Non-vitamin K-dependent oral anticoagulants have a positive impact on ischaemic stroke severity in patients with atrial fibrillation

Aims Several studies showed reduced stroke severity in patients with atrial fibrillation (AF) if the international normalized ratio (INR) was >= 2 at stroke onset. There are no respective data for non-vitamin K-dependent oral anticoagulants (NOACs). The aim of this study was to compare the impact of NOAC or phenprocoumon intake on stroke severity. Methods and results In this single-centre observational study, 3669 patients with acute ischaemic stroke were retrospectively analysed regarding AF status and medication immediately before admission. Using multivariable regression, we analysed the association of pre-admission anticoagulation with severe stroke (National Institutes of Health Stroke Scale score >= 11) on admission and poor outcome at discharge (modified Rankin scale score > 2). Before the index stroke, 655 patients had known AF and a CHA(2)DS(2)-VASc score >= 2. While 325 (49.6%) patients were anticoagulated, 159 (24.3%) were prescribed a NOAC and 75 (11.5%) phenprocoumon patients had an INR >= 2 on admission. Compared with AF patients without medical stroke prevention, an INR >= 2 [OR 0.23 (95% CI 0.10-0.53)] or NOAC intake [OR 0.48 (95% CI 0.27-0.86)] were associated with a lower probability of severe stroke after adjustment for confounders, while an INR < 2 [OR 0.62 (95% CI 0.33-1.16)] was not. Adjusted odds ratios for poor functional outcome at hospital discharge were 0.47 (95% CI 0.27-0.84) for NOAC patients, 0.33 (95% CI 0.17-0.65) for INR >= 2 and 0.61 (95% CI 0.32-1.16) for INR < 2. Conclusion NOAC intake before stroke did reduce the probability of severe stroke on hospital admission and poor functional outcome at hospital discharge as similarly demonstrated for phenprocoumon patients with an INR >= 2 on admission.