The NAG scale can screen for hematoma expansion in acute intracerebral hemorrhage–a multi-institutional validation

Abstract

BackgroundEarly hematoma expansion (HE) is seen in approximately 30% of patients with intracerebral hemorrhage (ICH), but detecting patients with a high HE risk is challenging. AimsThe NAG scale is a simple predictive scale for HE in acute ICH patients. Multi-institutional validation of the usefulness of this scale was the aim of this study. MethodsWe retrospectively reviewed 142 consecutive primary ICH patients admitted to our hospital between September 2016 and December 2018. The NAG scale consists of three factors: National Institutes of Health Stroke Scale (NIHSS) score ≥ 10, anticoagulant use, and glucose ≥133 mg/dl (1 point each). Patients underwent non-contrast computed tomography (CT) within 24 h of symptom onset and follow-up CT 6 h, 24 h, and 7 days after admission. We defined HE as increased hemorrhage volume > 33% or an absolute increase of >6 mL on follow-up CT. Poor prognosis was defined as a modified Rankin scale score of 4–6 at discharge. We performed logistic regression analysis and created receiver operating characteristic curves to determine the discrimination ability of the NAG score. ResultsPatients constituted 96 men and 46 women (median age: 64 years; median NIHSS: 11), and HE was observed in 38/142 patients (27%). Higher NAG sores were associated with HE (P < .001), poor prognosis (P < .001), and in-hospital death (P < .001). The C statistic was 0.72 (95% confidence interval [CI]: 0.63–0.82) for HE, 0.67 (95% CI: 0.58–0.76) for poor prognosis, and 0.85 (95% CI: 0.74–0.95) for in-hospital death. Multivariate logistic regression analysis with known risk factors showed that NAG scale score was an independent risk factor for HE (odds ratio: 2.95; 95% CI: 1.57–5.52; P = .001). ConclusionThe NAG scale showed good discrimination in our multi-institutional validation.