Featured Research

from universities, journals, and other organizations

When It Comes To Heart Attacks, Size Apparently Does Matter

Date:
March 9, 1999
Source:
Duke University Medical Center
Summary:
Just how do doctors figure out if a new drug for heart disease is effective? Most trials look at whether the drug reduces the number of deaths and heart attacks in group of patients taking it, compared to patients who don't. But what if the drug turns a large heart attack, one that could potentially kill the patient, into a smaller heart attack that does less damage?

NEW ORLEANS-- Just how do doctors figure out if a new drug for heart disease is effective? Most trials look at whether the drug reduces the number of deaths and heart attacks in group of patients taking it, compared to patients who don't.

Related Articles


But what if the drug turns a large heart attack, one that could potentially kill the patient, into a smaller heart attack that does less damage? Under the traditional way of testing medicines, the drug wouldn't be deemed effective, because it didn't reduce the number of heart attacks.

And that's far from an academic matter, say researchers at Duke University Medical Center, who argue that the way cardiology trials are conducted should be changed.

"Just counting the number of heart attacks may be the wrong way to measure a drug's effectiveness," says Dr. John Alexander, who prepared the results of his analysis for presentation Sunday at the annual scientific sessions of the American College of Cardiology.

"The fact that we may be able to reduce the size of myocardial infarction (MI) without necessarily reducing the incidence may be very important clinically," said Alexander, a cardiologist at the Duke Clinical Research Institute (DCRI).

Alexander based his findings on a close examination of data from the recently completed 10,948-patient PURSUIT trial of the drug eptifibatide (Integrilin), which was funded by the drug manufacturer, COR Therapeutics Inc., of San Francisco. He and his team found that while the drug slightly reduced the number of myocardial infarctions, it also reduced the size of MIs, possibly by converting larger ones into smaller ones.

Like many studies in heart disease, PURSUIT used the occurrence of an MI -- the death of heart muscle from the sudden loss of blood supply -- as a key part of the principal measurement of whether or not the patient benefited from the therapy. Since not all MIs are clear-cut, however, a committee of cardiologists not involved in the patient's care must determine whether or not an MI actually occurred, based on a review of enzyme levels, ECG tests and other clinical data.

After the trial was completed, the Duke researchers later went back and looked at the peak blood levels of an enzyme called creatine kinase-MB (CK-MB), which is released into the bloodstream by dying heart muscle cells. As more heart muscle dies, more CK-MB enters the bloodstream, making it a biochemical marker for the size of an MI.

They found that patients who received the drug eptifibatide tended to have smaller MIs, as measured by peak levels of CK-MB. More than 35 percent of patients who received eptifibatide had the lowest levels of CK-MB, compared to 29 percent for a placebo. At the highest levels of CK-MB in the blood, 38 percent received eptifibatide, 44 percent got the placebo. According to Alexander, several studies are in the planning stages at the DCRI incorporating the use of continuous endpoints that take into account MI size. The DCRI, which is made up of more than 700 cardiologists and other researchers, maintains the world's largest databank of cardiovascular disease. The fact that fewer people are dying from heart attacks during clinical trials places certain limitations on researchers, he said. For a study to have statistical significance using death as its only endpoint, more than 50,000 patients would need to be enrolled.

"Since this is not very practical, we have essentially been using MI as a surrogate for death," Alexander said. "This enables us to study the effects of drugs using a more manageable number of patients to achieve statistical significance."


Story Source:

The above story is based on materials provided by Duke University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Duke University Medical Center. "When It Comes To Heart Attacks, Size Apparently Does Matter." ScienceDaily. ScienceDaily, 9 March 1999. <www.sciencedaily.com/releases/1999/03/990309062812.htm>.
Duke University Medical Center. (1999, March 9). When It Comes To Heart Attacks, Size Apparently Does Matter. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/1999/03/990309062812.htm
Duke University Medical Center. "When It Comes To Heart Attacks, Size Apparently Does Matter." ScienceDaily. www.sciencedaily.com/releases/1999/03/990309062812.htm (accessed October 24, 2014).

Share This



More Health & Medicine News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
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