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Within a few hours of a stroke, adding endovascular therapy to clot-busting drugs improves people’s ability to manage on their own at 3 months

Sardar P, Chatterjee S, Giri J, et al. Endovascular therapy for acute ischaemic stroke: a systematic review and meta-analysis of randomized trials. Eur Heart J. 2015;36:2373-80.

Review question

In people having an ischemic stroke, does adding endovascular therapy (a tube to remove the clot) to clot-busting drugs improve outcomes?


Stroke occurs when an artery supplying blood to part of the brain becomes blocked (“ischemic stroke”). People with strokes may have short-term or longer-term problems with such things as moving, talking, swallowing, or thinking. These problems are less likely or less severe if a stroke is treated quickly with a “clot-buster” (tissue plasminogen activator [tPA]), a drug that is injected to dissolve the clot. However, this treatment must be given within the first few hours after the onset of the stroke.

Some people may not be able to use clot-busting drugs (e.g., people with a high risk of bleeding).

Now there is a new treatment to be used in addition to a clot-buster: Endovascular therapy uses a catheter (a thin tube), threaded through an artery to the brain to get directly to clots and break them up or remove them using clot-busting drugs or small mechanical devices, such as a “stent retrievers.” At present, this procedure can only be done if the blocked artery is a larger one in the front part of the head. This treatment also needs to be done within the first few hours of stroke onset.

How the review was done

The reviewers did a systematic review, searching for studies that were published in English up to May 2015. They found 8 randomized controlled trials with 2,423 people (53% were men and more than 50% were 62 years of age or older).

The key features of the trials were:

  • people had ischemic strokes with blockages in large arteries in the brain;
  • most people started treatment within about 4 hours after the symptoms of stroke started;
  • treatment was endovascular therapy, mostly using stent retrievers, plus intravenous (IV) clot-busting drugs in people who could use them;
  • treatment was compared with IV clot-busting drugs alone in people who could use the drugs; and
  • people were followed for an average of 3 months.

What the researchers found

Compared with IV clot-busting drugs alone, adding endovascular therapy:

  • improved people’s ability to manage on their own at 3 months; and
  • did not increase rates of death or bleeding within the brain.


In people having an ischemic stroke, adding endovascular therapy to IV clot-busting drugs within a few hours of the stroke improves their ability to manage on their own at 3 months after the stroke.

Endovascular therapy (EVT) plus clot-busting drugs vs clot-busting drugs alone in people having an ischemic stroke


Number of trials (people)

Rate of events with EVT

Rate of events with clot-busting drugs alone

Absolute effect of EVT

Independent functioning at 90 days

8 trials (2,419 people)



About 13 more people out of 100 had independent functioning at 90 days (from as few as 4 to as many as 22)


8 trials (2,419 people)



No difference in effect*

Bleeding within the brain along with symptoms

8 trials (2,423 people)



No difference in effect*

*Although the rates for the 2 groups look a little different, the differences were not statistically significant. This means that the differences could simply be due to chance rather than due to the different treatments.

Related Topics


Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.
The body's network of blood vessels. It includes the arteries, veins, and capillaries that carry blood to and from the heart.

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