An overview of Coronary Artery Disease (CAD)

Prepared by Dr Ang Chin Yong

Consultant Interventional Cardiologist 

Gleneagles Medini Hospital

What is coronary artery disease?

The coronary arteries run along the outside of the heart and supply blood to the heart muscle to allow it to function as a pump. Coronary artery disease (CAD) occurs when there are fatty plaques within the arterial wall, resulting in narrowing and reduced blood flow. It is a chronic ailment that develops over years. Hence, early diagnosis is crucial to stop its progression, and avoid heart attack and heart failure.

What are the risk factors for coronary artery disease?

Risk factors for CAD often include:

• Smoking
• High cholesterol (LDL-cholesterol, total cholesterol, triglycerides)
• High blood pressure
• Diabetes
• Physical inactivity
• Obesity
• High saturated fat diet

Controlling risk factors is the key to preventing illness and death from CAD.

What are the symptoms of coronary artery disease?

The symptoms of coronary heart disease will depend on the severity of the disease. Some people with mild CAD have no symptoms. Symptoms are present when narrowing is severe, which may include: chest heaviness, tightness or pain (which may radiate to the arms, jaw, neck, and/or back), shortness of breath, weakness and fatigue.

How is coronary artery disease diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for coronary artery disease may include any, or a combination of the following:

• Stress test (exercise ECG). An ECG test that is given while a patient walks on a treadmill to monitor the heart during exercise to help detecting CAD.

• Echocardiogram (ultrasound of the heart) to assess various cardiac structures and heart function.
• A CT coronary angiogram relies on a powerful X-ray machine to produce images of your heart and its blood vessels. This test is non-invasive and don't require recovery time. It only involves an intravenous injection of a contrast dye in the vein.

   

  

  Cardiac CT (CT coronary angiogram)                    
  

  

  Cardiac MRO
  

• Cardiac MRI scan to assess heart structures, heart muscle condition and function. When performed with stress protocol induced by medication, it can be used to help detecting CAD.
• Cardiac catheterization is the gold standard test for CAD. With this procedure, X-ray videos are taken after contrast agent is injected into an artery to locate the narrowing, occlusions, and other abnormalities of specific arteries.

   

  Treatment of CAD may include:
  

• Modification of risk factors including smoking cessation, treatment of elevated cholesterol levels, hypertension and elevated blood glucose levels, regular aerobic exercise, healthy dietary habits and weight reduction for overweight patients.
• Medications include: Antiplatelet medications (blood thinner), drug(s) for cholesterol and/or blood pressure reduction, and antianginal medicine to reduce chest pain.
• Coronary angioplasty (ballooning and stenting). With this procedure, a balloon is used to create a bigger opening in the vessel to increase blood flow.

Coronary angiogram showed severe blockage (A) and restoration of blood flow after angioplasty (B)

Coronary artery bypass graft (CABG) surgery. It is an open heart surgery to create new blood supply by grafting a piece of artery or vein above and below the blocked area of a coronary artery, enabling blood to flow around the obstruction. Vessel are usually taken from the leg veins, as well as arteries from the chest or arm.