Recurrent sustained atrial arrhythmias and thromboembolism in Fontan patients with total cavopulmonary connection Alexander C. Egbe a,⇑ , William R. Miranda a , Janaki Devara a , Likhita Shaik a , Momina Iftikhar a , Ahmed Goda Sakr a , Anitha John b , Ari Cedars c , Fred Rodriguez III d , Jeremy P. Moore e , Matthew Russell e , Jasmine Grewal f , Salil Ginde g , Adam M. Lubert h , Heidi M. Connolly a , for the Alliance for Adult Research in Congenital Cardiology (AARCC) investigators a Department of Cardiovascular Medicine, Mayo Clinic Rochester, MN, United States b Children’s National Hospital, Washington DC, United States c University of Texas, Southwestern Medical Center, United States d Emory University Hospital and Children’s Healthcare of Atlanta, GA, United States e Ahmanson/UCLA Adult Congenital Heart Disease Center, UCLA Medical Center, Los Angeles, CA, United States f University of British Columbia, Vancouver, United States g Children’s Hospital Wisconsin, United States h Cincinnati Children’s Hospital, OH, United States article info Article history: Received 2 January 2021 Received in revised form 25 February 2021 Accepted 27 February 2021 Keywords: Total cavopulmonary connection Fontan operation Atrial arrhythmia Thromboembolic complication abstract Background: Total cavopulmonary connection (TCPC) is associated with a lower risk of incident atrial arrhythmias as compared to atriopulmonary Fontan, but the risk of recurrent atrial arrhythmias is unknown in this population. The purpose of this study was to determine the incidence and risk factors for recurrent atrial arrhythmias and thromboembolic complications in patients with TCPC. Methods: This is a retrospective multicenter study conducted by the Alliance for Adult Research in Congenital Cardiology (AARCC), 2000–2018. The inclusion criteria were TCPC patients (age > 15 years) with prior history of atrial arrhythmia. Results: A total of 103 patients (age 26 ± 7 years; male 58 [56%]) met inclusion criteria. The mean age at initial arrhythmia diagnosis was 13 ± 5 years, and atrial arrhythmias were classified as atrial flutter/- tachycardia in 85 (83%) and atrial fibrillation in 18 (17%). The median duration of follow-up from the first episode of atrial arrhythmia was 14.9 (12.1–17.3) years, and during this period 64 (62%) patients had recurrent atrial arrhythmias (atrial flutter/tachycardia 51 [80%] and atrial fibrillation 13 [20%]) with annual incidence of 4.4%. Older age was a risk factor for arrhythmia recurrence while the use of a class III anti-arrhythmic drug was associated with a lower risk of recurrent arrhythmias. The incidence of thromboembolic complication was 0.6% per year, and the cumulative incidence was 4% and 7% at 5 and 10 years respectively from the time of first atrial arrhythmia diagnosis. There were no identifiable risk factors for thromboembolic complications in this cohort. Conclusions: Although TCPC provides superior flow dynamics and lower risk of incident atrial arrhyth- mias, there is a significant risk of recurrent arrhythmias among TCPC patients with a prior history of atrial arrhythmias. These patients may require more intensive arrhythmia surveillance as compared to other TCPC patients. Ó 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction Total cavopulmonary connection (TCPC) is now the standard of care for performing the Fontan operation, and the two modifica- tions that are currently used are the lateral tunnel Fontan connec- tion and extracardiac conduit connections [1–4]. TCPC involves diversion of caval blood flow directly to the pulmonary arteries https://doi.org/10.1016/j.ijcha.2021.100754 2352-9067/Ó 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Abbreviations: TCPC, total cavopulmonary connection; AAD, anti-arrhythmic drug therapy. ⇑ Corresponding author at: Mayo Clinic and Foundation, 200 First Street SW, Rochester, MN 55905, United States. E-mail address: egbe.alexander@mayo.edu (A.C. Egbe). IJC Heart & Vasculature 33 (2021) 100754 Contents lists available at ScienceDirect IJC Heart & Vasculature journal homepage: www.journals.elsevier.com/ijc-heart-and-vasculature