A deep dive into heart failure

Faculty members at the inaugural meeting of specialist nurses working in the closely linked specialties of heart failure, renal disease and diabetes (hFRenDs) presented a ‘deep dive’ into their respective specialties: this article focuses on heart failure – a clinical syndrome rather than a definitive diagnosis

In new onset heart failure, hospitalisation and deaths are increased in patients with type 2 diabetes (T2D) or chronic kidney disease (CKD) and are highest among those with both conditions.¹ HF prevalence is four-times higher in people with T2D compared with the general population.²

HF is a clinical syndrome, rather than a definitive diagnosis, which occurs due to underlying abnormalities affecting the structure and/or functioning of the heart. It requires a specialist assessment and diagnosis and key signs and symptoms include breathlessness, fluid retention, fatigue, crackling on the lungs and the presence of oedema.

HF is a frightening term and nurses can help to reassure newly diagnosed individuals by explaining that, although it is a serious condition, HF refers to the reduced efficiency of the heart and treatments can help to reduce symptoms.

NICE guidelines provide a pathway for HF diagnosis, which includes the measurement of N-terminal pro-B-type natriuretic peptide (NT-proBNP or BNP) in the blood.^3,4 A person with a negative NT-proBNP level would be unlikely to have HF, although it is not impossible as NT-proBNP can be lowered by certain drugs or obesity, and a discussion with a cardiologist might be appropriate for symptomatic individuals in such cases. A positive NT-proBNP requires specialist referral and, depending on the NT-proBNP threshold reached, either a 2-week or 6-week referral should be actioned.

EJECTION FRACTION

Ejection fraction is defined as the amount of blood pumped out of left ventricle with each contraction, expressed as a percentage.⁵ An ejection fraction of 50–70% is considered to be normal (100% would be abnormal/hyperdynamic).^3,4 Making a diagnosis of heart failure with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF) can help in directing therapy, but the cardiology team will still conduct investigations to understand the cause of HF (e.g. ischemic heart disease, amyloidosis) to provide additional treatments that may enhance management. A diagnosis of HFrEF is defined as having a left ventricular ejection fraction (LVEF) below 40% (severely reduced LVEF).^3,4 Those who have a LVEF between 41–49% have a mildly reduced ejection fraction (HFmrEF).^3,4 People with HFpEF may show signs and symptoms of HF with abnormalities in muscular contraction evident on the echocardiogram (or other issues), despite LVEF being within the normal range.⁵

PHARMACOTHERAPY

The management of HF is complex. The European Society for Cardiology (ESC) guidelines for HErEF management guidelines cover all aspects of heart failure, including the use of medication and cardiac devices.⁴ Medications with a Class I level of evidence should be used first-line and have been termed the ‘four pillars of pharmacotherapy in HFrEF’ – beta-blockers, angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARBs) or angiotensin receptor-neprilysin inhibitors (ARNi). Loop diuretics are also used to control fluid retention.^3,4,6

If LVEF remains low (<35%) and the person is still symptomatic despite pharmacotherapy, a cardiac device may be implanted. People with HFrEF with a high risk for sudden cardiac death, tachycardia or atrial ventricular arrest will be given an implantable cardioverter-defibrillator (ICD), which can also act as a pacemaker (beta-blocker dosage may need adjustment following implantation).⁴ Cardiac resynchronisation therapy (CRT) devices may be implanted with either a defibrillator (CRT-D) or pacemaker (CRT-P) function to provide better synchrony across the chambers to improve cardiac output.⁴ A CRT-D device may not be suitable for individuals with many comorbidities or advancing age.

Significant cross-over exists between cardiovascular, renal and metabolic medicine (CRM) specialties concerning pharmacotherapy in HFrEF. Heart failure specialist nurses may prefer to prescribe ARNi therapies first-line, although guidelines recommend beta-blockers, ACEi or angiotensin receptor blocker (ARB) treatments initially.^3,4 However, dose titration can be difficult and there should be a 48-hour washout period between the switch from ACEi/ARB to ARNi therapy.^3,4 Prescribing guidelines require systolic blood pressure to be ≥110 mmHg and diuretics should also be removed prior to ARNi therapy initiation (ARNi prescribing is contraindicated for those with an eGFR <30 mL/min/1.73m2).⁴ Mineralocorticoid receptor antagonist (MRA) and SGLT2i (dapagliflozin/ empagliflozin) medications may also be started.⁴

MRA medicines need to be titrated carefully (hyperkalaemia can be an issue), while the approved SGLT2is do not require titration.⁴ Cardiac rehabilitation represents the fifth pillar of care, with enormous benefit for quality of life, although it is not available for all HF patients across the country.

