This study explores the association of symptomatic episodes of atrial fibrillation (AF) occurrence and long-term risk of thromboembolic complications in a retrospective setting.

The study population consists of the FinCV-dataset, which includes 7660 acute cardioversions for atrial fibrillation. The electronic patient records of FinCV-study patients are reviewed to collect data on anticoagulation, number of cardioversions as well as mortality and stroke data. We seek to explore the possible association between the frequency of AF paroxysms in low stroke risk patients and the occurrence of death, stroke and major bleed as well as the net clinical benefit of anticoagulation. Data collection is performed by reviewing electronic patient records.

• primary diagnosis of atrial fibrillation (ICD-10 code I48)
• Cardioversion for acute (<48 h) atrial fibrillation
• >18 years of age
• living within the catchment area of the hospital

Original FinCV study (Airaksinen et al. JACC 2013) eligibility criteria: All patients with a primary diagnosis of atrial fibrillation (ICD-10 code I48) were identified from the institutional discharge registries in the 3 participating hospitals. Emergency clinic admission records and databases were then used to review all patients (>18 years of age) with acute (<48 h) atrial fibrillation who underwent cardioversion during the study period. In addition, only patients living in the hospital catchment area were included to get the adequate follow-up data after the cardioversion.