Pharmacological Difference Between Platelet Aggregations in Cardioembolic Stroke Patients with Direct Oral Anticoagulants: A Pilot Study

• Published in: Journal of stroke and cerebrovascular diseases Vol. 31; no. 7; p. 106520
• Main Authors: Nakazaki, Masahito, Oka, Shinichi, Magota, Hirotoshi, Kiyose, Ryo, Onodera, Rie, Ukai, Ryo, Kataoka-Sasaki, Yuko, Sasaki, Masanori, Honmou, Osamu
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2022
• Subjects: Dabigatran; Direct oral thrombin inhibitor; Factor Xa inhibitor; Ischemic stroke prevention; Platelet aggregation; Platelet aggregation; Direct oral thrombin inhibitor; Dabigatran; Factor Xa inhibitor; Ischemic stroke prevention
• ISSN: 1052-3057; 1532-8511
• DOI: 10.1016/j.jstrokecerebrovasdis.2022.106520

•Selecting the appropriate DOAC for embolic ischemic stroke patients.•Reports on interactions between DOACs and platelet aggregation.•Dabigatran had less impact on platelet aggregation than FXa inhibitor.
Background Selecting the appropriate direct oral anticoagulants (DOACs) for embolic ischemic stroke patients, especially on concurrent antiplatelet therapy, is important. However, a limited number of studies have reported on the pharmacological differences in platelet aggregation of each DOAC. We aimed to evaluate the antiplatelet effects of selected DOACs, by comparing dabigatran (a direct oral thrombin inhibitor) and factor Xa (FXa) inhibitors (apixaban and rivaroxaban) in patients who had suffered a cardioembolic stroke.
Methods We retrospectively evaluated 12 patients diagnosed with a cardioembolic stroke who took any DOAC without an antiplatelet drug and underwent platelet aggregation tests within 60 days from the onset of symptoms. The platelet aggregation tests were analyzed by both light transmission aggregometry and VerifyNow®.
Results Six patients (50%) took dabigatran, while the other six (50%) took an FXa inhibitor (n = 4 for apixaban and n = 2 for rivaroxaban). From the light transmission aggregometry analysis, it was found that the maximal extent of aggregation for adenosine diphosphate (ADP) was significantly higher with dabigatran than with FXa inhibitors, and the ED50 value of ADP on platelet aggregation was significantly lower with dabigatran than with FXa inhibitors. Moreover, the VerifyNow® analyses revealed that P2Y12 reaction units were significantly higher with dabigatran than with FXa inhibitors.
Conclusions Dabigatran had little impact on platelet aggregation compared to FXa inhibitors in patients who had suffered a cardioembolic stroke with atrial fibrillation, and who took DOACs for secondary prevention within 60 days from the onset.