Impact of diagnosis to ablation time on clinical outcomes in patients with atrial fibrillation: post hoc analysis of the CABANA trial

Abstract Background Current evidence is limited concerning the temporal impact of atrial fibrillation (AF) ablation timings on post-ablation outcomes. Methods Patients who experienced ablation in the CABANA trial were enrolled in our analysis. Diagnosis to ablation time (DAT) was calculated from the date when the initial AF episode was documented. The primary endpoint was a composite of death, disabling stroke, serious bleeding or cardiac arrest. Secondary end points included AF recurrence, all-cause mortality, and all-cause mortality or cardiovascular hospitalisation. Associations between DAT and post-ablation outcomes were evaluated by restricted cubic spline (RCS) curves based on Cox models. Results Out of 1145 patients (median age 67.0 years, interquartile range (IQR) 61.0–72.0; 36.7% female) included, 538 (47.0%) underwent early ablation (DAT ≤ 1 year), including 242 (45.0%) who received very early ablation (DAT ≤ 90 days). The overall median DAT was 423 days (IQR 118–1473). The L-shaped association was observed between DAT and the primary outcome (P for non-linear = 0.034). The lowest point was located at a DAT of approximately 1 to 3 years. For AF recurrences, the RCS curve rose progressively with increasing DAT (P for non-linear = 0.062), showing a reduced risk when DAT was less than 1 year. Effects of early ablation on the primary outcome favoured patients with initial AAD use (HR 0.86, 95% confidence interval (CI) 0.43–1.73 vs. HR 2.20, 95% CI p-interaction = 0.045). Conclusions The benefits of earlier ablation in reducing AF recurrence might not equate to improvements in post-ablation cardiovascular prognosis. Timely treatment combining AADs and ablation may provide additional cardiovascular benefits. Trial registration ClinicalTrials.gov Identifier: NCT00911508.