Study Population
From September 2016 to April 2017, 60 consecutive patients underwent two-staged hybrid ablation at Anthea Hospital, GVM Care&Research, Bari, Italy and were followed-up for 1 year to monitor recurrences. Patients were included on the basis of the following criteria: (A) symptomatic LSPAF as defined by current guidelines(9), (B) AF refractory to the maximal tolerated doses of antiarrhythmic therapy, and (C) at least 1 failed electrical or pharmacologic cardioversion attempt during the 6 months preceding the surgical evaluation. Left atrial dimension indexed to body surface area exceeding 35 mm/m2 was considered an exclusion criterion.
The study was designed as a two-arm non randomized interventional study.
All enrolled patients underwent epicardial isolation of the pulmonary veins and of the left atrial posterior wall (“box lesion”). In the interventional cohort (BB group, 30 patients), additional surgical ablations targeting the BB was performed. For comparison, BB group patients’ outcomes were compared with the conventional cohort (CONV group) comprising 30 consecutive patients who underwent the same surgical lesions without BB ablation.
All patients underwent a staged endocardial ablation within 6 weeks after the surgical procedure with the goal of verifying or ablating: (A) the surgical lines and completing the isolation if needed, (B) additional right and left atrial substrate modification and (C) other triggers of AF. Each ablation strategy was performed by the same operators in both groups. All procedures were performed by expert operators, with >10 years of experience both parts of the staged procedure, to correct for a potential learning curve effect. GVM Care&Research ethical board approved the study and all patients gave written informed consent for procedure and study enrollment.