When it comes to successfully minimizing physical — and subsequent mental and emotional — damage caused by stroke, timing is of the essence. Yet, according to new research published this week in Stroke: Journal of the American Heart Association too often patients suffering a stroke or their loved ones may wait too long to call 911 for emergency help. That may be of particular concern in light of research also published this week in the Lancet finding that, clot-busting medication known as tissue plasminogen activators (t-PA, or alternatively Alteplase, Reteplase) is most effective at limiting stroke damage the earlier it is given to the patient.
Epidemiologist Chris Fussman and colleagues at the Michigan Department of Community Health surveyed nearly 5,000 adults about when they would call 911 after witnessing certain symptoms — including sudden onset of slurred speech, blurry vision or numbness on one side of the body — that are indicative of stroke. They found that just 14% of respondents would dial 911 if they witnessed these symptoms, while 37% said they wouldn’t call 911 in response to any of those symptoms. Many opted instead to “stay with them until they feel better” or “give medicine or first aid” for example.
While Alteplase does not prove beneficial for all patients and future research is necessary to understand why certain stroke victims benefit more from clot-busting drugs, the researchers conclude that given the time-sensitivity of successful use of t-PAs, stroke centers should aim to cut time from admission to drug administration to under one hour.
Fussman and colleagues say that the number of people who would delay calling 911 for help points to a need for improved education about early stroke symptoms, as well as better education about the benefits of early paramedic intervention in an ambulance as opposed to private transport. En route to the hospital, paramedics can alert doctors to the patient’s condition, meaning that they are more quickly ready to administer the necessary care.
Part of that care may include the administration of a t-PA to break up clots that could potentially cause irreparable damage. Since these medications were approved in 1996, physicians have learned more about the importance of timely delivery — with estimates suggesting that the drugs are only safe and truly effective for patients when delivered within hours of the onset of stroke symptoms. (As NPR reported in December, for this, reasons of availability and other factors, as few as 5% of stroke patients currently receive t-PAs.)
Yet the new study published in the Lancet indicates that treatment success varies even within the recommended window. Researchers from the University of Glasgow, Germany’s University of Heidelberg and Mount Sinai School of Medicine in New York found that, when patients suffering from ischemic stroke (or a stroke that starves the brain of blood and oxygen) were given the drug Alteplase within 90 minutes of first stroke symptoms, they were 2½ times more likely to have a good stroke recovery compared with those given a placebo.
The later the drug was administered, the smaller the benefit researchers saw. In patients who weren’t given Alteplase until 4½ hours after a stroke, for example, chance of an improved recovery was just 22% higher than that of patients given a placebo. And after that point, they noted no overall benefit of administering the drug, and suggested that later than 4½ hours risks may outweigh benefits.
The American Heart Association stresses the importance of calling 911 immediately at the first sign of stroke — which can include sudden numbness, confusion, slurred speech and other symptoms. Learn more about signs of stroke here.