Featured Research

from universities, journals, and other organizations

Aspirin Resistance Increases Risk Of Death

Date:
March 27, 2002
Source:
American Heart Association
Summary:
For the first time, researchers have shown that people who are aspirin resistant have a higher risk of dying from heart disease than people who are not aspirin resistant, according to a study in the latest issue of Circulation: Journal of the American Heart Association.

DALLAS, March 26 – For the first time, researchers have shown that people who are aspirin resistant have a higher risk of dying from heart disease than people who are not aspirin resistant, according to a study in today’s rapid access issue of Circulation: Journal of the American Heart Association.

Related Articles


Aspirin blocks the formation of thromboxane A2, a chemical in the body that makes platelets sticky and promotes blood clotting. However, lead author John W. Eikelboom, MBBS, says it appears that aspirin does not effectively block thromboxane synthesis in some people. This makes them resistant to the protective effects of the drug.

In the study, patients taking aspirin who had a high level of thromboxane in their urine had a 3.5 times higher risk of cardiovascular death than patients who had the lowest level says Eikelboom, a clinical lecturer at the University of Western Australia, Royal Perth Hospital, Perth, Australia.

The American Heart Association recommends aspirin for all patients with artery disease and a second antiplatelet medicine for those with uncontrolled chest pain called unstable angina.

Eikelboom cautions that the findings don’t suggest a need to limit aspirin use. For most patients, aspirin therapy can reduce the risk for cardiovascular events by 25 percent. “Our results suggest that some patients may need more protection than aspirin alone can offer,” he says.

Researchers used data collected by the Heart Outcomes Prevention Evaluation (HOPE) study. This was a randomized, placebo-controlled study that compared the efficacy of a blood pressure drug, ramipril, and vitamin E to prevent heart attacks or stroke in patients with heart disease. The current study is based on data collected on 5,529 patients enrolled at 129 Canadian study sites. All patients provided baseline urine specimens, which were analyzed for levels of a chemical called 11-dehydro thromboxane B2, a byproduct of thromboxane A2.

High levels of 11-dehydro thromboxane B2 in urine can identify patients who are resistant to aspirin. These people may benefit from alternative antiplatelet therapies or treatments that more effectively block thromboxane production.

The researchers identified patients who were taking aspirin for at least six months before study entry and kept taking aspirin throughout the study. During a five-year follow-up, 488 of these patients had a heart attack, stroke or fatal event. Another 488 aspirin-therapy patients who were age and gender matched and did not have an event during follow-up were used as controls. Patients were free to select aspirin doses ranging from 80mg to 325mg a day.

When the researchers divided the cases and controls into quartiles based on 11-dehydro thromboxane B2 levels, those in the highest quartile had twice the risk for heart attack as those in the lowest quartile.

The risk for any cardiovascular event was 1.8 times higher for those in the highest quartile compared to those in the lowest quartile. “The increased risk was consistent. Those in the third quartile had a higher risk than those in the second quartile, while the second was higher than the first,” Eikelboom says. Moreover, the increased risk was independent of other risk factors such as high blood pressure, high cholesterol, obesity, diabetes and smoking.

The researchers didn’t find an association between 11-dehydro thromboxane B2 levels and stroke, but Eikelboom says this is probably due to the small number of stroke cases.

Co-authors are: Jack Hirsh, M.D.; Jeffrey I. Weitz, M.D.; Marilyn Johnston, ART; Qilong Yi, Ph.D.; and Salim Yusuf, D.Phil.


Story Source:

The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.


Cite This Page:

American Heart Association. "Aspirin Resistance Increases Risk Of Death." ScienceDaily. ScienceDaily, 27 March 2002. <www.sciencedaily.com/releases/2002/03/020327072842.htm>.
American Heart Association. (2002, March 27). Aspirin Resistance Increases Risk Of Death. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2002/03/020327072842.htm
American Heart Association. "Aspirin Resistance Increases Risk Of Death." ScienceDaily. www.sciencedaily.com/releases/2002/03/020327072842.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins