Time—specifically, the three-to-six-hour period following the onset of ischemic stroke known as the “golden window”—has generally been accepted as the key factor in determining treatment options for acute stroke victims.
But new research presented at the American Stroke Association’s (ASA) International Stroke Conference 2016 suggests that brain imaging may be just as capable as time in identifying patients likely to benefit from stroke clot removal.
Researchers led by Jenny Tsai, MD, of the Stanford Stroke Center, analyzed data on 102 patients who underwent endovascular therapy as much as 18 hours after the onset of a stroke and who also had a CT perfusion imaging scan before treatment showing where brain tissue may be salvaged.
Their results showed that nearly 62 percent of patients who were treated more than six hours after a stroke began had little to no disability after recovery. Patients treated within six hours has the same level of recovery 71 percent of the time, leading researchers to conclude that CT perfusion imaging showing salvageable brain tissue was effective in treating patients regardless of time.
“Using this image-based selection, we would be able to look at any patient who comes through the door to identify the ones likely to benefit from these therapies, regardless of what the clock shows,” said Tsai. “This is important because we want to offer the best treatments to every patient who suffers stroke and who may benefit from them. One of the best ways to do this is to have an objective imaging tool to evaluate every single patient.”
While time is still of the essence, said ASA spokesperson Bruce Ovbiagele, MD, the results of the study suggest that there may be hope for ischemic some stroke patients who may not have the benefit of more timely treatment.
“You still need to get intravenous TPA in. It's clear that the sooner you get that in, the better,” said Ovbiagele. “What this is suggesting is that all may not be lost once you get beyond six hours if you're the type of patient for whom this imaging is done and you seem to be a candidate because you have some brain cells that might still be potentially revived.”