Heart failure

Evidence-based therapies underused in heart failure patients


Patients admitted to hospital with heart failure are mostly elderly, frail and have multiple co-morbidities but evidence-based therapies, particularly ACE inhibitors and beta-blockers, appear to be underused, according to a snapshot of heart failure patients in NSW.

The NSW HF Snapshot study led by Professor Peter Macdonald a senior staff cardiologist in the Cardiopulmonary Transplant Unit at St Vincent’s Hospital in Sydney audited 811 patients with heart failure who were admitted to 24 NSW and Canberra hospitals over a two-month period.

The audit included 11 rural sites and all had an attending cardiologist who was responsible for confirming the admission diagnosis.

A lack of data on heart failure patients in Australia

The aim of the study was to identify the most common reasons for admission as well as determine the clinical characteristics of the patients and the treatments they received at baseline, during their admission and at discharge.

“There were no reliable data on the incidence and prevalence of heart failure in Australia, so we wanted to understand the scope of the problem,” said Professor Macdonald who is also a Conjoint Professor of Medicine in the University of New South Wales and co-head of the Transplantation Research Laboratory at the Victor Chang Cardiac Research Institute.

“We suspected, but needed to confirm, that heart failure patients admitted to hospital are generally elderly and have a high level of comorbidity,” he told the limbic.

“We also wanted a sense of the balance between heart failure with reduced ejection fraction (HFREF) and heart failure with preserved ejection fraction.”

The first formal paper reporting the study’s results was published in the Medical Journal of Australia in February.1

However before it was published information on heart failure management in Australia was very limited.

For example the CASE study published in 2001 investigated the management of heart failure by GPs.2 Heart failure was diagnosed in 13.2% of all patients aged 60 or older. ACE inhibitors were prescribed in only 58.1% of cases. Echocardiography had been performed in 64% of previously diagnosed patients but only 22% of possible cases.

The ADHERE International Asia Pacific study of acute decompensated heart failure included about 900 Australian patients among the 10,171 participants, but provided little specific information on their characteristics or management.3

The methodology used in Snapshot HF study1 was based on the methodology of the SNAPSHOT ACS study4 and aimed to overcome some of the limitations of registries, Professor Macdonald said.

“Existing international registries vary in quality and tend to enrol patients only from centres of excellence,” he said. “The oldest and sickest patients are often underrepresented.

“Although the Snapshot approach is less cumbersome than a registry, the preparatory work was complex, including the need for ethics approval at each site, and the month of data collection was very intensive.

A unique window onto the characteristics of HF patients

The audit revealed a wealth of information that gave a unique insight into the characteristics of heart failure patients in Australia. For instance of the 811 patients involved in the study 68% had an acute decompensation of previously recognised chronic heart failure. The remaining patients had not previously been admitted for heart failure.1

Furthermore preserved ejection fraction (HFPEF) — defined by a left ventricular ejection fraction of 50% or more at the most recent assessment — accounted for 42% of the cases.

These patients were more likely to be older, female and have hypertension as the antecedent cause.

Infection was the most commonly identified precipitant of admission (22%), a finding which the researchers suggested could reflect the winter timing of the study.

Non-adherence to medication or to dietary or fluid restrictions were implicated in 5% and 16% of admissions respectively.

Ischaemic heart disease (56%), renal disease (55%) and diabetes (38%) were identified by the audit as common comorbidities.

Median lengths of stay varied widely between the participating hospitals, from 3 days to 12 days, the audit revealed.

The researchers said this could reflect the broad range of institutions, from small rural hospitals to large tertiary referral centres, as well as variations in patient mix, available resources, and admitting speciality.

The research team also collected data on subsequent hospital admissions and mortality 30 days and 12 months after discharge. The researchers said that once published the findings will provide insight into the outcomes for patients once they return to community-based care.

An under-prescribing of evidence-based treatment?

Professor Macdonald said the use of guidelines recommended therapies at admission – ACE inhibitors, beta-blockers and mineralocorticoid receptor antagonists (MCAs) – was lower than expected.

For example, in those with an LVEF under 40%, only about 40% were receiving an ACE inhibitor, 26% an MCA and 60% a beta-blocker when admitted.

“This finding that medications are not being prescribed as recommended is hypothesis-generating. We are now analysing whether factors such as age, comorbidity and frailty influence the use of these medications and whether these decisions affect patients’ outcomes.”

“The proportion who needed hospital admission because of non-adherence with treatment, and the fact that only 59% were referred to a multidisciplinary care team during their stay, suggests there is an opportunity to improve on existing treatment and reduce exacerbation and admission rates,” Professor Macdonald said.

The study also detailed changes in medication during the admission. In patients with an LVEF of 40% of more there was little or no change except for an increase in loop diuretics, which increased from 64% at admission to 88% on discharge.

In patients with an LVEF <40%, there was a significant increase in the use of loop diuretics (from 69% to 88%) and MCAs (from 26% to 45%), and a non-significant increase in the use of beta- blockers (from 60% to 78%).

The research team said it was possible that patients who were not prescribed evidence-based treatments may have not responded to the medication in the past, or experienced adverse events or other signs of real or perceived contraindications.

“While this may partly explain the under-prescribing of evidenced-based heart failure therapy, our data suggest that the uptake of evidence-based recommendations can be improved,” the HF Snapshot team said.

The authors also intend to analyse the data to determine whether the use of complementary medicine is having an impact on patients’ outcomes.

“These range from over-the counter medicines, coenzyme Q10 and selenium to products recommended by naturopaths,” they said.

“We need to understand more about patients’ reasons for using them, and analyse any associations with outcomes,” they added.

Hope for the future

Overall the HF Snapshot researchers said they hoped the results would clarify how the characteristics of patients, institutions and systems contributed to variations in heart failure care and outcomes.

“The NSW HF Snapshot provides a unique window onto the characteristics of patients admitted with acute HF to public hospitals in urban and rural NSW and the ACT,” they said.

The extent to which patient, institutional and system characteristics contribute to variations in care and outcomes is being explored in further analyses, the researchers said.

“We anticipate that the results…will inform the development of strategies for improving the uptake of evidence-based therapies, and hence outcomes, for HF patients.”

 

The NSW HF Snapshot was supported financially by the National Heart Foundation New South Wales Cardiovascular Research Network.

 

References

  1. Newton PJ, Davidson PM, Reid CM et al. Acute heart failure admissions in New South Wales and the Australian Capital Territory: the NSW HF Snapshot Study. Med J Aust 2016; 204: 113.
  2.  Krum H, Tonkin AM, Currie R et al. Chronic heart failure in Australian general practice. The Cardiac Awareness Survey and Evaluation (CASE) Study. Med J Aust 2001; 174: 439-444.
  3. Atherton JJ, Hayward CS, Ahmad WAW et al. Patient characteristics from a regional multicenter database of acute decompensated heart failure in Asia Pacific (ADHERE International – Asia Pacific). J Card Fail 2012; 18: 82-88.
  4. Chew DP, French J, Briffa TG et al. Acute coronary syndrome care across Australia and New Zealand: the SNAPSHOT ACS study. Med J Aust 2013; 199: 185-191.

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