Decreased platelet-to-lymphocyte ratio as predictor of thrombogenesis in nonvalvular atrial fibrillation

Background. Inflammation plays a key role in the progression of atrial fibrillation and its related prothrombotic state. The platelet-to-lymphocyte ratio (PLR) is an easily obtainable biomarker of inflammatory burden. Decreased left atrial appendage flow velocity (LAA-FV) reflects blood stasis, and left atrial strain is a manifestation of atrial remodeling. This study examined the role of PLR in reflecting decreased LAA-FV and its correlation with impaired left atrial strain. Methods. In 54 patients with nonvalvular atrial fibrillation, LAA-FV and left atrial strain were measured by echocardiography. The PLR was calculated from a complete blood count. Results. The PLR was lower in the group of patients with decreased LAA-FV (84.22 [IQR, 69.87-98.17 cm/s] vs. 103.27 [IQR, 90.37-127.16 cm/s]; p= 0.018). PLR was predictive of decreased LAA-FV with a sensitivity of 66.7% and a specificity of 83.3%. In a receiver operator characteristic curve analysis, using a cut-off value of 88.16, the area under the curve for PLR as a predictor of decreased LAA-FV was 0.726 (p= 0.018). Furthermore, the patients with a PLR of< 88.16 had a lower left atrial strain than those with a PLR of> 88.16 (0.38 vs. 0.77, p= 0.02). Conclusion. The PLR was lower in patients with nonvalvular atrial fibrillation a nd with a decreased LAA-FV. Its correlation with left atrial strain might indicate the role of inflammation in the progression of atrial remodeling and in the prothrombotic state.