Fibrinogen depleting agents for acute ischaemic stroke

Fibrinogen depleting agents reduce fibrinogen in blood plasma, reduce blood viscosity and hence increase blood flow. This may help remove the blood clot blocking the artery and re-establish blood flow to the affected area of the brain after an ischaemic stroke. The risk of haemorrhage may be less than with thrombolytic agents.

The objective of this review was to assess the effect of fibrinogen depleting agents in people with acute ischaemic stroke.

We searched the Cochrane Stroke Group trials register, Embase (to January 1996) and the Index of scientific and technical proceedings (1982 to 1996). We handsearched 10 Chinese journals and the proceedings of the 4th Chinese Stroke Conference (1995). We contacted Chinese and Japanese researchers, and drug companies.

Randomised and quasi-randomised trials of fibrinogen depleting agents started within 14 days of stroke onset, compared with control in patients with definite or possible ischaemic stroke.

Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted the data.

Three trials involving 182 patients were included. All trials tested ancrod. Allocation concealment was adequate in two trials. Fibrinolytic therapy appeared to reduce the number of deaths during the scheduled treatment period (odds ratio 0.33, 95% confidence interval 0.13 to 0.85). There was no difference in death from all causes at the end of follow-up (odds ratio 0.57, 95% confidence interval 0.27 to 1.23). The risk of haemorrhage appeared to be small, but there were too few data to be conclusive. One trial in 132 people showed a statistically non-significant decrease in the odds of being dead or disabled at the end of follow-up (odds ratio 0.52, 95% confidence interval 0.26 to 1.03).

Although ancrod appears to be promising, it is not possible to draw reliable conclusions from the available data.