RESUMO
OBJECTIVES: The aim of this study was to analyze the long-term outcomes after intra-atrial re-entrant tachycardia (IART) ablation in congenital heart disease (CHD). BACKGROUND: IART increases morbidity and mortality in CHD patients. Radiofrequency catheter ablation has evolved into the first-line treatment of this complication. METHODS: This was a prospective, single-center study of all consecutive CHD patients who underwent first ablation for IART from January 2009 to December 2015 (n = 94, 39.4% female, age 36.55 ± 14.9 years, follow-up 44.45 ± 22.7 months). RESULTS: During the study period, 130 procedures were performed (n = 94, 1.21 ± 0.41 IART/patient). In the first procedure, 114 IART were ablated (short-term success 74.66%). Forty-nine percent of the patients whose IART was ablated had non-cavotricuspid isthmus (CTI)-related IART (alone or with concomitant CTI IART). After the first ablation, 54.3% maintained sinus rhythm (SR), 23.9% presented with recurrence of the ablated IART, 14.2% developed new IART, and 7.6% presented with atrial fibrillation (AF). After the second radiofrequency catheter ablation, 78.3% were in SR, 8.7% presented with AF, and 23.0% presented with IART (50% new IART). Multivariate predictors of recurrences were non-CTI IART (hazard ratio [HR]: 5.06; 95% confidence interval [CI]: 1.6 to 15.9; p = 0.006), PR interval >200 ms (HR: 4.02; 95% CI: 1.9 to 11.3; p = 0.009), AF induction (HR: 3.11; 95% CI: 1.1 to 9.1; p = 0.04). and previous AF (HR: 3.08; 95% CI: 1.1 to 9.3; p = 0.04). A risk score according multivariate model identified 3 levels of recurrence risk: 5.8%, 20%, and 58.5% (area under the receiver-operating characteristic curve 0.8 ± 0.03; p < 0.0001). CONCLUSIONS: Ablation of IART in CHD is a challenging procedure, but after ablation in experienced centers, SR can be maintained in 78.3%. Predictors of recurrences are non-CTI-related IART, long PR interval, and previous or induced AF. A risk score based on these factors can be useful for recurrence prediction.