Clot-busting medicine safe for use in warfarin-treated patients following stroke

June 26, 2012

The clot-busting medicine, tPA (tissue plasminogen activator), is safe to use in acute stroke patients already on the home blood thinner warfarin, according to researchers from Duke Clinical Research Institute (DCRI). This study helps allay previous concerns that tPA was too dangerous to use in patients on home anticoagulation and would lead to high risk for potentially fatal intracranial bleeding.

"To date, we have no or large cohort studies to guide us," says Ying Xian, M.D., Ph.D., assistant professor of medicine at Duke, and first author of the study published today in JAMA. "Our large national study found no statistically significant increase in risk, which supports using intravenous tPA in warfarin-treated following stoke if their INR is less than or equal to 1.7."

The International Normalized Ratio (INR) measures the rate at which while taking anti-clotting medications like .

The Duke researchers also found almost half of warfarin-treated patients who might have qualified for tPA following stroke did not receive treatment, according to DCRI Director Eric Peterson, M.D., the paper's senior author. "We noted a substantial under-treatment of patients on warfarin who were eligible, but did not receive tPA following their stroke."

Warfarin is an anticoagulant proven to reduce the rate of stroke in patients with atrial – irregular heart beats. If warfarin treatment fails and the patient suffers a stroke, tPA is the only effective treatment. However, it also carries an increased risk of symptomatic intracranial hemorrhage (sICH).

American Heart Association guidelines say IV tPA in warfarin-treated patients may be used if the INR is less than or equal to 1.7, but few small studies supported the guidelines.

The Duke observational trial included 23,437 stroke patients on warfarin treated at 1,203 hospitals, making it the largest to look at IV tPA use in warfarin-treated patients following stroke. While warfarin-treated patients had slightly higher crude rates of intracranial bleeding (5.7% vs. 4.6%) than non-warfarin patients, they were also older. After adjusting for age, stroke severity and other factors, warfarin and non warfarin users had similar intracranial hemorrhage risk.

"This study provides support for the current treatment guidelines," says Xian, and indicates that a portion of the population is being under-treated.

It also leaves several questions unanswered. "More studies are needed to look at tPA use in patients with an INR greater than 1.7, as well as in those who are taking one of the newer warfarin alternative anticoagulants (dabigatran and rivaroxiban)," Xian said.

Explore further: Clot-busting drug safe for stroke patients taking blood thinner

Related Stories

Clot-busting drug safe for stroke patients taking blood thinner

May 10, 2012
Acute ischemic stroke patients taking the blood thinner warfarin can be treated safely with the clot-busting drug tissue plasminogen activator (tPA), according to research presented at the American Heart Association's Quality ...

Warfarin related to low rate of residual stroke in patients with atrial fibrillation

March 26, 2012
A review of clinical trials comparing warfarin with other medications for stroke prevention suggests that warfarin was associated with a low risk of stroke or non-central nervous system embolism in patients with nonvalvular ...

Warfarin and aspirin are similar in heart failure treatment

February 3, 2012
In the largest and longest head-to-head comparison of two anti-clotting medications, warfarin and aspirin were similar in preventing deaths and strokes in heart failure patients with normal heart rhythm, according to late-breaking ...

Stroke risk high when anti-clotting drugs stopped

April 25, 2012
Some patients with irregular heartbeats who are taken off anti-clotting medication face a high risk of stroke or blood clotting within a month, according to new research presented at the American Heart Association's Emerging ...

Recommended for you

Early study shows shoe attachment can help stroke patients improve their gait

December 14, 2017
A new device created at the University of South Florida – and including a cross-disciplinary team of experts from USF engineering, physical therapy and neurology – is showing early promise for helping correct the signature ...

Deadly heart rhythm halted by noninvasive radiation therapy

December 13, 2017
Radiation therapy often is used to treat cancer patients. Now, doctors at Washington University School of Medicine in St. Louis have shown that radiation therapy—aimed directly at the heart—can be used to treat patients ...

Scientists rewrite our understanding of how arteries mend

December 13, 2017
Scientists from The University of Manchester have discovered how the severity of trauma to arterial blood vessels governs how the body repairs itself.

Ultra-thin tissue samples could help to understand and treat heart disease

December 12, 2017
A new method for preparing ultra-thin slices of heart tissue in the lab could help scientists to study how cells behave inside a beating heart.

Research reveals how diabetes in pregnancy affects baby's heart

December 12, 2017
Researchers at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA have discovered how high glucose levels—whether caused by diabetes or other factors—keep heart cells from maturing ...

Young diabetics could have seven times higher risk for sudden cardiac death

December 12, 2017
Young diabetics could have seven times more risk of dying from sudden cardiac arrest than their peers who don't have diabetes, according to new research.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.