For HFmrEF, ESC guidelines recommend beta-blockers/MRAs/ACEis for treatment alongside diuretics.⁴ The goal of treatment is to achieve stable therapy and prevent further reduction of LVEF. HFpEF can be difficult to manage as it is essentially a disease of other parts of the body that affects the heart. There is emerging evidence for the role of SGLT2is in HFpEF, mainly due to reduced hospitalisations.^7,8

Diuretics are the only type of therapy with Class I evidence for all subtypes of HF.^3,4 It is important to use them early and high doses may be required to achieve efficacy.^3,4 Renal patients will typically need high doses to obtain adequate effect.

Prognosis prediction can be challenging in HF as the risk of sudden cardiac death continues, even during stable phases. Red flags for HF include paroxysmal nocturnal dyspnoea (PND), reduced appetite and oedema, particularly above the knee. Continual assessment is required and drugs should not be stopped, even when blood pressure drops. If treatment is paused due to intercurrent illness, nurses should aim to restart it as soon as possible. People with HFrEF may also benefit from intravenous (IV) iron, and hospitalisation might be reduced with this intervention, although availability of IV iron varies across the country.

The BSH and Renal Association issued a joint consensus statement in 2019 about changes in renal function associated with drug treatment in HF, which focuses on maintaining HF therapies with the aim of reducing mortality and extending life.⁹

LVEF can normalise when therapy is administered, providing up to 8.3 years of additional life.¹⁰

KEY HEART FAILURE RESOURCES FOR PATIENTS AND CLINICAL STAFF

• British Society for Heart Failure: https://www.bsh.org.uk/
• 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: https://www.bsh.org.uk/wp-content/uploads/2021/09/ESC-HF-2021.pdf
• NICE NG106. Chronic heart failure in adults: diagnosis and management https://www.nice.org.uk/guidance/ng106

See also Nurses call for closer links across specialties, A deep dive into diabetes and A deep dive into renal failure

References

1. Lawson CA, Seidu S, Zaccardi F, et al. Outcome trends in people with heart failure, type 2 diabetes mellitus and chronic kidney disease in the UK over twenty years. eClinicalMedicine 2021;32:100739.

2. Dunlay SM, Givertz MM, Aguilar D, et al. Type 2 diabetes mellitus and heart failure: a scientific statement from the American Heart Association and the Heart Failure Society of America Circulation. 2019;140(7). doi:10.1161/CIR.0000000000000691

3. NICE NG106. Chronic heart failure in adults: diagnosis and management; 2018. https://www.nice.org.uk/guidance/ng106

4. McDonagh TA, Metra M, Adamo M, et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Revista Espanola de Cardiologia (English ed) 2022;75(6):523.

5. NICE Clinical Knowledge Summaries. Chronic Heart Failure; 2022. https://cks.nice.org.uk/topics/heart-failure-chronic/background-information/definition/

6. Straw S, McGinlay M, Witte KK. Four pillars of heart failure: contemporary pharmacological therapy for heart failure with reduced ejection fraction. Open Heart 2021;8(1):e001585

7. Filippatos G, Butler J, Farmakis D, et al. Empagliflozin for heart failure with preserved left ventricular ejection fraction with and without diabetes. Circulation. Published online 28 June 2022: 101161CIRCULATIONAHA122059785.

8. Böhm M, Butler J, Filippatos G, et al. Empagliflozin Improves Outcomes in Patients With Heart Failure and Preserved Ejection Fraction Irrespective of Age. J Am Coll Cardiol 2022;80(1):1-18.

9. Clark AL, Kalra PR, Petrie MC, et al. Change in renal function associated with drug treatment in heart failure: national guidance. Heart 2019;105(12):904-910

10. Vaduganathan M, Claggett BL, Jhund PS, et al. Estimating lifetime benefits of comprehensive disease-modifying pharmacological therapies in patients with heart failure with reduced ejection fraction: a comparative analysis of three randomised controlled trials. Lancet 2020;396(10244):121-128.