Incidence and risk factors of post-operative arrhythmias and sudden cardiac death after atrioventricular septal defect (AVSD) correction: Up to 47 years of follow-up

Background: Atrioventricular septal defect (AVSD) has an incidence of 4-5.3 per 10.000 live births and is associated with Down syndrome (DS). Data on arrhythmias and sudden cardiac death (SCD) after AVSD correction is scarce. Aim: To analyse the incidence of post-operative arrhythmias and SCD after AVSD correction and explore risk factors. Methods: This is a retrospective multicenter study including patients after biventricular AVSD correction. Univariate and multivariate analyses were performed to explore risk factors. Results: A total of 415 patients were included with a mean follow-up duration of 9 years (range; <30 days-47 years). Early post-operative SVTs were documented in 33 patients (8%) and late post-operative SVTs in 15 patients (3.6%). Non-syndromic AVSD (p = 0.022, HR = 2.64; 95% CI = 1.15-6.04) and cAVSD (p = 0.005, HR = 3.7; 95% CI = 1.39-7.51) were independent risk factors for early post-operative SVTs and significant more late post-operative SVTs occurred in non-syndromic patients (p = 0.016, HR = 6.38; 95% CI = 1.42-28.71) and in pAVSD (p = 0.045, HR = 3.703; 95% CI = 1.03-13.32). Fifteen patients (3.6%) received a pacemaker. Non-syndromic AVSD (p = 0.008. HR = 15.82; 95% CI = 2.04-122.47), pAVSD (p = 0.017, HR = 6.26; 95% CI = 1.39-28.28) and re-operation (p = 0.007, HR = 4.911; 95% CI = 1.54-15.64) were independent risk factors for postoperative pacemaker implantation. Late life-threatening ventricular arrhythmias and SCD occurred in 0.5% and 1.7% respectively. Conclusion: There is good long-term survival after AVSD correction and incidence of SCD is low. Non-syndromic AVSD and cAVSD are independent risk factors for early post-operative SVTs. Non-syndromic AVSD patients have significant more early 3rd degree AVB and late post-operative SVTs. Non-syndromic patients with partial AVSD who have undergone reoperation have a significant higher risk of pacemaker implantation. (C) 2017 Elsevier B.V. All rights reserved.