researchers found high blood levels of troponin T and NT-proBNP were
associated with as much as 3 and 3.5 times the amount of damaged brain
tissue, respectively. The findings are part of the large-scale
Atherosclerosis Risk in Communities (ARIC) study, funded by the National
Heart, Lung, and Blood Institute.
"The concept of prevention is
expanding," said principal investigator Christie Ballantyne, M.D.,
director of the Center for Cardiovascular Disease Prevention at The
Methodist Hospital. "It's not good enough to simply do a few tests and
try to assess risk for heart attack. What we need to do is assess the
risk for heart attack, stroke, heart failure and also asymptomatic
disease so we can start preventive efforts earlier. Waiting to correct
problems until after a symptomatic stroke may be too late."
One possible outcome is that patients determined to be in high-risk groups could be started on anti-stroke medications sooner.
another ARIC paper published two months ago in Stroke, Ballantyne and
coauthors reported a strong association between blood levels of troponin
T and NT-proBNP and more severe instances of stroke, called symptomatic
stroke. The current study looked at the two biomarkers and
"subclinical," asymptomatic events in the brain that are usually caused
by a lack of blood flow.
"Taken together, these two papers show
the biomarkers are effective at identifying people who are likely to
have mild brain disease and stroke well before damage is done," said
Ballantyne, who also is a Baylor College of Medicine professor. "This
hopefully will give doctors more time to help patients take corrective
steps to protect their brains."
For the subclinical brain disease
study, researchers gleaned data from about 1,100 patient volunteers who
agreed to have blood drawn and two MRI scans eleven years apart to look
for silent brain infarcts and also white matter lesions (WMLs) caused by
Statistical analysis showed a strong
relationship between high NTproBNP and the likelihood of brain infarcts
and WMLs. Study participants with the highest levels of NT-proBNP had as
much as 3.5 times the number of brain infarcts as participants with low
NT-proBNP levels, and more WMLs. Those with the highest levels of
troponin T had as much as 3.0 times the number of brain infarcts and
The protein troponin T is part of the troponin complex and its presence is often used to diagnose recent heart attacks. NT-proBNP is an inactive peptide fragment left over from the production of brain natiuretic peptide (BNP), a small neuropeptide hormone that has been shown to have value in diagnosing recent and ongoing congestive heart failure.
"The highly sensitive troponin T test we used is
not approved for general clinical use in the US yet, but the NT-proBNP
test is just now starting to be used more widely beyond making a
diagnosis for heart failure," Ballantyne said.