Managing patients with heart failure in primary care

1. Start with a diuretic

In the majority of patients with symptomatic heart failure, the first-line medicine used is a diuretic, which will work to reduce fluid overload to improve the patient’s symptoms, however, there is no evidence that diuretics improve mortality.¹

A loop diuretic such as furosemide is recommended as these are usually more effective than thiazide diuretics. A reasonable starting dose of oral furosemide for a patient in a community setting is 20 – 40 mg, once daily. Subsequent doses are then determined by the response to treatment – an improvement in symptoms and a weight loss of approximately 1.0 kg/day. Bumetanide (fully subsidised) is an alternative for patients who do not respond to adequate doses of furosemide. The recommended starting dose for oedema is 0.5 – 1 mg, once daily. In severe cases, the dose may be increased up to 5 mg per day.⁷

Doses of diuretic that are too low will not clear the fluid overload effectively, and may reduce the patient’s response to an ACE inhibitor when started and also can increase the risk of decompensation when a beta-blocker is initiated. Doses that are too high may lead to removal of too much fluid, which increases the risk of hypotension and renal impairment, particularly when an ACE inhibitor is started.

2. Add an ACE inhibitor and beta-blocker

The next step after the use of a diuretic is the addition of an ACE inhibitor (or an angiotensin-II receptor blocker – ARB) to reduce symptoms and a beta-blocker to improve ventricular function. There is good evidence that ACE inhibitors and beta-blockers improve both morbidity and mortality for patients with HF-REF.¹

Guidelines vary as to which of these medicines should be initiated first as they are regarded as complementary.^{1, 8} If a patient has acute fluid overload, a beta-blocker may not be tolerated until the fluid is reduced, although an ACE inhibitor can be initiated. Ideally both should be started as soon as practical after a diagnosis of HF-REF is made, with an aim of achieving an ejection fraction of > 40% as this is associated with improved prognosis. ACE inhibitors assist with LV re-modelling and beta-blockers can markedly improve the ejection fraction.¹

Any medicine from the ACE inhibitor class can be used, e.g. cilazapril. ACE inhibitors tend to give effective control of blood pressure and are generally well tolerated. If postural hypotension or other adverse effects occur, this is usually at low doses and increasing the dose does not tend to significantly change the incidence or severity of adverse effects. Initiation of an ACE inhibitor may result in an increase in potassium and creatinine. If the potassium is < 5.5 mmol/L and the increase in creatinine is no more than 50% above baseline, these changes are acceptable. If potassium or creatinine rises excessively, reduce the dose of the diuretic if there are no signs of congestion and stop nephrotoxic medicines such as NSAIDs. If potassium or creatinine remain raised, the dose of ACE inhibitor should be halved and the creatinine and electrolytes checked in one to two weeks. Discussion with a cardiologist is recommended as the ACE inhibitor may need to be stopped.^1,9

N.B. Guidelines for use of ACE inhibitors in people with chronic kidney disease take a more conservative approach and suggest altering the dose of ACE inhibitor if creatinine rises > 30%.¹⁰

If an ACE inhibitor is not tolerated, an ARB can be substituted. Losartan is the only fully subsidised ARB available. Candesartan is available under Special Authority (criteria are persistent ACE-inhibitor induced cough, history of angioedema or inadequate control on maximum tolerated dose of ACE inhibitor). Adverse effects from ARBs are usually mild and transient but may include headache, dizziness and gastrointestinal effects.

Beta-blockers approved for use in New Zealand for heart failure include metoprolol, carvedilol, and bisoprolol (see ”Bisoprolol – newly funded beta-blocker”). There is no clear evidence that any one of these medicines is superior to another, but specific patient factors may guide the choice.¹¹ For example, bisoprolol and metoprolol CR are once daily dosing, which may be more convenient for some patients. Bisoprolol may be preferable in patients with atrial fibrillation as it reduces heart rate more than other beta-blockers, but it also increases susceptibility to bradycardia. Bisoprolol may be preferable in people with COPD compared to carvedilol as it is more cardio-selective.

When initiating a beta-blocker the recommendation is to start at a low dose, increase slowly and aim for the highest tolerated dose (“go slow, aim high”). If a beta-blocker is initiated before an ACE inhibitor, e.g. in a patient with arrhythmia or angina but without acute fluid overload, the dose should be increased to mid-range and then an ACE inhibitor started.

