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Summary
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Heart failure affects about 900,000 people in the UK. It happens
when the heart becomes damaged, for example after a heart attack,
and cannot pump blood around the body properly. B-type natriuretic
peptide, and another chemical derived from it (collectively
referred to as BNP), are hormones secreted by the heart in response
to injury and their levels in the blood are raised in people with
heart failure. High levels of BNP predict people who will
experience a faster deterioration in their health from heart
failure and who have a higher risk of serious disease events, such
as death or deterioration in health requiring emergency admission
to hospital.
There is some evidence that people with heart failure do better
when BNP is measured regularly over time, so that doctors can
adjust patients' drugs (used to treat heart failure, such as
beta-blockers or ACE inhibitors) to try to lower BNP levels. Most
of this evidence comes from randomised controlled trials, in which
patients are allocated at random (by chance) to receive either
BNP-guided treatment or standard treatment without having BNP
measured. As part of our proposed project, we will bring together
the results from all trials (in effect, averaging and improving the
precision of the overall result) to determine whether those
patients with heart failure who have BNP-guided treatment
experience better outcomes than those who receive standard
treatment (STUDY 1).
However, we expect it to be difficult to conclude that the
overall finding from these trials should be applied to the general
population with heart failure, whether managed by their GPs or
hospital doctors, since the patients participating in clinical
trials are not representative of the general population with heart
failure - they are younger, with more men than women, having only a
certain type of heart failure (reduced ventricular ejection
fraction) and no other conditions. Also, most trials have been
conducted outside the UK, making it difficult to determine whether
measuring BNP is cost effective in the UK setting.
Therefore, we propose to supplement the IPD meta-analysis with
analyses of a representative group of patients with heart failure
in the UK (STUDY 2). We will create this patient group by linking
data from the Clinical Practice Research Database (CPRD, which
contains patient data from GP practices) and the UK National Heart
Failure Audit (NHFA, which contains data on patients admitted to
hospital with heart failure), as well as hospital record data and
death registry data. These data will allow us to profile how heart
failure patients are cared for in the NHS, from diagnosis, through
treatment, to outcome. Both databases have a subset of patients who
have had BNP values recorded. We propose to match these patients
with a similar group of patients who have not had a BNP value
recorded (taken from the same databases). We will compare groups
with and without BNP measurements for differences in risk of death,
hospital admission/readmission and length of hospital stay (for
those e admitted to hospital), prescribed medications, number of
outpatient appointments and patient management. We will also
undertake a health economic analysis to determine whether measuring
BNP is cost effective in the NHS (STUDY 3).
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Impact
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HF affects around 900,000 people in the UK, with an estimated
prevalence of 6 to 10% in people over 65 years of age, increasing
to 14% in people over 85 years of age. Prevalence is expected to
increase as a result of the ageing population and improved survival
of people with ischaemic heart disease. The prognosis of patients
with HF is poor; up to 40% of newly diagnosed patients die within
one year. HF is one of the most costly conditions to manage in the
NHS; it accounts for 5% of all emergency medical admissions and
consumes about 2% of the annual NHS budget. HF also markedly
impairs quality of life. This research will determine whether BNP
-guided therapy will improve outcomes for patients and whether it
is cost -effective for the NHS.
The immediate output of the research will be:
1. Aggregate and IPD meta-analysis of the clinical effectiveness
of BNP-guided therapy in patients with heart failure, including
identification of clinically relevant subgroups of participants who
benefit more than others from BNP-guided therapy and, potentially,
information about how to optimise BNP guided therapy.
2. A comprehensive description of the current care pathway in
the NHS, from diagnosis onwards, for a geographically
representative sample of patients with heart failure in the UK.
3. A cost-effectiveness model, built on information from 1 and 2
and other routine data sources. The model will allow the
cost-effectiveness of BNP-guided therapy in clinically relevant
subgroups of participants to be estimated. Sensitivity analyses
using the model will also describe how variation in key parameters
of the model within plausible ranges (informed by uncertainty in
the information from 1 and 2 and other routine data sources)
impacts on the cost -effectiveness estimates for clinically
relevant subgroups of participants.
We would expect the cost-effectiveness model to be adopted
rapidly by commissioning groups and integrated into national
guidance on BNP-guided therapy by the National Institute of Health
and Clinical Excellence. In turn, we would expect these health
policy impacts of the findings of the project to improve the health
of patients in the UK with heart failure. Depending on the
cost-effectiveness results, the project may increase NHS
expenditure on heart failure. However, the outputs cost -
effectiveness model will ensure that any such investment in heart
failure is based on the best current evidence about
cost-effectiveness and can be considered in the context of the cost
-effectiveness of other uses of the investment.
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Patient and public involvement
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Patients were not actively involved in the preparation of the
grant. The research question has been prioritised by the NHS
(Commissioned research programme), and there is no 'active' data
collection for the project. Nevertheless, we appreciate that
patient and public involvement is critical for the project itself,
especially with respect to interpretation of the findings of the
project and their dissemination. Therefore, one of the team members
is a patient with a past medical history of cardiovascular disease
and heart failure.
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