Biomarkers in Patients With Suspected HFpEF

Biomarkers in Patients With Suspected Heart Failure With Preserved Ejection Fraction

NT-proBNP does not adequately identify HF(pEF) in people with suspected HF at low levels, particularly in patients with obesity. This study will investigate:

1. alternative cut-offs for NT-proBNP to identify HF(pEF) in people with suspected HF and obesity
2. novel candidate biomarkers to identify HF(pEF) in people with suspected HF and obesity.
3. novel candidate biomarkers to identify HF(pEF) in people with suspected HF and NT-proBNP <125 ng/L
4. the prevalence of HF in people with suspected HF and low NT-proBNP <125 ng/L)

This will be a prospective observational, non-randomised study of patients in primary care with suspected HF.

Detection of HFpEF in people without obesity is well-served by NT-proBNP. In contrast, NT-proBNP does not perform well when used to detect HFpEF in populations with obesity. There is increasing evidence that some people with low levels of NT-proBNP can have HF. As many as 50% of people with obesity and HFpEF (detected by elevated filling pressures) have NT-proBNP <125 ng/L. Some patients with HFpEF who are not obese can also have low natriuretic peptides levels.

Delayed diagnosis can lead to adverse outcomes for patients, in particular presentation acutely to secondary care. In addition to this, some patients with HFpEF who are not obese can also have low natriuretic peptides levels.

Patients with NTproBNP levels performed in the community for stable symptoms of suspected heart failure will be invited to participate.

Assessments in this study will include clinical history and examination, patient-reported outcome measures, electrocardiography, echocardiography and biomarker (blood and urine) analysis. Heart failure diagnostic scores and clinical evaluation by heart failure experts will be used to make a clinical diagnosis of heart failure, and to correlate this with levels of plasma and urine biomarkers, both established and novel.

Patients will be followed up passively (for a minimum of 10 years) using record linkage for subsequent hospitalisations or deaths.

Inclusion Criteria:

• Written informed consent
• Age ≥ 18 years
• NT-proBNP sample taken by primary care physician as part of routine care for suspected heart failure

Exclusion Criteria:

• Unable to consent to inclusion in study due to significant cognitive impairment
• Geographical/ social reasons preventing attending study centre
• Unable to complete study assessments
• Patients presenting with acute HF or a previous diagnosis of HF