Stroke Severity in Patients on Non-Vitamin K Antagonist Oral Anticoagulants with a Standard or Insufficient Dose

Abstract

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.

Off-label Non-vitamin K Antagonist Oral Anticoagulants Does Not Decrease the Stroke Risk of Atrial Fibrillation Patients in East China

“…et al pointed out that off-label rivaroxaban was associated with an increased risk of ischemic stroke with 2.75 times [6]. The standard dose NOACs was associated with a relatively mild stroke in the patients compared to under-dosed NOACs [13]. The previous studies were similar to our study which showed a poor clinical bene t of off-label anti-coagulation.…”

Effects of dabigatran and rivaroxaban on stroke severity according to the results of routine coagulation tests

“…In patients with NVAF who suffer an ischemic stroke, stroke outcome has been shown to differ according to the activity of oral anticoagulants [9]. Notably, specific coagulation tests, including diluted thrombin time and chromogenic anti-Xa assays, have demonstrated a strong correlation with plasma concentrations of direct oral anticoagulants (DOACs) [10].…”

Dose Selection of Non-Vitamin K Antagonist Oral Anticoagulants in Korean Patients with Non-Valvular Atrial Fibrillation

“…Furthermore, along with the risk of adverse events, off-label underdosed NOAC was also associated with increased stroke severity than that of on-label standard doses or warfarin given at a therapeutic intensity. 46) Overall, previous studies consistently showed that the use of off-label underdosed NOACs attenuated the benefit of NOACs over warfarin.…”