The Clinical Impact of the Left Atrial Posterior Wall Lesion Formation by the Cryoballoon Application for Persistent Atrial Fibrillation: Feasibility and Clinical Implications.

Introduction The left atrial (LA) posterior wall (LAPW) has been targeted to improve the clinical outcomes in patients with persistent atrial fibrillation (PersAF). This study aimed to investigate the feasibility, safety, and clinical implications of cryoballoon (CB) applications on the LAPW to accomplish electrical isolation (EI) of the LAPW with CB. Methods A total of 100 patients (males, 84; mean age, 64 +/- 10 years) with PersAF were enrolled. The first 50 patients underwent only pulmonary vein isolation (PVI) (PVI-only group) and the remaining 50 patients underwent PVI and EI of the LAPW with CB (EI-LAPW group). Results One-year sinus rhythm maintenance probability was significantly higher in the EI-LAPW group than in PVI-only group (80.0% vs 55.1%, P = 0.01). The success rate of constructing an LA roof block line (LA-RB), bottom block line, and EI of the LAPW was 92%, 60%, and 58%, respectively. The nadir CB temperature (-45 degrees C +/- 4 degrees C vs -39 degrees C +/- 5 degrees C, P = 0.005) and anatomical angle of the left atrial roof (106 degrees C +/- 30 degrees C vs 144 degrees C +/- 17 degrees C, P < 0.001) significantly predicted the successful LA-RB construction. The left ventricular ejection fraction was significantly higher in unsuccessful cases than in successful cases of an EI of the LAPW (64% +/- 8% vs 58% +/- 11%, P = 0.041). Even though the EI of the LAPW was unsuccessful, CB freezing in LAPW significantly debulked the nonscar area (>= 0.1 mV) in LAPW (18.1 +/- 5.6 vs 2.2 +/- 3.1 cm(2), P < 0.001) and provided the equivalent 1-year outcome of successful cases (79.3% vs 81.0%, P = 0.90). Conclusion The combination of PVI and EI of the LAPW with CB provided better clinical outcomes than conventional PVI procedure for patients with PersAF.