Analysis of brain natriuretic peptide levels following traumatic acute subdural hematoma and the risk of postoperative cerebral infarction

Traumatic acute subdural hematoma (aSDH) is associated with a high mortality rate due to postoperative cerebral infarction. Recently, brain natriuretic peptide (BNP) was considered a reliable biomarker in the acute phase of traumatic brain injuries. We therefore aimed in this study to analyze BNP levels on admission, identify the predictors of their elevation, and assess the relationship between BNP and the risk of postoperative cerebral infarction. Patients with isolated, unilateral, traumatic aSDH who were admitted to our department between July 2017 and April 2020 were enrolled in this study. On admission, cranial computer tomography (CCT) and BNP sampling were simultaneously performed. Additionally, the time between head trauma and BNP sampling (TTS) was assessed. Admission radiographic variables included hematoma volumes, midline shift, and degree of brain edema. Cerebral infarction was detected on postoperative CCT. In total, 130 patients were included in this study. Surgical treatment was performed in 82.3% (n=107) of cases. The multiple regression analysis showed that larger hematoma volumes (p=0.032) and advanced age (p=0.005) were independent predictors of elevated BNP when TTS <24 hours. The binomial logistic regression analysis identified BNP with a cutoff value of <29.4 pg/ml (TTS=3-12 hours, aOR=16.5, p=0.023) as an independent predictor of postoperative cerebral infarction. Elevated BNP levels in the first 24 hours post-trauma were related to larger hematoma volumes and advanced age. Furthermore, an increased risk of postoperative cerebral infarction was identified in patients with lower BNP levels in the posttraumatic period 3-12 hours.