Coronary Calcium Scoring
Coronary calcium scoring is one of the most advanced cardiac diagnostic tests available today. A simple, noninvasive test, the calcium test is one of the best tools used to detect early signs of heart disease, greatly reducing a patient’s risk of a sudden heart attack.
Through the use of new technology called 64-slice CT scanning, which allows a patient’s heart and coronary arteries to be visualized in just a few breaths, calcium scoring measures the location and extent of calcified plaque. The test can suggest the presence of coronary artery disease even when the arteries are less than 50% blocked. And more than half of all heart attacks occur with less than 50% narrowing. Unlike similar coronary diagnostic tests, calcium scoring requires no injections and no need to drink any special fluids to diagnose coronary artery disease.
Your coronary artery calcium score can help you make lifestyle changes that may be needed depending on the severity of coronary artery disease, thus decreasing your chances of a future heart attack.
Calcium scoring is an easy, noninvasive exam used to detect coronary artery disease in its early stages. The test takes about five minutes. During that time, thousands of images are taken of your heart and arteries.
Who should know their calcium score?
If you’re diabetic or have any two of the following additional risk factors, you could be at risk for a sudden heart attack and should know your calcium score:
- Over 40 years of age
- Family history of heart disease
- High cholesterol
- Past or present smoker
- High blood pressure
What are the benefits?
There are many benefits to the coronary calcium scoring procedure including the ability to:
- Detect coronary artery disease at an early stage when there are no symptoms
- Calculate future risk of coronary artery disease
- Prevent a fatal heart attack
- Determine treatment plans if artery blockages are present
How does the test work?
The CT scanner works very much like other X-ray examinations. However, with CT scanning, numerous X-ray beams and a set of electronic X-ray detectors rotate around you while the examination table moves through the scanner. A special computer processes these pictures or slices of your body to create two-dimensional, cross-sectional images of your heart and coronary arteries that are displayed on a monitor. The image slices are then reassembled by computer software resulting in very detailed multidimensional views of the body’s interior.
How is Coronary Calcium Scoring performed?
A technologist will position you on the CT examination table, usually lying flat on your back. In some instances, it may be possible to lie on your side. Pillows and straps may be used to help you maintain the correct position and to hold still during the exam.
Small ECG electrodes will be attached to your chest and to an ECG machine that records the electrical activity of the heart. This makes it possible to record CT scans when the heart is not actively contracting.
Next, the examination table will move slowly through the scanner as the actual CT scanning is performed. You will be asked to hold your breath periodically throughout the scanning for 5–10 seconds while images are recorded. The actual CT scanning is usually completed within minutes.
How is the calcium test interpreted?
A radiologist will analyze the images and send a signed report to your primary care physician or referring physician. Your physician will then share the results with you and interpret the findings.
A negative calcium scoring test that shows no calcification within the coronary arteries suggests that plaque is minimal and that the chance of coronary artery disease developing over the next two to five years is very low.
A positive calcium score means that coronary artery disease is present, regardless of whether or not the patient is experiencing symptoms. The amount of calcification, known as the score, may help predict the likelihood of a heart attack in the coming years. At this stage, you and your doctor can discuss treatment and preventative measures.
How do I prepare for the test?
- Wear comfortable, loose-fitting clothing
- Take your usual medications
- Avoid caffeine and smoking for four hours before the exam — if your heart rate is 90 beats a minute or higher, you may be given medication to slow the rate in order to obtain accurate images
- Do not wear metal objects including jewelry, eyeglasses, hairpins or dentures, as they can affect the CT images
Women are advised to inform their physician or the technologist performing the procedure of any possibility of pregnancy.
What are the risks and limitations of calcium scoring?
- Radiation exposure, although the benefit of an accurate diagnosis far outweighs this risk
- Not recommended for pregnant women because of potential risk to the baby
- Not advised for routine screening for coronary artery disease
- Soft plaque cannot be detected by CT scan — soft plaque, the earliest form of coronary artery disease, can be unstable and are more likely to rupture and trigger blood clotting inside the arteries, resulting in a totally blocked artery and heart attack
Facts about calcium, cholesterol and plaque
Cholesterol is a substance made naturally by the liver. It can also be found in various foods we eat. Our bodies need cholesterol for many different functions but, when there is too much in your blood, cholesterol and other substances like calcium can build up in the body. This can include the walls of your arteries.
Calcium is also very important for our body. It is needed for strong bones and teeth, our heart, muscles and nerve function, and for blood to clot. Calcium is a vital substance that should be taken daily. However, calcium can exist in places where it is not suppose to be.
The build up of cholesterol and calcium is called plaque. Over time, this plaque can cause hardening of the arteries, which narrows the arteries causing a decrease in blood flow. This decrease in blood and oxygen can cause chest pain. When blood supply is cut off completely by the plaque, a heart attack can occur.