Ginkgol Biloba extract as an adjunctive treatment for ischemic stroke: A systematic review and meta-analysis of randomized clinical trials

OBJECTIVE: Ginkgo biloba extract (GBE) is widely used as an adjunctive treatment for ischemic stroke. This meta-analysis aimed to evaluate the effectiveness and safety of GBE specifically for long-term users at the convalescence stage of ischemic stroke. METHODS: MEDLINE, Cochrane Central Register of Controlled Trials, Embase Database, WHO Clinical Trials Registration Platform, Chinese National Knowledge Infrastructure, Wanfang Database, and Chinese Scientific Journal Database were searched from inception to 20 September 2018. Risk ratio (RR) and mean difference (MD) with a 95% confidence interval (CI) were used as effect estimates using RevMan software (5.3; Review Manager [RevMan], Nordic Cochrane Centre, Copenhagen, Denmark). A meta-analysis was performed where data were available. A trial sequential analysis was used to control random errors for recurrence rate and the GRADE (grading of recommendations, assessment, development, and evaluations) approach was used to assess the quality of the body of evidence. The meta-analysis design was registered on PROSPERO (CRD42018110211, http://www.crd.york.ac.uk/PROSPERO). RESULTS: We identified 15 randomized clinical trials involving 1829 participants. The majority of the included trials were of high risk of bias in methodological quality. For acute ischemic stroke, adding GBE to conventional therapy led to higher Barthel index scores (MD: 5.72; 95% CI: 3.11–8.33) and lower neurological function deficit scores (MD: −1.39; 95% CI: −2.15 to −0.62). For patients in their convalescence (or sequelae) stage of ischemic stroke, GBE was superior in improving dependence (MD: 7.17; 95% CI: 5.96–8.38) and neurological function deficit scores (MD: −1.15; 95% CI: −1.76 to −0.53) compared with placebo or conventional therapy, but there was no difference in vascular events (RR: 0.70; 95% CI: 0.44–1.14), recurrence rate (RR: 0.57; 95% CI: 0.26–1.25; trial sequential analysis: conclusive) and mortality (RR: 1.07; 95% CI: 0.41–2.81). CONCLUSIONS: GBE appears to improve neurological function and dependence compared with conventional therapy for ischemic stroke at different stages and appears generally safe for clinical application. The lack of improvement in recurrence rate was confirmed by trial sequential analysis. Due to the generally weak evidence, further large, rigorous trials are warranted.