LAUSR

Whether matrix metalloproteinase 9 (MMP-9) concentrations in plasma predict risk of spontaneous haemorrhagic transformation (sHT) in acute ischaemic stroke is unclear. From 1 March 2003 to 27 February 2006, patients with acute ischaemic stroke admitted to West China Hospital within 24 h of onset and healthy controls were enrolled and blood samples obtained. Plasma MMP-9 concentrations were determined using enzyme-linked immunosorbent assay, and sHT was diagnosed based on brain computed tomography or magnetic resonance performed 3-14 d after stroke onset. MMP-9 concentrations were compared for sHT patients, non-sHT patients and healthy controls. The threshold concentration for predicting sHT was determined using receiver operating characteristic analysis and the association between MMP-9 concentration and sHT was tested. One hundred and sixty-eight stroke patients and 40 healthy controls were included. Spontaneous HT occurred in 17.3% (29/168) of stroke patients and median plasma MMP-9 concentration in the sHT subgroup [244.3 ng/mL; interquartile range (IQR), 190.6-431.4] was significantly higher than in the non-sHT subgroup (110.0 ng/mL; IQR, 54.4-172.2) as well as in healthy controls (63.3 ng/mL; IQR 37.9-84.9) (both P < 0.001). We identified 181.7 ng/mL as the threshold MMP-9 concentration, for which the positive predictive value was 48% and the negative predictive value was 96%. After controlling for potential confounding factors, MMP-9 concentration >181.7 ng/mL was an independent predictor of sHT (odds ratio 18.8, 95% confidence interval 6.0-58.5, P < 0.001). Plasma MMP-9 concentration >181.7 ng/mL within 24 h after stroke onset independently predicts sHT in patients with ischaemic stroke.