It has been proposed that circulating levels of the B-type cardiac natriuretic peptides (BNP and NT-proBNP), which are released from the heart in proportion to stretch of the cardiac chambers, may be used to provide an objective index of circulatory status, to guide treatment in patients with heart failure. This hypothesis was first proposed in the 1990s and there have been several studies conducted since.
A number of organisations do not support routine NP-guided treatment over conventional care, due to insufficient evidence. The NICE clinical guideline on heart failure (2010) recommends that specialist monitoring of serum natriuretic peptides may be considered in some patients (for example, those in whom uptitration is problematic or those who have been admitted to hospital).
In the current analysis, 8 of the 11 identified studies provided individual patient data for the primary endpoint of all-cause mortality. There were differences between the studies in terms of target NP plasma level and treatment algorithm, for example. NP-guided treatment was associated with fewer deaths (172 vs. 207; HR 0.62; 95% CI 0.45-0.86; p=0.004). Although there was no significant heterogeneity, there was a significant interaction between age and treatment efficacy, with a benefit for NP-guided treatment seen only in younger patients (<75 years). Benefits were also noted in various secondary endpoints, including cardiovascular admissions and heart failure hospitalisations.
The authors believe that the results of their analysis should lead to reconsideration of the cautious recommendations from various speciality societies on the use of BNP-guided management of heart failure. However there are some limitations that need to be considered when interpreting the findings, including differences in study design and lack of individual data on adverse events.
The NICE guideline development group reviewed five trials evaluating the use of NP-guided treatment compared to standard clinical care when updating the heart failure guideline. They considered the quality of the evidence to be moderate for the majority of outcomes, and noted that the effects on mortality were only seen when NP-guided therapy was compared to a restricted form of ‘usual care’ (which was considered as suboptimal). Mortality outcomes where NP-guided medical therapy was compared to clinically-guided medical therapy were less dramatic (and not statistically significant).