Preventing Another Stroke, Blocked or Ruptured Arteries

by Food and Drug Administration (FDA)

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Preventing Another Stroke

According to the NINDS, about 25 percent of people who recover from a first stroke will have another within five years, and the chance of death and disability increases with each stroke. The good news is that there is a lot people can do to prevent a recurrence.

Besides lowering stroke risk through lifestyle changes and medication that lowers blood pressure and cholesterol, surgery may be beneficial. In a procedure called carotid endarterectomy, surgeons open up the carotid artery in the neck and scrape out plaque. This is sometimes done for acute stroke, but the procedure has more of a role in preventing recurrent strokes, experts say.

Surgeons also may open up a clogged carotid artery with a small balloon and insert a small tube called a stent to keep the artery open. In August 2004, the FDA approved the Acculink Carotid Stent System made by Guidant Corp. of Santa Clara, Calif. The stent is intended to prevent stroke by opening a blocked artery. The Acculink is inserted during angioplasty, a procedure in which the stent is threaded up to the neck artery via a catheter inserted in the groin.

The device helps prevent stroke in people who have had a TIA or stroke and who have at least 50 percent blockage of a carotid artery. It also may be used in those who have had no previous stroke but have a carotid artery that's at least 80 percent blocked and who are not good candidates for the surgical alternative. The FDA is requiring Guidant to conduct post-approval studies to confirm the stent's performance in more patients and to assess its long-term safety and effectiveness.

There are two main types of drugs approved by the FDA to prevent a recurrent ischemic stroke. Antiplatelet drugs, such as aspirin, Plavix (clopidogrel), Ticlid (ticlopidine), and Aggrenox (aspirin and dipyridamole), prevent clotting by decreasing activity of the platelets — the blood cells that make blood clot. These drugs are used to prevent recurrent thrombotic strokes.

Anticoagulants, such as Coumadin (warfarin) and heparin, thin the blood to prevent it from clotting and also prevent existing clots from growing. These drugs are particularly useful in preventing the formation of clots in people with atrial fibrillation.

Pagnotta takes Coumadin every day. She says she bruises easily, which is a side effect of the treatment. She also has to be careful to prevent cuts and other accidents because anticoagulants increase the risk of bleeding. She must have her blood levels checked regularly to monitor her risk of clotting and bleeding.

Pagnotta says, "The scary part is that I worry every time I have a headache or feel tingling or numbness. I'm wondering is this another stroke?" But this concern has lessened over time.

She is anxiously awaiting the results of a study comparing blood thinners to having her heart condition surgically corrected. "For now," she says, "I'm happy to be alive."

Blocked or Ruptured Arteries

Ischemic strokes occur because a blood clot blocks an artery or vessel in the brain. Hemorrhagic stokes occur because a blood vessel in the brain ruptures and causes bleeding in the surrounding brain tissue. With ischemic stroke, doctors want to open the artery up and dissolve the clot. With hemorrhagic stroke, they want to clot the blood and stop the bleeding.

Hemorrhagic strokes can be caused by an aneurysm, a thin or weak spot in an artery that bulges and can burst. Other causes include a group of abnormal blood vessels called arteriovenous malformation or leakage from a vessel wall that was weakened by high blood pressure.

One drug, Nimotop (nimodipine), is approved by the Food and Drug Administration for subarachnoid hemorrhage due to aneurysm. Subarachnoid hemorrhage occurs when a blood vessel ruptures and bleeds into the space between the brain and the skull.

Hemorrhagic stroke is also sometimes treated with surgery that removes abnormal blood vessels or places a clip at the base of an aneurysm. Aneurysms are increasingly being treated by using catheters to place wire coils inside the aneurysm to abolish it.

There is no currently FDA-approved treatment for intracerebral hemorrhage, which is when a vessel leaks blood into the brain itself. Joseph Broderick, M.D., chairman of the neurology department at the University of Cincinnati, says this type of stroke kills up to 40 percent of people within about a month after the stroke occurs.

One therapy under investigation is called NovoSeven, which is made by Denmark-based Novo Nordisk. The drug is approved by the FDA for treating bleeding in people with hemophilia, a condition in which a person's blood doesn't clot normally.

In a clinical trial led by Stephan Mayer, M.D., director of the neurological intensive care unit at New York Presbyterian Hospital at Columbia University, NovoSeven has shown promise for stopping early bleeding and improving outcomes in people with intracerebral hemorrhage.

The MERCI Retriever

In August 2004, the Food and Drug Administration cleared the first device to remove blood clots in the brain in people with ischemic stroke. The MERCI Retriever — Mechanical Embolus Removal for Cerebral Ischemia — is made by Concentric Medical Inc. of Mountain View, Calif.

"The device is a catheter with a coiled tip that grasps the clot and allows it to be removed by the physician," says Miriam Provost, deputy director of the FDA's Division of General, Restorative and Neurological Devices. "It may provide an option for some patients who aren't eligible for t-PA."

The risks of the MERCI Retriever include bleeding and vessel punctures. The National Institute of Neurological Disorders and Stroke is funding a clinical trial that continues to study the device. The MERCI Retriever is intended for use by interventional radiologists, doctors who are specially trained to use imaging techniques to view the inside of the body while they guide small instruments through blood vessels to the site of the problem.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.