Coronary Artery Disease
What is coronary artery disease?
Coronary artery disease (CAD) is a prevalent cardiovascular condition characterised by the narrowing or blockage of the coronary arteries which supply oxygen-rich blood to the heart muscle. CAD is a leading cause of heart attacks, chest pain and other serious complications.
CAD occurs when the coronary arteries become narrowed or blocked due to the buildup of plaque—a combination of cholesterol, fat, calcium and other substances—on the artery walls. This narrowing restricts blood flow to the heart depriving it of the oxygen and nutrients it needs to function properly. Over time CAD can lead to chest pain, shortness of breath, heart attacks and other cardiovascular events.
Although CAD’s mortality rates have steadily declined since 2011 it remains prevalent and accounted for over 10% of all Australian deaths in 2020.
Causes
CAD develops from a combination of factors primarily centred around the buildup of plaque within the coronary arteries.
As people age their arteries may become less flexible and more prone to damage, increasing the likelihood of atherosclerosis and plaque formation.
Atherosclerosis involves the gradual buildup of fatty deposits, cholesterol, calcium and other substances within the arterial walls. Over time these deposits (known as plaque) can narrow or block the coronary arteries, restricting blood flow to the heart.
High blood sugar levels associated with diabetes (particularly type 2 diabetes) and insulin resistance can damage the lining of the arteries, accelerating the development of atherosclerosis and increasing the risk of CAD.
Hypertension puts added stress on the arterial walls contributing to the development of atherosclerosis and increasing the risk of CAD. Elevated blood pressure can also lead to the formation of blood clots, further obstructing blood flow to the heart.
Elevated levels of low-density lipoprotein cholesterol (often referred to as “bad” cholesterol) can promote the accumulation of plaque in the arteries, narrowing the coronary vessels and predisposing individuals to CAD. High levels of high-density lipoprotein cholesterol (known as “good” cholesterol) can help remove cholesterol from the arteries and reduce the risk of CAD.
Regular exercise helps maintain healthy blood pressure, cholesterol levels and body weight as well as promoting optimal cardiovascular function and reducing the risk of atherosclerosis.
Tobacco smoke contains numerous harmful chemicals that can damage the arteries and accelerate the development of atherosclerosis. Smoking also increases blood pressure, reduces oxygen delivery to the tissues and promotes the formation of blood clots, all of which contribute to CAD.
Symptoms
- Chest pain and discomfort
- Squeezing or burning sensation
- Nausea
- Light-headedness
- Shortness of breath
- Weakness
Risks of Coronary Artery Disease
CAD leads to the accumulation of plaque within the arteries, increasing the risk of blood clot formation. These clots can trigger heart attacks or heart failure. Clots may also travel to the lungs or brain causing pulmonary embolism or stroke.
Due to the often-asymptomatic nature of CAD until significant plaque build-up occurs, many Australians are unaware of the condition until experiencing a heart attack. This emphasises the importance of regular check-ups—especially for people at risk—to detect and manage the disease early.
Diagnosis
Diagnosing CAD typically involves a combination of clinical evaluation, imaging and cardiac assessments to accurately assess the extent and severity of coronary artery blockages.
The diagnostic process often begins with a thorough review of your medical history including risk factors for CAD such as family history, smoking, diabetes, hypertension and high cholesterol. A comprehensive physical examination may also be conducted to assess for signs and symptoms of CAD such as chest pain, shortness of breath and abnormal heart sounds.
Blood tests may be performed to assess various markers of cardiovascular health including cholesterol levels, triglycerides and markers of inflammation (such as C-reactive protein). Elevated levels of certain biomarkers may indicate an increased risk of CAD or provide additional information about the severity of the disease.
An ECG is a non-invasive test that records the electrical activity of the heart. It can detect abnormal heart rhythms (arrhythmias) and provide information about the presence of ischemia or previous heart attacks. However, ECG findings may be normal in individuals with CAD particularly if they are not experiencing symptoms at the time of the test.
Stress testing, such as exercise stress testing or pharmacologic stress testing, may be performed to evaluate the heart’s response to physical exertion and detect signs of ischemia or reduced blood flow to the heart muscle. Stress testing may be combined with imaging techniques such as nuclear myocardial perfusion imaging or stress echocardiography to assess myocardial function and detect areas of ischemia or scar tissue.
Cardiac MRI provides detailed images of the heart and blood vessels which allows for the assessment of myocardial function, blood flow and the presence of coronary artery blockages or scar tissue.
CT angiography uses computed tomography (CT) scanning to create detailed images of the coronary arteries and identify areas of blockage or narrowing.
Coronary angiography is an invasive procedure that involves inserting a catheter into the coronary arteries and injecting contrast dye to visualise the arteries on X-ray images (angiograms). It’s considered the gold standard for diagnosing CAD and determining the severity and location of coronary artery blockages.
Treatments
The treatment of CAD aims to relieve symptoms, prevent complications and reduce the risk of heart attack and other cardiovascular events.
Medications
Statins and other cholesterol-lowering medications are commonly prescribed to reduce low-density lipoprotein cholesterol levels and slow the progression of atherosclerosis.
Drugs to lower blood pressure—such as ACE inhibitors, beta-blockers and calcium channel blockers—are often prescribed to reduce the workload on the heart and lower the risk of complications.
Nitro-glycerine and other nitrates may be prescribed to relieve chest pain by dilating the coronary arteries and improving blood flow to the heart.
Lifestyle changes
Adopting a heart-healthy diet rich in fruits, vegetables, whole grains, lean proteins and healthy fats can help lower cholesterol levels, control blood pressure and reduce the risk of CAD progression.
Engaging in regular physical activity such as brisk walking, cycling or swimming can improve cardiovascular health, promote weight loss and reduce the risk of CAD and its complications.
Quitting smoking is essential for people with CAD as smoking damages the arteries, accelerates the progression of atherosclerosis and increases the risk of heart attack and stroke.
Achieving and maintaining a healthy weight through diet and exercise can help reduce the burden on the heart and lower the risk of CAD progression.
Interventional procedures
Angioplasty involves inserting a balloon-tipped catheter into the narrowed coronary artery and inflating the balloon to widen the artery and improve blood flow. A stent (small mesh tube) may be placed in the artery to keep it open and prevent re-narrowing.
CABG surgery involves creating a bypass around the blocked or narrowed coronary arteries using blood vessels from elsewhere in the body (typically the chest or leg). This restores blood flow to the heart muscle and can relieve symptoms of CAD in people with extensive disease or those who are not candidates for angioplasty.
More information
Consult a cardiologist
Ready to see a cardiologist? Call Cardiography Specialists Melbourne for specialised care for coronary artery disease and other heart conditions.