Blood thinner dangerous for patients with artificial heart valves, study finds

September 26, 2013 by Steven Reinberg, Healthday Reporter
Blood thinner dangerous for patients with artificial heart valves, study finds
Trial, which was halted early, found Pradaxa increased risk for strokes and bleeding in this group.

(HealthDay)—When used by patients with mechanical heart valves, the blood thinner Pradaxa raises the risk of both dangerous clots and bleeding around the heart, a new study says.

The bottom line for lead researcher Dr. Frans Van de Werf, chairman of the department of at the University Hospitals Leuven in Belgium, is "don't use Pradaxa in patients with a ."

In fact, the trial was halted early and the U.S. Food and Drug Administration subsequently issued a 'black box' warning that said this particular group of should not take Pradaxa because of an increased chance of a stroke or heart attack.

Pradaxa (dabigatran) is a drug that prevents clotting. It has been approved as an alternative to for patients with an abnormal heartbeat called atrial fibrillation, the researchers noted.

"It was hoped that a novel oral direct clotting inhibitor would provide similar or better protection for patients with mechanical heart valves without the need for [the] monitoring or dietary restrictions associated with warfarin," said Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles.

After a , patients are typically put on or drugs that combat clotting to prevent a heart attack or stroke, but the danger of these drugs is a risk for severe bleeding.

"While the vitamin K antagonist warfarin is very effective at preventing clotting-related complications of mechanical heart valves, its use requires lifetime monitoring, with at least monthly blood tests, dietary restrictions and the potential for multiple medication interactions," Fonarow explained.

Unfortunately, this showed that Pradaxa was even more problematic than warfarin in terms of side effects, he said.

"As a result of these findings, the FDA added a 'black box' warning to the medication label warning against using dabigatran and similar medications in patients with mechanical heart valves," Fonarow said.

The report was published Sept. 26 in the New England Journal of Medicine and the trial was funded by Boehringer Ingelheim, the maker of Pradaxa.

For the study, an international team of researchers randomly assigned 252 patients who had an aortic or mitral valve replacement to either Pradaxa or warfarin. Some patients had the valve replacement within a week before the study began and others had the surgery three months earlier, the researchers noted.

Of those taking Pradaxa, 32 percent had their treatment stopped or dose changed. In addition, 5 percent of those on the drug suffered a stroke, compared with none of those taking warfarin.

Moreover, 4 percent of those taking Pradaxa had major bleeding around the heart, compared with 2 percent of those taking warfarin, the researchers found.

Explore further: FDA: Pradaxa not for patients with mechanical heart valves

More information: For more on heart valve replacement, visit the American Heart Association.

Related Stories

FDA: Pradaxa not for patients with mechanical heart valves

December 21, 2012
(HealthDay)—The blood thinner Pradaxa should not be used to prevent stroke or blood clots in patients with mechanical heart valves, the U.S. Food and Drug Administration said in a warning issued Wednesday.

New blood thinner beats older drug for vein clots

February 20, 2013
(HealthDay)—People who need to take a blood thinner because they've had a clot in the deep veins of their legs appear to do better with the new drug Pradaxa (dibigatran) than with the older drug warfarin, researchers report.

ESC: Complications noted after dabigatran heart valve Tx

September 4, 2013
(HealthDay)—Patients with heart valve replacements have greater rates of thromboembolic and bleeding complications after treatment with dabigatran compared with warfarin, according to a study published online Sept. 1 in ...

Low-dose anticoagulation therapy used with new design mechanical heart valve lowers bleeding risk

May 6, 2013
For more than 40 years, patients under 65 years of age requiring heart valve replacement have had to choose between a mechanical valve that offers life-long durability but requires aggressive warfarin anticoagulation or a ...

Plavix's new generic status could be boon for patients

May 15, 2012
(HealthDay) -- The blockbuster drug Plavix (clopidogrel), used to prevent clotting in some heart patients, will go off patent in the United States on Thursday, making it considerably more affordable.

Kcentra approved to stop severe bleeding in heart patients

April 30, 2013
(HealthDay)—Kcentra (prothrombin complex concentrate, human) has been approved by the U.S. Food and Drug Administration to treat severe acute bleeding in adults after administration of the anti-clotting drug warfarin and ...

Recommended for you

'Shapeshifter' that regulates blood clotting is visually captured for the first time

August 23, 2017
We are normally born with a highly sophisticated array of molecules that act as "sentries," constantly scanning our bodies for injuries such as cuts and bruises. One such molecular sentry, known as von Willebrand factor (VWF), ...

Dramatic new studies into inflammation in the infarcted heart could lead to changes in therapy

August 23, 2017
A medical research collaborative has demonstrated that the response of the human heart to an infarction is very different than previously thought. The study, led by cardiologist Borja Ibáñez and published as two independent ...

New molecule may hold the key to triggering the regeneration and repair of damaged heart cells

August 21, 2017
New research has discovered a potential means to trigger damaged heart cells to self-heal. The discovery could lead to groundbreaking forms of treatment for heart diseases. For the first time, researchers have identified ...

Researchers investigate the potential of spider silk protein for engineering artificial heart

August 18, 2017
Ever more people are suffering from cardiac insufficiency, despite significant advances in preventing and minimising damage to the heart. The main cause of reduced cardiac functionality lies in the irreversible loss of cardiac ...

Lasers used to detect risk of heart attack and stroke

August 18, 2017
Patients at risk of heart attacks and strokes may be spotted earlier thanks to a diagnosis tool that uses near-infrared light to identify high-risk arterial plaques, according to research carried out at WMG, University of ...

Cholesterol crystals are sure sign a heart attack may loom

August 17, 2017
A new Michigan State University study on 240 emergency room patients shows just how much of a role a person's cholesterol plays, when in a crystallized state, during a heart attack.

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.