Stroke Severity in Patients on Non-Vitamin K Antagonist Oral Anticoagulants with a Standard or Insufficient DoseFunding This work was supported by a grant of the Korea Heath Technology R&D Project through the Korea Health Industry Development (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HI08C2149) and a faculty research grant from the Yonsei University College of Medicine (6–2017–0128).
06 July 2018
22 September 2018
19 November 2018 (eFirst)
Background The stroke severity or functional outcomes could differ because the efficacy of non-vitamin K antagonist oral anticoagulants (NOACs) could be different according to the dose. We investigated whether there was any difference in the stroke outcomes in patients with non-valvular atrial fibrillation (NVAF) by their prior medication status, including standard-dosed versus under-dosed NOACs.
Materials and Methods We enrolled 858 patients with acute ischaemic stroke with chronic NVAF admitted at six hospitals in Korea. We categorized their prior medication status as follows: (1) no anti-thrombotics (n = 219), (2) only anti-platelet (n = 347), (3) warfarin with a sub-therapeutic intensity (n = 185), (4) warfarin with a therapeutic intensity (n = 37), (5) under-dosed NOAC (n = 27) and (6) standard-dosed NOAC (n = 43). We compared the initial stroke severity between groups.
Results Among the 858 patients, the patients on standard-dosed NOACs had the lowest initial National Institute of Health Stroke Scale (NIHSS) score, followed by those on warfarin with a therapeutic intensity and those on only anti-platelet (p < 0.05). Multivariate analysis demonstrated that the NIHSS score was significantly low in the patients on warfarin with a therapeutic intensity (B, –5.602; 95% confidence interval [CI], –8.636 to –2.568; p < 0.001) or those on standard-dosed NOACs (B, –3.588; 95% CI, –6.405 to –0.771; p = 0.013), while there was no difference in the NIHSS score between the patients not taking any anti-thrombotics and those on warfarin with a sub-therapeutic intensity or under-dosed NOACs.
Conclusion Use of warfarin with a therapeutic intensity or standard-dosed NOACs was associated with a relatively mild stroke in the patients with NVAF.
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