A  A  A   Print
Blood Thinner Dangerous for Patients With Artificial Heart Valves, Study Finds

Blood Thinner Dangerous for Patients With Artificial Heart Valves, Study Finds

THURSDAY, Sept. 26 (HealthDay News) -- 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 cardiovascular medicine at the University Hospitals Leuven in Belgium, is "don't use Pradaxa in patients with a mechanical valve."

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 heart patients 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 warfarin 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 heart valve replacement, patients are typically put on blood thinners 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 randomized clinical trial 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.

More information

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

SOURCES: Frans Van de Werf, M.D., Ph.D., professor and chairman, department of cardiovascular medicine, University Hospitals Leuven, Belgium; Gregg Fonarow, M.D., professor, cardiology, University of California, Los Angeles; Sept. 26, 2013, New England Journal of Medicine

 
Today's Interactive Tools

The third-party content provided in the Health Library of phoebeputney.com is for informational purposes only and is not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. If you or your child has or suspect you may have a health problem, please consult your primary care physician. If you or your child may have a medical emergency, call your doctor or 911 or other emergency health care provider immediately in the United States or the appropriate health agency of your country. For more information regarding site usage, please visit: Privacy Information, Terms of Use or Disclaimer.

Follow us online:

© 2014 Phoebe Putney Health System  |  417 Third Avenue, Albany, Georgia 31701  |  Telephone 877.312.1167

Phoebe Putney Health System is a network of hospitals, family medicine clinics, rehab facilities, auxiliary services, and medical education training facilities. Founded in 1911,
Phoebe Putney Memorial Hospital (the flagship hospital) is one of Georgia's largest comprehensive regional medical centers. From the beginning, Phoebe's mission and vision
has been to bring the finest medical talent and technology to the citizens of Southwest Georgia, and to serve all citizens of the community regardless of ability to pay.