In this study researchers want to learn more about on the safety of the drug Xarelto. The study will enroll patients for whom the treating doctor are prescribing Xarelto for the prevention of brain attack or the prevention of blockage of an artery in the non-central nervous system. Only patients suffering from decreased renal function and irregular heart beat will be considered. The study plans to include 500 Taiwanese adult male and female patients with the age above 20 years. Patients will be followed up based on routine medical practice over a period of 12 months and information on their well-being and any medical events will collected.

Inclusion Criteria:

• Female and male patients ≥ 20 years of age
• Diagnosis of non-valvular atrial fibrillation (NVAF)
• Patients for whom the decision to initiate treatment with rivaroxaban is made as per physician's routine treatment practice
• Previously documented CrCl of 15-50 mL/min within 6 months before enrollment (last available value)

Exclusion Criteria:

• Contraindications for rivaroxaban according to the local market authorization/ Summary of Product Characteristics
• Patients participating in an investigational program with interventions outside of routine clinical practice.
• Planned treatment with other anticoagulants
• Expected renal-replacement therapy within the next 3 months

The study population is composed of Taiwanese NVAF patients with documented CrCl of 15-50 mL/min, requiring rivaroxaban for the prevention of stroke or non-central nervous system (CNS) systemic embolism (SE). Patients must also meet all the eligibility for the study.

Availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA "Principles for responsible clinical trial data sharing". This pertains to scope, timepoint and process of data access. As such, Bayer commits to sharing upon request from qualified researchers patient-level clinical trial data, study-level clinical trial data, and protocols from clinical trials in patients for medicines and indications approved in the US and EU as necessary for conducting legitimate research. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014.

Interested researchers can use www.vivli.org to request access to anonymized patient-level data and supporting documents from clinical studies to conduct research. Information on the Bayer criteria for listing studies and other relevant information is provided in the member section of the portal.