SEDMAN study is a prospective multicenter investigator initiated study (IIS). The main idea is to look by Genome Wide Association (arrays that determine more than 1 million polymorphisms) genetic risk factors associated with response to dabigatran. To conduct the study, the goal is to recruit 300 patients with ischemic stroke with cardioembolic etiology treated with dabigatran and 200 treated with Acenocoumarol to determine if genetic risk factors are associated with the occurrence of any bleeding or vascular event in a year follow-up.

Data will be analyzed through GWAS analysis. The results will be analyzed by experienced genotypic bioinformatics: Plink, Haploview, STATA, IMPUTE2, SNPtest, GTOOL, Galaxy management. In addition, the investigators have support of Spanish Consortium for Genetics of Stroke (Genestroke). The PLINK software is the main program for the analysis of GWAS. Using this software we can clean the raw results of genotyping platforms and determine the presence of risk alleles associated with resistance to the study drugs. Haploview software will be used for data management and graphics for significance analysis. STATA statistical software is a data management and very useful for the creation of Q_Q plots graphs that assist in the interpretation of genotypic results. GTOOL, SNPtest and IMPUTE2 are software for data imputation and analysis of imputed data through the information available in the 1000 Genomes Project.

Inclusion Criteria:

• Patients of both sexes who are ≥ 18 years of age
• Patients with stroke or TIA in last 14 days and a diagnosis of non-valvular atrial fibrillation who initiate treatment with dabigatran or classical ACOs (acenocoumarol) to prevent stroke or non-CNS systemic embolism.
• Patients with mild/moderate strokes (i.e. strokes less than 2/3 of vascular territory with initial ASPECTS on first CT/MRI > 6 and NIHSS <25).
• Patients who have an overall condition which allow the 12 months' follow-up.

Exclusion Criteria:

• Patients with an indication of oral anticoagulants for primary prevention or with an indication other than cardioembolic etiology.
• Patients with contraindications to use anticoagulants.
• Patients who do not wish to participate in the study and have not signed informed consent.
• Patients with non-controlled hypertension or hypertensive crisis will be also excluded.
• Patients with a life expectancy of less than one year.
• Patients with psychological or social factor which not allow a correct follow-up.
• Patients with severe/disabling strokes (i.e. more than 2/3 of vascular territory, NIHSS≥25).

Patients of both sexes who are at least 18 years of age with a diagnosis of non-valvular atrial fibrillation and stroke or TIA and after taking the decision to perform pharmacological prophylaxis with dabigatran or acenocoumarol under the approved indication and the recommendations.