Background:

It has been shown recently that ablation of paroxysmal and persistent atrial fibrillation (AF) using very high-power-short duration (vHPSD) ablation protocol is safe and effective. Data for vHPSD ablation protocol in adult patients with congenital heart disease (ACHD) are lacking. We searched our database for ACHD patients undergoing AF ablation using vHPSD ablation regarding periprocedural safety and outcome. 

Methods:

The data of 62 consecutive ACHD patients with mild (n=43; 69.4%), moderate (n=15; 24.2%) or complex (n= 4; 6.4%) CHD were analysed (Table 1 ). Mean age was 60,43 ± 12,7 years ( 46% male) with a Cha2ds2-VASc2 Score median of  2.  Patients were diagnosed with paroxysmal AF (n= 24; 38%) or persistent AF (n= 38; 61%). In 6 patients (9,6 %), a previous conventional pulmonary vein isolation (PVI) had been performed.

Settings used for vHPSD ablation were 70 W/5-7 s or 60 W/7-10 s using irrigated-tip catheters (Flexability SE, AbbottMedical or STSF, Biosense-Webster). Circumferential PVI was performed in all 62 patients; in 30 patients (48%) additional substrate ablation was performed. The 30-day incidence of adverse events was analyzed and patients followed-up in regular visits at our outpatient clinic using repetitive 7 days Holter ECGs every 3 months. 

Results:

No adverse events such as cardiac tamponade, pericardial effusion >10mm, transient ischemic attack/stroke, atrio-esophageal fistula, cardiac arrest or death occurred. Vascular  access complications were detected in 7/62 patients (11%), including 4 patients with a need of intervention (surgical n=2, thrombin injection n=2).

Complete PVI was performed in all patients (mean procedure time 129 ± 42min, mean fluoroscopy time 9,09 ± 5.44 min. Radiofrequency (RF) time was 127.27 ± 7,25 min (111,43 ± 27,83 min PVI only, 148,76 ± 46,07 min PVI + substrate ablation). 

After a mean follow up of 249 days, freedom of any atrial arrhythmia off antiarrhythmic drugs (AAD) after a single ablation procedure was present in 26/47 patients (55.3%).   Success rate was significantly higher in patients with paroxysmal AF (n=16/18; 88%) compared to patients with persistent AF (n=10/29; 34.5%; p< 0.001; Figure 1)

Conclusion:  In this first study using vHPSD in ACHD patients of variable complexity with  paroxysmal or persistent AF, the technique was safe and effective.  Major periprocedural complications were rare and limited to vascular access problems.  No vHPSD ablation modality-related complications occurred. vHPSD was fast in all patientes regardless of CHD complexity. Results in the paroxysmal CHD group were excellent and encouraging for persistent AF.