Cardiovascular disease

Cardiovascular disease (CVD) refers to damage to, or disease of, the heart, arteries, veins and/or smaller blood vessels. It has been identified as a health priority area because it is a major health and economic burden on Australia. It is one of the leading causes of sickness and death in Australia (almost 30 per cent of all deaths in 2015), although there are significant differences in the incidence and prevalence of the disease among population subgroups.

Males are more likely than females to die from the disease, for example, and Indigenous people die from the disease at twice the rate of the total population. Cardiovascular disease can be attributed to a number of modifiable risk factors. The potential for change is evident and recent statistics reveal a decline in the death rate from coronary heart disease. OUTCOMES 2

Nature of CVD

The three major forms of this disease are:

• coronary heart disease — the poor supply of blood to the muscular walls of the heart by its own blood supply vessels, the coronary arteries

• stroke — the interruption of the supply of blood to the brain

• peripheral vascular disease — diseases of the arteries, arterioles and capillaries that affect the limbs, usually reducing blood supply to the legs.

Cardiovascular disease is most evident as stroke, heart attack, angina, heart failure and peripheral vascular disease. Atherosclerosis is the underlying cause of most of these conditions. CVD refers to all the diseases of the circulatory system (heart and blood vessels). These include diseases such as: coronary heart disease, stroke, myocardial arrhythmia, and heart failure. The main cause of many of these diseases is atherosclerosis, which refers to the build up of fat and plaque inside the arteries, which can block the blood vessel. A blockage can result in the death of cells that were relying on these arteries for their oxygen supply – such as in a heart attack.

Coronary heart disease includes heart attacks and angina. While a heart attack results from momentary blockage of the artery to a section of heart muscle, angina results from a partial blockage and produces chest pain, particularly on exertion. A Stroke is a temporary blockage of the blood vessels to the brain, resulting in the death of some brain cells, or a vessel begins to bleed, reducing the delivery of oxygen to part of the brain. Stroke (cerebrovascular disease) can result in a range of debilitations including: communication, mobility, thinking and can also be fatal. Heart failure is a condition where the heart is unable to maintain a strong enough blood flow. It can result in chronic tiredness, reduced capacity for physical activity and shortness of breath. It is a life-threatening condition and cannot be cured in most cases.

Hypertension is a risk factor for a stroke. Blood vessels directly damaged as a result of high blood pressure tend to either rupture more easily or result in an aneurysm (which may eventually result in a rupture). The bleeding following the rupture increases the pressure within the cranium and may lead to the death of some tissue due to lack of oxygen.

A heart attack is also known as myocardial infarction, coronary thrombosis and coronary occlusion. Generally caused by the complete closure of a coronary artery by atherosclerosis, it may also occur when a blood clot forms and blocks a narrowed artery (thrombosis). The efficient functioning of the heart relies on a regular oxygenated blood low, so the cessation of the low to any part of the heart results in tissue death. This is a heart attack. It can result in sudden death or the impaired function of the heart muscle, such as occurs with arrhythmia (that is, the disturbed rate and rhythm of the heartbeat).

Angina pectoris is the medical term used to describe the chest pain that occurs when the heart has an insufficient supply of oxygenated blood. Therefore, angina is not really a disease but, rather, a symptom of oxygen deprivation. The pain of angina may be experienced by a heart attack sufferer or someone who has never had, and never will have, an attack. Angina is generally caused by coronary atherosclerosis.

Heart failure is a reflection of the heart’s inability to cater for the demands placed on it during everyday life. Atherosclerosis, heart attacks, high blood pressure, defective heart valves and infections of the heart may mean the heart cannot contract sufficiently to supply the body with its oxygen requirements. Such a condition generally occurs because the heart is unable to compensate for the damage caused by one of the above problems.

Peripheral vascular disease is the result of reduced blood low to the legs and feet, usually due to atherosclerosis and/or arteriosclerosis. It usually affects the arteries, arterioles and capillaries of the legs and feet. The blood supply to the muscles of the legs or to the skin is damaged by atherosclerosis and/or arteriosclerosis. Given a slowed low of blood to the leg muscles, walking results in a cramping feeling.

A stroke results from a blockage of the blood low to the brain. A stroke occurs either when the blood supply to the brain is interrupted by a clot or atherosclerosis or when a burst blood vessel haemorrhages into the brain. Hypertension is a risk factor for a stroke. Blood vessels directly damaged as a result of high blood pressure tend to either rupture more easily or result in an aneurysm (which may eventually result in a rupture). The bleeding following the rupture increases the pressure within the head and may lead to the death of some tissue due to lack of oxygen. If the affected artery is large, then paralysis of one side of the body may occur; on the other hand, if the damage occurs in the dominant hemisphere of the brain, then the individual may lose the ability to speak.

