Published online May 26, 2019. doi: 10.4330/wjc.v11.i5.149
Peer-review started: February 11, 2019
First decision: April 16, 2019
Revised: April 19, 2019
Accepted: May 14, 2019
Article in press: May 14, 2019
Published online: May 26, 2019
The prevalence of atrial fibrillation (AF) is on the rise in the aging population with congenital heart disease (CHD). A few case series have described the feasibility and early outcomes associated with radiofrequency catheter ablation of AF centered on electrically isolating pulmonary veins (PVs) in patients with CHD. In contrast, cryoballoon ablation has not previously been studied in this patient population despite its theoretical advantages, which include a favorable safety profile and shorter procedural time.
To assess the safety and feasibility of cryoballoon ablation for AF in an initial cohort of patients with CHD.
The study population consisted of consecutive patients with CHD who underwent cryoballoon ablation for AF at the Montreal Heart Institute between December 2012 and June 2017. Procedural complications, acute success, and 1-year freedom from recurrent AF after a single procedure with or without antiarrhythmic drugs were assessed. Procedures were performed under conscious sedation. Left atrial access was obtained via a single transseptal puncture or through an existing atrial septal defect (ASD). Cryoballoon occlusion was assessed by distal injection of 50% diluted contrast into the PV. At least one 240-s cryothermal application was performed when complete PV occlusion was obtained. Following ablation, patients were routinely followed at outpatient visits at 1, 3, 6, and 12 mo, and annually thereafter.
Ten patients with a median age of 57.9 (interquartile range 48.2-61.7 years) and 60% female, met the inclusion criteria and were followed for 2.8 (interquartile range 1.4-4.5) years. Two patients had moderately complex CHD (sinus venosus ASD with partial anomalous pulmonary venous return; aortic coarctation with a persistent left superior vena cava), with the remainder having simple defects. AF was paroxysmal in 8 (80.0%) and persistent in 2 (20.0%) patients. The PV anatomy was normal in 6 (60.0%) patients. Four had left common PV (n = 3) and/or 3 right PV (n = 2). Electrical pulmonary vein isolation (PVI) was acutely successful in all patients. One patient had transient phrenic nerve palsy that recovered during the intervention. No major complications occurred. One year after a single ablation procedure, 6 (60%) patients remained AF-free. One patient with recurrent AF had recovered PV conduction and underwent a second PVI procedure. A second patient underwent ablation of an extra-pulmonary vein trigger for AF.
Cryoballoon ablation for AF is feasible and safe in patients with simple and moderate forms of CHD, with an excellent acute success rate and modest 1-year freedom from recurrent AF.
Core tip: A few studies have described radiofrequency ablation for atrial fibrillation (AF) in patients with congenital heart disease (CHD). Herein, we report the first case series of cryoballoon ablation for the treatment of AF in patients with CHD. Ten patients with CHD, median age 57.9 years, underwent cryoballoon ablation and were followed for a median of 2.8 years. Pulmonary vein isolation was acutely successful in all patients. No major complications occurred. One year after a single procedure, 6 (60%) patients remained AF-free. In conclusion, cryoballoon ablation is feasible and appears to be safe, with an excellent acute success rate and modest 1-year freedom from recurrent AF.