The Use of Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation Patients with History of Intra-Cranial Hemorrhage
Background—The risk of further intra-cranial hemorrhage (ICH) and benefit of stroke risk reduction with the use of oral anticoagulants for patients with atrial fibrillation (AF) with a previous history of ICH remains unclear. We aimed to investigate the risks and benefits in AF patients with previous ICH treated with warfarin or antiplatelet drugs compared to no antithrombotic therapies.
Methods and Results—This study used the "National Health Insurance Research Database" in Taiwan. Among 307,640 AF patients with a CHA2DS2-VASc score ≥2, 12,917 patients with a history of ICH were identified, and were divided into 3 groups, that is, no treatment, anti-platelet therapy and warfarin. Among patients with prior ICH, the rate of ICH and ischemic stroke in untreated patients was 4.2 and 5.8 per 100 person-years, respectively. The annual ICH and ischemic stroke rates in warfarin users was 5.9% and 3.4%, respectively. Amongst users of anti-platelet agents, the rates were 5.3%/year and 5.2%/year, respectively. The number needed to treat (NNT) for preventing one ischemic stroke was lower than number needed to harm (NNH) for producing one ICH with warfarin use for patients with a CHA2DS2-VASc score ≥6 (37 versus 56). The NNT was higher than NNH for patients with a CHA2DS2-VASc score <6 (63 versus 53).
Conclusions—Warfarin use may be beneficial for AF patients with prior ICH having a CHA2DS2-VASc score ≥6. Whether the use of non-vitamin K antagonist oral anticoagulants (NOACs) could lower the threshold for treatment deserves further study.
- Received October 6, 2015.
- Revision received February 11, 2016.
- Accepted March 3, 2016.