Long-Term Follow-up after Radiofrequency Catheter Ablation of Atrial Tachycardias in Patients with Congenital Heart Disease

Objectives: Atrial tachycardias (AT) in patients with congenital heart disease (CHD) are significantly contributing to morbidity and mortality in this population. Aim of the present study was to evaluate the long-term course of CHD patients after radiofrequency catheter ablation (RFA) of AT with reference to complexity of CHD.

Methods: A retrospective single-center study was performed. All patients with CHD with primary RFA of AT at our center between January 2003 and February 2016 were enrolled and followed-up until October 2018. Patients were classified into three groups according to the complexity of the CHD: complex CHD (cCHD), moderate CHD (mCHD), and simple CHD (sCHD).

Result: Primary RFA of AT was performed in 144 subjects. Of those, cCHD was present in n = 73, mCHD in n = 53, and sCHD in n = 18 individuals. Acute success rate for primary EPS was 81% (116/144). Recurrence occurred in 55% of the patients. A total of 101 repeat ablation procedures (RAP) were performed: 64 patients underwent one RAP, 24 patients two RAP, 11 patients three RAP, and one patient five RAP. Acute success rate for RAP was 82% (83 of 101). Acute success was not associated with complexity of CHD (p = 1.0). Mean number of procedures was not different between the three groups (sCHD 1.3 ± 0.6, mCHD 1.7 ± 0.9, and cCHD 1.8 ± 1.0 procedures), but patients after Fontan’s palliation or atrial switch procedures (n = 45) had significantly more procedures than all other patients (2.0 ± 1.1 vs. 1.6 ± 0.9 procedures, p = 0.026). Complete follow-up was available in 136 of 144 patients. After a maximum of six ablation procedures 124 of 136 patients (91%) needed no further RFA after a mean follow-up of 53 ± 40 months. Ablation in the LA/PVA was significantly more common in RAP than in primary procedures 22 versus 6% (p < 0.001) and was more common patients with cCHD (33%). A new ablation site in RAP was targeted in 55/101 procedures (54%), in these cases success rates were significantly lower (73 vs. 93%, p = 0.007). Major complications occurred in 8 of 245 procedures (3.3%), five related to vascular access and three due to RF-ablation.

Conclusion: Although acute success was not associated with complexity of CHD, long-term outcome with regard to number of repeat procedures was worse in patients after Fontan palliation or atrial switch procedure. Despite a high-recurrence rate after the primary procedure, RFA of AT in patients with CHD results in an acceptable long-term success rate of >90% including up to five repeated ablations.