A coronary calcium score shows how much calcified atherosclerotic plaque can be detected in the coronary arteries.
But why does a higher score matter for long-term heart health?
A major study published in 2025 followed more than 66 000 asymptomatic adults for a median of 12.5 years. Researchers examined whether the amount of coronary artery calcium was associated with long-term mortality related to heart failure.
They found a clear pattern: as the coronary calcium score increased, heart failure-related mortality also increased.
Compared with people with no detectable coronary calcium, the association became progressively stronger as CAC increased. People with CAC ≥400 had about a seven-fold higher relative risk of heart failure-related death than those with CAC = 0, after adjustment for major cardiovascular risk factors.
This does not mean that coronary calcium causes heart failure. It also does not mean that someone with a high calcium score will develop or die from heart failure.
In fact, heart failure-related deaths were relatively uncommon in the study.
Instead, a high calcium score may identify people who have accumulated a greater burden of cardiovascular disease and risk over time.
This is why the result can be useful for prevention. A higher CAC score can provide doctors with additional information when assessing long-term cardiovascular risk and deciding how intensively risk factors should be managed.
