Results of a survey of the patients with atrial fibrillation (AF) in Fushimi-ku, Kyoto published in the October 2018 issue of the journal Stroke show that AF progression was associated with increased risk of clinical adverse events - systemic embolism and ischemic stroke - during arrhythmia progression period from paroxysmal to sustained (persistent or permanent). The risk of adverse events was transiently elevated during progression period and declined to the level equivalent to SAF after the progression.