Objectives 　To study the relationship between matrix metalloproteinase-9 (MMP-9) and hemorrhagic transformation (HT) in ischemic stroke patients and provide evidence for the further clinical studies, thrombolytic therapy selection, and application of MMP inhibitors to clinical practice to extend the windows for thrombolytic therapy.
Methods 　The studies on relationship between MMP-9 and hemorrhagic transformation in ischemic stroke were identified, in which HT was followed-up based on plasma level of MMP-9 or comparison of plasma level of MMP-9 was conducted based on HT or not, regardless of language of publication and type of design. MEDLINE (1966-Jan. 2006), EMBASE (1966-Apr. 2006), CNKI (1977-Feb.2006), and Wanfang database (1989-2005) were searched and the references lists of eligible studies were manually searched. Two reviewers independently evaluated the quality of studies and extracted data. The data were analyzed using the RevMan 4.2. and SPSS11.0 softwares.
Results 　Six trials fulfilled the inclusion criteria, including 558 patients, 130 of them developed hemorrhagic transformation. The heterogeneity between studies was statistically significant; (P lt;0.0001). We didn’t pool the data of studies of plasma MMP-9 level. Most of the studies showed that the plasma MMP-9 level in HT or in a certain type of HT was higher than that in non-HT patients. The result of subgroup analysis showed that the plasma MMP-9 level was independently associated with HT, summary OR=14.45, 95%CI (4.90, 43.65).
Conclusions 　The values of plasma MMP-9 in HT or in a certain type of HT are higher than that in non-HT. MMP-9 may independently be a risk of hemorrhagic transformation. The sample size of the included studies is small. So the conclusions need to be confirmed with further studies.

Citation： CAO Xinhui,LIU Ming,WU Bo. Relationship Between Plasma Matrix Metalloproteinase-9 and Hemorrhagic Transformation in Ischemic Stroke: A Systematic Review. Chinese Journal of Evidence-Based Medicine, 2006, 06(5): 361-369. doi: Copy