Extracting Clot Beats Clot-Busting Drug Alone in Study of Stroke Patients
People who had removal procedure were more likely to have functional independence after 90 days
By Dennis Thompson
TUESDAY, Nov. 3, 2015 (HealthDay News) -- Extracting a stroke-causing blood clot is better than just using a clot-busting drug for preserving brain function, a new analysis concludes.
About 45 percent of patients who underwent the clot-removal procedure experienced functional independence at 90 days, compared with about 32 percent of patients treated with the clot-busting IV medication called tissue plasminogen activator (tPA), the researchers found.
The evidence also showed that clot removal is as safe as tPA, said senior study author Dr. Saleh Almenawer, a neurosurgeon at McMaster University in Hamilton, Ontario.
"We didn't find more deaths, and we didn't find this therapy to cause more brain bleeds," Almenawer said.
Stroke victims appeared to have the best chances of all if doctors used an angiogram to locate the offending blood clot, if the latest clot-removal device was used, and if patients were given tPA before clot removal, Almenawer said.
"The combination therapy is perhaps the way to go," he said. "When stroke patients arrive to the hospital, the protocol should be followed. The IV tPA should be administered, and the angiogram should be performed to locate the blockage."
The study is published in the Nov. 3 issue of the Journal of the American Medical Association.
Nearly nine out of 10 strokes are caused by a blood clot that blocks one of the arteries supplying blood to the brain, according to the American Heart Association. Standard stroke treatment relies on powerful blood-thinning medications that break up the clot and restore blood flow to the brain.
But when those drugs don't work, doctors now can turn to a new catheter-based device that will physically remove the blood clot. The tool, called an endovascular stent retrieval device, is made up of wire mesh that resembles a tiny ring of chicken wire.
Skilled surgeons run the device up through a person's arteries via a catheter, and then open it smack in the middle of a stroke-causing blood clot. They then use the mesh to drag the clot out through the artery.
To compare this device against clot-busting tPA, Almenawer's team combined data from eight trials involving more than 2,400 stroke patients, including about 1,300 who underwent clot removal and 1,110 who received standard medical care with tPA.
People who had their clots removed via a catheter enjoyed a full recovery more often than those treated with tPA alone, the researchers found.
Both procedures caused a damaging brain bleed about 5 percent of the time, and patients had about the same death rate -- 16 percent for those treated with clot removal versus 18 percent for those who received tPA, the findings showed.
The investigators found that patients treated with newer stent retrieval devices had better outcomes than those treated using earlier devices that remove clots using a hook or suction.
"We found the patients who had the stent clot removal had way better outcomes than the patients who had the first-generation device," Almenawer said.
Dr. Ralph Sacco is chair of neurology at the University of Miami Miller School of Medicine. He pointed out that patients in the study also did better when they first received tPA and, in fact, the more recent clinical trials featured patients who underwent clot removal following tPA therapy.
But for tPA to work effectively, people need to receive the drug within 4.5 hours of suffering their stroke, Sacco added.
"The public needs to know the warning signs of stroke and call 911 immediately, since time delays are still the major factor limiting the number of patients who can benefit from these devices," according to Sacco, who was not involved with the new report.
The device is more expensive to use than the IV drug, Almenawer said, but it's likely to save money in the long run by preventing long-term disability in stroke victims.
"If you look at the amount of money spent on the hospitalization, it's way, way more than the money spent on that small device," Almenawer said. "And I'm talking about the difference between people who leave the hospital normal versus people who leave the hospital in a wheelchair."
For more about stroke, visit the U.S. National Institutes of Health.
SOURCES: Saleh Almenawer, M.D., neurosurgeon, McMaster University, Hamilton, Ontario, Canada; Ralph Sacco, M.D., chair, neurology, University of Miami Miller School of Medicine; Nov. 3, 2015, Journal of the American Medical Association
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