DIAMOND-AF is a multicenter, randomized, open-label trial evaluating whether discontinuing oral anticoagulation after successful atrial fibrillation ablation can reduce bleeding risk without increasing death or thromboembolism risks. Adults aged 18-80 years, 60-365 days post-ablation, with CHA2DS2-VA ≥2, no prior stroke/TIA/systemic embolism, continuous NOAC use, and no documented atrial tachyarrhythmia recurrence will be randomized 1:1 to stop NOACs immediately or to continue NOAC therapy. All participants use intensified rhythm surveillance including smartwatch ECG and Holter/patch monitoring (at least every 6 months; every 2 months encouraged) to detect recurrence. Co-primary endpoints are (1) non-inferiority for the composite of all-cause death, ischemic stroke, or systemic embolism and (2) superiority for the composite of ISTH major bleeding or ISTH clinically relevant non-major bleeding. The planned sample size is 4,100 participants.