Coronary Artery Disease

Overview

Coronary arteries are the arteries that supply blood flow to your heart muscle. Coronary artery disease occurs when cholesterol-containing plaques build up on the inside and block the flow of bloods in the coronary arteries. Decreased blood flow to the heart muscle most commonly causes chest pain (angina), shortness of breath, dizziness or decreasing exercise tolerance.

A coronary plaque contains a build-up of a type of cholesterol, low density lipoprotein (LDL), that has accumulated in the arterial wall over many years. This build up of low density lipoprotein (LDL) and other cellular components, are caused by and accelerated due to many factors.

  • Family history
  • Hypertension
  • Smoking
  • Obesity
  • Insulin resistance
  • Diabetes
  • High cholesterol
  • Lack of exercise
  • High dietary carbohydrate and fat
  • Inflammation of the coronary arteries
  • Age
  • Sleep apnoea
Symptoms

Coronary artery disease starts with changes to the inner layer of a coronary artery, sometimes as early as childhood. At first, small plaques form on the inside of the coronary arteries. These early plaques do not restrict the coronary artery flow and are unlikely to cause symptoms.

As the plaque builds up, your coronary arteries narrow and the blood flow to the heart becomes restricted and stable symptoms may start to appear.
The most common stable symptoms and clues to progression of coronary artery disease are:

Chest pain or chest pressure that usually occurs with exercise and is relieved with rest. Often pain which often moves to, or starts in the jaw, neck, back or arms.

  • Shortness of breath – with exercise and relieved with rest
  • Fatigue
  • Dizziness or palpitations – due to new onset of abnormal rhythms
  • New onset of high blood pressure
  • New onset of swelling

Unstable symptoms occurs when the surface of the plaque develops a crack and blood cells called platelets go at the site to try to repair the artery and form a clot. Previous symptoms of chest pain and shortness of breath may now occur at rest.

These unstable symptoms can occur just prior to the coronary artery completely blocking.
A completely blocked coronary artery will cause a heart attack or myocardial infarction. The signs and symptoms of a heart attack include crushing pressure in your chest and pain in your shoulder or arm, sometimes with shortness of breath, nausea and sweating.
Women are less likely to experience typical signs and symptoms of a heart attack, such as neck or jaw pain. Women may present with heart attack after only having fatigue, breathlessness and minor sharp pain. Sometimes a heart attack occurs without any apparent signs or symptoms especially in people with diabetes.

If you suspect you are having a heart attack, call an ambulance, or if there is no ambulance, have someone drive you to the nearest hospital.

Risk Factors

Risk factors for coronary artery disease include:

