A Lifesaving Stroke Drug That Few People Get
Despite its effectiveness, hurdles often block the use of tPA, experts say
SUNDAY, Feb. 19, 2006 (HealthDay News) -- An 80-year-old stroke victim was brought recently to Massachusetts General Hospital in Boston. Unable to move or speak, she was immediately given a CT scan and then a very effective clot-busting drug approved for her condition.
Ninety minutes later, she was able to move and talk again, her neurologist, Dr. Eric Smith, recalled.
While Smith said there's no way to know if the woman might have recovered without tPA, the textbook use of the drug was just what the doctor ordered.
Unfortunately, it is the exception rather than the rule in treating stroke, according to doctors who work with stroke victims.
"The number of acute stroke victims who are given tPA is very low -- 94 to 97 percent of stroke patients do not get the drug," said Smith, associate director of acute stroke services at Massachusetts General.
Approximately 700,000 people suffer a stroke every year, and it is the leading cause of serious, long-term disability in the United States, according to the American Heart Association. Its incidence rises sharply with age, from approximately 3 percent of those aged 55 to 64, to 6 percent of those between 65 to 74, to 12 percent of those over 75.
Tissue plasminogen activator (tPA) is a very effective clot-busting drug that can result in a dramatic reversal of stroke symptoms. It's approved for use in certain patients having a heart attack or stroke, and works by dissolving blood clots, which cause most heart attacks and strokes. It was approved by the U.S. Food and Drug Administration for treating strokes almost 10 years ago, but is still not given to most stroke victims who could benefit from it.
There are several reasons for this disconnect, according to doctors who treat stroke victims.
First, tPA can only be given within three hours of the onset of stroke, because the risk of hemorrhage is too high after that time. Because many stroke victims don't seek treatment quickly enough -- often they ignore the symptoms or the stroke occurs while they're sleeping -- it's too late to get the drug when they get to the hospital.
Second, patients must have a CT scan before receiving the drug because tPA is only effective in treating ischemic strokes, which are those caused by a blood clot. While 85 percent of strokes are due to clots, the rest are caused by bleeding, and tPA cannot be used to treat them. A CT scan is needed to determine the type of stroke, Smith said.
"A lot of hospitals don't have the systems in place [to get CT scans done quickly]," he said. "Time is of the essence."
And third, some doctors, particularly those who work in an emergency room, where stroke victims are often admitted, are reluctant to give the drug because of its possible risks. It can cause potentially fatal hemorrhaging in about 5 percent of those patients who get the drug, Smith said.
"There have been concerns on the part of some practitioners that the drug is too risky," Smith said.
Their worries are echoed in the conflicting guidelines offered about tPA by various medical organizations, with the American Heart Association, the American College of Chest Physicians and the American Academy of Neurology supporting the use of tPA. But, the Society for Academic Emergency Medicine and the American College of Emergency Physicians both express strong reservations about the drug's use in most clinical settings.
Dr. Phillip A. Scott, an assistant professor of emergency medicine at the University of Michigan, said, "Emergency medical practitioners understand that the drug works in a clinical setting with doctors with stroke expertise, but are concerned about being asked to do something that hasn't been shown to be effective in a community setting. Can community physicians replicate what very dedicated researchers did in a study?"
Scott thinks doctors can deliver tPA safely and effectively, and is heading up a study among 24 randomly selected Michigan hospitals to help them streamline their systems to treat stroke victims.
"We want to prove that the program can work anywhere," Scott said.
Making doctors more comfortable in prescribing tPA when appropriate is an important goal of the study, he said.
Because one in 20 stroke patients who receive the drug could develop symptomatic bleeding in the brain, doctors are naturally hesitant to prescribe it despite the fact that statistics favor its use, he said.
But, while doctors are taught the ancient oath, "First, to do no harm," they must also learn that in an era of scientific examination of effective therapies, "sometimes to do nothing is to do harm," he said.
Scott explained that, on average, if you don't treat 100 people who suffer from stroke and who meet the criteria for receiving tPA, 21 will die within three months, 20 will be able to return home with normal functioning, and the remainder will have some impairment. But if those same 100 people are given tPA, 17 will die within three months, 31 will return to normal functioning and the remainder will suffer less impairment than those who did not receive the drug.
"There's a natural avoidance behavior, and you have to get around the emotions and the fear of malpractice, which is of considerable importance to emergency room physicians," Scott said.
To learn more about stroke and tPA, visit the American Heart Association.