Association between incomplete surgical ligation of left atrial appendage and stroke and systemic embolization

BACKGROUND Surgical exclusion of the left atrial appendage (LAA) can frequently yield incomplete closure. OBJECTIVE We evaluated the ischemic stroke/systemic embolization (SSE) risk in patients with atrial fibrillation (AF) and complete LAA closure (cLAA) vs incompletely surgically ligated LAA (ISLL) and LAA stump after surgical suture ligation. METHODS Seventy-two patients (CHA(2)DS(2)-VASc score 4.1 +/- 1.9) underwent surgical LAA ligation in conjunction with mitral valve/AF surgery and postoperative LAA evaluation using computerized tomographic angiography. RESULTS Overall, cLAA was detected in 46 of 72 patients (64%), ISLL in 17 patients (24%), and LAA stump in 9 patients (12%). The incidences of oral anticoagulation (OAC) and recurrent AF were similar among the 3 groups during 44 +/- 19 months of follow-up. SSE occurred in 2 % of patients with cLAA vs 24% with ISLL and 0% with LAA stump (P=.006). None of the patients with SSE were receiving OAC, and all had recurrent AF during follow-up. Additionally, patients with SSE exhibited a significantly smaller ISLL neck diameter (2.8 +/- 1.0 vs 7.1 +/- 2.1 mm; P=.002). The annualized SSE risk was 1.9% (entire cohort), 6.5% (ISLL patients), 14.4% (ISLL patients not receiving OAC), and 19.0% (ISLL neck diameter <= 5.0 mm) per 100 patient-years of follow-up. The latter risk was nearly 5 times greater than predicted by conventional risk-stratification schemes. Moreover, ISLL emerged as an independent predictor of SSE in univariate analyses and as the sole predictor of SSE in a multivariate analysis. CONCLUSION In patients with AF, ISLL is a predictor of SSE, independent of conventional risk stratification schemes. Consequently, OAC should be strongly considered in this high-risk cohort.