What in your view are the major advantages of early NT-proBNP testing in patients suspected with acute or chronic heart failure?
NT-proBNP is such a useful test in patients with suspected heart failure (HF). The beauty of it is that, if you have someone who has shortness of breath, particularly attending the emergency department of a hospital and the NT-proBNP is below 300pg/mL, or BNP is below 100pg/mL, then it’s very unlikely to be heart failure. If it is elevated, then it is probably heart failure as long as you are excluding other causes like renal dysfunction, ischemic heart disease, atrial fibrillation, sepsis, tachycardia, chronic lung disease and hypoxia. If you’ve excluded those things and the NT-proBNP is elevated, it is heart failure. It is a way of improving clinical confidence and it is a way of triaging patients to the right care. So, if they are in an emergency department, it’s a good way of saying “that patient is respiratory, and that patient is probably cardiology”. It improves that clinical confidence.
It is also a good marker of severity. So if it’s really high, we can say that this patient has got pretty bad heart failure, we need to get on to things and treat them more aggressively. Also, it’s a good way of monitoring their progress. So if you have an NT-proBNP which is elevated and then it goes up further, and if the patient is not doing well, they are not responding to therapy, then you have got to be more intensive, more aggressive with their therapy. If it is coming down, you know they responded to the treatment and you did a good job.
The other thing is that it’s a good way of triaging patients into whether to do echocardiography or not. If it’s low, we can avoid that expensive test. If it’s elevated, we will then go on to do echocardiography. Remember there are problems with echocardiography access, particularly in rural areas, in remote areas and in some places where the waiting times can be long. So, it is a good thing to do to triage our patients. So, NT proBNP can be very helpful in those situations.
The other place where it’s been shown to be a benefit is in patients with type 2 diabetes. The PONTIAC study looked at patients with type 2 diabetes and they measured the NT proBNP. If it was elevated, they were then randomised to standard care or they were randomised to more aggressive treatment to bring down the NT proBNP by using things like uptitrating ACE inhibitors and ARBs, and uptitrating the beta-blockers. The patients showed improvement in clinical outcomes by uptitrating those medications in patients with type 2 diabetes with elevated NT proBNP versus standard therapy. So, it can be a way of helping us to be more aggressive in the high-risk patients in type 2 diabetes. I think this would be a great way to be able to triage a patient with type 2 diabetes to the high-risk and low-risk patients because two-thirds of type 2 diabetes patients die of cardiovascular disease. If you look at people who have got type 2 diabetes for more than 5 years, at least two-thirds will have either systolic dysfunction, diastolic dysfunction or other parameters of heart failure. So basically, type 2 diabetes, more than 5 years, we should be considering whether they have some heart failure in their background as far as they can be the least concern.
