Recurrences at long-term follow-up after flutter ablation in patients with congenital heart disease: types and predictors

Abstract

Ablation of intra-atrial reentrant tachycardia (IART), either isthmus-dependent (CTI-F) or scar-related flutter (SC-F) can be a challenging procedure in patients with congenital heart disease (CHD). Few data is published about long-term follow-up (FU) and predictors of recurrence. We describe ablation success, type and predictors of recurrences in a tertiary care hospital. Methods: Between 1999 an 2012 we performed 81 flutter ablation procedures (RF) in 58 patients (age 34,1±15,5 years, mean 1,39 procedures per patient, flutter type: 50% CTI-F, 20.7% SC-F and 29,3% CTI-F and SC-F) with surgically repaired CHD. The most frequent CHD was transposition of great arteries (TGA, 17p, 29%) with atrial switch procedure, repaired atrial septal defect (11pt.,19%) and Tetralogy of Fallot (11pt., 19%). Cardiac history (specially arrhythmia burden), imaging and RF procedure details were analysed. Results: After a FU of more than 3 years (38.09±34,4 months), 76.4% of the patients were in sinus rhythm (23 pts. with more than one procedure). The most frequent arrhythmia in the recurrences was a flutter different than the one that was ablated (44%), followed by the same kind of flutter (40%) and atrial fibrillation (AFib, 16%). Predictors of any kind of arrhythmia recurrence at the end of FU were: acute RF failure (45.5% vs. 15%, p=0.08), QRS width >120 ms (21.2 vs. 0%, p=0.05), number of arrhythmia episodes before RF (1.7±1.38 vs. 0.82±1.05 months, p=0.019) and time between the first arrhythmia and RF procedure (RF Delay) (80.41±106 vs. 25.69±42 months, p=0.009). Previous Afib (80 vs. 42.2%, p=0.04) and SC-F (76.5 vs. 36.8%, p=0.009) were specific predictors of recurrence after a single procedure but were not related with overall recurrence at the end of FU. Predictors of recurrence of the same arrhythmia after a single procedure were: previous Afib (40 vs. 15.5%, p=0.09), acute RF failure (50 vs. 13.5%, p=0.021) and RF delay (97.8±115.7 months vs. 22.5±31.6 months, p=0.005). None of the parameters related with echocardiogram neither with the RF procedure were predictors of recurrence. Conclusions: Despite the complexity and cardiac disease progression, after a flutter ablation procedure a high proportion of CHD patients maintain sinus rhythm after long-term FU. Parameters related not only with acute success but also with arrhythmia burden and with not aggressive treatment at the beginning of arrhythmia appearance were predictors of recurrence during FU. Our data suggests that an early invasive arrhythmia treatment in these patients could decrease the recurrences, but more studies are needed in this field.