Prospective assessment after pediatric cardiac ablation: design and implementation of the multicenter study.

A multicenter prospective study was designed and implemented as an activity of the Pediatric Electrophysiology Society to assess the risks associated with radiofrequency ablation in children. Patients (age 0-15 years) with supraventricular tachycardia due to accessory pathways or atrioventricular nodal reentry were enrolled and studied prior to ablation and periodically by clinical evaluation, electrocardiogram (ECG), Holter monitor, and echocardiogram. In addition, a national registry was established, to which the contributing centers report all pediatric patients undergoing ablation at their center. Initial electrophysiological study tracings and all noninvasive studies undergo blinded outside review for quality control. Clinical endpoints were death, recurrence, proarrhythmia, and echocardiographic abnormality. A pilot study demonstrated excellent agreement concerning diagnoses of previously reported ablation patients between the reporting center and the blinded reviewer (kappa = 0.938 +/- 0.062). A total of 317 patients were enrolled in the ongoing study from April 1, 1999 to December 31, 2000. The success rate of ablations was 96% with a complication rate of 4.3% for electrophysiological study and 2.9% for the ablation procedure. Comparison of the registry group versus the study group shows that the groups are comparable in terms of patient characteristics, diagnoses, and the results of ablation making it less likely that the sample of prospectively enrolled patients is biased.