The relation between atrial arrhythmias and heart failure in adult patients with congenital heart disease

Abstract Background Advances in care have significantly improved survival in patients with adult congenital heart disease (ACHD). This growing population is now confronted with new challenges due to their structural malformations, surgical scars, cyanosis and/or longstanding abnormal pressure and volume load that lead to progressive atrial fibrosis. Atrial arrhythmias (AA) and heart failure (HF) have become the leading causes of hospitalisation in patients with ACHD and pose specific challenges in management. Purpose To assess the relationship between a first AA diagnosis and development of HF in patients with ACHD and investigate the impact of HF on the treatment success of radiofrequency ablation (RFA) for AA. Methods This single-centre, retrospective study included 3995 patients with ACHD. AA was defined as: (I) Atrial fibrillation (AF); (II) Intra-atrial re-entrant tachycardia (IART); (III) Atrial flutter (AFL); or (IV) Focal atrial tachycardia (AT). HF was defined as clinical signs and/or symptoms of HF necessitating medical intervention, along with one of the following: (I) impaired ventricular function with elevated intracardiac pressures; (II) elevated N-terminal B-type natriuretic peptide; (III) peak oxygen consumption in the lowest quartile as per specific ACHD subtype; or (IV) distinctive HF manifestations in patients with a Fontan circulation. Both AA and HF were collected with corresponding dates of first presentation. Details on RFA procedures were collected and acute and long-term success rates were calculated using Kaplan-Meier analysis. Results The mean age of the ACHD cohort at last follow-up was 35.4 ± 13.2 y. As per Bethesda complexity classification, 28.0% of ACHD patients had mild defects, 59.4% moderate and 12.6% severe defects. AA was documented in 348 (8.7%) patients with mean age at first presentation of 37.3 ± 19.6 y (Figure 1). Patients with Fontan circulation (38.5%), cyanotic ACHD (21.0%), and systemic right ventricle (24.2%) were more likely to present with AA. Furthermore, patients with a Fontan circulation (18.8 ± 12.4 y) or a systemic right ventricle (29.7 ± 16.1 y) presented with AA at younger age. The overall prevalence of HF was 6.4%. A total of 130 (3.3%) patients were diagnosed with AA as well as HF. Of these, 103 (79.2%) patients were diagnosed with AA 8.2 ± 7.4 y before HF diagnosis. RFA procedures were performed in 119 patients (34.2%), of which 45 (21.0%) were performed in patients with HF. Overall, 72% of patient