Heart failure (HF) is defined as a complex, chronic condition where the heart is unable to pump enough blood to meet the metabolic demands of the body. There are many causes of heart failure but it is often considered the cumulative effects of damage to the heart muscle that leads to a reduction in the pump effectiveness of the heart, unable to meet metabolic demands of the patient.
Population based estimates of the prevalence of heart failure in Australia is limited however, in 2014 it was estimated that there were 480,000 patients over the age of 18 living with heart failure. This represents approximately 2.1% of the adult population1.
It must be noted that in Australia’s indigenous population, the age standardised prevalence rates of heart failure is approximately 1.7 times higher than non-Indigenous Australians2. This is largely due to the high rates of rheumatic heart disease and cardiovascular disease within these communities. The prevalence estimates of rheumatic heart disease have been steadily increasing to approximately 2% of the Indigenous population in the Northern Territory and 3.2% of Indigenous people aged 35-44 years old3.
In 2015 -2016 data shows that there were approximately 173,000 admissions where cardiomyopathy and heart failure were the main diagnosis, this represents an estimated hospitalisation rate of 1.6% of all hospital admissions4.
Survival rates vary widely in clinical studies depending on the study group having acute or chronic heart failure. Contemporary studies into acute heart failure are generally consistent with approximately 80% survival at one month and 57-80% survival at one year5. Chronic heart failure survival rates may range from 81% one year survival to 63% at 5 years, which may be comparable to some non-haematological malignancies6.
Patients living with heart failure can have a significant impact on the individual quality of life. This chronic condition may reduce the individuals’ ability to meet activities of daily living, such as shopping, washing, and leisure activities. Therefore, requiring patients affected by heart failure to increasingly need ongoing assistance from others such as their family members. Limited abilities to mobilise due to increased shortness of breath or other symptoms of heart failure can also lead to social isolation, depression and other mood disorders7.
Heart Failure can also have a high cost to the wider community through frequent hospital admissions and the economic impact of lost day productivity for family members. It has been estimated that in the UK, two-thirds of patients with heart failure are readmitted to the hospital within a year. The total estimated costs for patients with heart failure is approximately 1-2% of the total National Health Service (NHS) budget, or >£ 626 million8.
Currently, the classification of heart failure is based on Left Ventricular Ejection Fraction (LVEF).
Heart Failure with Reduced Ejection Fraction (HFrEF), can be considered in the presence of clinical symptoms with or without signs of heart failure and a measured LVEF of less than 50%9. This may have been known as systolic heart failure previously.
Heart Failure with Preserved Ejection Failure (HFpEF), is a more complicated definition given the LVEF can be > 50% PLUS:
This staging process classifies patients heart failure status dependent on the severity of their symptoms.
There are many causes of heart failure, each can lead to a decrease in the ability of the pumping mechanism of the heart. Heart failure can include the left and right ventricles, or both together. The causes of heart failure can affect the pumping ability of the heart to meet metabolic demands, which may lead to a wide range of clinical symptoms. Heart failure may be caused through the heart muscle enlarging or becoming stiff therefore affecting the ability of the heart to pump effectively12.
Other causes may also include: