March 10 , 2008
Bolder With Strokes
By Kathy Hardy
Vol. 9 No. 5 P. 14
Christopher Zylak, MD, Advocates More Aggressive Treatment of Ischemic Strokes
Historically, the focus of acute stroke treatment concerned recovery and rehabilitation. When the brain suffered significant oxygen loss due to a blood clot, doctors evaluated the results—paralysis and speech or memory problems—and selected appropriate therapy methods. Rehabilitation often continued for the remainder of a patient’s life.
“Traditionally, stroke treatment meant no treatment happened,” says Christopher Zylak, MD, director of neurointerventional radiology at Sacred Heart Medical Center in Spokane, Wash. “The results of stroke were dealt with in rehabilitation. Steps were also taken to prevent future strokes, with procedures like carotid artery surgery to restore adequate blood flow to the brain and prescribing blood thinners to prevent clots.”
Then came what is now standard operating procedure for stroke treatment: placing an intravenous (IV) device in the patient’s arm to administer clot-dissolving drugs, a percentage of which reach the blockage site that is causing the stroke. “This is the first-line, FDA-approved treatment for stroke patients,” Zylak says. “But it needs to be performed within the first three hours of the stroke occurring.”
Time is of the essence in stroke treatment. During a brief one- to three-hour period after the onset of stroke symptoms, aggressive and appropriate treatments can spare patients from more extensive brain damage and disability. According to the American Stroke Association, for every minute that treatment is delayed during an ischemic stroke, 1.9 million brain cells are lost. If an acute stroke runs its full course—10 hours on average—that number jumps to 1.2 billion.
That’s where a relatively new stroke therapy comes in. Study data reported by Zylak at the 20th annual International Symposium on Endovascular Therapy in January suggests intra-arterial (IA) therapy that directly attacks blood clots in the brain can successfully treat stroke patients, even when standard IV stroke therapy fails. This treatment, developed during the past five to 10 years, involves delivering clot-dissolving drugs through a catheter directly into the clot in the brain.
During the procedure, the physician places a guide catheter into the femoral artery and advances it through the arterial system into the brain until it reaches the blockage. The physician then inserts smaller microcatheters through the guide catheter to deliver clot-dissolving drugs, usually tissue plasminogen activators (tPA), to break it up. The goal is restoring blood flow to brain tissue as quickly as possible to prevent or minimize any damage.
In addition to anticoagulating medication, a concentric drive can be used with the catheter to pull out or remove the clot, or a balloon or stent can be inserted to open up the artery in much the same way that patients with heart disease are treated with angioplasty.
“Often, patients who fail to improve with standard IV stroke therapy aren’t given the chance to succeed with more advanced IA therapy,” Zylak says. “That’s because it’s thought that IA therapy won’t work if IV therapy didn’t and that IA therapy will increase the risk of bleeding in the brain. After the first three hours, it’s best to begin IA therapy.”
IA therapy is most effective when provided within at least 12 hours of the stroke onset but preferably within three to six hours. With IA therapy, recovery begins while the patient is still undergoing treatment for the stroke, according to Zylak. Because the clot-busting medication reaches and removes the clot directly and completely, immediately rejuvenating the flow of oxygen to the brain, patients regain basic skills such as eating, speaking, dressing, and walking.
“IA therapy is life changing,” Zylak says. “Patients who could not speak can speak; patients who suffered paralysis can move again. Relief is nearly immediate.”
Reducing Stroke Deaths
At the symposium, Zylak reported results from a subset of patients treated at Sacred Heart from 2004 to 2007. Of those patients, 80 received IV therapy, and 43 received IA therapy. (Some of those 43 patients had received IV therapy first.) IA therapy successfully opened blocked blood vessels in 85.7% of cases in 2006 and 83.3% in 2007. Although death rates were 30.8% in 2006 and 27.8% in 2007, they were one half the death rates of 50% to 80% that historically occur with large-vessel strokes.
“With something like stroke, which has a 50% to 80% death rate in the case of a large-vessel stroke, the thought is that there’s not much that can be done” Zylak says. “But if you can reduce that number even a small amount, the death rate may be high, but you’re still reducing the chances of a poor outcome.”
According to the National Stroke Association, stroke is the third leading cause of death in the United States, killing about 160,000 people every year, and it’s also the No. 1 cause of disability in adults. Approximately 750,000 Americans suffer from stroke annually.
There are two types of stroke. Ischemic strokes are caused by a small blood clot that blocks an artery in the brain and stops blood flow. Hemorrhagic strokes occur when a blood vessel ruptures in the brain. Eighty-three percent of all strokes are ischemic and are potentially treatable with IA therapy.
Zylak explains that stroke patients at Sacred Heart first undergo brain CT to determine if the stroke is ischemic or hemorrhagic. If the patient arrives at the hospital less than three hours after the onset of an ischemic stroke, he or she will be given IV therapy. If the symptoms don’t improve within one hour, IA therapy is administered. If the patient comes to the hospital more than three hours after the stroke began, IA therapy is used immediately.
“When it’s clear that IV treatment will not work, it would be more efficient to proceed directly to IA therapy,” Zylak says. “In the study, we were able to help patients who failed IV therapy by providing IA therapy. In the future for large vessel clots, IA therapy may well be the best direct therapy, bypassing IV therapy.”
IA therapy is considered experimental at this time and only sanctioned for use after IV therapy is unsuccessful during the first three hours of treatment. However, Zylak says there are certain conditions that can occur when a stroke patient enters the hospital where it’s evident the stroke is so severe that IV treatment will not be enough and IA treatment should begin. “There’s very little aimed at stroke intervention to prevent damage,” he says. “Acute intervention is needed.”
Stroke Center Network
Only certain hospitals and stroke centers across the country offer IA therapy. The Joint Commission recognizes Sacred Heart as a primary stroke center, and the hospital is also one of 150 members of the nationwide Stroke Center Network, a National Stroke Association membership program for hospitals dedicated to advancing stroke care at their facilities.
“It’s an exciting time in our field now” Zylak says. “It’s like when the cardiac care used today was first developed.
“While not all techniques used in the course of treating a heart attack can be used in the course of treating the brain as a patient is suffering from a stroke, the theories are the same,” he adds. “You have a clot in an artery, and you need to remove it as quickly and safely as possible to enable the patient to return to as normal as possible.”
He notes that unlike the heart, the brain is full of small blood vessels that all play a major role in the functioning of the body. “You can’t just go into the brain and smash the clots without causing further damage,” he says.
Zylak would like to see equality between cardiac care and stroke in the public’s attention and awareness. Early stroke treatment, which is vital to the patient’s successful recovery, is often difficult, as stroke symptoms are not as widely known as heart attack symptoms. Many people suffering from a stroke aren’t treated because they don’t recognize the warning signs—vision and speech disturbances; sudden numbness or weakness of the face, arm, or leg; and memory problems.
“Stroke patients often don’t seek medical care soon enough,” he says. “Or as they are experiencing stroke symptoms, they are unable to communicate what’s happening to them. Immediate medical attention is key because the sooner a stroke is treated, the more likely the treatment will be successful.”
Public awareness of the benefits of IA therapy may also go a long way toward removing it from the experimental list, Zylak says. “We need to remove the term experimental from this procedure,” he says. “We need to continue with studies of IA therapy to show that IA should be performed sooner.”
Zylak plans to continue educating the medical community about the benefits of IA therapy by teaching the procedure to other physicians and speaking on the topic at medical conferences to spread the word and try to have this procedure performed uniformly nationwide.
In the meantime, he encourages patients and their families to ask for IA therapy. Through publicizing this treatment, he believes more people will be aware of its benefits and will ask for it. If a medical center doesn’t offer IA therapy, a patient can be taken to a center that performs the therapy, even if IV therapy wasn’t successful, he says.
“This is all part of the undertreatment of strokes,” Zylak says. “People need to be proactive. They need to be more aware of the symptoms of stroke and know what to ask for when it comes to their treatment. There are many patients who could benefit from stroke treatment who aren’t receiving it for various reasons. Treatment therapies today are really getting dramatic results.”
— Kathy Hardy is a freelance writer and editor based in Phoenixville, Pa.