More than 3 million cases per year are reported every year with Coronary artery disease affecting 16.5 million Americans in the last 5 years with cases in the age range 41-60+ affected the most. For patients with no risk factors for heart diseases lifetime risk of having a Coronary artery disease is 3.6% for men and less than 1% for women. Having 2 or more risk factors increase the lifetime risk of coronary artery disease to 37.5% for men and 18.3% for women posing a serious problem to a good majority of the Americans.
This write up deals with the ways to identify the issue and the ways to address it.
What exactly is a Coronary Calcium Scan or Heart Scan?
Coronary artery calcium scoring or Heart scan is used typically to determine the cardiovascular risk of a person. It is a fast, non-invasive, simple, convenient and possibly the best screening test to identify the presence, location, extent of calcium plaques and quantify the calcium load in the coronary arteries that cause narrowing of blood vessels thus decreasing blood supply to the heart leading to heart attacks. The quantification of coronary artery calcium on CT/Heart scan is correlated with the severity and total plaque burden in the artery. Calcium phosphate and hydroxyapatite, the deposits of which appear as bright spots in the scan, are primarily responsible for calcification of coronary artery leading to the artery disease.
Exploring the basics leads us to the following questions.
Who should get a coronary calcium scan?
Men: 35-70 years of age with one or more risk factors for heart disease. Women: 40-75 years of age with one or more risk factors for heart disease. Also for patients with symptoms of chest pain, shortness of breath, fatigue and with an abnormal EKG should get the heart scan.
What are the risk factors associated with heart disease?
Major risk factors that are modifiable
- High blood pressure
- Diabetes mellitus
- Dyslipidemias: Tobacco use
- Elevated cholesterol
- Elevated triglycerides
- Elevated lipoprotein
- Low HDL
- Physical inactivity
Major risk factors that are non-modifiable
Other risk factors include
- Diet and Nutrition
How should I prepare for the scan?
No specific preparations are necessary for patients. Fasting is not necessary and patients should continue to take their medication. Patients are advised to avoid caffeine and smoking 4 hours prior to the scan as the high heart rate may reduce imaging quality.
Metal objects like ear rings, hair pins, and dentures should be avoided. Women should inform the physician if there is any possibility of them being pregnant.
How does the procedure work?
Ultrafast CT spiral scan machine is used for this purpose making the procedure time very short, approximately 15 seconds.
CT scan works like any other x-ray examinations and allows for the acquisition of thin image slices of heart and coronary arteries. Radiation dose is as low as possible and with no known side effects.
Interpretation of the coronary calcium scoring
Presence of Plaque
Risk of Heart attack
|0||No identifiable plaque. You have less than 5% chance of having heart disease.||<5% chance||Very low|
|1-10||Minimal identifiable plaque. You have less than 10% chance of having heart disease.||<10% chance||Low|
|11-100||Mild plaque is present. You have mild heart disease.||Mild||Moderate|
|101-400||Moderate amount of plaque is present. You have heart disease and plaque may be blocking an artery.||Moderate||Moderate to high|
|>400||Large amount of plaque is present. You have more than a 90% chance that plaque is blocking one of your arteries.||Severe||High|
Benefits of coronary calcium scan
- Identifies risk of having heart attack and if identified the level of severity helping the patient to plan treatment and relief.
- Helps screen patients with chances of having heart attack even 5-10 yrs. prior to the occurrence of symptoms.
Risks of coronary calcium scan
- Risks are minimal with no immediate side effects. Benefits of the scan outweighs the exposure to radiation and radiation is minimal compared to the natural radiation received from our atmosphere.
What about Insurance coverage?
- Most of the insurances do not cover this test. At the Cardiac Center of Texas, the cost of a scan is ~$45. It is one of the few places where the heart scan is available.
Management of the patients with positive screening test
- Based on the results and considering other risk factors your cardiologist may order other diagnostic tests like stress test and Echocardiography to further evaluate the condition.
- Coronary catheterization with angiography of the coronary arteries may be indicated to assess the severity and extent of coronary narrowing.
- There is no specific treatment available to lower coronary artery calcium deposition. Treatment of patients with high calcium scores should aim at reducing risk of heart attack. This involves treating lipid disorders, diabetes mellitus, and high blood pressure.
- Patients are advised to avoid smoking and do regular and moderate exercise.
Coronary artery calcium scoring test is simple and is lifesaving.
A 63-year-old female with coronary artery disease visited our clinic for follow up on her condition. She has a family history of heart disease, her father died at the age of 36 with heart attack. She had heart scan during her previous visit as part of screening for heart disease and her calcium score was 400. She was educated about the screening tests and its benefits. Because of her family history, she advised her brother who is 70-year-old to get the scan. He was asymptomatic and never had any heart problems. On testing the calcium score was 2500. Patient had coronary angiogram which showed 100 % blockage of coronary vessels and patient had coronary artery bypass surgery. Now the patient is doing well after the surgery and back to his normal activities. Truly lifesaving!
Statistics of heart disease: Heart Disease and Stroke Statistics 2017 Update: A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2017, January 25 http://circ.ahajournals.org/content/early/2017/01/2
Risk factors for heart disease:
Procedure of heart scan, risks and benefits:
Interpretation of calcium scoring http://www.umm.edu/programs/diagnosticrad/services/technology/ct/cardiac-calcium-scoring
Calcium scoring of the heart scan www.RadiologyInfo.Org