In Paroxysmal Atrial Fibrillation Patients, the Neutrophil-to-Lymphocyte Ratio Is Related to Thrombogenesis and More Closely Associated with Left Atrial Appendage Contraction than with the Left Atrial Body Function

: Objective The neutrophil-to-lymphocyte ratio (NLR) is an inflammation marker that can be used to detect atrial inflammatory changes, which may contribute to a reduced left atrial (LA) function and thrombosis. Our study aimed to determine whether or not the association of NLR with the LA appendage (LAA) function in relation to thrombogenesis differs from the association with the LA body function in paroxysmal atrial fibrillation (PAF) patients. Methods A total of 183 PAF patients were studied. The LA volume index, mitral flow velocity (A), and mitral annular motion velocity (A') were examined using transthoracic echocardiography. The LAA area, LAA wall motion velocity, and presence of spontaneous echo contrast (SEC) were examined using transesophageal echocardiography. Results The NLR of patients with cerebral embolism was significantly greater than in patients without the disorder. A cut-off point of 2.5 for the NLR had a sensitivity of 71% and a specificity of 74% in predicting cerebral embolism. The patients with an NLR ≥2.5 had a higher CHADS2 score and greater LA volume index or LAA area than those with an NLR <2.5. The NLR was an independent risk factor for SEC and was significantly correlated with the LAA wall motion velocity (r=-0.409) in 153 patients without SEC and with the LAA wall motion velocity and LAA area (r=-0.583, r=0.654, respectively) in 30 patients with SEC, but not with the LA volume index, A, or A' in either group. Conclusion In PAF patients, a high NLR indicates thrombogenesis with a high degree of certainty and is associated with reduced LAA contraction rather than with the LA body function.