Marker for Heart Failure Works in Kidney Patients
Study found renal disease did not alter accuracy of blood test
TUESDAY, Dec. 27, 2005 (HealthDay News) -- A blood test that checks for a marker called NT-proBNP can diagnose heart failure in people with chronic kidney disease and identify which ones are at higher risk for death, says a new Massachusetts General Hospital (MGH) study.
"It is well understood that kidney disease reduces the usefulness of testing for both NT-proBNP and a related biomarker called BNP, and the conventional understanding was that NT-proBNP was the more affected of the two," study senior author Dr. James Januzzi Jr., of the MGH Cardiology Division, said in a prepared statement.
"However, while kidney disease did lead to higher values of NT-proBNP in our study, what really matters is clinical performance; and at optimal cut-points, no matter how hard we looked, we found the relationship between chronic kidney disease and the diagnostic accuracy of NT-proBNP was no different than that of BNP. Our findings thus directly contradict observations based on smaller, less-characterized patient populations," Januzzi said.
The study received funding from Roche Diagnostics, which makes the NT-proBNP assay used in the study.
Previous research found that testing for NT-proBNP was highly effective in diagnosing acute heart failure and risk of death in patients with shortness of breath. However, there was concern that kidney disease -- a common problem for heart failure patients -- might confound the results of NT-proBNP testing.
Some researchers have argued that BNP was less affected by chronic kidney disease than was NT-proBNP, Januzzi noted.
"When you consider the data in totality, there just does not seem to be much difference between these two markers with respect to their diagnostic usefulness in patients with kidney disease. While kidney disease modestly reduces the diagnostic accuracy of both markers, when used in the appropriate manner, both tests appear to return identical information," Januzzi said.
The study will be published in the Jan. 3 issue of the Journal of the American College of Cardiology.
The American Heart Association has more about heart failure.