Point of Care NT-proBNP Testing for Suspected New Heart Failure Acute Care

Heart failure (HF) is a serious condition in which the heart is unable to pump blood effectively around the body. It affects millions of people worldwide and is a common cause of hospital admission. Symptoms of HF, such as breathlessness, tiredness and swelling, can be difficult to distinguish from other medical conditions, which may lead to delays in diagnosis and treatment. Earlier diagnosis and treatment are associated with improved patient outcomes and may reduce the need for prolonged hospitalisation.

National and international clinical guidelines recommend measuring levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), a hormone released by the heart when it is under strain, to help diagnose or exclude HF. Currently, NT-proBNP samples are typically sent to a laboratory for analysis. Although accurate, laboratory testing may take several hours before results are available, potentially delaying clinical decision-making.

Point-of-care testing (POCT) is an alternative method that enables NT-proBNP levels to be measured at the patient's bedside. Results are available within approximately 12 minutes, allowing clinicians to use the information much earlier during assessment and treatment planning. While POCT has the potential to improve the speed of care, there is limited evidence regarding its impact on clinical outcomes in patients presenting to hospital with suspected new HF.

This study will evaluate whether introducing POCT NT-proBNP testing improves the timeliness of HF diagnosis and treatment compared with usual care. The study will also explore the impact of POCT NT-proBNP testing on hospital outcomes and evaluate healthcare professionals' experiences of implementing the test in routine clinical practice.

The study will be conducted in three phases.

Phase 1: Intervention Cohort

During Phase 1, adults presenting to hospital with symptoms suggestive of new HF will receive POCT NT-proBNP testing as part of their clinical assessment. The test will be performed using a point-of-care device, providing results within minutes of blood collection.

Clinical data will be collected prospectively over a six-month period. The primary outcomes will be:

Time from hospital presentation to confirmed HF diagnosis. Time from hospital presentation to initiation of HF treatment.

Secondary outcomes will include:

Length of hospital stay. Thirty-day hospital readmission. Thirty-day all-cause mortality.

The study will assess whether rapid availability of NT-proBNP results is associated with earlier diagnosis and treatment of HF.

Phase 2: Retrospective Comparison Cohort

Phase 2 will involve reviewing data from patients diagnosed with HF during the six months before the introduction of POCT NT-proBNP testing at the study site. These patients received standard care without access to bedside NT-proBNP testing.

Clinical records will be reviewed to collect the same outcomes measured in Phase 1. Comparing these two cohorts will allow evaluation of whether introduction of POCT NT-proBNP testing changes the speed of diagnosis and treatment and influences subsequent patient outcomes.

Particular attention will be paid to the time taken to reach a diagnosis of HF and the time taken to commence appropriate HF therapy following hospital presentation.

Phase 3: Implementation Evaluation

Successful introduction of new technologies into healthcare depends not only on patient outcomes but also on how acceptable and practical they are for healthcare staff. In Phase 3, multidisciplinary healthcare professionals involved in the use of POCT NT-proBNP testing will be invited to complete a questionnaire evaluating their experiences.

The questionnaire will explore areas such as:

Ease of use of the testing system. Impact on clinical decision-making. Perceived benefits and challenges. Acceptability within routine practice. Feasibility of wider implementation.

Responses will help identify factors that support or hinder successful adoption of POCT NT-proBNP testing within acute care settings.

Data Analysis

Data from the intervention and comparison cohorts will be analysed to compare the time taken to reach important clinical milestones, including HF diagnosis and treatment initiation. Time-to-event (survival) analysis methods will be used to evaluate differences between groups. Additional analyses will examine length of hospital stay, hospital readmission and mortality outcomes.

Questionnaire responses from healthcare professionals will be summarised using descriptive statistical methods to provide an overview of staff experiences and perceptions of implementation.

Expected Impact

The findings of this study will provide evidence regarding the effectiveness of POCT NT-proBNP testing in the assessment of patients with suspected HF. The results will help determine whether faster diagnostic testing can lead to earlier treatment and improved patient outcomes. The implementation evaluation will also provide important information about the practical considerations of introducing POCT NT-proBNP testing into routine clinical care.

The study aims to inform future service development, support evidence-based healthcare decision-making, and determine whether larger-scale evaluation of POCT NT-proBNP testing is warranted.

Inclusion criteria

• Aged 18 years or older
• Presenting with new suspected heart failure
• Presenting with unexplained breathlessness suggestive of heart failure
• Able to provide written informed consent
• Has capacity to consent to study participation

Exclusion criteria

• Previous or existing clinical diagnosis of heart failure
• Aged less than 18 years
• Lacks capacity to provide informed consent
• Acute myocardial infarction at presentation