A heart scan is a very useful way to individualize a patient’s care in my patient population. The heart scan and coronary calcium score are terms used interchangeably. It allows me to see the burden of plaque in the coronary arteries and helps determine risk along with other testing. One thing I like about heart scans is that often it is the first wake-up call for a patient. This leads to a further workup and can go a long way in preventing cardiovascular events.
How to Interpret a Heart Scan/Calcium Score
By definition having a positive coronary calcium score means that you have coronary artery disease. However, the amount matters, especially over 400. Calcium scoring has been found to be more accurate at predicting risk than blood tests. A heart scan tells you how much calcified plaque you have as well as which arteries are affected. Risk increases as the calcium score gets higher but there’s a catch. It’s the rate of progression that matters more. A rate of progression greater than 15% is too high. There is another catch that makes understanding calcium scoring hard. In some cases the healing process leads to more calcification. This is not always the case but it can occur. To determine this, inflammation markers must be done in addition to carotid artery ultrasound. Carotid artery plaque must be monitored with the coronary calcium. Left untreated, rates of progression can be very high. The worst one I ever saw was 150% in one year. A rapidly progressing calcium score means that new plaque is forming and indicates active disease. One drawback to the heart scan is the fact that it can only see older calcified plaque, and not newer uncalcified plaque. A carotid artery ultrasound is able to visualize new soft uncalcified plaque and is a critical part of my practice.
It’s not enough to just get a scan though. There needs to be adequate treatment and further blood testing to determine why there is disease.
There is a documentary called the Widowmaker on heart scans and how they can save lives.
Malguria N, Zimmerman S, Fishman EK. Coronary Artery Calcium Scoring: Current Status and Review of Literature. J Comput Assist Tomogr. 2018;42(6):887-897.