P1911The impact of pulmonary vein morphology and orientation on the outcomes of cryoballoon ablation in patients with paroxysmal atrial fibrillation

Abstract

Abstract Background Circumferential contact of cryoballoon and pulmonary vein (PV) ostium is an important factor for pulmonary vein isolation (PVI). PV ostium shape and orientation can make challenges for PV occlusion. Purpose We aimed to assess the impact of pulmonary vein morphology and orientation on cryoablation outcomes in patients with paroxysmal AF. Material and methods The single-center prospective study included 122 patients (males: 46.7% (57), mean age 57 (53; 62) with drug-refractory paroxysmal AF. The mean AF duration was 4 years (2; 4). A multislice cardiac computed tomography (MSCT) was performed prior to CBA in order to evaluate the PV anatomy (maximal and minimal ostium diameters, ovality of PV ostium, angle of PV orientation in the frontal and axial plane (Figure1)). The presence of typical anatomy (4 separate ostia of PVs) was inclusion criteria. Procedures were performed with 28-mm second generation balloon. A procedural endpoint was the achievement of PVI. Outcomes of PVI were defined as freedom from any AF episodes documented by ECG from the end of blanking period to 12 months. Results PVI was achieved in 97.5% of PVs (476/488). Freedom from AF was 78.7%. Difficult occlusion of right inferior PV was observed in 12 patients and associated with a more horizontal PV orientation in the frontal plane: −15.2±6.20 versus −26.5±6.3°, p<0.001. A total of 11 (9%) patients experienced transient phrenic nerve injury (PNI) during ablation of right superior PV (RSPV). PNI was associated with the maximum and minimum diameter of the RSPV 20.0–24.0 mm (OR=13,2; 95% CI: 3.4–51; p<0.05) and 17.5–20.0 mm (OR=12.5; 95% CI: 4.7–41.9; p<0.05), respectively. Patients with AF recurrence had significantly larger maximum and minimum diameters of left superior PV (LSPV): 18.8 versus 17.5 mm, p=0.048, and 13.4 versus 12.5 mm, p=0.05, respectively. Ovality of PV ostium was larger in the recurrence group: 0.36 versus 0.18, p=0.05. Figure 1. Evaluation of PV orientation Conclusions Evaluation of PV morphology and orientation can be used to predict CBA results. AF recurrence was associated with larger diameters and ovality of LSPV ostium. More horizontal RIPV orientation was associated with difficult PV occlusion. RSPV morphology can affect safety of procedure.