  • Age. As you get older your risk of coronary artery disease increases
  • Sex. Men are at slightly higher risk than women. After menopause the risk for women increases and approaches that of men
  • Family history. A family history of heart disease is associated with a higher risk of coronary artery disease. Your risk is highest if your father or a brother was diagnosed with heart disease before age 55 or if your mother or a sister developed it before age 65
  • Smoking. People who smoke or have exposure to second hand smoke have a significantly increased risk of heart disease
  • High blood pressure. High blood pressure can damage the internal lining of the arteries and increases the risk of coronary artery disease
  • High blood cholesterol levels. A high level of low-density lipoprotein (LDL) “bad” cholesterol increases your risk of coronary artery disease. Low level or low function of high-density lipoprotein (HDL) “good” cholesterol, also contributes to the development of coronary artery disease
  • High triglycerides. Triglycerides are a type of fat (lipid) in your blood. High levels of triglycerides usually associated with high carbohydrate intake, insulin resistance and diabetes, raises the risk of coronary artery disease
  • Insulin resistance or pre-diabetes. Insulin resistance is exacerbated by excessive high carbohydrate foods and lack of exercise, increases the risk of coronary artery disease
  • Diabetes. Diabetes is associated with an increased risk of coronary artery disease
  • Overweight or obesity. Not maintaining a healthy weight increases you risk of coronary artery disease and worsens other risk factors
  • Unhealthy diet. Eating too much food and food that has high amounts of carbohydrate that is combined with saturated fats and trans fats increases your risk of coronary artery disease. Reduction in carbohydrate and saturated fat is associated with an improved cardiac risk reduction, reversal and stabilisation coronary artery disease. The Nightingale Healthy Eating diet outlines in more detail the changes that you will need to make to reduce your cardiovascular risk and can be downloaded here
  • Physical inactivity. Lack of exercise also is associated with coronary artery disease and some of its risk factors as well
  • High stress. High stress in your life increases blood pressure, cortisol levels damaging the lining of your arteries and worsens other risk factors for coronary artery disease
  • Sleep apnoea. Sudden and repeated drops in blood oxygen as a result of sleep apnea is associated with increase risk for coronary artery disease and other cardiac disease such as atrial fibrillation
  • Homocysteine. Homocysteine is a biomarker in the blood that your doctor can measure that is associated with increased risk for coronary artery disease. Folate in your diet and supplements may reduced homocsyteine and cardiovascular risk
  • Inflammation of the arteries. Inflammation of the coronary arteries is associated with increased cardiac risk. Coronary arterial inflammation can be measured by your doctor with a blood biomarker test called high sensitivity C-reactive protein (hs-CRP). Increased hs-CRP levels are a risk factor for heart disease. As you develop more coronary plaque arteries, you’ll likely have more hs-CRP detectable in your blood
  • Pre-eclampsia. This condition causes high blood pressure in pregnancy and can lead can lead to a higher risk of heart disease later in life
  • Lupus and rheumatoid arthritis. Autoimmune conditions such as lupus and rheumatoid arthritis are associated with increased risk of coronary artery disease
Complications

Coronary artery disease can lead to:

  • Angina. If one or more of your coronary arteries in severely narrowed by plaque (usually >70%), blood flow to the heart muscle is inadequate during exercise. This can cause “angina” which usually presents s chest pain but may also occur as shortness of breath, decreased exercise capacity or fatigue. Angina can be reduced with aggressive cholesterol lowering, lifestyle and dietary modification, risk factor modification, medications, coronary stent or coronary bypass
  • Heart attack. Coronary artery plaques can crack or rupture if the disease is not stable. Once a coronary artery plaque ruptures, platelets form on the site of the crack or rupture and form a clot and may block the artery completely. Usually this results in damage to the heart muscle and is called a heart attack or myocardial infarction. The amount of damage that occurs to the heart muscle partly depends on how quickly the artery is opened up and blood flow returned to the heart muscle. Blood flow can be returned using a coronary stent or medication to dissolve the clot
  • Heart failure. After a heart attack, the heart muscle may be damaged and heart function reduced. Also, some areas of your heart may be chronically deprived of oxygen and nutrients because of reduced blood flow. Heart failure occurs if the heart function is reduced and the heart is unable to pump property. As a result fluid may build up in the lungs or legs resulting in decreased exercise capacity, shortness of breath or leg swelling
  • Arrythmia. Damaged heart muscle and heart muscle that does not have enough blood flow may become irritable the hearts electrical system may be compromised causing abnormal arrythmias. Depending on the nature of the abnormal rhythm, your cardiologist may give you medications or recommend a pacemaker or ICD
Prevention

Prevention of coronary disease before it causes cardiac events and complications, is the best possible approach everyone can take.  Prevention is an important part of Nightingale Cardiology’s comprehensive approach to coronary artery disease.

Healthy eating – follow the Nightingale Healthy Eating guide.
Exercise – exercise every day for at least 30 minutes with minimum brisk walking or equivalent. Your cardiologist may recommend alternatives depending on your circumstances and underlying fitness.

Blood pressure – get your blood pressure checked regularly either at home or with your doctor. For most people, the guidelines recommend an office blood pressure less than 135/85mmHg is desirable. Your doctor or cardiologist may recommend alternatives values depending on your circumstances and age.

Cholesterol target – if you have coronary artery disease, the European Society of Cardiology guidelines recommend a lowering of your low density lipoprotein (LDL) by at least 50% of the baseline level and to less than 1.5 mmol/L and less than 1.0 mmol/L if you have had two events. Your cardiologist may recommend medications to achieve this.