Effect of left atrial activity after the maze procedure on clinical and echocardiographic outcomes

Background: Although the maze procedure reduces the risk of adverse cardiac events, the clinical importance of post-maze left atrial (LA) activity on long-term surgical outcomes is not well defined. Methods and Results: Between January 2000 and December 2009, 416 consecutive patients with sinus conversion after a modified Cox III procedure with cryoablation were enrolled and subdivided into patients with restored LA activity (group ReA; n=231) and those without LA activity (group NoA; n=185) assessed using Doppler echocardiographic examination at 3-6 months after the maze procedure. During the long-term follow-up (4.6±2.6 years), the NoA group showed more frequent major adverse events (P=0.001) including cardiac death (P=0.145), heart failure events (P=0.032), and thromboembolic stroke (P=0.048) than the ReA group. In multivariate analysis, lack of LA activity was associated with a 2.2-fold increased risk for major adverse events (95% confidence interval [CI], 1.1-6.8; P=0.029) and with a 2.4-fold increased risk for late progression of tricuspid regurgitation (95% CI, 1.0-3.5; P=0.041). Conclusions: Absence of LA activity after the maze procedure was independently associated with a significantly increased risk of major adverse events and late progression of tricuspid regurgitation.