December 8, 2010

Mortality Predicted By New Blood Test

(Ivanhoe Newswire) -- An ER blood test used to confirm the presence of a heart attack now has another, preventative use.  In more sensitive version, this test can efficiently recognize undetected heart disease in non-symptomatic middle aged individuals, and can consequently prolong their lives.

Researchers at the UT Southwestern Medical Center closely observed this sensitive test, which looks for the presence of a heart disease-linked protein called cardiac troponin T (cTnT).  In a sample group of 3,500 people, 25% of the blood screenings contained cTnT.  Those with the protein in their blood were found to be seven times more likely to die from heart disease within six years.

"This test is among the most powerful predictors of death in the general population we've seen so far," lead author of the study Dr. James de Lemos was quoted as saying.  "It appears that the higher your troponin T, the more likely you are to have problems with your heart, and the worse you're going to do, regardless of other risk factors."

The more sensitive version of the test has been proven to be much more effective than the standard version, which can only recognize cTnT in a small fraction of the population.  The sensitive test, on the other hand, is able to recognize the protein in nearly every victim of chronic heart failure and chronic coronary artery disease.

"Because this test seems to identify cardiovascular problems that were previously unrecognized, we hope in the future to be able to use it to prevent some death and disability from heart failure and other cardiac diseases," Dr. de Lemos was quoted as saying.

Dr. de Lemos' study is an expansion of his previous, innovative research on cardiovascular disease called the Dallas Heart Study, in which he observed over 6,100 Dallas County citizens.  That study concluded that the standard testing technology could only find cTnT in 1% of the entire population.

In the latest study, newer and more sensitive technology was brought in to test the same group of people, including magnetic resonance imaging and computer tomography.  These methods helped the researchers study the heart and other organs of the participating men and women.  After making these observations, they then looked at the participants' cause and time of death.

A companion paper confirmed the study's results.  Co-written by Dr. de Lemos and led by University of Maryland School of Medicine researcher Dr. Christopher deFilippi, the subsequent study used the sensitive test to exclusively observe participants older than 65.  The study confirmed the relationship between cTnT and the likelihood of mortality, and also linked the protein to heart failure.  The risks of those grave problems increased and decreased in tandem with the fluctuation of cTnT levels over time.

SOURCE: JAMA, December 8th, 2010