Comparison of cryomaze with cut-and-sew maze concomitant with mitral valve surgery: a randomized noninferiority trial

In this trial, we sought to evaluate the efficacy and safety of the addition of the Maze performed by cryoablation (CryoMaze) to the mitral valve surgeries. The trial is a randomized, single-center trial to determine whether CryoMaze was noninferior to cut-and-sew Maze procedure (CSM) in patients with persistent or longstanding persistent atrial fibrillation (AF), with a 15% margin to establish non-inferiority. The primary endpoint was freedom from AF off anti-arrhythmic drugs (AADs) at 12 months. Secondary endpoints included freedom from AF off AADs at 3 and 6 months, and a composite of serious adverse events. 200 patients were randomized to either CryoMaze (n=100) or CSM (n=100). Freedom from AF was achieved in 85 % (95% CI, 0.76–0.91) in the CryoMaze group and 88% (95% CI, 0.80–0.94) in the CSM group, showing that CryoMaze was non­inferior to CSM at 12 months (P-value for non­inferiority=0.0065). There was no significant difference in serious adverse effects(n=12 in CryoMaze; n=17 in CSM;P=0.315). Perioperative bleeding and the length of surgery, ICU stay, postoperative hospital stay; and the need for temporary pacing decreased significantly in the CryoMaze group. CryoMaze was non-inferior to CSM for efficacy and safety for patients with persistent or long-standing persistent AF undergoing mitral valve surgeries. CryoMaze significantly decreased bleeding, the length of surgery, ICU and hospital stay as well the need for temporary pacing.(Chinese Clinical Trial Register number, ChiCTR-IOR-16008112)