A software program permits a score, called the Agatston score, to be calculated after the scan. If there is no calcium in the coronary arteries, the score is zero. Alternatively, even in persons with NO symptoms, the score can be tens, hundreds and even thousands indicating small to huge amounts of calcified heart artery plaque that can lead to symptoms, sudden heart attacks, or sudden deaths.
Research studies like those cited above indicated that the heart calcium score is the most accurate way to detect silent heart disease and also the strongest predictor of future cardiac events like heart attack and death. In my area the scan can be done for as little as $75 so there is easy availability to all who do not know they have early heart disease but want to find out.
If you have not heard of a heart calcium score it may be because it has not been promoted as much as more expensive and invasive stress tests and heart catheterizations that expose you to much more radiation, sometimes 10-15 times the amount of the CACS. This dilemma is the focus of a provocative and “must watch” documentary called The Widowmaker. Although you may need a prescription from your healthcare provider, I am quite certain that after watching this documentary, you will conclude that you must know your CACS. I know mine and it is zero.
What about the possibility that arteries have plaque but that it is not calcified and missed by the CACS. A new study addresses this in a large patient sample who had the CACS and also had the more advanced CT study that involves injecting dye (coronary CT angiography or CCTA) which most do NOT consider as a screening test for the asymptomatic person due to the risk of allergies and kidney reaction to the contrast agent administered.
According to the authors:
In this prospective cohort study, consecutive patients with stable chest pain underwent CCTA as part of routine clinical care over 7 years. Major adverse cardiac event (MACE) was defined as cardiac death, non-fatal myocardial infarction and/or non-elective revascularization.
Of the 751 (82%) patients with a zero CAC in whom CTCA was performed, 674 (90%) had normal coronary arteries free of all blockages. This is even though they had some chest pains.
Of the remainder, 8% had minor non-calcified CAD with < 50% stenosis and 2% had ≥ 50% narrowing in at least one coronary artery. The “negative predictive value” of a zero CACS for excluding a ≥ 50% narrowing was 98.1%.
Over a follow-up period of 2.2 years (range 1.0-7.0 years), the absolute annualized rates of MACE were as follows: for a zero CACS it was 1.9 per 1000 person-years and non-zero CAC 7.4 per 1000 person-years (HR 3.8, p = 0.009). After adjusting for age, gender and cardiovascular risk factors, the hazard ratio (a statistical measure of the amount of increased risk) for all-cause mortality among the zero CACS group vs. the non-zero CACS was 2X.
THE AUTHORS CONCLUDED THAT:
A zero CACS score in patients undergoing CT scanning for suspected stable angina has a high negative predictive value for the exclusion of obstructive CAD and is associated with a good medium-term prognosis.
What You Should Consider:
Whether you have never had symptoms suspicious for heart disease, or whether you have had symptoms like the study presented here, a CACS of zero buys you 98% peace of mind for a few years at least. This is far in excess of stress tests that may be 85% accurate, expose you to much more radiation, and cost 10-15 times more.
This holiday season, invest in the gift of health and knowledge by scheduling a CACS at your local hospital (unless you have had a heart attack, stent, or heart bypass in which case you do not need this examination).
