Anatomical Characteristics of the Left Atrial Appendage in Patients with Atrial Fibrillation with Stroke

Background: Strokes can develop in patients with atrial fibrillation (AF) having low CHADs2 score. We aimed to clarify the characteristics of left atrial appendages (LAAs) in non-valvular AF stroke patients with low CHADs2 score. Methods and Results: A total of 333 AF patients (paroxysmal : n=222) who underwent computed tomography (CT) and ablation were examined, out of whom 29 patients(8.7%) had strokes(22 males, 60±9yo, 22 paroxysmal). The average CHADs2 score at the onset of stroke was 0.6±0.6, the size of left atrium was 3.9±0.5cm and the blood flow velocity of LAA was 51 ±22cm/sec. LAA anatomy was classified into 4 types of morphologies: “Cauliflower”, “Windsock”, “Cactus”, and “Chickenwing”, and the distribution was compared with 51 age and sex matched control. Comparing stroke group vs. control group, Cauliflower was 69% vs. 31%, Windsock was 19% vs. 31%, Chickenwing was 4% vs. 22% and Cactus was 4% vs. 31%, respectively. Regarding the position of the LAA, lower position of LAA orifice than the left superior pulmonary veins were more common in stroke patients (stroke vs. control; 12 (80%) vs. 16 (31%), respectively. Conclusion: AF patients with low CHADs2 score and strokes had well-lobulated and lower positioned LAA. The anatomy of LAAs might be helpful to identify risks for strokes.