Adequacy of preadmission oral anticoagulation with vitamin K antagonists and ischemic stroke severity and outcome in patients with atrial fibrillation

It is unclear whether vitamin K antagonists affect stroke severity and outcome in patients with atrial fibrillation (AF). We aimed to evaluate this association. We prospectively studied 539 consecutive patients admitted with acute ischemic stroke (41.2 % males, age 78.9 ± 6.6 years). The severity of stroke was assessed at admission with the National Institutes of Health Stroke Scale (NIHSS). The outcome was assessed with dependency rates at discharge (modified Rankin scale 2–5) and with in-hospital mortality. 177 patients had a history of AF. The median NIHSS at admission did not differ between patients on acenocoumarol with INR 2.0–3.0, on acenocoumarol with INR < 2.0, on single antiplatelet treatment, on dual antiplatelet treatment, or on no treatment [4 (range 0–26), 13 (0–39), 8 (0–33), 3 (2–23) and 7 (0–33), respectively; p = 0.433]. Dependency rates were lower in patients on acenocoumarol with INR 2.0–3.0 or on dual antiplatelet treatment than in those on acenocoumarol with INR < 2.0, single antiplatelet treatment, or no treatment (20.0, 22.2, 61.5, 58.7 and 68.0 %, respectively; p = 0.024). Independent predictors of dependency were age, NIHSS at admission and history of ischemic stroke. In-hospital mortality did not differ between patients on acenocoumarol with INR 2.0–3.0, on acenocoumarol with INR < 2.0, on single antiplatelet treatment, on dual antiplatelet treatment, or on no treatment (7.7, 18.2, 16.1, 16.7 and 22.2 %, respectively; p = 0.822). In conclusion, optimally anticoagulated patients with AF have more favorable functional outcome after stroke and a trend for less severe stroke whereas patients with subtherapeutic anticoagulation have similar stroke severity and outcome with those on no treatment.