The Effectiveness of TNK as a Treatment for Strokes

According to the Centers for Disease Control, stroke is a leading cause of death in the United States. The American Stroke Association, a division of the American Heart Association, indicates that globally, stroke is the second-highest cause of death worldwide and a leading cause of disability.

A stroke occurs when the blood flow to an area of the brain is interrupted by a blocked or broken blood vessel. When a stroke occurs, it kills brain cells in the immediate area.

There are two main types of strokes: ischemic and hemorrhagic. Ischemic strokes are the most common, accounting for approximately 87 percent of all strokes. Ischemic strokes occur when a vessel that supplies blood to the brain is blocked – usually by fatty deposits – and a blood clot forms. The clots can form in the brain or somewhere in the body along the circulatory system and travel to the brain. Hemorrhagic strokes are caused by bleeding in the brain and account for roughly 13 percent of all strokes.

Covenant Health is proud to be the region’s only stroke-certified hospital network, using the most effective stroke treatments to promote better outcomes. Our network has adopted tenecteplase, more commonly known simply as TNK, for ischemic stroke patients. In studies of patients who are medically eligible to take TNK, the drug has proven successful in reducing mortality while being a more effective option for breaking up blood clots.

What is Tenecteplase (TNK) and How Does it Work?

“TNK is a potent anti-coagulant, or ‘clot buster,’” explains Dina Miller, DNP, FNP-BC, MBA, neurohospitalist nurse practitioner at Fort Sanders Regional Medical Center.

“It belongs to a class of drugs called thrombolytics. These types of drugs work to dissolve clots by targeting clotting factors in the blood. Simply put, TNK can break up a clot in a vessel in the brain that is causing a stroke. For patients having a stroke who are candidates for treatment with TNK, the restoration of normal blood flow to the brain can minimize, and in some cases, eliminate life-changing deficits that may have occurred without treatment.”

While TNK isn’t new, many leading health systems have waited for research and studies to confirm its effectiveness. Covenant Health has been a regional leader in implementing TNK, now considered now to be the most effective treatment for dissolving blood clots.

Miller says, “Fort Sanders Regional Medical Center began using TNK in January 2022 and completely replaced the previous standard anti-coagulant, alteplase, in early August 2022. By the end of August 2022,  Covenant Health transitioned exclusively to TNK.”

 How is TNK Administered?

TNK is delivered through an IV and takes just seconds to be administered. TNK needs to be administered shortly after symptoms start – the TNK treatment window is up to four and a half hours after the onset of symptoms. It’s vital to call 911 immediately if you suspect a stroke.

Miller says one of the most common mistakes people make when having a stroke is waiting to see if their symptoms go away. “A delay in seeking medical attention could cause irreversible damage to the brain and place the patient outside of any window for treatment,” she says. The message is clear: do not delay.

Tenecteplase (TNK) versus Alteplase (tPA) for Stroke

In a 2024 article from the American Stroke Association, a comparison of tenecteplase versus alteplase (tPA), the previous preferred clot-busting drug for treatment of stroke, describes tenecteplase as a safer, faster and simpler treatment.

Time is of the essence when treating strokes, and tenecteplase can be administered in a single injection in mere seconds, compared to an hour to administer two injections of alteplase. This allows stroke patients to be treated quickly, helping stabilize them faster – which is especially important when transporting patients to medical facilities.

TNK also has a higher attraction to the protein found in blood clots compared to alteplase, which may help the drug work more quickly once it’s administered.

According to the National Library of Medicine, there are several contraindications for TNK, which means that patients with certain conditions should not take the drug.

These include:

• Active internal bleeding within the last 21 days
• Evidence of intracranial/subarachnoid hemorrhage on CT/MRI
• Severe uncontrolled hypertension
• History of cerebrovascular accident (stroke) within the last three months
• Intracranial neoplasm or arteriovenous malformation (AVM)
• Major surgery or trauma within the last 15 days
• Intracranial or intraspinal surgery or serious trauma within the last three months
• Head or spinal trauma within the previous two months
• Conditions that increase the risk of bleeding
• Those who have taken anticoagulants in the last 48 hours
• Stroke thought to be associated with aortic arch dissection

TNK and Stroke Recovery

Clinical studies have shown that TNK can help reduce disabilities after stroke and help patients recover to resume pre-stroke activities – a finding that aligns with outcomes at Covenant Health.

Miller notes, “While every patient is different, we have seen numerous positive outcomes after using TNK. In 2023, just over 70 percent of our patients with stroke who were treated with TNK were able to leave the hospital with minimal or no residual symptoms of stroke.” That is an encouraging outcome for an event that has the potential to cause extensive damage.

How to Identify Stroke Symptoms

Miller reiterates that if stroke is suspected, seeking medical attention is the first critical step. “Call 911 and get to the emergency department for evaluation, even if the symptoms have improved,” she said.

Covenant Health’s stroke team promotes the BE FAST stroke symptom recognition guide. Every letter of BE FAST corresponds with areas to check and actions to take:

• Balance: Is the person uncoordinated and having difficulty walking?
• Eyes: Ask the person if they have double or blurred vision.
• Face: Ask the person to smile. Does one side of the face droop?
• Arms: Ask the person to raise both arms. Does one arm drift downward?
• Speech: Ask the person to repeat a simple sentence. Are the words slurred? Is the sentence repeated correctly?
• Time for help: If the person shows any of these symptoms, time is important –  call 911.

“Stroke symptoms are not unique to age, race or gender,” Dina shares. “Besides weakness, numbness and slurring of speech, additional symptoms that may be dismissed include sudden loss of balance, sudden loss of vision, sudden confusion or an inability to speak appropriately.”

Click here for more information about Covenant Health’s Stroke Network.  Fort Sanders Regional Medical Center in Knoxville, Tennessee, is certified as a Comprehensive Stroke Center by The Joint Commission the American Heart Association/American Stroke Association, the highest designation a hospital can receive for stroke care. Patricia Neal Rehabilitation Hospital, with locations at Fort Sanders Regional and Covenant Health-West, is East Tennessee’s elite rehabilitation hospital for stroke, spinal cord and brain injury patients.

The stroke specialists of Covenant Health are working every day to reduce the devastating effects of stroke and help patients recover. With their expertise and faster, more effective drugs such as TNK, our network is leading the way in stroke care in East Tennessee.