The updated NICE clinical guideline on the management of chronic heart failure (CG108) heralds a new dawn in the diagnosis of heart failure in primary care.1 It is one of the most difficult organ failures to detect through history and examination. Patients with very severe heart failure may have few or even no physical signs, and GPs have been proven to be unreliable in interpreting electrocardiograms (ECG).2
B-type natriuretic peptide
The major changes in the NICE recommendations cover the use of B-type natriuretic peptide (BNP) and N-terminal (NT) proBNP as tools for the GP to use in the front line, and the speed with which patients should be assessed by the heart failure team.
Recommendations on using BNP in primary care have been a long time coming, dogged by perceived high costs and resistance by some consultants who have access to diagnostics in hospital and do not see things from the GP’s point of view. It is not the GP’s job to make a definite diagnosis of heart failure; it is their job to send the patient—promptly—to the right specialty. B-type natriuretic peptide now allows us to do this as no test ever has before for heart failure. Put very plainly, a normal BNP just about rules out heart failure; add in a normal ECG and you really have excluded this condition. A raised BNP is simply a ‘ticket for echocardiography’ for that patient.
The challenge for GPs is to embed this thinking into everyday practice, to remember to measure BNP, and to get a ‘feel’ for what the results indicate. Raised BNP is a reflection of cardiac stress and strain and so will be raised by—well almost anything! The main causes of a raised BNP level are:1,3,4
- cardiac ischaemia
- atrial fibrillation
- valve diseases
- lung disease
- hypertension/left ventricular hypertrophy leading to diastolic dysfunction (resistance to filling)
- left ventricular systolic dysfunction (LVSD).
So BNP is not the ‘blood test for heart failure’ and it would be wrong to start treatment, for example with an angiotenin-converting enzyme (ACE) inhibitor without the echocardiogram, but with a 2-week wait you should not need to. All that you need to do is prescribe a little diuretic for patient comfort while they await referral.
When to measure BNP
Patients with previous cardiac form (e.g. a myocardial infarction) are excluded—the reason being that in this population the incidence of LVSD is high (22% in a study by Davis et al5 and 28% in my own practice list). To avoid the cost of measuring BNP levels, refer directly—it is likely that a breathless patient with a previous myocardial infarction does have left ventricular failure.
Signs that may indicate heart failure are listed below:
- Symptoms in a patient with a previous history of diabetes and hypertension
- Unexplained fatigue—tired all the time with cardiac risk factors
- The chest infection that fails to improve
- Frequent exacerbations of chronic obstructive pulmonary disease—some studies have shown a 20% incidence of LVSD in this group of patients so it is worth considering heart failure in these individuals.6
The 2-week rule is brave and bold and I applaud the Guideline Development Group for this.1 Grade IV heart failure has a worse prognosis than most common cancers except lung cancer.7 If a woman presented with an obvious breast cancer, with lymph nodes, no GP would ever send her away with tamoxifen and a review appointment in a month. The same is true of heart failure, the consultations that used to result in a month of frusemide and a follow up in 4 weeks are now history. Patients can expect a rapid diagnosis and a treatment plan on a par with cancer. And rightly so; heart failure has spent a decade not being recognised as the severe illness that it is.
The NICE guidance ‘ups the ante’ for GP commissioners, and for the half of the country that does not have access to BNP testing it will certainly be a challenge. For some commissioners it is going to be a headache—investing in a new service when it is increasingly hard to pull the money out of other areas. But prompt diagnosis and management can result in cost savings in the long run—if we can stop that myocardium stretching and failing, patients can expect a longer delay until their first hospital admission.
The impact of the NICE guideline on heart failure will be felt in a number of ways:
- No more referring to respiratory specialists when the diagnosis is heart failure
- No more wondering ‘what if’ when the patient has left the room
- GPs can be thankful that they can access a test that reduces uncertainty—and there is plenty of this in general practice
- Patients with heart failure can be thankful that a blood test that has been around for 20 years, can help lift them out of their misery
- Echocardiography departments can be thankful that the number of normal and ‘wasted’ echocardiograms are reduced (approximately 40% of BNP tests are normal [author’s own audit])
- Cardiologists can be thankful that their clinics are full of cardiology patients because measuring BNP helps to identify these individuals.
We can be thankful that we can now rule out heart failure with confidence, and set patients with a raised BNP on the correct pathway swiftly—isn’t that what GPs are supposed to do?
- National Institute for Health and Care Excellence. Chronic heart failure: Management of chronic heart failure in adults in primary and secondary care. London: NICE, 2010. Available at: www.nice.org.uk/guidance/CG108
- Jeyaseelan S, Struthers A, Goudie B et al. The accuracy of ECG screening by GPs and by machine interpretation in selecting suspected heart failure patients for echocardiography. Br J Cardio 2006; 13 (3): 216–218.
- National Clinical Guideline Centre for Acute and Chronic Conditions. Chronic heart failure: National clinical guideline for diagnosis and management in primary and secondary care. London: NCGC, 2010. Available at: www.nice.org.uk/guidance/CG108
- Gardner R, McDonagh T, Walker N. Oxford handbook of heart failure. Oxford: Oxford University Press, 2007.
- Davis R, Hobbs F, Kenkre J et al. Prevalence of left ventricular systolic dysfunction and heart failure in high risk patients: Community based epidemiological study. BMJ 2002; 325 (7373): 1156.
- Rutten F, Cramer M, Grobbee D et al. Unrecognized heart failure in elderly patients with stable chronic obstructive pulmonary disease. Eur J Heart Fail 2005; 26 (18): 1887–1894.
- Survival with common cancers and heart conditions. Bandolier 2002; 95 (2). Available at: www.medicine.ox.ac.uk/bandolier/band95/b95-2.html G