Neutrophil-to-albumin ratio as a novel marker predicting unfavorable outcome in aneurysmal subarachnoid hemorrhage

Compelling evidence shows that inflammation contributes to the development of aneurysmal subarachnoid hemorrhage (aSAH). Several studies have conducted in the recent past have revealed that the neutrophil-to-albumin ratio (NAR) is a new marker of inflammation. However, whether NAR can predict the prognosis of patients with aSAH has not been fully elucidated. Therefore, the aim of this study was to investigate the relationship between NAR and prognosis of aSAH.A total of 555 consecutive patients diagnosed with aSAH were retrospectively enrolled. The NAR was assessed for each patient upon admission. At the same time, the demographic and clinical parameters of patients were collected. The Glasgow Outcome Scale (GOS, a score of 1-3) at 3 months was used to evaluate disease outcomes.Patients with unfavorable outcomes at 3 months were considerably older, had high levels of intraventricular and subarachnoidal hemorrhage, exhibited severe clinical conditions at admission, developed in-hospital complications, such as pneumonia and delayed cerebral ischemia. At admission, the NAR for GOS scores 4-5 was median [IQR] 0.231 [0.177-0.288] whereas that for GOS score 1-3 was 0.349 [0.264-4.449]; p < 0.001. The analysis revealed that the NAR was independently associated with unfavorable outcomes in patients with aSAH after adjusting for potential confounding factors (risk ratio [95% CI] 3.554 [2.601-4.857] per 0.1-point increment; p < 0.001). Moreover, a NAR of 0.274 was determined to be the best cutoff threshold for distinguishing between favorable and unfavorable outcomes in ROC analyses (AUC [95% CI] 0.782 [0.740-0.823]; p < 0.001; GOS 3-5: NAR ≥ 0.274 134/247 [54.3%] vs NAR < 0.274 47/308 [15.3%]; p < 0.001).This study demonstrates that NAR may be a novel prognostic marker in patients with aSAH. Elevated NAR is an independent factor predicting unfavorable outcome in patients with aSAH.