Time Trends in Patient Characteristics, Anticoagulation Treatment, and Prognosis of Incident Nonvalvular Atrial Fibrillation in the Netherlands.

Importance: The temporal trend in adverse events regarding stroke prevention for nonvalvular atrial fibrillation (NVAF) in the direct oral anticoagulant (DOAC) era was rarely investigated comprehensively, especially taking into account potential changes in patient characteristics and anticoagulation treatment. Objective: To investigate time trends in patient characteristics, anticoagulation treatment, and prognosis of patients with incident NVAF in the Netherlands. Design, Setting, and Participants: This retrospective cohort study assessed patients with incident NVAF initially recognized within a hospitalization between 2014 and 2018, using data from Statistics Netherlands. Participants were followed-up for 1 year from the hospital admission at which the incident NVAF diagnosis was made or until death, whichever occurred first. Data were analyzed from January 15, 2021, to March 8, 2023. Exposure: Calendar year of the incident NVAF diagnosis, according to which the participants were categorized into 5 cohorts. Main Outcomes and Measures: Outcomes of interest were baseline patient characteristics, anticoagulation treatment, and occurrence of ischemic stroke or major bleeding within the 1-year follow-up after incident NVAF. Results: Between 2014 and 2018, 301 301 patients (mean [SD] age, 74.2 [11.9] years; 169 748 [56.3%] male patients) experienced incident NVAF in the Netherlands, each of whom was categorized into 1 of 5 cohorts by calendar year. Baseline patient characteristics were broadly the same between cohorts with a mean (SD) CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years [doubled], diabetes, stroke [doubled], vascular disease, age 65 to 74 years, and sex category [female]) score of 2.9 (1.7). The median (IQR) proportion of days covered by OACs (ie, vitamin K antagonists or DOACs) within the 1-year follow-up increased from 56.99% (0%-86.30%) to 75.62% (0%-94.52%), and DOACs increased from 5102 patients (13.5%) to 32 314 patients (72.0%) among those who received OACs, gradually replacing VKAs as the first choice of OACs. Over the course of the study, there were statistically significant decreases in the 1-year cumulative incidence of ischemic stroke (from 1.63% [95% CI, 1.52%-1.73%] to 1.39% [95% CI, 1.30%-1.48%) and major bleeding (from 2.50% [95% CI, 2.37%-2.63%] to 2.07% [95% CI, 1.96%-2.19%]), and the association was consistent after adjusting for baseline patient characteristics and excluding those with preexisting chronic anticoagulation. Conclusions and Relevance: This cohort study of patients with incident NVAF diagnosed between 2014 and 2018 in the Netherlands found similar baseline characteristics, increased OAC use with DOACs being favored over time, and improved 1-year prognosis. Comorbidity burden, potential underuse of anticoagulation medications, and specific subgroups of patients with NVAF remain directions for future investigations and further improvement.