Incidence and characteristics of silent cerebral embolisms after radiofrequency-based atrial fibrillation ablation: A propensity score-matched analysis between different mapping catheters and indices for guiding ablation.

INTRODUCTION: The difference in the incidence and characteristics of silent cerebral events (SCEs) after radiofrequency-based atrial fibrillation (AF) ablation between the different mapping catheters and indices used for guiding radiofrequency ablation remains unclear. This study aimed to compare the incidence and characteristics of postablation SCEs between the following two groups: Group C, Ablation Index-guided ablation using two circular mapping catheters with CARTO (Biosense Webster); Group R, local impedance-guided ablation using one mini-basket catheter and one circular mapping with Rhythmia (Boston Scientific). METHODS AND RESULTS: Of 211 consecutive patients who underwent an AF ablation and brain magnetic resonance (MR) imaging after the ablation, 120 patients (each group, n = 60) were selected by propensity score matching. SCEs were detected in 37 patients (30.8%). Group R had a higher incidence of SCEs (51.7% vs. 10.0%; p < .001) and more SCEs per patient (median, 3 vs. 1, p = .028) than Group C. A multivariate analysis demonstrated that nonparoxysmal AF and being Group R were independent positive predictors of SCEs (odds ratios, 6.930 and 15.464; both p < .001). On the follow-up MR imaging, all SCEs in Group C and 87.9% of the SCEs in Group R disappeared (p = .537). CONCLUSIONS: Group R had a significantly higher incidence of SCEs than Group C. Most probably the use of a complexly designed basket mapping catheter is the reason for the difference in the incidence of SCEs but further validation is needed. A nonparoxysmal form of AF may also increase the risk of SCEs during these ablation procedures.

Nine-year trend of oral anticoagulant use in patients with embolic stroke due to nonvalvular atrial fibrillation.

BACKGROUND: Direct oral anticoagulants (DOACs) are increasingly used as an alternative to warfarin in patients with nonvalvular atrial fibrillation (NVAF). However, whether there is sufficient prescription of oral anticoagulants (OACs) to decrease the incidence of embolic stroke remains unclear. METHODS AND RESULTS: We conducted a retrospective observational study of patients hospitalized with ischemic stroke between January 1, 2010 and December 31, 2018. During the 8 years, the annual incidence ratio of embolic stroke to all ischemic strokes did not decrease over time (21-33%) except for that in 2018. The proportion of OAC users did not also change over time (from 23% to 45% [overall 31%], P = .78). Among the OAC users, 19% patients were warfarin users, and 12% patients were DOAC users. In 73% of warfarin users, prothrombin time was subtherapeutic, whereas in 60% of DOAC users, the dose was adequately prescribed. OACs were prescribed more often in patients with high CHADS2 score than in those with low score (P = .01). The number of patients who had no medical history of a doctor visit before admission increased significantly in the recent period of 2015-2018 (22% vs 8% in the previous period of 2010-2014) (P = .01). CONCLUSIONS: The incidence of embolic stroke patients without OACs did not decrease over time, and OACs in patients with NVAF have not been sufficient, even in DOAC era. In recent years, the incidence of undiagnosed AF has increased. To prevent embolic stroke, a correct AF diagnosis beforehand is important.