(HealthDay News) -- Using the biomarker molecule known as brain natriuretic peptide (BNP) to guide treatment for older people with chronic heart failure did not improve the clinical outcome in most cases in a Swiss study. There have been conflicting reports about the value of monitoring blood levels of BNP, a protein produced by stressed heart cells, for better management of heart failure. For example, a French study reported in 2007 found that BNP monitoring reduced deaths and hospitalizations in a 115-participant trial. But the new study, published in the Jan. 28 issue of the Journal of the American Medical Association by physicians at University Hospital Basel, found that BNP-monitored therapy guidance generally did not improve 18-month survival or quality of life over conventional symptom-guided therapy. All the people in the trial were 60 or older. All were hospitalized for heart failure, and all had BNP blood levels at least double the normal readings.…