Retrospective Observational Analysis of a Cohort With Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a complex condition with various causes that is not yet fully understood. Most significantly there is no single method of diagnosing or treating the condition. Recently a novel non-invasive diagnostic criterion to predict the likelihood of HFpEF was proposed called H2FPEF. The main limitation of this study was the use of a single centre population from the Mayo clinic in Rochester, US. Another limitation is that the H2FPEF diagnostic criterion consists of common and often co-existing conditions which could as a result overestimate HFpEF probability. The aim of the investigators is to retrospectively test the H2FPEF criteria on the population at Queen Alexandra Hospital (QAH) in Portsmouth, which is of a lower socio-economic status and greater ethnic diversity. Implications of the proposed project if H2FPEF is proved to be generalizable to the study population is that it can be used within the Trust and rolled out to others. This would allow diagnosis to be made quicker and more cost effectively using echocardiography and without the need for invasive cardiac catheterisation. On the other hand if H2FPEF is found not to be applicable to the population then further research would be required to find the ideal diagnostic tool.

HFpEF was previously characterised as 'diastolic dysfunction' but this terminology was changed as it was found that diastolic dysfunction was also seen in patients with 'systolic dysfunction'. Myocardial stiffness which leads to increased filling pressures is a common pathophysiologic attribute of HFpEF despite its multifactorial aetiology. Other common conditions associated with HFpEF include: atrial fibrillation (AF), chronotropic incompetence, pulmonary hypertension, right ventricular dysfunction and endothelial dysfunction; with common non-specific risk factors such as: age, gender, hypertension, obesity, diabetes, metabolic syndrome and renal failure. This complex heterogeneity of HFpEF which is not yet fully understood highlights the difficulty that clinicians have in being able to diagnose the condition.

Diagnosis of HFpEF is difficult and as of yet there is no test to confirm diagnosis, with current guidelines saying initial diagnosis should include the presence of typical signs and symptoms, an elevated B-type natriuretic peptide (BNP) (\>35 pg/mL and/or N-Terminal pro-B-type Natriuretic Peptide \[NT-proBNP\] \>125 pg/mL) and ejection fraction ≥50%. Echocardiography is the preferred method of assessing for HFpEF due to it being widely available, non-invasive, and able to provide immediate results. Recent studies comparing the use of echocardiography against 'gold standard' invasive cardiac catheterisation to assess cardiac filling pressures found echocardiography to be just as accurate and reliable. Implications of this research would be that patients could be assessed as outpatients by focus echocardiography rather than invasively in the cardiac catheterisation lab, which would improve patient experience, enhance patient outcomes and prove cost-effective for trusts.

In response a recently proposed non-invasive diagnostic criteria called H2FPEF which assesses patients based on body mass index (BMI), the number of hypertensive medications they take, presence of AF, pulmonary pressure, age and filling pressure. The advantage of the H2FPEF score is that it uses only non-invasive echocardiography data alongside routine clinical data making it easy to derive. However one key limitation of their study is the population they used was all from the Mayo clinic and so the generalisability of their results has not been tested for other populations, such as those of lower socioeconomic status like in Portsmouth. A further limitation is the parameters chosen to create H2FPEF are all relatively common morbidities and usually co-exist, making it likely that it will over diagnose HFpEF.

Eligibility Criteria:
Inclusion Criteria:

* Age 18-95yrs inclusive
* Currently or previously attended a heart failure clinic with a cardiology consultant at QAH
* Had an echocardiogram, ECG, BNP blood biomarker test in addition to a routine clinical evaluation (including age, weight and number of hypertensive medications) during January 1st 2016 - December 31st 2016.

Exclusion Criteria:

* Known structural heart disease
* Significant heart valve disease (greater than mild stenosis, greater than moderate regurgitation)
* Pulmonary arterial hypertension
* Constrictive pericarditis
* Pre-existing cardiomyopathy
* Heart transplantation