About 15 percent of stroke patients are eligible for endovascular therapy, which involves using a catheter to remove clots in the brain, according to Bijoy K. Menon M.D., lead author of the most recent and largest of four studies that looked at results from endovascular therapy.
The therapy is reserved for the more-severe strokes with larger clots. In some cases, the patients didn’t respond to clot-busting treatment with intravenous tissue plasminogen activator. In other cases, they’re not tPA candidates.
“The clot-busting drug would only be able to dissolve larger clots in, maybe, 20 to 30 percent of cases. So, a significant proportion of these patients would not benefit and would die,” Dr. Menon said. “With this therapy, we take a catheter up to the brain; then use a device called a stent retriever to pull out the clot. We are able to open up arteries quicker and better. Therefore, these patients, who would have either died or would have been left with severe disability, are now doing very well.”
Researchers said that the one in every three or four treated patients will benefit.
“An effect of this magnitude is huge in any field,” said Dr. Menon, assistant professor in neurosciences and radiology at University of Calgary in Calgary, Canada.
Endovascular therapy hasn’t always been so successful. Previous studies showed a lack of benefit in important areas, such as quality of life. Dr. Menon said results from the therapy changed markedly for the better around 2010, when new clot-retrieving devices became available.
While the study doesn’t confirm the newer devices changed results, it suggests the association.
Researchers analyzed health information from 1,087 hospitals in the American Heart Association/American Stroke Association Get With The Guidelines stroke registry.
They studied documentation on about 1.5 million stroke patients from 2003 to June 2013.
Dr. Menon, who presented his findings in mid-February at the American Stroke Association’s International Stroke Conference 2015, said that from 2010 onward, the researchers tracked a notable trend toward important improvements in the therapy’s results.
The rate of in-hospital death among stroke patients receiving endovascular therapy was 29.6 percent in 2004; in 2013, it was 16.2 percent. Bleeding in the brain, which is a known complication of the therapy, diminished from 11 percent in 2010 to 5 percent in 2013.
Patients who could independently walk out of the hospital after treatment rose from 24.5 percent in 2010 to 33 percent in 2013, and those discharged home increased from 17.7 percent in 2010 to 26.1 percent in 2013.
That’s the good news.
The researchers also found only an average 2.6 percent of all stroke patients received endovascular therapy.
“Obviously, not all these patients were eligible for the therapy. But even if you consider the number of patients that were eligible, only a small proportion of those received the therapy. And that’s a concern,” Dr. Menon said.
Of the hospitals studied, two in five provided endovascular therapy in the last decade, but many of those had low volumes of less than one case a year. Only 9.4 percent of the hospitals that provide the therapy reported one or more endovascular therapy cases in each of the years studied.
The researchers also found disparities in treatment rates. There were regional and ethnic disparities. Older patients were less likely to receive endovascular therapy than younger stroke patients.
That was despite clinical trials that suggest older patients might actually benefit from it more, Dr. Menon said.
Researchers found a notable disparity based on when stroke patients were treated. Those who arrived during the day were more likely to receive endovascular therapy than patients who were hospitalized at night.
Researchers also found that hospitals treating 50 or more patients a year with endovascular therapy had better results than lower-volume hospitals.
“It makes sense because the endovascular procedure is a procedure that needs expertise,” Dr. Menon said.
The implications from this and the three prior clinical trials suggest the need to have systems in place to provide all stroke patients with access to the therapy when needed.
Ideally, this would include having more primary care stroke centers, where staff would be able to quickly detect when patients would benefit from endovascular therapy, and a network of accessible, high volume centers where patients could be transported for quality care, according to Dr. Menon.
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