See your heart-health future
*This is not an emergency service. If you are experiencing persistent chest pain, pain or tingling in your arms or other areas of your upper body, shortness of breath or irregular heartbeat, call an ambulance (dial 000 in Australia)*
Stable chest pain (or angina pectoris) is the term used to describe discomfort from coronary artery disease. It occurs when the heart muscle does not get the oxygen it needs to function correctly. Atherosclerosis (narrowing of the arteries) is caused when plaque builds up inside the arteries. High risk plaque, also referred to as vulnerable plaque, is most prone to rupture and block an artery. This blockage can lead to a heart attack.
There are various tests available to detect coronary artery disease biomarkers which a healthcare professional will guide a patient through if they have suspected coronary heart disease. These tests help clinicians determine the severity of a patient's coronary artery disease and, therefore, the best treatment plan for them.
Talk to your clinician about your heart health. See your future of heart health.
Understanding Coronary Artery Disease
What you need to know about atherosclerosis and the underlying causes of heart attacks.
Real cause of heart attack
Atherosclerosis is the major disease process underlying the majority of heart attacks. It occurs when fat (cholesterol) and calcium build up inside the lining of the artery wall, forming a substance called plaque.
Cholesterol plaques start forming in the walls of arteries. Long before they can be called plaques, hints of atherosclerosis called “fatty streaks” can be found in the walls of arteries. Even some teenagers have these "fatty streaks" of cholesterol in their artery walls. Atherosclerosis develops over years. It happens through a complicated process that involves:
- Damaged endothelium. The smooth, delicate lining of blood vessels is called the endothelium. High cholesterol, smoking, high blood pressure, or diabetes can damage the endothelium, creating a place for cholesterol to enter the artery's wall.
- Cholesterol invasion. "Bad" cholesterol (LDL cholesterol) circulating in the blood crosses the damaged endothelium. LDL cholesterol starts to gather in the wall of the artery.
- Plaque formation. Inflammatory white blood cells stream in to digest the LDL cholesterol. Over years, the toxic mess of cholesterol and cells becomes an atherosclerotic plaque in the wall of the artery.
There are two types of plaque which can affect people in different ways:
Stable plaques: occur when the walls of your coronary arteries, which carry oxygen and nutrients to your heart, become thickened and stiff because of a build-up of fatty cholesterol deposits. Healthy arteries are elastic and flexible. A person with atherosclerosis will have hardened arteries due to a build-up of fatty substances, particularly cholesterol, which is deposited in the wall of the arteries. As plaque builds up it can narrow the coronary artery and reduce blood flow to your heart muscle.
Vulnerable/Unstable plaques: are plaques that are more likely to rupture. A ruptured plaque can result in a heart attack by causing a sudden blockage of the artery. This stops the blood flow, reducing oxygen supply and can result in permanent damage to heart muscle. Unstable plaques can be identified by their composition. They typically consist of a large fat/cholesterol content, the presence of inflammatory cells (i.e. macrophages) and thinning of the vessel wall which contains the plaque, making it easy to crumble and more vulnerable to rupture. The presence of vulnerable plaque increases the risk of heart attack, even before significant coronary artery narrowing develops. The presence of atherosclerosis and plaque in the coronary artery increases the risk of similar plaque being found in vessels of the body such as the aorta and brain, increasing the risk of stroke and vascular disease.
Atherosclerotic plaques typically get worse with time. They are also preventable. These risk factors are to blame for the majority of all heart attacks:
- High cholesterol
- High blood pressure
- Abdominal obesity
- Poor diet - not eating many fruits and vegetables
- Drinking too much alcohol
- Not enough physical activity (exercise)
The diagnosis of vulnerable plaque has traditionally relied on specialised imaging tests performed during an invasive coronary angiogram. These tests involve placing an imaging probe directly into the coronary artery. This is associated with risk of complications and patient discomfort. CT coronary angiography (CTCA) is an increasingly utilised non-invasive test that is able to accurately identify the presence of plaque in the coronary artery. Recent advances in image processing also allow for characterisation of plaques that are vulnerable to rupture. Clinical studies have consistently demonstrated that patients with vulnerable plaques identified on CTCA are at increased risk of future heart attack compared to patients without vulnerable plaque.
Once atherosclerotic plaque is present, it's generally there to stay. The goal of treatment with medication and lifestyle changes is to slow or stop the plaques from further growth and convert vulnerable plaques to stable plaques. This is proven to lower the risk of heart attack and stroke. Some evidence shows that with strong treatment and a significant reduction in blood cholesterol levels, atherosclerotic plaques can even shrink slightly.
Lifestyle changes that are helpful in reducing blood cholesterol levels and the treatment of atherosclerosis include:
- Exercise which increases "good" HDL cholesterol and reduces the risk of heart attacks and strokes.
- Eating a healthy diet, which includes a diet high in fibre and low in fats which can lower "bad" LDL cholesterol. Also oily fish and other foods high in omega-3 fatty acids can raise “good” HDL cholesterol.
- Not smoking and reducing stress levels.
These lifestyle treatments won't unclog arteries. But they can lower the risk of heart attacks and strokes.