Effect of anticoagulation on cardioembolic stroke severity, outcomes and response to intravenous thrombolysis.

Our objective was to evaluate the effect of anticoagulation on cardioembolic stroke (CS) severity, outcomes, and response to intravenous thrombolysis (IVT). Observational study of CS patients admitted to a Stroke Center (2010-2013). The sample was classified into three groups based on pre-stroke oral anticoagulants (OAC) treatment (all acenocumarol) and the international normalized ratio (INR) on admission: (1) non-anticoagulated or anticoagulated patients with INR <1.5, (2) anticoagulated with INR 1.5-1.9 and (3) anticoagulated with INR ≥2. We compared demographic data, vascular risk factors, symptomatic intracranial hemorrhage, severity on admission (NIHSS) and 3 month outcomes (mRS). Overall 475 patients were included, 47.2 % male, mean age 75.5 (SD 10.7) years old, 31.8 % were on OAC. 76 % belonged to the INR <1.5 group, 13.3 % to the INR 1.5-1.9 and 10.5 % to the INR >2. 35 %of patients received IVT. Multivariate analyses showed that an INR ≥2 on admission was a factor associated with a higher probability of mild stroke (NIHSS <10) (OR 2.026, 95 % CI 1.006-4.082). Previous OAC in general (OR 2.109, 95 % CI 1.173-3.789) as well as INR 1.5-1.9 (OR 3.676, 95 % CI 1.510-8.946) were associated with favorable outcomes (mRS ≤2). OAC was not related to stroke outcomes in the subgroup of IVT patients. Therapeutic OAC levels are associated with lesser CS severity, and prior OAC treatment with favorable outcomes. In this study, OAC are not related with response to IVT.