We very much agree with the comments regarding variability in laboratory testing for BNP and NT-pro-BNP. As pointed out, this variability is an important factor in considering the use of sequential levels of this peptide to guide the treatment of the individual patient with heart failure. However, this was not the purpose of our analysis. Our analysis was to pool the individual studies that addressed BNP-guided therapy (with all of its attendant caveats including biological variability and laboratory error) and ascertain the robustness of its utility in reducing subsequent major events.
Krum H, Porapakkham P. The Challenges of Properly Identifying the Cause of Heart Failure Hospitalization—Reply. Arch Intern Med. 2010;170(14):1274-1275. doi:10.1001/archinternmed.2010.232