Left atrial appendage exclusion during mitral valve surgery and stroke in atrial fibrillation

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.