Atrial fibrillation (AF) is a significant risk factor of ischemic strokes, and patients with risk factors for thromboembolism are treated with oral anticoagulant therapy (OAC). [1] However, some patients are deemed not suitable for OAC due to a high risk of bleeding, a history of major bleeding while treated with OAC, or an ischemic stroke/systemic embolism despite OAC. [1] Since 2016, LAAO has been considered by the European Society of Cardiology (ESC) guidelines, as a class IIb, level B alternative for patients not suitable for OAC. [1,2]

Randomized controlled trials (RCT) comparing LAAO to OAC have primarily reported noninferiority. [[3], [4], [5]] However, one RCT did not achieve noninferiority at the primary endpoint another RCT reported procedure-related complications at 4.8% and two deaths. [4,5] Further, the included patients may not be representative of patients undergoing LAAO in real-world clinical practice. An American registry reported peri-procedural complication rates over the study period of 26.4% in 2015 vs 7.9% in 2017. [6] As such, LAAO is not without risk of severe complications, which should be considered when comparing LAAO versus OAC for stroke prevention. This highlights the importance of examining current clinical practice and if the patients' characteristics and indication for LAAO have changed. Studies from different registries have previously reported patient's characteristics. [[6], [7], [8], [9], [10], [11], [12]] However, only few studies have focused on time trends, and with the introduction of LAAO as a novel procedure, potential changes in the population could be expected. [6,7] We therefore aimed to investigate how possible indications for LAAO as well as comorbidity and mortality have changed since the introduction of LAAO.