Preventing Secondary Strokes
Close to 8 million Americans are stroke survivors, according to the Centers for Disease Control and Prevention (CDC). And the American Stroke Association (ASA) estimates that a quarter of them will have another one.
“There’s a risk of recurrent or secondary strokes if you don’t manage the risk factors that caused the first one,” says Christopher David Anderson, MD, MSc, a neurologist and chief of the stroke division at Mass General Brigham.
Recovering from a stroke while facing the possibility of another one is worrying. But as Dr. Anderson explains, you can take steps to prevent a second stroke.
What you should know about secondary strokes
Secondary strokes happen for the same reasons a first stroke occurs. A condition, such as high blood pressure (hypertension), weakens or hardens an artery. Your arteries carry blood from your heart to your brain and the rest of your body. When something stops this blood flow, cells start to die.
Ischemic strokes — the kind that happen when a blood clot or piece of plaque stops blood flow to the brain — are the most common. Less often, an artery in the brain weakens and ruptures, causing a hemorrhagic stroke. This type of stroke causes bleeding inside the brain, or between the brain and skull.
You can also have a transient ischemic attack (TIA). More commonly called ministroke, a TIA occurs when there’s a momentary blockage of blood to the brain that resolves on its own. While the effects of a TIA aren’t as devastating, they’re a warning sign that you’re at risk of having a stroke.
Any stroke can cause irreversible brain changes that lead to mental and/or physical disability. The risk of severe disability and death increases with each recurrent stroke. “After a stroke, your brain has fewer cells to do its job and has to work harder to recover. In many cases, survivors are left with lasting disabilities,” says Dr. Anderson. “Additional strokes destroy more brain cells, further reducing this ability to recover.”
Recurrent strokes can happen at any time. A 2002 Neurology study found there’s about a 13% chance of a second stroke happening within 10 years of the first one.
Factors that increase risk of second stroke
You’re more likely to have another stroke if the first stroke was due to:
Blood vessel injury: Hardening and stiffening of larger arteries (arteriosclerosis) due to plaque buildup (atherosclerosis), or weakening and tearing of tiny arteries in the brain (arteriolosclerosis) are lasting risk factors for stroke.
Atrial fibrillation (AFib): An irregular heart rhythm (cardiac arrhythmia) can cause blood clots to form in the heart.
Carotid artery stenosis: Narrowing of the carotid arteries on the side of the neck that carry blood to the brain, due to plaque from atherosclerosis. This plaque can rupture, causing pieces to block the carotid arteries, or travel to the brain and cause a blockage.
Prevention of secondary strokes
Because of the increased risk for future strokes — and the potential for significant damage and loss of life — health care providers are more aggressive about treating conditions that pose a risk.
These treatments help prevent secondary strokes:
Daily aspirin
For many patients, a daily aspirin is among the first recommendations providers make after someone has an initial stroke. Aspirin keeps platelets from clumping together. “Platelets are helpful when you have a cut because they encourage the blood to form clots that stop bleeding,” says Dr. Anderson. “But when you’ve had a stroke, inflammation in blood vessels can cause platelets to clump together or stick to artery walls, posing a stroke risk.”
He notes that only people who’ve already had a vascular event, such as a stroke or heart attack, benefit from daily aspirin treatment. “You shouldn’t take an aspirin every day unless your provider recommends it,” he says. “It increases your risk of gastrointestinal bleeding or blood loss from an accident, so we always make sure this risk is offset by a potential benefit.”
Blood pressure medications
High blood pressure is the top controllable risk factor for stroke, according to the ASA. A healthy blood pressure reading is below 120/80 millimeters of mercury (mm Hg). You may need one or more blood pressure medications to achieve your target blood pressure.
Because blood pressure can vary throughout the day, Dr. Anderson recommends measuring your blood pressure at home twice a day at least 3 days a week until you’re confident that you’re within the goal range. After that, you should check your blood pressure at least once a month. Your provider also may recommend participating in a remote blood pressure monitoring program.
Cholesterol-lowering medications
High levels of low-density lipoprotein (LDL) cholesterol increase stroke risk. This “bad cholesterol” forms plaque deposits that make arteries narrow and stiff. The plaque can also break off and cause a blockage.
An ideal LDL level is 100 milligrams per deciliter (mg/dL) of blood or lower for people at low risk for vascular events. But if you’ve had a stroke, the target range is 70 mg/dL or lower. The goal is to stop plaque from collecting in your arteries. Statins and other cholesterol-lowering medications help bring down LDL levels.
Lifestyle changes
Medications are only one part of a stroke prevention plan. It’s also important to make healthy lifestyle changes, such as:
Achieve and maintain a healthy weight.
Stay active with aerobic exercise for healthy arteries and strength training to manage blood pressure.
Get help to quit smoking.
Manage other conditions like diabetes.
Reduce stress.
Signs of second stroke
Strokes affect everyone differently. Common signs of stroke include facial drooping, arm weakness, and speech difficulties. “A recurrent stroke may affect you differently than the first one,” says Dr. Anderson. “Symptoms vary depending on the affected artery and which area of the brain is affected.”
Always call 9-1-1 if you or someone you know shows signs of stroke.
