March 10, 2017
Health Day News

Tissue plasminogen activator (abbreviated tPA or PLAT) is a protein involved in the breakdown of blood clots. It is a serine protease (EC 3.4.21.68) found on endothelial cells, the cells that line the blood vessels. As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown. Moreover, the success of tPA motivated the search for additional acute stroke treatments, including interventions to remove large clots resistant to the clot-busting drug. In 2015, multiple clinical trials demonstrated the benefit of clot-retrieval devices as compared to tPA alone for the treatment of severe strokes affecting large arteries to.

Stroke victims can be saved through the timely use of a powerful clot-busting drug, but certain groups of patients still aren't getting the medication quickly enough to help, a new study reveals.
Blacks, Hispanics, women, seniors on Medicare and people in rural areas are less likely to be treated with tissue plasminogen activator (tPA) after suffering a stroke, researchers found.
The drug works by dissolving clots that have blocked flow of blood to the brain, causing what is called an ischemic stroke.
To have any effect, tPA must be administered within 4.5 hours of the start of a stroke, and it appears many patients aren't getting to the hospital and through emergency evaluation in time to receive the drug, said lead researcher Dr. Tracy Madsen. She's an assistant professor of emergency medicine at Brown University's Warren Alpert Medical School in Providence, R.I.
Her study team reviewed the records of more than 563,000 patients who suffered an ischemic stroke between 2005 and 2011.
Every year, patients were 11 percent more likely to be treated by tPA, even though across the entire period of time only 3.8 percent of total patients got the clot-busting drug, researchers reported.
The team found certain types of patients were less likely to receive tPA:
Blacks were 38 percent less likely than whites.
Hispanics were 25 percent less likely than whites.
Women were 6 percent less likely than men.
People with private insurance were 29 percent more likely to receive tPA compared to those on Medicare.
People living in the so-called 'Stroke Belt' in the southeastern United States were 31 percent less likely than those living elsewhere to receive tPA.
'I think it's something that's probably decreasing over time, but unfortunately still existed in our findings,' Madsen said of the disparities.
On the other hand, stroke victims treated at a large urban hospital, a teaching hospital or a designated stroke center had a better chance of prompt treatment that would include tPA.
'They are much more likely to have stroke protocols in place that make things happen faster,' Madsen said. 'Patients get their brain scans faster. Patients are evaluated more quickly when they arrive at the door. It really is treated as an emergency.'
People also were more likely to get tPA if they were treated at a hospital participating in a program sponsored by the American Stroke Association that focuses on faster delivery of treatment to stroke patients, Madsen said.
Participating hospitals are awarded based on their performance. Patients treated at a top-performing hospital in the program were twice as likely to get tPA compared to being at a hospital not in the program, the researchers found.
Factors that might slow stroke treatment for minority groups include access to health care or insurance, Madsen said.
'There's been a long history of these groups being treated less aggressively for stroke,' she said.
Women may also exhibit atypical stroke symptoms, which can slow their evaluation, Madsen said. In addition, many women have strokes at an advanced age, and doctors can be reluctant to administer tPA to elderly people over fear of side effects.
The findings were to be presented Thursday at the International Stroke Conference, in Houston. Research presented at meetings is viewed as preliminary until published in a peer-reviewed journal.
A second study presented at the same meeting indicated that people who get tPA before they arrive at the hospital do even better.
Patients transported in a 'mobile stroke unit' -- an ambulance specially equipped to diagnose and treat stroke on route to the hospital -- had a lower risk of stroke-related disability than people who received tPA at the hospital, researchers from the University of California, Los Angeles, found.
Led by Dr. May Nour, the team compared 305 patients given tPA in a mobile stroke unit with 353 patients who got tPA at the hospital.
The researchers concluded that for every 1,000 stroke patients given tPA on their way to the hospital, 182 will be less disabled by their stroke and 58 will have no disability at all.
People can improve chances for themselves and their family members by learning the signs of stroke and calling 911 for help, rather than driving the victim to the hospital, said Daniel Lackland, a professor of neurology with the Medical University of South Carolina.
That way, paramedics can evaluate the patient and communicate ahead with the hospital, speeding up treatment time by making sure brain scanners are available and specialists are ready for the incoming patient, he said.
'Everybody needs to know if I see one of these signs of a stroke, I need to call 911,' said Lackland, a spokesman for the American Stroke Association. 'You don't wait and wonder if the symptoms of a stroke are going to go away.'
Experts recommend the F.A.S.T. guidelines for recognizing a stroke: Face drooping, Arm weakness or Speech difficulty means Time to call 911.
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Health Education Articles

