tPA

Tissue Plasminogen Activator (tPA) is a thrombolytic agent (clot-busting drug). It's approved for use in certain patients having a heart attack or stroke. The drug can dissolve blood clots, which cause most heart attacks and strokes.

Criteria for administration of tPA - You need an answer Yes to all questions

• > or = 18 years of age
• Clinical diagnosis of stroke with NIH stroke scale score < 22
• Time of onset of stroke known and is < 3 hours (defined as completely free of any stroke symptom)

To be eligible for TPA – You need to answer Yes to all questions

• BP Systolic <= 185, diastolic <= 110
• Not a minor stroke or rapidly resolving stroke
• No seizure at onset of stroke
• Not taking Warfarin (Coumadin)
• Pro time <= 15 seconds or INR <= 1.7
• Not receiving heparin during the past 48 hours with elevated PTT
• Platelet count >= 100,000
• Blood Glucose => 50 and <= 400 mg/dl
• No acute myocardial infarction
• No prior intracranial hemorrhage, neoplasm, AVM or aneurysm
• No major surgical procedures within 14 days
• No stroke or serious head injury within 3 months
• No gastrointestinal or urinary bleeding within last 21 days
• No lactation or Pregnancy within 30 days
• And consent from patient or family

Patient or family should be aware of

• Risk of bleeding into the brain is 1 in 16
• Potential benefit - 30% greater chance of improvement to no or minimal disability
• Patient or family sign consent form (read it!)

TPA may be beneficial in small strokes

• Neurology Today 4(4) 65-69 says that tPA is beneficial in minor strokes without increasing the risk of hemorrhage. “For all the definitions we used for minor stroke, tPA is still more likely to be associate with favorable outcomes than placebo.” Patients who were given tPA were less likely to deteriorate in the first 24 hours and these patients tended to have smaller lesions at three months
• tPA treated patients had shorter hospital stays and 78% of them were discharged home compared to 63% of patients receiving placebo
• The authors go on to say that using tPa in minor stroke may improve the chances of good outcome. “Depending on the definition of minor stroke, there are still many minor stroke patients who do not have good outcomes. We found 30 to 40% had significant disability after minor stroke and that tPA can improve the chance of a good outcome.”
• Dr. Levine — one of the authors of the study acknowledged that some neurologists and emergency physicians are reluctant to use tPA, particular for minor strokes but says that “The data support the idea that most patients with minor stroke will benefit from this treatment.” Reference: Neurology Today 4(4) 65-69

Information

• Statewide Assessment of Hospital-Based Stroke Prevention and Treatment Services in North Carolina.pdf
• Effects Of Thrombolysis For Acute Stroke In Patients With Pre-Exist Disability.pdf
• Findings From the Reanalysis of the NINDS Tissue Plasminogen Activator for Acute Ischemic Stroke Treatment Trial.pdf
• Equivocal Roles Of Tissue-Type Plasminogen Activator In Strokeinduced Injury.pdf
• A Systematic Review Of Barriers To Delivery Of Thrombolysis For Acute Stroke.pdf
• VA Stroke Study.pdf - Neurologist care is associated with increased testing but improved outcomes
• The Impact Of Neuroimaging On Clinical Decisions In Minor Stroke.pdf

Related News

Researchers Find Ultrasound Helps Drug Dissolve Stroke-Causing Blood Clots

HOUSTON — In a study  published Nov. 18 in The New England Journal of Medicine, Stroke Team doctors at The University of Texas Medical School at Houston say they may have discovered a new tool to use in the treatment of strokes

Physicians in Houston and three other centers used a hand-held extracranial ultrasound device to target stroke-causing blood clots during the pilot study. The sound waves are believed to seek out the clot and deliver a heavy dose of the clot-busting drug tPA to and through it, relieving the obstruction to blood flow and helping the brain heal. All of the patients also received the clot-busting tPA, and their results were compared with 63 other patients who received tPA alone

Andrei Alexandrov, M.D., assistant professor of neurology at the UT Medical School, initially used the ultrasound device to track the efficacy of tPA, the only approved drug for treating blood clots in stroke victims. However, emergency room nurses began telling him that patients who had been monitored in this way were recovering faster than those he had not monitored. Alexandrov began a pilot study to determine whether the ultrasound itself had therapeutic uses

“We had 126 patients enrolled in the study, with an average age of 70,” Alexandrov said. "“Thirty-eight percent of the patients on whom I used ultrasound sustained a complete clearance of their clots within two hours (compared to 12 percent of the patients receiving tPA alone), and over 70 percent experienced a complete or partial clearance."”

Alexandrov fitted the patients with a frame similar to the protective framework inside a hard hat and then used a Food and Drug Administration-approved diagnostic frequency setting of two megahertz to single out blood clots in the brain while tPA was administered

“This frequency is fast but gentle, safe to use and efficacious. It creates micro-vibrations that work on the surface of the clot to open up a larger surface that the tPA can then bind to and penetrate,” he said

In addition to killing more than 167,000 Americans a year, strokes permanently disable many victims, making it the top cause of disability in the nation. Optimum stroke care is often difficult to obtain outside of major trauma centers

Note: Remember this has to be within 3 hours, and only for ischemic strokes. From the total number of strokes it will still be a small percentage!

As well, the CTV report says of those that get tPA alone around 20% of people who get tPA will benefit significantly

With this technique about 40% benefit significantly