Duration of sinus rhythm after direct current cardioversion does not predict recurrence of atrial fibrillation after subsequent catheter ablation: a multicentre study

Abstract Background Catheter ablation (CA) for persistent atrial fibrillation (PsAF) is associated with high rates of AF recurrence. DC cardioversion (DCCV) is often performed before CA, with wide variation in duration of maintenance of sinus rhythm (SR) post-DCCV. Factors associated with short duration of SR after DCCV, such as raised body mass index, prior duration of AF, prolonged p wave duration on the 12-lead ECG, and indexed left atrial volume, are either associated with or indicative of atrial electrical and structural remodelling, suggesting that shorter duration of SR after DCCV reflects a more advanced substrate for AF, which could in turn also influence the likelihood of success after CA. Objective To determine if post-DCCV SR duration is associated with AF recurrence after subsequent CA. Methods We performed a multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015-2018 with prior DCCV. SR duration after the last DCCV prior to CA was recorded. The primary outcome was the first recurrence of atrial arrhythmia post-CA (after a 90-day post-CA blanking period). We also performed a pre-specified sensitivity analysis for amiodarone use at DCCV, by performing repeat analysis after excluding all such patients across the three groups. Results A total of 331 patients were identified across five centres and categorised by post-DCCV SR duration: <7 days (group 1); 7-31 days (group 2); >31 days (group 3; Table 1). Over median post-CA follow-up of 591 days, 207 patients (62.5%) met the primary outcome. There was no significant between-group difference in the time to primary outcome (log rank p=0.82; Figure 1). There were significantly more blanking period arrhythmias in groups 1 and 2 than group 3 after post hoc Bonferroni correction (pairwise p=0.001, 0.002 respectively; Table 1). After exclusion of patients on amiodarone at time of DCCV, there remained no significant between-group difference in the time to primary outcome (log rank p=0.85). Conclusion Shorter duration of SR post-DCCV is associated with blanking period arrhythmia after CA, but crucially does not predict long-term AF recurrence. Early AF recurrence after DCCV should not influence decisions on CA suitability or be used to predict long-term CA success.