Arrhythmias in congenitally corrected transposition of the great arteries: an international study.

There is a paucity of data on arrhythmia burden in patients with congenitally corrected transposition of the great arteries (ccTGAs). The present study sought to quantify the incidence of atrial arrhythmia (AA), ventricular arrhythmia (VA), and complete atrioventricular block (CAVB) in patients with ccTGA and identify associated factors. An international, multi-centre, retrospective cohort study was conducted in 29 tertiary hospitals (six countries) between 1990 and 2018. Primary analyses consisted of determining the incidence of a combined outcome consisting of AA, VA, or CAVB, along with its individual components. Factors associated with the different types of arrhythmias were assessed by uni-variable and multi-variable Cox regression analyses. A total of 1131 patients with ccTGA were followed for 9.0 (interquartile range 4.0-17.2) years. Cumulative rates of the primary endpoint at 10, 15, and 20 years were 44.5%, 51.0%, and 58.8%, respectively. AA, VA, and CAVB occurred in 2.1, 1.4, and 2.0 cases per 100 person-years, respectively. In multi-variable analyses, surgery/intervention conferred a greater than three-fold higher risk of AA [hazard ratio (HR) 3.01, 95% confidence interval (CI) 1.90-4.78, P < .001]. Furthermore, surgery/intervention was significantly associated with a greater risk of VA (HR 1.73, 95% CI 0.98-3.05, P = .003) and CAVB (HR 3.65, 95% CI 2.20-6.05, P < .001). The left bundle branch block was associated with a higher risk of VA (HR 4.03, 95% CI 1.59-10.23, P = .003) and the right bundle branch block with a higher risk of CAVB (HR 3.71, 95% CI 1.81-7.63, P < .001). The arrhythmia burden in patients with ccTGA is substantial, with a high incidence of AA, VA, and CAVB.