Treatments through the artery versus clot-dissolving drugs for the early treatment of stroke

Review question

Are there differences in the safety and effectiveness of treatments delivered into the blocked artery (percutaneous vascular interventions) and clot-dissolving drugs (intravenous thrombolysis) in the early treatment of stroke.

Background

Most strokes are caused by a blockage of an artery in the brain by a blood clot. Prompt treatment with clot-dissolving drugs (thrombolysis) can restore blood flow and prevent brain damage. The development of treatments delivered through a tube into the artery (percutaneous vascular interventions) has led to new possibilities in the treatment of stroke. This approach gives direct access to the blood clot, which can be mechanically removed or dissolved. Despite widespread use of these treatments it is unclear whether they are more effective and safe than clot-dissolving drugs given by injection (intravenous thrombolysis).

Study characteristics

We included four trials with 450 participants randomised to either percutaneous vascular intervention or clot-dissolving drugs given by injection.

Search date

The evidence is current as of September 2017.

Key results

Compared with clot-dissolving drugs, percutaneous vascular interventions did not increase the chance of making a good recovery by the end of the trial. There was no significant increase in the risk of dying or of suffering a brain bleed. New, larger trials are needed, particularly because of the rapid development of new techniques and devices for percutaneous vascular interventions.

Quality of the evidence

We judged the quality of the evidence to be low because of the limited amount of trial information available.

Authors' conclusions: 

The present review directly compared intravenous thrombolytic treatment with percutaneous vascular interventions for ischaemic stroke. We found no evidence from RCTs that percutaneous vascular interventions are superior to intravenous thrombolytic treatment with respect to functional outcome. Quality of evidence was low (outcome assessment was blinded, but not the treating physician or participants). New trials with adequate sample sizes are warranted because of the rapid development of new techniques and devices for such interventions.

Read the full abstract...
Background: 

Most ischaemic strokes are caused by blockage of a cerebral artery by a thrombus. Intravenous administration of recombinant tissue plasminogen activator given within 4.5 hours is now standard treatment for this condition. Percutaneous vascular interventions use an intra-arterial, mechanical approach for thrombus disruption or removal (thrombectomy). Recent randomised trials indicate that percutaneous vascular interventions are superior to usual care (usual care usually included intravenous thrombolysis). However, intravenous thrombolysis was usually given in both arms of the trial and there was a lack of direct comparison of percutaneous vascular interventions with intravenous thrombolysis.

Objectives: 

To assess the effectiveness and safety of percutaneous vascular interventions compared with intravenous thrombolytic treatment for acute ischaemic stroke.

Search strategy: 

We searched the Cochrane Stroke Group Trials Register (last search: August 2018). In addition, in September 2017, we searched the following electronic databases: CENTRAL, MEDLINE, Embase, and Science Citation Index; and Stroke Trials Registry, and US National Institutes of Health Ongoing Trials Register, ClinicalTrials.gov.

Selection criteria: 

Randomised controlled trials (RCTs) that directly compared a percutaneous vascular intervention with intravenous thrombolytic treatment in people with acute ischaemic stroke.

Data collection and analysis: 

Two review authors applied the inclusion criteria, extracted data, and assessed risk of bias. We obtained both published and unpublished data. We assessed the quality of the evidence using the GRADE approach.

Main results: 

We included four trials with 450 participants. Data on functional outcome and death at end of follow-up were available for 443 participants from three trials. Compared with intravenous thrombolytic therapy, percutaneous vascular intervention did not improve the proportion of participants with good functional outcome (modified Rankin Scale score 0 to 2, risk ratio (RR) 1.01, 95% confidence interval (CI) 0.82 to 1.25, P = 0.92). The quality of evidence was low (outcome assessment was blinded, but not the treating physician or participants). At the end of follow-up, there was a non-significant increase in the proportion of participants who died in the percutaneous vascular intervention group (RR 1.34, 95% CI 0.84 to 2.14, P = 0.21). The quality of evidence was low (wide confidence interval). There was no difference in the proportion of participants with symptomatic intracranial haemorrhages between the intervention and control groups (RR 0.99, 95% CI 0.50 to 1.95, P = 0.97). The quality of evidence was low (wide confidence interval). Data on vascular status (recanalisation rate) were only available for seven participants from one trial; we considered this inadequate for statistical analyses.

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