The blood test that detects heart failure
Channel: York Cardiology
Date: 2019-08-18

Today I am going to talk about a really interesting blood test that detects weakness of the heart muscle (heart failure). This test is called BNP.  BNP stands for brain natriuretic peptide and this test is already being used commonly in medical practice.

Before I talk about this BNP, I wanted to start off by talking about heart failure.  In heart failure, the fundamental problem is that the heart is unable to pump blood to match the body’s requirements. The common symptoms therefore include breathlessness, fatigue, ankle swelling and exercise intolerance. Patients with heart failure can’t push themselves as much as normal people and therefore have a much more limited exercise capacity. It is also worth understanding that in the early stages, the heart failure may not cause any symptoms at all and therefore can be very difficult to detect.

There are several problems with heart failure:

People with a weak heart don’t, in general, live as long as people with a strong heart (but with treatment, we can definitely improve prognosis)

People with a weak heart,in general, don’t have as good a quality of life as people with a strong heart (but with effective treatment we can definitely improve quality of life)

We recognise that without treatment, the weakness of the heart can continue to worsen and therefore early detection and treatment is essential

The symptoms can be quite non specific and don’t necessarily immediately point to the diagnosis (Breathlessness/ tiredness/leg swelling etc). They also don’t correlate with severity of heart failure.

The gold standard test to make the diagnosis is an echocardiogram which is a specialist investigation, needs trained personnel and therefore not as easily available.

So in essence, Heart failure is an important, disabling and dangerous condition which can be treated quite effectively (if treated early) but the symptoms are non-specific and the gold standard test is not as easily or quickly available; and therefore the idea of a simple blood test to make the diagnosis is really very attractive. This is where the BNP blood test comes in.