Continuing the same DOAC was associated with the lowest risk for recurrent stroke.

Despite the effectiveness of direct oral anticoagulants (DOACs) in preventing stroke in patients with atrial fibrillation (AF), a finite proportion of patients have breakthrough strokes. The optimal antithrombotic strategy for these patients is uncertain. Options include continuing the same DOAC, switching to another DOAC, switching to warfarin or adding antiplatelet therapy. These authors conducted a population-based, observational study among all public hospitals in Hong Kong over a six-year period. Patients who had strokes while on DOAC therapy were identified and the antithrombotic strategy following the event was recorded. The researchers evaluated medical records to assess recurrent ischaemic stroke; intracranial haemorrhage (ICH) and mortality were secondary outcomes.

Of 2337 patients identified with nonvalvular AF, 71% continued the same DOAC (DOAC-same), 20% switched to another DOAC (DOAC-switch) and 5% switched to warfarin (warfarin switch). During a median follow-up period of 16.5 months, the annualised rate of  recurrent ischaemic stroke was 8.7% in the DOAC-same group, 12.8% in the  DOAC-switch group and 12.6% with conversion to warfarin. ICH rates were 1.5% in the DOAC-same group, 1.6% in the DOAC-switch group and 5.3% with warfarin switch. Addition of an antiplatelet agent to the same DOAC (in 16% of cases) was not clearly beneficial. There was no difference in mortality among the three strategies. Advanced age, diabetes, use of CYP-P/gp modulating agents and large-artery atherosclerosis were associated with increased recurrent events.

Comment: These are intriguing data in that, despite the inclination of some clinicians to try a different strategy following a breakthrough stroke, continuing the same DOAC was associated with the lowest stroke rate. The finding that diabetes and atherosclerotic disease were associated with recurrent events emphasises the importance of multifaceted prevention efforts, including glucose and lipid control.

Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Seemant Chaturvedi, MD, Stewart J. Greenebaum Endowed Professor of Stroke Neurology and Stroke Program Director, University of Maryland Medical System, Baltimore; Vice-Chair for Strategic Operations, Department of Neurology, University of Maryland, Baltimore, USA.

Bonaventure Ip YM, et al. Association of alternative anticoagulation strategies and outcomes in patients with ischemic stroke while taking a direct oral anticoagulant. Neurology 2023 May 24; e-pub (https://doi.org/10.1212/WNL.0000000000207422).

This summary is taken from the following Journal Watch title: Neurology