In patients with heart failure, there is impaired ability of the heart to effectively pump blood around the body.
In patients with heart failure, there is impaired ability of the heart to effectively pump blood around the body. This could be due to a weak or stiff heart. Although heart failure can occur at any age, it tends to occur more frequently in older patients. Common symptoms include breathlessness with physical activity or when lying flat in bed, and water retention such as leg swelling.
By Dr Ng Choon Ta, Consultant, Department of Cardiology
Compared to the western population, the onset of heart failure in Singapore occurs earlier and at a younger age. The average age of onset is at 50 years old in Singapore as compared to 60 years old in the west. A significant number of patients also have pre-existing medical conditions such as diabetes mellitus.
Classifying Heart Failure
Most patients with heart failure are diagnosed when they have clinical signs and symptoms, with the aid of imaging tools such as echocardiography or cardiac magnetic resonance imaging, and blood tests for special biomarkers.
Heart failure can be classified into two main groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). The left ventricle ejection fraction, which measures how much blood gets pumped out per cardiac cycle, is an indicator of how well the heart is pumping and can be used to help classify heart failure and subsequently guide treatment. Assessment of the heart function can be performed using transthoracic echocardiogram or cardiac magnetic resonance imaging.
Optimal Medical Therapy
The care of heart failure patients involves a multi-disciplinary approach. At NHCS, there is a dedicated heart failure team comprising heart failure cardiologists, trained heart failure nurses, pharmacists, physiotherapists, dieticians, transplant coordinators and medical social workers to look after the needs of this unique group of patients. Referral to a cardiologist for workup and early initiation of medical therapy is important. Patients are advised to restrict their fluid intake, and to take a low-salt diet. They should also go for regular influenza and pneumococcal vaccinations. For smokers, they are advised to quit smoking. In the community, our primary care physicians also play a pivotal role in ensuring that chronic medical conditions such as high blood pressure, high blood cholesterol and diabetes mellitus are well controlled.
Although heart failure is a chronic disease, medications can help improve symptoms and reduce frequency of hospitalisations. In the past decade, there has been tremendous progress in the pharmacological sector, with new and effective classes of medications being discovered. Recently, the Heart Failure Society (Singapore) published an updated 2020 clinical practice guidelines on heart failure intended for healthcare professionals.
For patients with heart failure with preserved ejection fraction, novel agents such as angiotensin receptor neprilysin inhibitors (ARNIs) and sodium glucose cotransporter inhibitors have shown to significantly decrease mortality and hospitalisation in clinical trials. This is in addition to standard medications such as beta blockers and mineralocorticoid receptor antagonists.
ARNI is recommended as a replacement for angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB) to further reduce the risk of heart failure hospitalisation and death in patients with HFrEF who remain symptomatic despite optimal treatment. When replacing ACEi with ARNI, physicians should stop existing ACEi for at least 36 hours before initiation of ARNI to reduce the risk of adverse effects.
Sodium-Glucose Cotransporter-2 Inhibitors (SGLT2i) have shown to reduce the risk of heart failure-associated events in patients with type 2 diabetes and concomitant renal impairment. In recent clinical trials, SGLT2i such as dapagliflozin and empagliflozin have shown to reduce the risk of heart failure hospitalisation and death in patients with HFrEF who remain symptomatic despite optimal medical treatment, even in non-diabetic patients.
To date, there is no proven therapy to improve survival and reduced morbidity in HFpEF. The treatment of HFpEF lies in managing co-existing conditions such as high blood pressure and diabetes mellitus, controlling symptoms and treating precipitating factors.
While optimal medical therapy in heart failure patients significantly reduces the risk of sudden cardiac death, those with severely impaired heart function of less than 35% may benefit from devices such as Implantable Cardioverter Defibrillator (ICD) to reduce the risks of life threatening arrhythmias (abnormal heart rhythm).
What happens in advanced heart failure?
Advance care planning is important for heart failure patients to make plans about their future health care, especially when they are not in a position to make or communicate their healthcare choices. Shared decision-making among patients, their families, and the medical team in establishing the goals of care should be initiated early. Unlike cancer patients, some heart failure patients can experience an unpredictable pattern of decline.
Heart transplantation can be considered for advanced heart failure in selected patients who are repeatedly hospitalised despite being on optimal medical therapy. Mechanical heart pumps such as the Left Ventricular Assist Device can be considered as a permanent or destination therapy in selected patients with refractory advanced heart failure.
In summary, heart failure is an increasingly common condition in Singapore. Multi-disciplinary care and a combination of appropriate medications, lifestyle modifications, and accessibility to care can help to improve symptoms and reduce hospitalisation.
(For healthcare professionals: The full version of the 2020 Clinical Practice Guidelines on Diagnosis and Management of Heart Failure published by the Heart Failure Society (Singapore) is now available for download at https://www.hfss.org.sg/ under Resources (Professional Guidelines))
This article is from Murmurs Issue 37 (May – August 2020). Click here to read the full issue.