aTrial arrhythmias in inhEriTed aRrhythmIa Syndromes: results from the TETRIS study
Authors: Conte Giulio , Bergonti Marco , Probst Vincent , Morita Hiroshi , Tfelt-Hansen Jacob , Behr Elijah R , Kengo Kusano , Arbelo Elena , Crotti Lia , Sarquella-Brugada Georgia , Wilde Arthur A M , Calò Leonardo , Sarkozy Andrea , de Asmundis Carlo , Mellor Greg , Migliore Federico , Letsas Kostantinos , Vicentini Alessandro , Levinstein Moises , Berne Paola , Chen Shih-Ann , Veltmann Christian , Biernacka Elżbieta Katarzyna , Carvalho Paula , Kabawata Mihoko , Sojema Kyoko , Gonzalez Maria Cecilia , Tse Gary , Thollet Aurélie , Svane Jesper , Caputo Maria Luce , Scrocco Chiara , Kamakura Tsukasa , Pardo Livia Franchetti , Lee Sharen , Juárez Christian Krijger , Martino Annamaria , Lo Li-Wei , Monaco Cinzia , Reyes-Quintero Álvaro E , Martini Nicolò , Oezkartal Tardu , Klersy Catherine , Brugada Josep , Schwartz Peter J , Brugada Pedro , Belhassen Bernard , Auricchio Angelo 
Published: November 2024

Abstract

Aims
Little is known about the distribution and clinical course of patients with inherited arrhythmia syndrome (IAS) and concomitant atrial arrhythmias (AAs). The aim of the study is (i) to characterize the distribution of AAs in patients with IAS and (ii) evaluate the long-term clinical course of these patients.

Methods and results
An international multicentre study was performed and involved 28 centres in 16 countries. Inclusion criteria were (i) IAS and (ii) electrocardiographic documentation of AAs. The primary endpoint was a composite of sudden cardiac death, sustained ventricular arrhythmias (VAs), or appropriate implantable cardioverter defibrillator (ICD) interventions. Strokes, inappropriate ICD shocks due to AAs, and the occurrence of sinus node dysfunction were assessed. A total of 522 patients with IAS and AAs were included. Most patients were diagnosed with Brugada syndrome (n = 355, 68%) and long QT syndrome (n = 93, 18%). The remaining patients (n = 71, 14%) presented with short QT syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, progressive cardiac conduction diseases, or idiopathic ventricular fibrillation. Atrial fibrillation was the most prevalent AA (82%), followed by atrial flutter (9%) and atrial tachycardia (9%). Atrial arrhythmia was the first clinical manifestation of IAS in 52% of patients. More than one type of AA was documented in 23% of patients. Nine patients (3%) experienced VA before the diagnosis of IAS due the use of anti-arrhythmic medications taken for the AA. The incidence of the primary endpoint was 1.4% per year, with a two-fold increase in patients who experienced their first AA before the age of 20 (odds ratio 2.2, P = 0.043). This was consistent across the different forms of IAS. Inappropriate ICD shock due to AAs was reported in 2.8% of patients, strokes in 4.4%, and sinus node dysfunction in 9.6%.

Conclusion
Among patients with IAS and AAs, AA is the first clinical manifestation in about half of the cases, with more than one form of AAs present in one-fourth of the patients. The occurrence of AA earlier in life may be associated with a higher risk of VAs. The occurrence of stroke and sinus node dysfunction is not infrequently in this cohort.