The purpose of this study was to determine whether surgical left atrial appendage (LAA) exclusion performed during mitral valve surgery is associated with a reduction in cerebrovascular events in patients with atrial fibrillation.

We retrospectively studied patients with atrial fibrillation who underwent mitral valve surgery from 1/1/2001 through 12/31/2014. We screened 1352 patients using ICD-9 codes and included 281 patients in the study. The primary end point was a composite of strokes and transient ischemic attacks occurring within 5 years after surgery. Secondary end points were stroke, transient ischemic attack, and all-cause mortality.

The LAA exclusion group (n = 188) had a lower prevalence of female gender, hypertension, and diabetes mellitus compared with the non-LAA exclusion group (n = 93). The CHA₂DS₂VASc scores were comparable between groups (2.6 vs 2.9, P = .11), as was anticoagulant use (82.4% vs 85.0%, P = .60). Concomitant surgical ablation was performed in 73.9% of patients who underwent LAA exclusion. Nine cerebrovascular events occurred in the LAA exclusion group and 13 in the non-LAA exclusion group (HR 0.30 [0.12–0.75], P = .01). There was no difference in all-cause mortality between groups. On multivariate analysis of the primary end point of strokes or transient ischemic attacks, significant variables were LAA exclusion (HR 0.31 [0.12–0.76], P = .01) and CHA₂DS₂VASc score (HR 1.44 [1.11–1.87], P = .006). The benefit of LAA exclusion was detected only when performed together with surgical ablation (HR 0.27 [0.09–0.72], P = .01).

LAA exclusion was associated with fewer cerebrovascular events. However, this benefit was seen only with concomitant surgical ablation.