Predictors of stroke or systemic embolism in patients with non-valvular atrial fibrillation with CHA2DS2-VASc score of 0

BackgroundAnticoagulant therapy has been important for stroke prevention in patients with atrial fibrillation (AF). However, it was not recommended due to its relatively higher risk of bleeding than its lower risk of stroke in patients with a CHA(2)DS(2)-VASc score of 0. HypothesisThis study aimed to evaluate the predictors of stroke in AF patients with very low risk of stroke. MethodsBetween 1990 and 2020, 542 patients with non-valvular AF (NVAF) with a CHA(2)DS(2)-VASc score of 0 followed up for at least 6 months were enrolled. Patients with only being woman as a risk factor were included as a CHA(2)DS(2)-VASc score of 0 in this study. The primary outcome was stroke or systemic embolism. ResultsThe primary outcome rate was 0.78%/year. In Cox hazard model, age of >= 50 years at diagnosis (hazard ratio [HR] 6.710, 95% confidence interval [CI] 1.811-24.860, p = .004), LVEDD of >= 46 mm (HR 4.513, 95% CI 1.038-19.626, p = .045), and non-paroxysmal AF (HR 5.575, 95% CI 1.621-19.175, p = .006) were identified as independent predictors of stroke or systemic embolism. Patients with all three independent predictors had a higher risk of stroke or systemic embolism (4.21%/year), whereas those without did not have a stroke or systemic embolism. ConclusionThe annual stroke or systemic embolism rate in NVAF patients with CHA(2)DS(2)-VASc score of 0 was 0.78%/year, and age at AF diagnosis, LVEDD, and non-paroxysmal AF were independent predictors of stroke or systemic embolism in patients considered to have a very low risk of stroke.