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.