NEW YORK (Reuters Health) – The management of heart failure guided by an individualized target level of N-terminal pro-B-type natriuretic peptide (NT-proBNP) doesn’t lead to clinically significant improvements in mortality and morbidity, according to the results of the PRIMA study.

“Natriuretic peptides may be attractive biomarkers to guide management of heart failure and help select patients in need of more aggressive therapy,” Dr. Yigal M. Pinto at the University of Amsterdam, the Netherlands, and colleagues note in the December 14/21 issue of the Journal of the American College of Cardiology.

The PRIMA study involved 345 patients hospitalized with decompensated heart failure and elevated NT-proBNP who were randomized after discharge to therapy guided by an individually set NT-proBNP target level in addition to clinical signs, or by clinical signs only.

“The individual NT-proBNP target value was set at the lowest level at discharge or at 2 weeks follow-up,” the investigators explain. “If at subsequent outpatient visits, NT-proBNP levels were more than 10% with a minimum of 850 pg/ml above this individual target level, NT-proBNP level was considered ‘off-target,’ and therapy was intensified.”

Almost two-thirds (64%) of heart failure-related events were preceded by an increase in NT-proBNP, according to the report.

However, heart failure management guided by NT-proBNP targets did not significantly prolong survival after hospital discharge, the primary endpoint, Dr. Pinto and colleagues report. Specifically, the patients managed by targeted NT-proBNP levels survived a median of 685 days outside the hospital after the index admission, compared with 664 days among the clinically managed group.

“A number of reasons may account for this lack of significant Improvement,” the authors suggest. For example, it may be that intensifying treatment when use of evidence-based therapy is already high is not enough to avert an adverse event, or perhaps “gold-standard” heart failure therapy is just altogether inadequate.

Dr. Pinto and colleagues conclude, “PRIMA shows that unstable NTproBNP levels indeed indicate imminent events, but that intensification of currently used medication in patients on optimal HF therapy does not prevent further deterioration.”

The authors of an accompanying editorial say the results highlight the limitation of individualized NT-proBNP targets.

Drs. Richard W. Troughton, Chris M. Frampton, and M. Gary Nicholls, at the University of Otago in Christchurch, New Zealand suggest, “Use of a single target level of BNP or NT-proBNP, perhaps adjusted for clinical covariates such as age, appears to offer the best opportunity for the biomarker-guided strategy to alter management.”

J Am Coll Cardiol 2010;56:2090-2100.