Peripheral vascular disease was also found to be a relevant comorbidity explaining some of the association between the treatment affect and age. However, the authors of that analysis emphasise that these potential reasons for the lower effectiveness of more intensified therapy (NP monitoring) must remain speculative and should be best regarded as hypothesis generating until confirmed by further prospective Chronic Heart Failure Monitoring NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Recommendations Consider measuring NT-proBNP (N-terminal pro-B-type natriuretic peptide) as part of a treatment optimisation protocol only in a specialist care setting for people aged under 75 who have heart failure with reduced ejection studies. Based on the above, the committee discussed whether the existence of comorbidities could be substituted for age in the recommendation, in terms of the population in which NP monitoring may be suitable. The committee decided against this given the speculative nature of the finding that comorbidities rather than age per se explained the differential results in different age groups, and the uncertainty about which comorbidities were most relevant. The committee agreed that as the evidence reviewed clearly showed an age- effect above and below 75 years, it was appropriate to stratify the recommendation by this factor. However, it was unanimously agreed that age should not be an absolute barrier to (or indication for) NP monitoring, and that a person s general health and the presence of comorbidities should always be considered on a case by case basis when considering NP monitoring. Role and scope of NP monitoring The committee discussed the heterogeneous nature of the NP-guided treatment protocols used in the included studies. 