Atrial arrhythmias are common complications in adults with congenital heart disease (ACHD) and are associated with a high morbidity and mortality. Intra-atrial reentrant tachycardia (IART) is the most prevalent arrhythmia in this population. This study aimed to compare outcomes according to arrhythmia management.

All hospitalisations for IART in ACHD patients were retrospectively identified from medico-administrative database from September 2006 to September 2016. Outcomes of patients with IART managed with direct-current cardioversion (DCCV) were compared with patients referred for catheter ablation (CA). Atrial arrhythmia recurrence, death, stroke and first admission for heart failure (HF) were analyzed during follow-up.

Ninety-one ACHD patients with IART (baseline median age 38 years [IQR 29-50], male 64%, 45% moderate CHD and 41% complex CHD) were included. Median follow-up was 3 years [IQR 1.6-6.7]. Twenty-six (28.6%) patients underwent DCCV and 65 (71.4%) CA. No significant difference in CHD complexity, past medical history of atrial arrhythmia and HF were observed between the 2 groups. Patients who underwent DCCV were significantly older (43 years [IQR 34–51] vs. 36 years [IQR 26–44], P=0.03), with a higher CHADS-VASC score (CHADS-VASC ≥1 in 61% in DCCV group vs. 44% in CA group, P=0.001). Atrial arrhythmia recurrence was observed in 52% after CA and 65% after DCCV (Fig. 1A, P=0.28). Most of recurrence were IART, but atrial fibrillation was recorded in 37.5% after DCCV and 25.8% after CA (P=0.4). At the end of follow-up, patients who were initially treated by CA were more frequently in sinus rhythm (84% vs. 27%, P=0.02), with a significant lower incidence of severe cardiovascular events (Fig. 1B, P<0.01).

A proactive management of IART by catheter CA is associated with better mid-term outcomes in adult patients with CHD.