Larger Left Atrial Appendage Is an Independent Predictor of Stroke in Patients with Atrial Fibrillation

Background: Left atrial appendage (LAA) is an important source of thromboembolism in patients with atrial fibrillation (AF). This study evaluated the features of LAA associated with stroke in patients with AF. Methods: We compared the size of LAA using computed tomography (CT) between 224 AF patients with non-hemorrhagic stroke (Group 1, 71 women, age 67± 10 years) and 365 AF patients without stroke (Group 2, 77 women, age 56 ±11 years). Results: Group 1 included more female patients (31.7% vs. 21.1%, p=0.004), and was older than group 2 (p<0.001). There was no difference in the type of AF between two groups. CHADS2 score (3.2 ±0.8, vs. 0.6±0.7, p<0.001) and LA dimension (4.76±0.82 vs. 4.12±0.59 cm, p<0.001) were significantly lager in group 1 than group 2. The orifice size (3.85± 1.66 vs. 2.57±0.93 cm², p<0.001) and depth of LAA (3.18±0.67 vs. 2.67±0.57 cm, p<0.001) were significantly larger in group 1 than group 2. In multivariate analysis, age (OR 2.08 per decade increase, 95% CI 1.59-2.71, p<0.001), LA size (OR 1.89, 95% CI 1.29-2.76, p=0.001), the orifice size (OR 1.58, 95% CI 1.26-1.99, p<0.001) and the depth of LAA (OR 1.91, 95% CI 1.24-2.95, p=0.004) were independent predictors of stroke. Conclusion: In patients with non-valvular atrial fibrillation, the larger orifice size and depth of LAA were independent predictors of stroke with advanced age and LA enlargement.