N-terminal proBNP—the most cost effective way to identify post myocardial infarction left ventriular dysfunction?

The idea that plasma levels of natriuretic peptides might be clinically useful to identify cardiac patients at high risk has been around for a long time and has attracted much attention. It is an idea which has always appealed more to non-cardiologists, especially family practitioners than to cardiologists. Understandably, cardiologists have more access to echocardiography than other doctors and prefer the more detailed information on cardiac structure and function which come from echocardiography. Noncardiologists are more often in the business of trying to decide which patients to refer to cardiologists and it is here that plasma levels of natriuretic peptides are likely to be of benefit. Hence non-cardiologists are often more attracted to the idea of natriuretic peptide screening than are cardiologists. The above is one of the reasons for the slow uptake of natriuretic peptide levels into clinical practice. Another reason is that natriuretic peptide experts appear to keep changing their minds on which natriuretic peptide level provides the best clinical information. Initially, it was ANP, followed by N-terminal proANP followed by BNP. Now there is N-terminal BNP. The paper in this issue on N-terminal BNP by Talwar et al. adds greatly to the information required to decide which peptide to sample, when to sample it and how to interpret its value and I will discuss these issues below. However, perhaps the most important contribution to this whole debate comes from one sentence in their discussion where they say, ‘assays of N-BNP are highly cost effective, each test costing under £1, compared to the cost of echocardiography (£60-£80).’ No doubt, experts will argue about these precise costs, but even if they are only ballpark figures, it is very striking that there is a 70 cost difference between these two tests. Since we all now live and work in health care systems which are concerned about spiraling costs, such a cost difference cannot be ignored. It could even cause