Extent of the problem (trends)

1 in 5 Australian’s suffers from a Cardiovascular disease. Cardiovascular diseases are the second leading causes of death in Australia (after cancers), but coronary heart disease is still the leading single cause of death with cerebrovascular disease coming in second. Cardiovascular diseases account for the second largest burden of disease, with both coronary heart disease and cerebrovascular disease in the top five. Cardiovascular disease is also the most costly disease in Australia. The current trend in death rates because of coronary heart diseases is downward – falling 73% in the last 30 years. This downward trend is mostly due to improvements in medical and surgical treatments.

The rate of strokes has fallen by 25% in the last 10 years, while the total number of people who have had a stroke has increased by 6% over the same period. Over a third of people who have a stroke have a resulting disability. Stroke death rates have fallen by 70% over the last 30 years. Hospitalisation rates for stroke have fallen by 17% in the last 10 years

Use this site to get the most up to date stats for the disease

https://www.aihw.gov.au/reports/heart-stroke-vascular-diseases/cardiovascular-health-compendium/contents/how-many-australians-have-cardiovascular-disease

Risk factors and protective factors for cardiovascular disease

The major risk factors for developing cardiovascular disease include some that cannot be controlled or modified. These include:

• a family history of heart disease. People with a family history of heart disease tend to be more likely to develop cardiovascular disease.

• gender. CVD death rates in men aged up to 50 years is higher than that in women. This difference is thought to be related to female hormones. It is thought that the hormone oestrogen is a a protective factor for cardiovascular disease. Protection is not so apparent after menopause when oestrogen levels drop.

• advancing age. The risk of cardiovascular disease increases with age.

Major risk factors that can be reduced or eliminated by lifestyle changes or medical treatment include:

• smoking. This is the most significant modifiable risk factor. The risk of heart attack and stroke is doubled by heavy smoking. The risk of sudden cardiac death is also higher. These risks decrease when smoking stops and as the non-smoking period lengthens.

• raised blood fat levels. Generally, the higher the blood cholesterol and triglyceride levels, the higher the risk of heart disease. A diet high in saturated fat can raise blood cholesterol levels.

• high blood pressure. The risks of heart disease, stroke and heart failure all increase with hypertension. High blood pressure can overload the heart and blood vessels, and speed up atherosclerosis.

• obesity and overweight conditions. These are thought to increase directly the risk of heart disease. They also contribute to other risk factors such as high blood pressure, high blood cholesterol and diabetes. Seventy per cent of Australian males and 63 per cent of Australian females were overweight or obese in 2014–5. Twenty-five per cent of children in Australia were overweight or obese in that period.

• abdominal obesity. This is measured by the waist-to-hip ratio. A ratio of 1.0 for men and 0.9 for women indicates excessive abdominal obesity. It is a good indicator of an individual’s risk of developing chronic disease.

• physical inactivity. The association of inactivity with obesity, high blood pressure and high fat levels makes it a significant contributor to the development of heart disease.

Other risk factors also exist, but are not considered to be as important because either they occur in a minority of cases or the evidence connecting them to cardiovascular disease is inconclusive. These factors include:

• diabetes. This condition generally damages blood vessels and the arteries tend to develop atherosclerosis as a result.

• the contraceptive pill. Use of the pill can increase a woman’s risk of heart and blood vessel disease. This risk particularly applies to those women using the contraceptive pill who also smoke, have high blood pressure, have diabetes, are aged 35 years or more, or have a family history of the disease.

The nature of the problem

Cancer refers to cells that have become abnormal and begin to multiply rapidly and cannot be controlled by the body. Most times the body’s immune system controls abnormal cells and removes them, but some times it cannot be controlled. Cancer cells invade surrounding tissues and can be deadly. Often to help minimise the damage the body places the multiplying abnormal cells into a sack, called a tumour. Tumours can be both benign (non-cancerous) and malignant (cancerous), where malignant tumours contain cells that grow out of control and can invade surrounding tissue. Sometimes cancer moves away from the original or primary site to other sites and organs of the body. This is referred to as metastasis or secondary cancer. There are multiple cancers, most of which are named according to their location in the body – skin, lung, prostate, bowel, cervical etc. If the cancer moves to a secondary site it maintains its original site name, e.g. skin cancer that has spread to the lymph glands is still called skin cancer.

Extent of the problem (trends)

Cancer is the second leading cause of death in Australia, despite survival rates improving and death rates declining. The probability of being diagnosed with a cancer before 85 is 1 in 2 for males and 1 in 3 for females. The main cancers in Australia are: prostate, bowel, breast, skin and lung cancers.

Current trends in Australia for cancer are: increased incidence, increased survival, and decreased death rates, resulting in an increase in cancer prevalence, though there is still only 3.6% of the population who have been diagnosed with cancer. The increased incidence rate is mostly due to increased detection of prostate, bowel and breast cancers.

