HEART FAILURE IN PRIMARY CARE

Heart failure is common, deadly and preventable, affecting around 900,000 people in the UK. Heart failure accounts for about 5% of admissions to general medical or elderly care hospital beds, and readmission rates can be as high as 50% in the six months following initial hospital stay. Annual mortality ranges from 10-50% depending on initial severity. We have developed this Evidence Update to provide clinicians and commissioners with the best available evidence to help them provide better patient care.

Overview: Heart failure is abnormal cardiac function which prevents the heart from pumping efficiently. About 900,000 people in the UK have heart failure, costing the NHS more than £600m every year. The incidence of heart failure increases steeply in the elderly and is more common in men than women.There are many treatments available to keep the condition under control and relieve symptoms. Accurate diagnosis is important to determine the underlying cause and initiate treatments to alleviate symptoms, delay progression and improve prognosis.

Current diagnostic strategies: There is no single diagnostic test for heart failure. Diagnosis relies on clinical judgement based on a combination of history, physical examination and appropriate investigations.

NICE recommends healthcare professionals carry out the following investigations:. 12-lead electrocardiogram (ECG) . and/or natriuretic peptides (BNP or NTproBNP) – where available.If one or both are abnormal, transthoracic Doppler 2D echocardiography should be performed because it consolidates the diagnosis and provides information on the underlying functional abnormality of the heart.

Alternative methods of imaging the heart should be considered when a poor image is produced by echocardiography. Such methods may include radionuclide angiography, cardiac magnetic resonance imaging, or transoesophageal Doppler 2D echocardiography.

New evidence: Two recent systematic reviews on the diagnosis of heart failure in primary care have found potential cost savings of sending some patients with symptoms suggestive of heart failure directly for echocardiography.

Madhok et al (BMC Family Practice 2008, 9:56) looked at symptoms, signs and diagnostic tests in the diagnosis of left ventricular dysfunction (which is responsible for about 50 per cent of heart failure). They found that the clinical sign of a displaced apex beat was very useful, if present, at raising suspicion of heart failure (positive likelihood ratio of 16), and confirmed previous findings that ECG and natriuretic peptide measurements have similar potential as 'rule out' tests.

Mant et al (Health Technol Assess. 2009 Jul;13(32):1-207, iii) supplemented a systematic review of symptoms and diagnostic tests with individual patient data analysis. They found natriuretic peptides superior to ECG in diagnosing heart failure. Natriuretic peptides BNP and NT-proBNP were found to be of similar utility. The review also states that simple clinical features (basal crepitations, previous history of myocardial infarction; ankle oedema and gender) could be used as a way of determining which patients should be referred directly for echocardiography without prior testing.

The potential implications of this work are currently being reviewed by NICE; updated guidance will be published later next year.

Commentary: "The evidence from Mant et al's analysis may need to be taken into account by NICE when reviewing the current guideline. The evidence suggests that BNP (or NT-proBNP) should be recommended over ECG and that some patients should be referred straight for echocardiography without undergoing any preliminary investigation. "Mant et al's cost-effectiveness analysis suggests that a clinical decision rule for diagnosis of heart failure in primary care is likely to be considered cost-effective to the NHS in terms of cost per additional case detected. The cost-effectiveness analysis further suggests that, if the likely benefit to the patient in terms of improved life expectancy is taken into account, the optimum strategy would be to refer all patients with symptoms suggestive of heart failure directly for echocardiography."

Professor Tom Quinn is clinical lead for NHS Evidence - cardiovascular, stroke and vascular collections and Professor of Clinical Practice at the Faculty of Health and Medical Sciences, University of Surrey.