There are many predictors for development of cardiovascular disease, with the first line of testing usually being a blood test for your lipid profile – total cholesterol, triglycerides (fats in your blood), HDL (protective) cholesterol and LDL (atherogenic) cholesterol.
A high level of ‘small dense particle’ LDL cholesterol and/or a high triglyceride/HDL ratio are considered risk factors for depositing plaque in your arteries, leading to heart disease.
You may not be aware that you can also ask your doctor for a Coronary Artery Calcium Score referral – a CT scan of your arteries to determine if you do have plaque in your arteries and, if so, how much.
Coronary Artery Calcium Score – CAC – explained
When we age, calcium deposits can be found in many parts of our bodies.
Plaque deposits on the walls of our arteries (atherosclerosis) is composed of cholesterol, calcium, inflammatory cells and other substances. To function optimally, your heart needs a continuous supply of oxygen and nutrients, so when plaques begin to obstruct this blood flow, symptoms such as chest pain may result. Plaque may also rupture, leading to a heart attack.
There are many risk factors for atherosclerosis, including by not limited to:
High blood pressure
Calcification in the arterial walls is common in people aged 65 and older. Most of us will accumulate some degree of build-up over a lifetime. While it’s not inevitable, it is commonly regarded as a normal part of aging. If the amount of plaque is higher than anticipated by age (see chart below), it may represent an increased risk for heart attack. However, recent evidence reveals this process may be triggered by inflammation in the blood vessel wall.
While the CAC score doesn’t reflect blockages or impaired blood flow, a high CAC score suggests you are at higher risk of an arterial blockage than someone with a low score. A zero score suggests you are very unlikely to have a severe blockage of a coronary artery.
CAC Score ranges:
CAC score “0” – no identifiable coronary artery disease
CAC score “1-99” – mild coronary artery disease
CAC score “101-400” – moderate coronary artery disease
CAC score “>400” – extensive coronary artery disease
There are a few unique considerations relating to age, gender and ethnicity.
If everything is normal, we would expect our arterial biological age to be the same (or preferably lower) than our chronological age.
For example, if a 50-year old man had a CAC score of 200, his arterial age will be 78 years.
The arterial biological age can be predicted from the CAC score
There is no specific treatment available that lowers coronary calcium once accumulated. Treatment of individuals with high calcium scores should aim at reducing risk. This involves treating lipid disorders, high blood pressure, and insulin resistance, pre-diabetes and/or diabetes if present. Quitting smoking and remaining physically active are also important.
Treatment with statin drugs is often prescribed with a high CAC score, based on their ability to reduce plaque size. However, statins do not reduce arterial calcifications. In fact, some studies suggest that statins may promote coronary calcification.
Statins are often recommended if the CAC score is above 100.
Inadequate calcium intake can lead to decreased bone density, thereby increasing the risk of osteoporosis and bone fractures. Supplemental calcium can increase bone mineral density and bone strength. However, recent data suggests that high consumption of calcium supplements may also increase calcification of the arteries.
Vitamin K2* deficiency is associated with an increased risk of calcification of the blood vessels. While further studies are needed to confirm the role of K2 supplements in those with high CAC scores, research indicates that the use of vitamin K2 supplements is associated with decreased arterial calcification.
*always consult a health professional before introducing a new dietary supplement as they may be contraindication with some medications.
The bottom line: if you have a family history of heart disease, or you are concerned about risk factors or pathology results, speak with your doctor about whether a CAC Score scan is appropriate for you.