Stent retrievers and tPA drugs both are effective at removing clots and increasing the chance for functional recovery, whether or not a patient receives one of the two fast enough to prevent permanent brain damage depends on the hospital an ambulance drives them to, according to researchers. Photo by xdbzxy/Shutterstock
WASHINGTON, April 20 (UPI) -- Patients treated with stent retrievers, or another method of clearing blood clots in the brain, have a significantly better chance of functional recovery, as long as they are taken to a hospital capable of delivering the relevant treatment, according to a recent study.
Researchers at the University of Calgary found stroke patients treated within a couple of hours using the best clot-busting methods available have a more than 90 percent chance of functional independence after recovery, but not all hospitals are trained or equipped to provide this care.
Stent retrievers, devices threaded through blood vessels to find and remove blood clots, and intravenous tissue plasminogen activator, or tPA, have been shown to be effective at busting clots and allowing better recovery if given to patients fast enough.
Although most Americans live within an hour of a stroke center capable of giving one or both of the treatments, location can still effect outcome if a patient goes to the wrong place and needs to be transferred or if tPA or a stent retriever is not used.
"Two-thirds of the patients in our study went directly to the endovascular-capable center and one-third went to a primary stroke center," Dr. Mayank Goyal, a researcher at the University of Calgary, said in a press release. "For those who went to the stroke center, there was a loss of about two hours in overall workflow, which is pretty significant. Given the substantial decrease in functional independence with increase in time to restoration of blood flow, every step in the work up and treatment of these patients should be weighed against the time spent versus the potential benefit."
For the study, published in the journal Radiology, the researchers recruited 196 patients for the study, finding those treated within 2.5 hours had a 91 percent chance of functional independence after recovery.
For patients who did not receive treatment for 3.5 hours after a stroke, the chance for functional independence dropped by 10 percent, and fell by 20 percent for each additional hour treatment was delayed. For patients who had to be referred to another hospital, the wait time averaged 4.5 hours, as compared with just 3 hours for those who went to a hospital capable of providing the two stroke treatments.
"The earlier that patients with acute ischemic stroke get to a hospital offering the appropriate treatment, the higher the likelihood is of a good outcome," Goyal said.