Jan. 9, 2007 -- A simple blood test may help doctors identify heart patients
who are at high risk for having heart attacks, strokes, and heart
The test, which measures blood levels of a protein called NT-proBNP, was
found to be highly predictive of such cardiovascular events in a study
involving almost 1,000 heart patients thought to have stable coronary heart
Patients with the highest levels of the protein in their blood were eight
times as likely as patients with the lowest levels to die or suffer a heart
attack, stroke, or heart failure
during the study. Even taking into account other risk factors such as sex, age,
smoking, and cholesterol levels, there was still an increased rate of such
NT-proBNP was found to independently predict cardiovascular risk, suggesting
it can be a useful addition to tests already used in heart disease, like
echocardiograms (a sonogram of the heart), stress tests, and other
The study is published in the Jan. 10 issue of The Journal of the
American Medical Association.
"We have known that this marker was predictive, but the question has been,
'Does it really tell us anything that these other tests don't tell us?'"
researcher Kirsten Bibbins-Domingo, MD, PhD, tells WebMD. "We found that it
does, and the hope is that it can be used with these tests to help physicians
pinpoint which patients have the highest risks."
The blood test is already used in hospital emergency departments to help ER
doctors identify heart failure in patients who have shortness of breath and
other symptoms of the disease. Heart failure occurs when the heart's ability to
pump blood is weakened, which can result in a backup of fluid in the lungs and
Protein Levels vs. Heart Risk
It has not been clear if the test has value for predicting risk in
asymptomatic heart patients thought to have stable heart
In an effort to address this issue, Bibbins-Domingo and colleagues from the
University of California, San Francisco and the San Francisco VA Medical Center
assessed the association between plasma NT-proBNP levels and cardiovascular
risk in 987 patients followed for an average of 3.7 years.
The annual event rate among patients with the highest NT-proBNP levels at
study entry was 19.6%, compared with just 2.6% among patients with the lowest
There were four times as many heart attack cases reported among patients
with the highest levels of the protein compared with those with the lowest, and
four times as many strokes.
But the strongest association was seen for heart failure. Eighty cases of
heart failure were reported among patients with the highest NT-proBNP levels,
compared with just three cases among patients with the lowest levels.
"After adjusting for all other risk factors, it's clear that this marker is
picking up something that we are otherwise unable to detect with standard tests
such as echocardiography," says study researcher Mary Whooley, MD.