Introduction:
Pulmonary vein isolation (PVI) with radiofrequency (RF) or cryoballoon ablation (CBA) is a common therapy for patients with drug refractory paroxysmal atrial fibrillation (AF).1 However, studies have reported the success rate of ablation to be around 70-80% after one year of follow-up.2-4 The exact etiology for certain patients not benefiting from this procedure remains unclear but likely includes pulmonary vein anatomy, underlying cardiovascular disease, valvular heart disease (VHD), older age, dilated left atrium (LA), obesity, undiagnosed sleep apnea and the procedure being performed at less experienced centers.5-11 Since CBA requires circumferential adhesion of the ablation catheter to the PV ostium, the role of PV anatomy influencing the success of CBA has always been debated.12,13Isolation of a left common pulmonary vein (LCPV) can be particularly challenging as complete circumferential occlusion with a cryoballoon catheter is often not possible given the large size or ovality of the ostia. Furthermore, studies evaluating the presence of an LCPV affecting CBA outcomes have shown variable results.5,14,15A number of single-center studies have also assessed the role of PV anatomical indices such as eccentricity index (EI), area of vein (PVA) and ovality index (OI) in relation to CBA outcomes.12,13,16However, these studies were limited by a small sample size and the inclusion of a mixed population of both paroxysmal and persistent AF patients.
To date, the influence of PV anatomical characteristics on mid-term outcomes in a select patient population of paroxysmal AF patients only has never been systematically investigated. We sought to evaluate whether the presence of an LCPV or individual PV characteristics such as PVA, OI and EI serve as predictors of success following CBA for paroxysmal AF patients.