Supplementary Material for: Volumetric Infarct Size Predicts Secondary Hemorrhagic Transformation of Ischemic Stroke

Abstract
Background: The aim was to identify the clinical, laboratory, and radiological predictors of spontaneous secondary haemorrhagic transformation in acute ischemic stroke and after systemic thrombolytic therapy with rt-PA.
Methods: A total of 909 acutely treated (rt-PA, n=161) and non-treated (No-rt-PA, n=748) patients with ischemic stroke in MRI were investigated regarding the occurrence of haemorrhagic infarction (HI) and parenchymal haemorrhage (PH) within the first 5 days after stroke onset. Clinical, laboratory and radiological data were analysed using a one-way analysis of variance (ANOVA) and univariate and multiple regression analyses.
Results: In the rt-PA group the patients were clinically more severely affected, the infarct lesions were significantly larger, and HI and PH occurred more frequently than in the No-rt-PA group. In the No-rt-PA group the clinical condition of patients with HI and PH was not different. Multiple regression analyses revealed atrial fibrillation, diabetes mellitus, and infarct volume as predictors of HI and of PH.
Conclusions: The results support the association between greater infarct size and an increased risk of secondary haemorrhagic transformation both after systemic thrombolysis with rt-PA as well as in non-treated stroke patients. We hypothesize that risk factor reduction may be beneficial not only for the prevention of ischemic stroke but also for the prevention of secondary haemorrhagic transformation. Pragmatically, the radiological assessment of infarct volume appears as a relevant prognostic factor.