Left atrial appendage resection versus preservation during the surgical ablation of atrial fibrillation.

Background: Left atrial appendage (LAA) resection during the Maze procedure may decrease thromboembolic risks, but its preservation may improve left atrial contractile function. This study compared the clinical effects of LAA resection and preservation after the Maze procedure.

Methods: A retrospective review was made of 379 patients (mean age 53.3 ± 12.6 years, 244 females) who underwent the cryo-Maze procedure in conjunction with mitral surgery from 1999 to 2011. The LAA was resected in 187 patients (resection group) but preserved in 192 patients (preservation group). Outcomes were compared using a propensity score study design based on 20 baseline characteristics to obtain well-matched patient pairs.

Results: Propensity score matching yielded 119 pairs of patients in whom there were no significant differences in baseline profiles between the two groups. During a mean follow-up of 3.1 ± 2.8 years, there were 16 deaths, 6 cases of stroke, and 39 cases of atrial fibrillation recurrence. There were no significant differences in stroke-free survival (p = 0.88) and freedom from AF while off antiarrhythmic drugs (p = 0.46) between the two groups. On serial echocardiographic assessments, patients in the preservation group showed a higher transmitral A-wave velocity (peak atrial contraction wave velocity; p = 0.47, 0.020, and 0.001 at 3, 6, and 12 months, respectively) and lower E/A ratio (peak early filling wave [E-wave] velocity / A-wave velocity; p = 0.34, 0.065, and 0.001 at 3, 6, and 12 months, respectively) at each timepoint compared with the resection group.

Conclusions: Preservation of the LAA during the Maze procedure resulted in similar clinical and rhythm outcomes, but LA contractile function superior to that of LAA resection.