Use of neutrophil‐lymphocyte ratio for risk stratification and relationship with time in therapeutic range in patients with nonvalvular atrial fibrillation: A pilot study

Background Atrial fibrillation is one of the most common abnormal heart rhythms. Neutrophil‐lymphocyte ratio (NLR) has emerged as a potential marker for the level of inflammation in cardiac disorders. Hypothesis NLR might be associated with thrombosis and bleeding risk scores and might predict cardioembolic risk in nonvalvular atrial fibrillation (NVAF) patients within the therapeutic international normalized ratio (INR). Methods We enrolled 272 patients taking warfarin for NVAF and classified them into 2 groups: Group A consisted of patients (n = 132) whose time in therapeutic range (TTR) was ≥65%, and Group B comprised patients (n = 139) whose TTR was <65%. Results NLR values were higher in group B than in group A ( P < 0.0001). Patients classified as high risk according to CHA 2 DS 2 ‐VASc score had significantly higher NLR levels ( P = 0.002) than those classified as low and intermediate risk. Furthermore, NLR levels were significantly correlated with CHA 2 DS 2 ‐VASc and HAS‐BLED scores ( P < 0.001 and P < 0.0001, respectively). NLR predicted patients within therapeutic INR range (TTR ≥65%) with sensitivity of 81% and specificity of 71% in a receiver operator characteristic curve analysis, using a cutoff value of 2.17. Area under the curve for NLR was 0.81 ( P < 0.0001). Conclusions To our knowledge, this is the first study showing correlation of NLR with both CHA 2 DS 2 ‐VASc and HAS‐BLED risk scores. NLR might represent a useful marker to identify patients with high risks of stroke and bleeding and may have predictive value in identifying patients within the therapeutic INR range.