The risk of dying from cancer is 1 in 4 for males and 1 in 6 for females. The cancers with the highest mortality rates were: lung, bowel, prostate, breast and pancreatic cancer. In the last 20 years mortality rates from cancer have fallen 17%. People diagnosed with cancer have a 66% chance of surviving 5 years, 91% of people who survive the first 5 years will survive the next 5. The greatest survival gains are for prostate and kidney cancers.

Lung cancer incidence is on the decline for men, but has been increases for females. This is mostly due to the decreased smoking rates amongst men, which begun later for women.

The incidence of melanoma (main skin cancer) has almost halved over the last 30 years dropping from 5% to 2.8%. This drop is mostly attributed to greater awareness and better behavioural choices regarding UV exposure.

Breast cancer incidence has risen since the introduction of breast screening in 1992, but mortality rates from breast cancer have steadily declined and survival rates of improved.

Bowel cancer is on the decrease in Australia reducing by 1/3 from 3% to 2%. This decline is mostly attributed to a decrease in the prevalence of the bacterium Helicobacter pylori, and decreased smoking rates.

Risk factors and protective factors

The cause of most cancers is still debated, though there is growing awareness that chronic inflammation is associated with the production of abnormal cancer cells. There are a number of factors that are well recognised as risk factors for cancer:

• Behavioural factors such as tobacco smoking, alcohol, diet, obesity and physical inactivity

  • Tobacco smoking is the largest single risk factor for lung cancer in Australia – causing about 90% of lung cancers in males and 65% in females (AIHW: Ridolfo & Stevenson 2001)

  • The major causes of stomach cancer are the bacterium Helicobacter pylori, poor nutrition and smoking.

• Family history, genetic susceptibility and reproductive and hormonal factors

  • Women with a family history of breast cancer are more likely to be diagnosed with breast cancer.

• Occupational and environmental exposures (for example, radiation, asbestos, ultraviolet light and chronic infection)

  • Ultraviolet radiation is the leading risk factor for melanoma of the skin.

• Medical and iatrogenic factors (AIHW & AACR 2012; IARC 2008; WCRF & AICR 2007).

  • chronic infection with the human papillomavirus (HPV) is associated with around 70–80% of all cervical cancers (Brotherton 2008).

Protective factors for cancers include:

• HPV vaccination helps prevent pre-cervical cancer lesions in young women (Gertig et al. 2013).

• Screening tests for breast, cervical and bowel cancer increase the survival rate and decrease mortality rates for the cancer as early detection improves outcomes of treatment. (BreastScreen Australia introduced in 1991 & National Bowel Cancer Screening Program introduced in 2006).

• Prostate examinations help early detection and increase the success of treatment for prostate cancer.

• Balanced diet, high in vegetables and fruit help reduce the probability of most cancers.

• Being sun-smart and not using solariums helps reduce the risk of melanoma of the skin.

The sociocultural, socioeconomic and environmental determinants

Sociocultural determinants of cancer include: family, peers, media, culture and religion. The Australian culture has often revolved around the heat of summer, beaches and getting a tan. However, recent educational actions, including advertising in the media have helped Australians know sun exposure increases the risk of melanoma of the skin. Genetics are inherited through family lines, and a history of cancer in the family increases the risk of cancer diagnosis. Other behavioural risk factors can also be affected by family and peers as people who have family and friends who smoke or are sedentary are more likely to adopt these lifestyle choices.

Socioeconomic determinants of cancer include: employment, education and income. People who have lower levels of education have lower levels of health literacy and are les aware of the risk factors and protective factors for a range of cancers. Lower levels of education also limit opportunities for employment. People who work outside have greater exposure to the sun, which places them at higher risk for skin cancers. People who work with other known sources of radiation, such as X-ray or are around electromagnetic fields frequently also have higher risk of cancer. Income can restrict access to some health services, especially some specialists. People with lower socioeconomic status have higher rates of cancer and higher mortality rates for cancer when compared to other Australians.

Environmental determinants of cancer include: geographic location and access to health services and technology. People living in rural and remote areas have higher mortality rates than other Australians. This is connected with their lack of access to specialists in cancer and less technology being available for treatment. Often rural and remote people need to travel to a major city for come cancer treatments. People who live on the beach are more inclined to be outside in the sun, which places them at more risk of some cancers.

Groups at risk

Groups at risk of cancer include:

• The elderly – 70% of diagnosis and 80% of cancer deaths were in people over 60 years of age.

• Males – cancer incidence was 1.4 times higher among males and death rates were 1.6 times higher than females.

• ATSI – are 10% more likely to be diagnosed and have 50% higher mortality rates from cancer.

• Low SES – had higher rates of all cancers and higher death rates.

• Rural and remote people – have higher mortality rates than other Australian from all cancers, though their incidence is lower.