Featured Research

from universities, journals, and other organizations

Chemical Marker Of Heart Muscle Death Accurately Predicts Future Heart Attack Risk

Date:
November 15, 2001
Source:
Duke University Medical Center
Summary:
Patients who test positive for the presence of a specific biochemical marker of heart cell death in their blood but who do not exhibit other risk factors for future heart attack should be treated as higher risk patients, according to a new analysis by cardiologists at Duke University Medical Center.

ANAHEIM, Calif. – Patients who test positive for the presence of a specific biochemical marker of heart cell death in their blood but who do not exhibit other risk factors for future heart attack should be treated as higher risk patients, according to a new analysis by cardiologists at Duke University Medical Center.

The researchers found that troponin, a protein that is released into the bloodstream as heart muscle cells die, can be a reliable indicator of future risk even when other traditional measures of heart health are negative. This is important, the researchers say, in light of the recent recasting of the definition of heart attack by the major cardiology organizations to place more emphasis on the results of troponin testing, in addition to the presence of chest pain and electrocardiogram abnormalities.

When a patient comes to the emergency room as a possible heart attack victim, physicians typically measure the heart's electrical activity (EKG) and also look for chemicals in the blood that might indicate if heart muscle is damaged or dead. For years, they have measured the levels of creatine kinase-MB (CK-MB) and, more recently, they also have been testing for troponin. Because the test for troponin can detect even small amounts of heart muscle damage, patients previously testing positive for troponin but negative for CK-MB were not always treated as being at high-risk.

"Our analysis shows that patients who test positive for troponin but not for CK-MB should still be treated as if they tested positive for both," said Duke cardiology fellow Dr. Sunil Rao. "This is important because in the past, these patients would usually not be treated aggressively."

Rao prepared the results of his study for presentation during the 74th annual scientific sessions of the American Heart Association. Both troponin and CK-MB are proteins within cells that spill out into the bloodstream as the cell wall breaks apart during cell death. The difference between the two is that troponin is only released by heart muscle, while CK-MB can be released by both dying heart and skeletal muscle.

"We believe that even low levels of troponin in the bloodstream indicate the presence of tiny heart attacks, or infarctlets," Rao explained. "The question is, does the death of a few heart cells matter, and can they be a reliable predictor of larger infarctions, or heart attacks, in the future?"

According to the Duke analysis, it does matter.

Rao and colleagues scoured the data collected from three different multi-center trials to measure the prognostic value of elevated and isolated troponin levels. Two of trials – PARAGON-B and GUSTO IIa – followed high-risk heart attack patients, and the other, CHECKMATE, looked at low-risk patients.

Patients were divided into three groups – those who were positive for both troponin and CK-MB, those who were positive for only troponin, and those positive only for CK-MB. The team found the incidence of death or heart attack after 30 days was the same for patients who only tested positive on the troponin test as for those who tested positive on both.

The researchers feel that the troponin test, which is an extremely specific and sensitive indicator of cardiac cell damage, can help physicians detect those patients who would be described as low-risk, but who actually are at a higher-risk of future cardiac events. They would even argue that troponin levels should be used instead of CK-MB in the definition of heart attack.

"For patients who come in with chest pain, EKG abnormalities and elevated markers, it is a straightforward decision to admit them to cardiac care units and begin treatment," said Duke cardiologist Dr. Kristin Newby, senior member of the research team. "However, there are many patients who may have some chest pain and unremarkable EKGs, so the chemical markers become an important determinant in how we treat them. Based on this analysis, for those with apparently ischemic symptoms, we should place equal emphasis on aggressively managing patients with only troponin elevation as on those with elevations of both markers.

"The risk of future cardiac events appears to be proportionate to degree of elevation of cardiac markers like troponin – so any elevation means risk," Newby said. "Any cell death, even if small, can be a powerful indicator of future bad events."

Other members of the Duke team were Vic Hasselblad, Robert Christenson, Dr. W. Brian Gibler, Dr. Christopher Granger and Dr. Magnus Ohman. The data analysis was supported by the Duke Clinical Research Institute.


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. "Chemical Marker Of Heart Muscle Death Accurately Predicts Future Heart Attack Risk." ScienceDaily. ScienceDaily, 15 November 2001. <www.sciencedaily.com/releases/2001/11/011115072345.htm>.
Duke University Medical Center. (2001, November 15). Chemical Marker Of Heart Muscle Death Accurately Predicts Future Heart Attack Risk. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2001/11/011115072345.htm
Duke University Medical Center. "Chemical Marker Of Heart Muscle Death Accurately Predicts Future Heart Attack Risk." ScienceDaily. www.sciencedaily.com/releases/2001/11/011115072345.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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:
from the past week

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