Impact of atrial tachycardia management on outcomes in adult patients with congenital heart disease

Background: Atrial arrhythmias are common complications in adults with congenital heart disease (ACHD) and are associated with high morbi-mortality. Atrial tachycardia (AT) including intra-atrial reentrant tachycardia and focal atrial tachycardia are the most prevalent arrhythmias in ACHD. We aimed to compare mid-term outcomes according to arrhythmia management.Methods: All hospitalizations for AT in ACHD were retrospectively identified from medico-administrative database from September 2006 to September 2016 in two centers. Outcomes of patients with AT managed with direct-current cardioversion (DCCV) were compared with patients referred for catheter ablation (CA). Atrial arrhythmia recurrence, stroke, admission for heart failure and death were analyzed during follow-up.Results: One hundred and twenty-one ACHD with AT (median age 41 [IQR 32-52] years, male 62%, 41% mod-erate CHD and 38% complex CHD) were included. Median follow-up was 3.3 years [IQR 1.4-6.2]. Thirty-seven (30.5%) patients underwent DCCV and 84 (69.5%) CA. No significant difference in age, CHD complexity, history of atrial arrhythmia, heart failure, and CHA2DS2-VASC score were observe. Patients undergoing DCCV had higher NYHA class. Atrial arrhythmia recurrence was lower in CA group (Log-rank test, p = 0.045). Most recurrences were AT, but atrial fibrillation was recorded in 35.1% after DCCV and 9.5% after CA (p = 0.001). At the end of follow-up, patients who were initially treated by CA had a significantly lower incidence of severe cardiovascular events (48.6% in DCCV group vs. 16.7% in CA group, HR: 0.46, CI 95%: 0.22-0.93, p = 0.031). Conclusions: A proactive management of AT by CA is associated with better long-term outcomes in ACHD.