Prognostic factors for the effectiveness of catheter ablation of focal atrial tachycardia in school-age children: data from a single-center registry study

Aim. To identify factors associated with the effectiveness of radiofrequency catheter ablation (RFA) of focal atrial tachycardia (AT) in school-aged patients in the long-term period. Methods. The study group consisted of 57 children aged 11 to 17 years 11 months (Me 15.83, IQR 14.63-17.0), who underwent catheter ablation, including repeated, for focal AT in the Almazov National Medical Research Centre from December 2009 until April 2023. We analyzed clinical and demographic data, laboratory data, parameters of tachyarrhythmia, electrophysiological study and RFA. Structural heart diseases were present in 13 children, and idiopathic arrhythmia was present in 44 patients. The criterion for intraoperative effectiveness were the absence of arrhythmia at the end of the waiting period in the X-ray operating room, delayed - within 12 months after the procedure. Results. Intraoperative effectiveness of RFA was achieved in 51 patients (89.5%), long-term - in 32 patients (56.1%). Based on the data obtained, a prognostic model of the delayed effectiveness of RFA of focal AT in school-age children was developed (p<0.001). Predictors included in the model: percentage of arrhythmia during the day (odds ratio (OR): 0.981; 95% confidence interval (CI) 0.962-0.999; p=0.043), presyncope (OR: 0.177; 95% CI 0.035-0.903; p=0.037), number of ectopic foci (OR: 0.289; 95% CI 0.128-0.649; p=0.003), right atrium localization (OR: 0.097; 95% 0.013-0.699; p=0.021). The area under the ROC curve corresponding to the association of the absence of arrhythmia after ablation and the values of the logistic regression function was 0.843±0.54 with 95% CI: 0.738-0.938. The sensitivity was 81.3%, specificity - 76.0%. No significant association with effectiveness of RFA was found between the method of arrhythmia induction and the use of drug sedation. Conclusion. It was established that factors such as percentage of arrhythmia during the day, the presence of presyncope, the number of ectopic foci and the presence of an ectopic foci in the right atrium had an inverse relationship with the effective outcome of RFA.