Factors affecting rhythm after the maze procedure for atrial fibrillation

The maze procedure failed to abolish atrial fibrillation (AF) in 14% of patients with underlying organic cardiac lesions. Identification of contributing risk factors will improve results either by treatment of such factors or by avoidance of high-risk patients.

We analyzed 192 consecutive patients with AF undergoing three variations of the maze procedure performed simultaneously with correction of valvular diseases (n = 165), congenital anomalies (n = 19), isolated AF (n = 7), and ischemic disease (n = 1). Twenty-six preoperative factors and two postoperative cardiac size parameters were analyzed by multivariate analyses between patients with successfully ablated AF (n = 165) and those who remained in AF (n = 27) after the maze procedure. Among all factors, postoperative left atrial dimension was the most potent in predisposing patients to persistent AF. Duration of AF left atrial dimension, and cardiothoracic ratio were identified as preoperative risk factors, whereas modifications of the maze procedure and pathogenesis and location of underlying disease failed to have a significant prognostic impact on rhythm after surgery. Individual risk analysis using the three preoperative variables revealed that left atrial size reduction to normalize its dimension played a pivotal role in determining rhythm after the maze procedure.

Results favor earlier performance of the procedure before these risk factors develop, after which omission of the procedure or extensive left atrial plication may be appropriate. This requires further study.