DALLAS, Nov. 3 – The life you save may be your own – if you can react quickly to stroke warning signs.
Two studies reported in the November issue of Stroke: Journal of the American Heart Association examined reasons for delays in administering stroke treatment that can often spell the difference between full recovery and permanent disability. They found the patients’ awareness of their symptoms – which could include headache, dizziness, confusion, loss of speech, visual impairment, numbness or paralysis – and how they decide to get to the hospital to be key factors.
"The time a patient takes deciding to seek care is the biggest portion of the time between onset of symptoms and treatment," says Emily Schroeder, MSPH, lead author of one of the two studies. "Once EMS (emergency medical service) is alerted, things can happen quickly, but people don’t call 911 unless they percieve their symptoms to be urgent."
The urgency is tied to a promising treatment with the clot-busting agent known as tPA, which is ineffective if given more than three hours after the first sign of stroke. "There’s a limited window of opportunity of three hours after the onset of stroke symptoms in which the patient’s outcome can be altered by thrombolytic [clot-busting] therapy," says Dexter L. Morris, M.D., Ph.D., vice chairman of the department of emergency medicine at the University of North Carolina School of Medicine, Chapel Hill, who took part in both studies. "This treatment appears to give a patient a 30 percent better chance of having minimal or no stroke-related disability."
The researchers led by Morris in the Genentech Stroke Presentation Survey examined pre-hospital and emergency room delays in treating stroke. They monitored 1,207 patients diagnosed with stroke or transient ischemic attack, or "mini strokes," in 48 hospital emergency rooms nationwide. The median delay time between onset of symptoms and treatment was four hours and in some patients, the elapsed time was more than eight hours.
Delays were shortened somewhat when someone other than the patient noticed their symptoms. The most signficant factor in reducing the time to treatment was calling EMS. The second study, the Second Delay in Accessing Stroke Healthcare (DASH II) Study, was reported by Schroeder and colleagues and focused on understanding how patients and witnesses react to stroke symptoms. It tracked the course of 617 patients arriving at emergency departments in three U.S. cities.
Patients who used EMS had a median pre-hospital delay time of 2.85 hours, compared to 4.03 hours for those who used private transportation.
Even the 2.85-hour median elapsed time for patients using EMS is far too slow, Schroeder says. "It can take an hour or more to complete and interpret necessary tests like a CT scan, which have to be done before thrombolytic therapy can be given."
These tests are essential because only ischemic stroke, the type caused by interrupted blood flow to the brain, can be helped by tPA. The other major type of stroke, hemorrhagic stroke, involves intracranial bleeding that would be worsened by the clot-busting agent. "This underscores the need for a multi-faceted approach to acute stroke care, involving public health agencies, EMS personnel, emergency room physicians and nurses, and neurologists," she says. "Clearly, one group working independently won’t be able to deliver thrombolytic therapy in time to help all the acute stroke patients who need it."
The findings of both new studies strongly support a consensus statement issued this summer by a national group of healthcare experts, including representatives of the American Stroke Association, recommending the establishment of acute stroke teams in hospital emergency rooms and a network of primary stroke centers across the country. The American Stroke Association is a division of the American Heart Association.
"Currently, only about 5 percent of stroke patients arrive at the hospital in time to receive tPA because most people don’t know the warning signs or don’t realize they should seek medical help immediately," says Edgar J. Kenton, III, M.D., chair of the American Stroke Association Advisory Committee. "Improving early recognition of stroke, reducing the time to treatment and controlling the risk factors for stroke are our best defenses in the war against stroke."
Operation Stroke, a community-based program of the American Stroke Association, is a grassroots initiative to raise awareness of stroke warning signs and the critical need for immediate emergency treatment.
The public must play a role in solving the problem, Schroeder emphasizes. "People at risk of stroke and their friends and family members must recognize the signs and symptoms of stroke and act quickly to call 911, because every minute counts," she says.
Other researchers participating in the DASH II study include Morris; Wayne D. Rosamond, Ph.D.; Kelly R. Evenson, Ph.D.; and Albert R. Hinn, M.D. Other participants in the Genentech study are Rosamond; Kenneth Madden, M.D., Ph.D.; Carol Schultz, M.D.; and Scott Hamilton, Ph.D.