Game changer: Stents for stroke patients
Stroke experts are reporting a major advance: Stents similar to the ones used to open clogged heart arteries can also be used to clear a blood clot in the brain, greatly lowering the risk a patient will end up disabled.
Patients treated with these brain stents were far more likely to be alive and able to live independently three months after their stroke, doctors reported at a recent American Stroke Association conference.
The treatment was so successful that three studies testing stents were stopped early so the devices could be offered to more patients. One study also found the death rate was cut almost in half for those given the treatment.
“This is a once-in-a-generation advance in stroke care,” said the head of one study, Dr. Jeffrey Saver, stroke chief at the University of California, Los Angeles.
An independent expert, Dr. Lee Schwamm of Massachusetts General Hospital, called it “a real turning point in the field.” For many patients, “this is the difference between returning home and not returning home,” although only certain types of patients can be offered it, he said.
Stroke care “needs to be completely changed” to make the treatment more widely available, said Dr. Walter Koroshetz, acting director of the National Institute of Neurological Disorders and Stroke.
“This has taken stroke therapy to the same place that heart attack therapy is now,” he said.
Work faster, less damage
Most of the 800,000 strokes in the U.S. each year are caused by a blood clot lodged in the brain. The usual treatment is clot-dissolving medicine called tPA. When that doesn’t work, doctors sometimes try devices pushed through blood vessels to pluck out the clot, but several studies found they didn’t help.
However, newer devices — metal mesh cages called stent retrievers — open an artery much faster and with less damage to the blood vessel. Unlike heart stents, which stay in place to prop the artery open, the brain stents flatten the clot, trap it and are removed with it.
Two brands are sold in the U.S. — Trevo, made by Stryker Corp. of Kalamazoo, Michigan, and Solitaire, made by Covidien, now part of Minneapolis-based Medtronic Inc. They won FDA approval in 2012 based on their ability to remove a clot — not because there was evidence they improved patient outcomes.
Last fall, the first solid evidence that these devices actually improved patient recovery arrived. A study in the Netherlands that tested a variety of clot removers, mostly stents, found these treatments greatly lowered the risk of disability in patients whose clots were not dissolved by tPA.
Stroke experts said at the time that more studies were needed to confirm the success. The three new studies do that. All were stopped early because independent monitors saw better results three months later in those treated with devices after tPA failed to dissolve their clots.
Two studies tested just the Solitaire stent, and the third tested a mix of devices, but mostly stents. Patients all sought help fast, had clots that were not opened by tPA, and had no evidence of irreversible brain damage on CT scans.
Highlights of the studies
— A study in the U.S. and Europe on 196 patients found 60 percent of those treated with a Solitaire stent were free of major disability versus 35 percent of those given just tPA. Covidien sponsored the trial.
— A study led by Australian researchers of 70 patients found 71 percent of those given a Solitaire stent were free of major disability versus 40 percent of those given tPA alone. The Australian National Health and Medical Research Council and others paid for the trial.
— A study led by Canadian doctors of 316 patients found 53 percent treated with a stent or other clot-removing devices were free of major disability versus 29 percent of those given just tPA. Ten percent of patients given both treatments died versus 19 percent of those given just tPA. Covidien and others paid for the study, and some study leaders have financial ties to the companies.
The Canadian and Australian studies were published in the New England Journal of Medicine.
Stent treatment is not for everyone, and it won’t help people who had a stroke some time ago. It is not known if stents would help people who were not given tPA first, or those who seek help too late to get it.
The key to surviving a stroke is getting help fast — tPA must be given within four and a half hours after symptoms start.
For more stroke information online, see http://stroke.nih.gov and www.strokeassociation.org.