Recommendations for research

The guideline committee has made the following key recommendations for research. The committee's full set of research recommendations is detailed in the full guideline.

1 Diuretic therapy for managing fluid overload in people with advanced heart failure in the community

In people with advanced heart failure and significant peripheral fluid overload, what is the clinical and cost effectiveness of oral, subcutaneous and intravenous diuretic therapy in the community?

Why this is important

This research is critical to inform practice of how best to manage people with advanced heart failure in the community if they develop significant peripheral fluid overload. These people are more likely to have multiple admissions that, together with fluid overload, have a negative impact on their quality of life. Management in the community can minimise disruption for the person and reduce costs from hospital admissions. Knowledge of the most clinically and cost-effective routes of administration for diuretic therapy will dictate the level of resource needed to provide the service. Intravenous and subcutaneous diuretics usually need to be administered by nursing or healthcare staff. although a pump for self-administration of subcutaneous diuretics has recently been developed. Oral formulations can be self‑administered.

2 Cardiac MRI versus other imaging techniques for diagnosing heart failure

What is the optimal imaging technique for the diagnosis of heart failure?

Why this is important

The role of cardiac MRI in the detection and characterisation of several structural and functional cardiac abnormalities has become well established over the past 25 years. In people with heart failure, cardiac MRI provides reliable and reproducible assessments of the left ventricular (and to a degree the right ventricular) shapes, volumes and ejection fractions. It also provides spatial assessments of the congenital and acquired structural abnormalities of the heart and their interrelationships with the remainder of the heart, as well as functional and haemodynamic assessments of these abnormalities on the heart's performance. Finally, cardiac MRI provides valuable information about the myocardial structure and metabolism, including the presence of inflammation, scarring, fibrosis and infiltration. Cardiac MRI is an expensive form of imaging, and much of this diagnostic information could be provided by less costly non-invasive imaging techniques, chiefly echocardiography. This question aims to find the most clinically and cost-effective imaging technique for the clinical diagnosis of heart failure.

3 The impact of atrial fibrillation on the natriuretic peptide threshold for diagnosing heart failure

What is the optimal NT‑proBNP threshold for the diagnosis of heart failure in people with atrial fibrillation?

Why this is important

Atrial fibrillation is a common arrhythmia in the general population, and occurs in 30 to 40% of people with heart failure. Atrial fibrillation can raise the level of serum natriuretic peptides, including NT‑proBNP, even in the absence of heart failure. This is complicated further in heart failure with preserved ejection fraction, in which 2 echocardiographic diagnostic criteria become unreliable (the left atrial volume and the tissue doppler imaging assessment of diastolic function). These factors contribute to the complexity of the diagnosis and have a potential impact on the usual thresholds for NT‑proBNP in people who have atrial fibrillation. This has been recognised in several ongoing randomised controlled trials of heart failure, which are using higher NT‑proBNP thresholds for the diagnosis of heart failure in people with atrial fibrillation.

4 The impact of advanced kidney disease on the natriuretic peptide threshold for diagnosing heart failure

What are the optimal NT‑proBNP thresholds for diagnosing heart failure in people with stage IIIb, IV or V chronic kidney disease?

Why this is important

Heart failure incidence and prevalence increase with age, with the rise starting at age 65 and peaking between 75 and 85. Both advancing age and heart failure are associated with a gradual and progressive decline in renal function. In addition, the progression of heart failure and some treatments for heart failure lead to progressive deterioration of renal function. A decline in renal function is associated with increased fluid retention and a rise in the level of the serum natriuretic peptides, including NT‑proBNP, even in the absence of heart failure. There is some evidence that the use of higher NT‑proBNP thresholds would improve diagnostic accuracy for heart failure in people with significant deterioration of creatinine clearance.

5 Risk tools for predicting non-sudden death in heart failure

What is the most accurate prognostic risk tool in predicting 1‑year mortality from heart failure at specific clinically relevant thresholds (for example, sensitivity, specificity, negative predictive value and positive predictive value at a threshold of 50% risk of mortality at 1 year)?

Why this is important

There are a number of validated prognostic risk tools for heart failure but most do not report sensitivity and specificity at clinically relevant thresholds. This information is crucial to enable accurate prediction of a person's risk of mortality. The ability to accurately predict a person's prognosis would allow clearer communication and timely referral to other services such as palliative care. Inaccurate prediction has the potential to lead to significant psychological harm and increased morbidity.