• But right now, there's only one weapon in a doctor's clot-busting arsenal. That weapon is tissue plasminogen activator, or tPA. The drug tPA was approved by the FDA for use in 1996. It's intravenously administered and it works to dissolve the clot so that blood can flow again.
• Start by grabbing your supplies: a three-way stopcock valve, an empty 10 mL syringe, and your TPA syringe. Connect these to the PICC line as shown in the picture on the right. Position the stopcock so it is open to the empty syringe and closed to the rTPA. Pull back the empty syringe to create a vacuum within the PICC line tubing.
• Why this might matter wasn't clear at the time, however, and it did not seem connected to tPA's clot-busting power. But drugs often have more than one molecular target, including targets not.

Tpa For Blood Clot

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Disease Information

When you are having a stroke, you need to go to the ER ASAP, undergo a CT STAT and receive tPA through an IV if necessary. In other words, upon recognizing the symptoms of a stroke, you should proceed to the nearest emergency room (ER) as soon as possible (ASAP). Upon arrival, you would undergo a computed tomography (CT) scan immediately (STAT) to determine the cause of the stroke. If a blood clot is detected during the scan, you may receive tissue plasminogen activator (tPA) intravenously (IV) to help break up the blood clot.

More than 80 percent of strokes are caused by a blood clot that moves into a vessel and blocks blood flow. These ischemic strokes typically are treated with tPA, a clot-busting drug that helps dissolve the blood clot and restore blood flow to the brain. Strokes also may be caused by the rupture of a weakened blood vessel, resulting in blood leaking into the brain. These hemorrhagic strokes should not be treated with tPA because the medication could cause increased bleeding.

The key to successful treatment for ischemic strokes is rapid treatment. That is because when tPA is administered within three hours of the onset of symptoms, it can help reduce disability and limit damage caused by lack of blood flow to the brain. Although tPA usually is given through an IV, it also can be delivered through a long catheter that is guided through blood vessels directly to the blockage. This alternative may benefit patients when treatment cannot begin within three hours after stroke symptoms started or when initial tPA treatment has not been sufficient to dissolve the blood clot. The local administration of tPA can occur up to six hours after the onset of stroke symptoms.

The decision to use tPA or other clot-busting drugs, also called thrombolytics, is based on numerous factors, including age, gender and medical history.

Names Of Clot Busting Drugs

In general, tPA is not recommended for patients who are pregnant or have:

• A history of bleeding problems.
• Uncontrolled high blood pressure or endocarditis
• (infection of the lining of the heart).
• Had recent surgery or injury.
• Diabetic retinopathy (eye problems due to diabetes).

In addition to treating ischemic strokes, thrombolytic therapy using tPA also may be used to treat clots in the lungs, deep veins in the legs, heart, or arteries elsewhere in the body. However, clots may reform in blood vessels, especially if the underlying cause for the blockages is not properly diagnosed and treated. Following treatment with tPA, patients are advised not to take anticoagulants or antiplatelets, such as aspirin, which could interfere with normal clotting.

If you experience the warning signs of a stroke, such as sudden numbness or weakness on one side of the body, confusion, difficulty speaking, blurred vision, sudden headache or trouble walking, call 9-1-1 right away. A stroke is an emergency that requires immediate medical attention.