Developing an algorithm to identify patients with intracerebral haemorrhage secondary to a macrovascular cause

Introduction: Determining the cause of spontaneous (non-traumatic) intracerebral haemorrhage (ICH) is critical to guide treatment and prognosis. We investigated whether small vessel disease (SVD) in addition to clinical and other radiological findings on acute neuroimaging predicts a low risk of a macrovascular cause (e.g. an arterio-venous malformation, aneurysm or dural arteriovenous fistula). Patients and methods: We identified patients with acute spontaneous ICH who underwent acute non-contrast CT, CT angiography (CTA) and intra-arterial digital subtraction angiography (IADSA) at our institution from January 2010 to April 2014. Logistic regression including CTA result, SVD, age, pre-ICH hypertension and ICH location was used to derive a prediction model, validated using bootstrapping. Results: 173 patients (46% female, median age 49) of whom 78 had a macrovascular cause on IADSA were included. Predictors of a macrovascular cause were: abnormal CTA (OR 67.4; p < 0.001); absence of SVD (OR 5.0; p = 0.019); and absence of pre-ICH hypertension (OR 3.4; p = 0.05). In our internally derived prediction model, the combination of CTA, SVD and pre-ICH hypertension predicted the likelihood of an underlying macrovascular cause (optimism-adjusted ROC area 0.919). Patients with negative CTA, SVD and pre-ICH hypertension have a low likelihood of an underlying macrovascular cause (1.8%). Discussion and conclusion: A combination of CTA, SVD and pre-ICH hypertension predict the likelihood of finding a macrovascular cause in patients with acute spontaneous ICH, allowing informed decisions regarding the likely benefit and risk of IADSA.