Inside the science of strokes
Strokes are responsible for around 140,000 deaths a year in the United States alone. For World Stroke Day, learn how Johnson & Johnson is innovating to help change that stat.
Back in 2018, Johnson & Johnson set off on a mission to revolutionize the study of blood clots. The goal was to figure out how different clot characteristics—like size, composition and density—could impact patient outcomes and how two of the company’s medical devices performed during clot removal. To do so, they enrolled 1,000 stroke patients at 36 clinical trial sites across the world to study actual blood clots that had been removed from stroke patients.
The Excellent Registry, as it is called, is the largest acute ischemic stroke registry in the world that collects patient data, imaging and clots on a per-pass basis and has independent evaluators review them. It’s just one way the company has proved its commitment to innovating in the advancement of stroke care.
And there’s good reason for this commitment.
Every 40 seconds someone in the United States has a stroke. Every 3.5 minutes, someone dies of one.
“The scale of the burden is massive,” says Patrick Brouwer, M.D., Senior Medical Director, Cerenovus Inc., part of Johnson & Johnson MedTech. “Strokes are one of the leading causes of death in many countries, as well as a leading cause of disability. As the largest, most diversified healthcare products company in the world, Johnson & Johnson has made it its mission to make a difference for patients.”
For World Stroke Day, we’re taking an in-depth look at strokes—how they happen, who’s at risk, how to prevent them—and how Johnson & Johnson is paving the way with new treatments and cutting-edge research.
What exactly is a stroke?
A stroke—sometimes called a “brain attack”—occurs when a blood vessel that carries oxygen and other nutrients to the brain is either blocked by a clot or bursts. When that happens, brain cells become damaged or die.
There are two types of stroke. The most common is ischemic, which occurs when a blood vessel to the brain is obstructed. Hemorrhagic stroke occurs when a weakened blood vessel to the brain ruptures. Both result in brain tissue death.
Contrary to popular belief, strokes don’t discriminate on the basis of age. Granted, the majority of strokes do occur among older adults, but they can happen to young, otherwise healthy people, as well: in fact, almost 40% of people hospitalized for stroke are under the age of 65.
And while stroke is a leading killer for all Americans, the risk of having one varies by race.
For instance, the risk of a first stroke is nearly twice as high for Black Americans as for white Americans. Black people also have the highest rate of death due to stroke. “They are more likely to experience high blood pressure, diabetes and being overweight or obese—all of which raise risk of stroke,” explains Richard Browne, M.D., Senior Medical Executive, Health Systems Strategy at Johnson & Johnson. A study published last year in JAMA Network Open found that people with lower socioeconomic status and from ethnic minority populations are more likely than white Americans to experience a severe stroke, as well as worse health outcomes afterward.
One reason may be racial disparities in stroke care. A review of 30 studies published in 2022 in the medical journal Stroke found that white patients were more likely than African American, Hispanic and Asian patients to receive lifesaving stroke treatments such as tPA (short for tissue plasminogen activator) or a medical procedure known as mechanical thrombectomy.
We know that with stroke care, speed is critical. With every minute, someone who’s had a stroke loses close to 2 million brain cells.
Research also showed that once stroke symptoms started, white patients arrived at the emergency room (ER) earlier than Black or Hispanic patients. Non-white stroke patients, for example, are less likely to arrive by emergency medical services (EMS) and more likely to experience longer ER wait times compared to white patients. “We know that with stroke care, speed is critical,” says Dr. Brouwer. Indeed, every minute, someone who’s had a stroke loses close to 2 million brain cells.
Another sobering statistic: Fewer than one-third of people in the U.S. who have a severe ischemic stroke receive the treatment that could save their lives or prevent a lifetime of disability.
Harnessing high-tech tools to help change stroke outcomes
Today, the most common treatment for ischemic stroke is to administer a medication through an IV in the arm. The drug works to dissolve clots that block blood flow to brain arteries. But many people don’t arrive at the ER in time or they have a symptom or other medical condition that prevents them from getting this treatment, and sometimes the clots themselves can be too big for the medication to be effective, says Michael Gilvarry, General Manager at Cerenovus Galway. In these cases, patients need a mechanical thrombectomy; the surgical procedure involves inserting a clot-removing device into the artery.
“No two clots are alike—they can have a variety of compositions and properties, which is why they respond so differently to treatment,” explains Gilvarry. “Some are tough, like chewing gum, making them very difficult to remove. Others are so soft they can fragment easily, which makes them more likely to embolize.” Cerenovus—which was launched by Johnson & Johnson in 2017 to advance the treatment of both ischemic and hemorrhagic stroke—has studied over 500 patient clots as part of the Excellent Registry and recreated different ones in benchtop experiments so that they can better understand which procedures and techniques are most effective to remove clots.
