32 and 1.28). Post-stroke warfarin was associated with a significantly increased risk of major bleeding compared with NOACs (aHR, 1.23). Of 769 patients receiving NOACs before stroke and continuing NOACs after stroke, those switching to a different NOAC were associated with significantly higher risk of ischemic stroke (aHR, 2.07) and composite outcomes (aHR, 1.36-1.85) with no difference in intracranial hemorrhage, major bleeding, or mortality compared with those receiving the same NOAC after stroke. Of patients receiving NOACs before stroke, the risks of clinical events were similar between patients taking NOACs alone and those taking NOAC plus AP after stroke.

NOAC alone after stroke was associated with a better clinical outcome compared with nonanticoagulation, AP, or warfarin. Of patients already taking NOACs before stroke, the addition of AP did not confer additional benefits compared with NOACs alone. A change of NOAC types after stroke was associated with a 2-fold higher risk of ischemic stroke and composite outcomes.