Blog | Monday, February 16, 2015

Retrievable stents offer improved outcomes for stroke patients


There are few illnesses as disabling as a stroke. A stroke is the cessation of blood flow to part of the brain. It can cause sudden difficulty speaking, difficulty moving a limb, facial drooping, or the loss of vision in a fragment of the field of view. In many stroke patients the loss of function never improves and the patients remain permanently disabled.

Before the 1980s there was no effective treatment for this devastating illness. Stroke patients were simply observed and given physical therapy. Some improved, and many didn't. In the 1980s a blood clot dissolving medication called tissue plasminogen activator (tPA) began to be used for stroke patients with encouraging results.

tPA is given intravenously and has to be given within 4 hours of symptom onset. In patients with small clots who present to the emergency department in time, it can make a dramatic improvement in outcome. In the 1990s a large study proved that treating stroke patients with tPA is better than not. The main limitation of tPA was the narrow time window and its lack of effectiveness against large clots in large arteries.

By the late 1990s many large stroke centers were trying to improve on tPA. At UCLA, where I trained, stroke patients were treated by inserting a catheter in the clotted artery and delivering clot-dissolving medications directly to the clot. That became the standard of care at many centers, though there were never large studies to show that this was better than intravenous tPA.

More recently, various devices have been designed to remove blood clots from brain arteries. But again, there has never been evidence that these are more effective than intravenous tPA, until now.

A study performed in the Netherlands and published online this week in the New England Journal of Medicine (NEJM) attempted to determine the best treatment for stroke patients who have large clots in large arteries. These are the patients at greatest risk of serious permanent disability. The study randomized about 500 such patients into 2 groups. Patients in 1 group received usual care, which for the vast majority meant intravenous tPA. Patients in the second group received intravenous tPA and an attempt to remove the clot from the artery. In most of the patients this was done with a retrievable stent, a wire cage that is pushed through an artery, envelops the blood clot, and allows the stent and clot to be pulled out of the artery. This treatment can be performed as late as 6 hours after the onset of symptoms.

Ninety days later 33% of the patients in the group randomized to clot retrieval were functionally independent, compared to 19% of the patients in the group that only received tPA. That means for every 7 patients that receives clot retrieval in addition to tPA one additional person is functionally independent 3 months later.

Note that even though the patients in the clot retrieval group did better, even in that group two-thirds of the patients were not functionally independent at 90 days. That means they needed assistance for their activities of daily living. That is a sobering reminder of the poor outcomes that await most patients with large clots in large arteries.

There was no difference in mortality or severe bleeding between groups. The group receiving clot retrieval did have an increased risk of another stroke within 90 days, but this risk was numerically smaller than the improved functional independence. This NEJM Quick Take Video summarizes the findings of the study.

So stroke is more treatable now than ever. But the time from the onset of symptoms to the initiation of therapy is still critical for a good outcome. So if you ever suddenly develop difficulty speaking, or can't move a limb, or lose vision in a fragment of your field of view, call 911. Getting to an emergency room promptly can make the difference between getting 1970s care for your stroke and getting 2014 care.
Learn more:
For First Time, Treatment Helps Patients With Worst Kind of Stroke, Study Says (New York Times)
Stents Boost Stroke Recovery, Study Finds (Wall Street Journal)
Clot-grabbing devices offer better outcomes for stroke patients, study finds (Washington Post)
Video: MR CLEAN (NEJM Quick Take)
A Randomized Trial of Intraarterial Treatment for Acute Ischemic Stroke(NEJM, subscription required)
Interventional Thrombectomy for Major Stroke—A Step in the Right Direction (NEJM editorial, subscription required)
The Stroke – Billy Squire (YouTube)

Albert Fuchs, MD, FACP, graduated from the University of California, Los Angeles School of Medicine, where he also did his internal medicine training. Certified by the American Board of Internal Medicine, Dr. Fuchs spent three years as a full-time faculty member at UCLA School of Medicine before opening his private practice in Beverly Hills in 2000. Holding privileges at Cedars-Sinai Medical Center, he is also an assistant clinical professor at UCLA's Department of Medicine. This post originally appeared at his blog.