Coronary artery calcium (CAC) scoring is one of the most useful tools in long-term cardiovascular assessment — not because it predicts an event with certainty, but because it tells you something about what is actually happening inside your arteries that no blood test can.
What it measures
A CAC scan is a low-dose CT scan of the chest that detects calcified plaque in the coronary arteries. Calcium deposits in arterial walls are a marker of atherosclerosis — the gradual build-up of plaque that can narrow arteries over time. The scanner quantifies how much calcification is present and produces a score, expressed as the Agatston score.
A score of 0 means no calcified plaque was detected at the time of the scan. Scores above 0 are stratified into ranges that carry different implications for long-term risk: 1–100 (mild), 101–400 (moderate), above 400 (extensive).
Why a score of 0 is meaningful
Most cardiovascular risk tools work from indirect signals — age, cholesterol levels, blood pressure, family history. They estimate the probability of plaque without looking for it directly. A CAC score of 0 provides direct evidence that, at the time of the scan, no calcification was detected in the coronary arteries. In people at intermediate risk based on traditional factors, a score of 0 substantially reassigns that risk downward.
It does not mean the arteries are completely clear of all plaque — non-calcified plaque is not captured by this scan. But calcified plaque tends to develop as atherosclerosis progresses, so its absence is a genuinely useful data point.
What it cannot tell you
A CAC score is a snapshot. It reflects the state of calcification at the time of the scan, not the current rate of progression. Two people with a score of 80 may be on very different trajectories depending on how long ago that plaque formed and what has changed in their lifestyle or treatment since.
It also does not capture non-calcified or soft plaque, which can rupture even in the absence of high calcium scores. And it carries a small radiation dose — typically equivalent to a few months of background radiation — which is why it is not a test for annual repetition in most cases.
How often to retest
Repeat scanning intervals depend on the initial score and individual risk factors, and are a decision for your doctor. A common approach is no rescan for several years following a score of 0 in a lower-risk individual, with shorter intervals for higher scores where tracking progression has more clinical value.
What Intentra shows
Intentra records your CAC scores as you log them and plots them over time. Because scans are infrequent, the chart will often show just one or two data points — that is expected. The value of tracking is not in daily updates but in having a long-term record that you can bring to any clinical appointment and that gives context to other cardiovascular markers like blood pressure trends.
Intentra is not a diagnostic tool. Abnormal or unexpected CAC results should be discussed with your doctor.