Significance of early recurrence of atrial fibrillation after catheter ablation: a nationwide Danish cohort study

BACKGROUND: Recurrence of atrial tachyarrhythmias after ablation of atrial fibrillation (AF) is common, although consensus guidelines advise against immediate re-ablation of "early recurrences" (occurring ≤ 90 days after ablation). However, recent studies show early recurrence is associated with "late recurrence" (occurring > 90 days) and question the duration of this "blanking period." We investigated incidence and timing of early recurrence in relation to late recurrence in a large nationwide cohort.

METHODS: From Danish nationwide registers, we included all patients aged 18 and older who underwent first-time ablation for AF between January 2005 and April 2017 and followed them for up to 2 years.

RESULTS: Of the total 7339 patients included (72% male; median age 62 years), 2801 (38%) experienced early recurrence. The odds of late recurrence were 2.34 times higher (95% confidence interval, 2.09-2.63; P < 0.001) given early recurrence, compared with those without early recurrence. In particular, both timing and frequency of early recurrences were associated with a significantly higher odds of late recurrence in a graded relationship: odds ratio (OR) 2.08/4.96/6.25 for early recurrences in the first/second/third month respectively (all P < 0.001); and OR 1.64/2.83/5.14 for those experiencing one/two/more than two episodes respectively (all P < 0.001); compared with those without early recurrence.

CONCLUSION: In patients undergoing first-time ablation for AF, both the frequency and later onset of early recurrence are significantly associated with higher odds of late recurrence. This suggests the arbitrary blanking period should be abandoned in favor of a case-by-case assessment when evaluating candidates for re-ablation.