Multicenter Cohort Study on Duration of Antiarrhythmic Medication for Supraventricular Tachycardia in Infants

Purpose Antiarrhythmic medication (AM) is commonly used to prevent supraventricular tachycardia (SVT) recurrence in infants. Our aim was to determine whether a shorter duration of AM is sufficient to prevent atrioventricular reentrant tachycardia (AVRT) recurrence and evaluate risk factors for recurrence of SVT after discontinued AM. Methods This multicenter cohort study included all infants diagnosed with SVT in the five university hospitals in Finland between 2005 and 2017. Those diagnosed between 2005 and 2012 received AM for 12 months (Group 1), and those diagnosed between 2013 and 2017 received AM for six months (Group 2). Results A total of 278 infants presented with AVRT (Group 1, n = 181; Group 2, n = 97), and the median AM duration was 366 days (interquartile range [IQR] 345–407) and 212 days (IQR 181–310), respectively. Propranolol was the most frequently used first-line AM (92% and 95%). Recurrence-free survival rates were over 88% until 12 months after AM prophylaxis in both groups, without any statistically significant difference between them. Independent risk factors for recurrence of SVT after discontinuation of AM were need of combination AM (HR 2.2, 95% CI 1.14–4.20), Wolff-Parkinson White (WPW) syndrome (HR 2.4, 95% CI 1.25–4.59) and age older than one month at admission (HR 2.2, 95% CI 1.12–4.48). Conclusions Shortening AM duration in infants from 12 to six months does not lead to more frequent SVT recurrence. The risk factors for recurrence of SVT were WPW syndrome, need of combination AM and age older than one months.