Thanks to this research, Cerenovus launched a suite of technologies called Cerenovus Stroke Solutions™ in 2020. The goal: Make it easier and quicker for doctors to reach and remove a clot when they perform a thrombectomy. “If the entire clot doesn’t come out at the first attempt, what remains is often more of a challenge to remove,” explains Gilvarry. “Clots that require several attempts to remove tend to have fewer red blood cells and more proteins, including fibrin, which make them stiffer and harder to remove than red-cell dominant clots.”
Cerenovus has three devices that help doctors successfully remove clots:
- A sheath that helps doctors reach the clot.
- A balloon guide catheter that optimizes removal of clots by controlling blood flow locally during mechanical thrombectomy procedures. The Emboguard™ Balloon Guide Catheter, as it’s known, allows doctors to get to the clot faster, with more stability and support. “It’s designed to be more flexible at one end to navigate through arteries with a lot of curves in them and to be stiffer at the other end to provide stability during the procedure,” explains Gilvarry.
- A stent retriever that’s designed to grip clots more effectively. Research shows that the Embotrap® III Revascularization Device, as the stent retriever is known, is able to remove more clots on first try, something known as first-pass recanalization. “We know that if you can remove a clot in a single pass, it improves patient outcomes and speeds up recovery time,” says Gilvarry. The hope is that Embotrap will help prevent stroke-related long-term disabilities.
Gilvarry recalls meeting with a 38-year-old woman who had the procedure done with the Embotrap device after a stroke. “Right before the procedure started, she couldn’t even raise or squeeze her hand,” he says. “By the end of the procedure, which lasted around 20 minutes, she had full use of her arms and hands again.” While results vary from patient to patient, this experience left a memorable impression and reaffirms why his work is so important for patients.
The treatment for hemorrhagic stroke differs from that of an ischemic stroke. Rather than remove a clot, the goal is to prevent the aneurysm from rupturing and causing a brain bleed, or prevent re-rupturing from an aneurysm that has already bled. Until the 1990s, doctors did this by placing a clamp at the base of the aneurysm, or burst blood vessel, to prevent further bleeding. But it’s major surgery and requires putting a patient under general anesthesia.
Doctors have since turned to a newer procedure, aneurysm embolization, which is less invasive. The most popular way to embolize an aneurysm is with coils. A doctor inserts a catheter into a groin, arm or wrist artery, and the catheter is then guided along blood vessels in the body until it reaches the aneurysm in the brain. The doctor places tiny coils into the aneurysm, which in turn triggers a blood clot that blocks blood flow from entering into the aneurysm. “While there are other newer devices also touted to treat aneurysms, like flow diverters that decrease blood flow to the area, coils continue to be used as a safe treatment option for aneurysm,” says Melissa Clinger, a neurovascular research and development manager at Cerenovus.
The challenge of this procedure is to get the coil up to the aneurysm quickly and safely. That’s why Cerenovus created Cerepak™ Detachable Coils designed to embolize aneurysms from start to finish.
The coils are shaped specifically to fill an aneurysm, and they also have a large volume, which allows them to fill the area faster. They received clearance from the U.S. Food and Drug Administration last year and are being introduced in physician offices now.
Preventing strokes from happening in the first place
Fascinating fact: Up to 90% of all strokes are preventable. One of the best ways to lower your risk is to get underlying medical conditions under control, says Dr. Browne.
High blood pressure, for example, is a leading risk factor for stroke—in fact, some research suggests it’s responsible for almost half of all strokes. Type 2 diabetes, high cholesterol and being overweight or obese also raise risk. If you’re over the age of 65, you should also be aware of atrial fibrillation (AFib), an irregular and often very rapid heart rhythm (arrhythmia) that increases the risk of blood clots. People with AFib are about five times as likely to have a stroke as those without it.
That’s why Johnson & Johnson is researching new treatments for people with AFib. For example, the Janssen Pharmaceutical Companies of Johnson & Johnson is currently studying a new anticoagulant for patients who are currently untreated or undertreated with existing treatments due to the risk of bleeding. And the company’s Heartline Study aims to determine whether an app-based heart health engagement program, used in combination with Apple Watch’s Irregular Rhythm Notification feature and ECG app, can potentially help lead to the earlier detection and diagnosis of AFib.
While companies like Johnson & Johnson are doing groundbreaking research into stroke prevention and treatment, the best way to protect yourself, stresses Dr. Browne, is to know the signs of a stroke. The American Stroke Association uses the acronym FAST to spot signs of a stroke:
If it turns out that you have, indeed, had a stroke, your doctor may prescribe medications for you to take to reduce further risk, including medications such as blood thinners. “There’s an expression that ‘time saved is brain saved,’ ” says Dr. Browne. “Time is of the essence with a stroke. The faster you act, the faster you’ll be able to get lifesaving care.”