I. What Is It?
Coronary artery calcification is a process that can naturally occur along with the development of atherosclerotic plaque development. However, it must be stated that not all atherosclerotic plaques have calcium deposits. Older people tend to have more calcified plaques than younger people.
Atherosclerosis is a thickening or hardening of the arteries. This thickening, or hardening is caused by a buildup of plaque in the inner lining of an artery.
Plaque is made up of various deposits of fatty substances, cholesterol, cellular waste products, calcium, and fibrin.
When a person has coronary artery plaques, this can lead to various problems - For example, if the plaque gets too big, it can limit or cut off blood flow to certain areas of the heart (causing angina or a heart attack - myocardial infarction). If a plaque ruptures, tiny emboli might be sent to the brain and block off blood flow causing a stroke.
II. How Do We Assess it?
One way we have of determining what is going on in the blood vessels of the heart is a procedure called coronary artery calcium scoring. This test is basically a special CAT scan of the heart that detects and quantifies calcium deposits in the heart/coronary arteries.
The coronary artery calcium score is given as a number.
0 Agagston Units (AU) - No identifiable disease
1-99 AU - Mild Disease
100-399 AU - Moderate Disease
> 400 AU -
III. How are these numbers generally interpreted?
When a provider considers a CAC level, that number is usually considered in combination with other assessment measures (labs, family history, cardiac risk calculators, etc).
The 2008 Framingham risk calculator is a very common cardiovascular risk assessment tool that is used to assess a person's ten-year risk for experiencing a cardiovascular event. There is a calculator for males and females.
This calculator uses the following data to arrive at a percentage risk:
Age
Systolic BP
Total Cholesterol
HDL Cholesterol
On HTN Medication?
Cigarette Smoker?
Diabetes Present?
A person who scores <5% is considered low risk for a coronary event within ten years. Borderline risk is 5-7.4%. The intermediate risk is 7.5-10%. High risk is considered 10% or greater. Very high risk is 20% or greater.
The value and utility of the Coronary Artery Calcium Score as a predictive indicator for future ASCVD (Atherosclerotic coronary vascular disease) have been validated through various means.
Patients are generally selected for the CAC score CT scan based on several criteria:
>40 years of age.
An intermediate to high-risk score on the 10-year cardiovascular risk calculator
If a patient is already on a cholesterol-lowering medication, the CAC score CT scan is not usually performed.
IV. So what is done based on the CAC Score?
General measures for all scores:
Healthy Diet
Stop Smoking.
Regular Exercise.
Optimize Blood Pressure.
Decrease Stress.
CAC Score 1-99
Consider Statins (a medication that helps to reduce triglycerides and cholesterol) if the LDL is between 100-190) - Actual benefit of lipid-lowering in this category of patient is low.
Aspirin is not generally recommended (Regardless of the 10-year risk is)
CAC Score > 100
Treat with a Statin if the LDL is between 100-190
Possibly Aspirin (Regardless of their 10-year risk category.