Impact of pulmonary vein ostia anatomy on efficacy of cryoballoon ablation for atrial fibrillation

Abstract

Background Introduction. Cryoballoon (CB) ablation has become a widely accepted method for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Due to the fact that the size and shape of balloon is predefined, PV anatomy, including PV ostium area and ovality, may have impact on CB ablation efficacy. Material and methods The study group consisted of 32 patients (21 males, mean age 56 ±12 years) who underwent CB ablation. The PV ostium area and ovality index were measured on computed tomography scans Results In 32 patients 128 PV were identified. The right superior PV (RSPV) ostium area was the largest, and left inferior PV (LIPV) – the smallest (294±136.8 vs 197.1 ± 47.6 mm2, p<0.001). The left superior PV (LSPV) was the most oval PV (ovality index 0.26±0.35), followed by LIPV and RSPV. During the procedure, 122 (95%) out of 128 veins were isolated. During follow-up period (mean 33±8 months), 22 (69%) patients remained free from AF recurrences. Patients with AF recurrences had significantly greater ostial area in both inferior PV compared with patients without AF recurrences (LIPV: 225.6±57.6 vs 185.2±37.1 mm2, p=0.038, and RIPV: 369.2±144.4vs 231.1±57.8 mm2, p=0.001). The mean values of ovality index did not significantly differ between effectively and non-effectively treated patients. Conclusions PV ostium area may be related to the CB AF ablation efficacy. This finding together with other anatomical parameters reported in literature may suggest that pre-procedural imaging may be helpful in deciding which technique – cryoballoon or radiofrequency point-by-point technique, is more suitable for a given patient.