Sinus rhythm duration after direct current cardioversion for persistent atrial fibrillation and long-term outcomes after subsequent catheter ablation

BACKGROUND: Patients undergoing catheter ablation (CA) for persistent atrial fibrillation (PsAF) experience high rates of AF recurrence. Direct current cardioversion (DCCV) is often performed prior to CA, with variable post-DCCV duration of sinus rhythm (SR). OBJECTIVE: We aimed to determine whether shorter SR duration after DCCV is associated with AF recurrence after subsequent CA. METHODS: We performed an international multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015 and 2024 with a prior DCCV. SR duration after the last DCCV preceding CA was recorded. The primary outcome was freedom from atrial arrhythmia after CA (after a 56-day postablation blanking period). RESULTS: 938 patients undergoing first-time CA for PsAF were identified from six centres and categorised by post-DCCV SR duration: <7 days (group 1, n=212); 7-31 days (group 2, n=236); and >31 days (group 3, n=490). Over median post-CA follow-up of 511 days, 512 patients (55%) experienced atrial arrhythmia recurrence. There was no significant between-group difference in freedom from atrial arrhythmia (log-rank p=0.10). When analysed as a continuous variable in a Cox regression model, there was no association between post-DCCV SR duration and time to first recurrence of atrial arrhythmia (HR per 10-day increment 1.00, 95% CI 1.00 to 1.01, p=0.07). In secondary analyses, there were significantly more blanking period arrhythmias in groups 1 and 2 compared with group 3 (both pairwise p<0.001), and presentation for CA in persistent atrial arrhythmia was associated with a time-dependent increased risk of atrial arrhythmia recurrence compared with presentation in SR. CONCLUSION: In this large multicentre cohort, shorter duration of SR after DCCV was associated with blanking period arrhythmia after subsequent CA, but we did not find evidence of an association with long-term AF recurrence. Clinicians should consider these findings when making decisions regarding suitability for CA or predicting long-term CA success.