3. Add spironolactone if still symptomatic

The use of spironolactone (the only subsidised aldosterone receptor antagonist), is recommended for patients who remain symptomatic, or who have an ejection fraction < 35%, despite maximal doses of an ACE inhibitor and a beta-blocker. If the patient’s LV function has improved somewhat with the use of an ACE inhibitor and beta-blocker, spironolactone may not be required, however, consultation with a cardiologist and referral for echocardiography is recommended. Spironolactone has been shown to reduce both morbidity and mortality in patients with heart failure. Spironolactone should be used with caution in patients with impaired renal function and may cause hyperkalaemia. Renal function and electrolytes should therefore be monitored regularly. Other adverse effects may include gastrointestinal symptoms such as nausea and diarrhoea.⁷

For further information see:
“Drug monitoring – Monitoring diuretics in primary care”, Best Tests (Mar, 2009).

4. Add ARB, digoxin and anticoagulants as appropriate

If the patient has failed to respond to treatment with maximal doses of all these medicines, an ARB may be considered. However, spironolactone would not usually be continued if an ARB is added as this combination (ACE inhibitor, ARB and spironolactone) can worsen renal function. Discussion with a cardiologist is recommended.

Digoxin can be used to slow the ventricular rate and therefore improve symptoms in patients who have symptomatic heart failure and atrial fibrillation. There is some evidence that digoxin may improve symptoms and reduce the rate of hospitalisation, however, it does not improve mortality.¹

N.B. All patients with heart failure and atrial fibrillation should be assessed using stroke risk assessment tools, e.g. CHA2DS2-VASc to determine their need for anticoagulation.

For further information see:
"The use of antithrombotic medicines in general practice”, BPJ 39 (Oct, 2011)

Patient education and self-management are important aspects in the management of heart failure. Educate patients to be aware of their symptoms and how to manage them if their condition deteriorates. Many patients will be comfortable with modifying their doses of diuretic. Patients may also be able to gradually increase the dose of other medicines such as beta-blockers, e.g. by increasing the dose by half a tablet at night and then waiting for a few weeks. A heart failure action plan (e.g. from the Heart Foundation) can assist patients with self-management.

Encourage patients to:

• Weigh themselves daily. It is useful to establish a “dry weight” so that changes in the patient’s condition are detected and managed early. If the patient’s weight increases rapidly and they become increasingly symptomatic, have a plan in place for the patient to increase their furosemide dose for a few days until the weight decreases again.
• Participate in regular exercise and if appropriate, suggest dietary measures to assist with fat weight loss (as opposed to fluid weight loss)
• Avoid an excessive intake of salt and alcohol
• Monitor their fluid intake – fluid should be restricted to between 1.5 and 2 L/day in patients with moderate or more severe symptoms of fluid overload. There is less evidence that fluid restriction is beneficial in patients with mild symptoms of heart failure.
• Maximise adherence to medicines
• Have an annual influenza vaccination

A new booklet “Staying well with heart failure” has been developed by the Heart Foundation. It contains information for patients on heart failure (e.g. on symptoms and management), lifestyle modification, daily checks and a heart failure action plan to assist with self-management. The booklet is available from www.heartfoundation.org.nz under the Programmes and Resources section.

Device therapy

Device therapy for heart failure includes implantation of a cardioverter defribillator or cardiac resynchronisation therapy (CRT), using devices that provide biventricular pacing or may combine the ability for both pacing and defibrillation.

Device therapy may be considered for some patients with heart failure, e.g. those who remain symptomatic despite optimal use of medicines, those with an ejection fraction that remains low (< 35%) or those with left bundle branch block (LBBB) on ECG. Device therapy can improve symptoms, quality of life and ventricular function and reduce the risk of sudden death.¹ Patients with co-morbidities that are likely to reduce their life expectancy (within one year) are generally considered not suitable for device therapy.

Referral to a cardiologist is recommended for patients with:

• Valvular heart disease
• Heart failure and syncope – insertion of a pacemaker may be required
• Heart failure and LBBB and a wide QRS on ECG associated with dyssynchrony – CRT may be indicated
• A history of cardiac arrest or ventricular tachycardia - defibrillator therapy may be indicated

Implanted cardioverter defibrillators

Implantation of a cardioverter defibrillator may be beneficial for selected patients with heart failure as this can reduce mortality in patients at risk of life-threatening ventricular tachyarrhythmias.

Cardiac resynchronisation therapy

A CRT device or biventricular pacemaker that provides simultaneous pacing of both ventricles may be beneficial for patients who have an ejection fraction < 30– 35%, ongoing symptoms despite optimal medical management, LBBB on ECG and a prolonged QRS duration (>150 milliseconds).¹ Some CRT devices also include a defibrillator.

Other surgical treatments

Depending on the underlying cardiac pathology, some patients may benefit from other surgical treatments such as coronary artery bypass grafting, valve replacement or rarely in selected patients with end-stage heart failure, heart transplantation.