Platelet-to-lymphocyte ratio but not neutrophil-to-lymphocyte ratio predicts high on-treatment platelet reactivity in clopidogrel-treated patients with acute coronary syndrome

Objectives: Dual antiplatelet therapy (DAPT), consisting of clopidogrel and aspirin, is the main-stay treatment of acute coronary syndromes (ACS). However, major adverse cardiovascular events may occur even in patients undergoing DAPT, and this has been related to the variable pharmacodynamic efficacy of these drugs, especially clopidogrel. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are novel inflammatory markers for cardiovascular risk stratification, which may reflect an inflammatory state and thus high on-treatment platelet reactivity (HPR). Methods: We investigated the usefulness of PLR and NLR in predicting HPR in clopidogrel-treated patients with ACS. A total of 244 patients were enrolled in this study, and 43 of them were nonresponsive to clopidogrel. Results: Logistic regression analysis indicated that PLR was significantly associated with HPR (P < 0.001). Using a cutoff level of 331, PLR predicted HPR with a sensitivity of 73% and a specificity of 69% (odds ratio: 376.15, 95% confidence interval = 37.813-3741.728 P < 0.001, receiver operating characteristic curve: 0.885). Conclusions: We suggest that more attention should be paid to the PLR values of these patients on admission to identify individuals who may not benefit from clopidogrel during the course of ACS.