EvidenceAStrongGood randomized trials in people that agree, with no serious weaknesses. New studies are unlikely to change the answer.
A coronary calcium score measures hardened plaque in the heart's arteries. A higher score is linked to more heart attacks and strokes, and a score of zero points to low risk.
Who it's for
Adults with uncertain heart risk, such as borderline or intermediate risk; not shown to help others.
What to expect
Higher scores track with steadily higher risk; zero usually means low risk over years.
Watch out for
The extra predictive gain is modest, and it adds cost and radiation.
Higher calcium scores go with much higher risk of heart events
Each dot shows how many times higher the risk of a coronary event was than with no calcium, and the line shows the range of likely values.
For adults 40 to 75 without diabetes, with LDL cholesterol of 70 to 189 mg/dL and a 10-year risk of 7.5% to 19.9%, the American Heart Association and American College of Cardiology advise a calcium score when the choice to start a statin is uncertain1Guideline · 20182018 Guideline on the Management of Blood CholesterolFor people at intermediate risk whose score is zero, the guideline considers it reasonable to hold off on a statin and repeat the calcium score in 5 to 10 years, unless higher-risk conditions are present.American Heart Association and American College of Cardiology. If an intermediate-risk person scores zero, holding off on a statin and repeating the scan in 5 to 10 years is considered reasonable, unless higher-risk conditions are present1Guideline · 20182018 Guideline on the Management of Blood CholesterolFor people at intermediate risk whose score is zero, the guideline considers it reasonable to hold off on a statin and repeat the calcium score in 5 to 10 years, unless higher-risk conditions are present.American Heart Association and American College of Cardiology. An American Heart Association statement notes that calcium found on chest scans done for other reasons can also flag risk without extra radiation3Guideline · 2025Opportunistic Detection of Coronary Artery Calcium on Noncardiac Chest Computed Tomography: An Emerging Tool for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association.Systematic approaches are needed to ensure appropriate reporting, interpretation, and action while avoiding unnecessary downstream testing. Implementation that includes tailored preventive care and streamlined care pathways involving multidisciplinary clinical teams including radiology, cardiology, and primary care is…Circulation.
What the studies show
A study that followed 6,814 adults (aged 45 to 84, no heart disease) for about 11 years found risk rose in steps with the score. Over 10 years, heart attack and stroke rates were 1.3% to 5.6% with a score of zero. They were 13.1% to 25.6% with a score above 300. Each doubling of the score was linked to a 14% higher relative risk How much more or less likely something is in one group than another, as a ratio. A big relative change can still be a small change for any one person.9Observational study · 2018 · 6,814 peopleTen-year association of coronary artery calcium with atherosclerotic cardiovascular disease (ASCVD) events: the multi-ethnic study of atherosclerosis (MESA).Coronary artery calcium is associated strongly and in a graded fashion with 10-year risk of incident ASCVD as it is for CHD, independent of standard risk factors, and similarly by age, gender, and ethnicity. While 10-year event rates in those with CAC = 0 were almost exclusively below 5%, those with CAC ≥ 100 were…Eur Heart J. The pattern held across age, sex and ethnic groups9Observational study · 2018 · 6,814 peopleTen-year association of coronary artery calcium with atherosclerotic cardiovascular disease (ASCVD) events: the multi-ethnic study of atherosclerosis (MESA).Coronary artery calcium is associated strongly and in a graded fashion with 10-year risk of incident ASCVD as it is for CHD, independent of standard risk factors, and similarly by age, gender, and ethnicity. While 10-year event rates in those with CAC = 0 were almost exclusively below 5%, those with CAC ≥ 100 were…Eur Heart J.
A study of 6,722 people from four racial and ethnic groups, followed a median 3.8 years, found much higher risk of heart events with scores of 101 to 300 and above 300 than with a score of zero. Risk was about 7.7 and 9.7 times higher8Observational study · 2008 · 6,722 peopleCoronary calcium as a predictor of coronary events in four racial or ethnic groups.The coronary calcium score is a strong predictor of incident coronary heart disease and provides predictive information beyond that provided by standard risk factors in four major racial and ethnic groups in the United States. No major differences among racial and ethnic groups in the predictive value of calcium…N Engl J Med. The score added information beyond standard risk factors8Observational study · 2008 · 6,722 peopleCoronary calcium as a predictor of coronary events in four racial or ethnic groups.The coronary calcium score is a strong predictor of incident coronary heart disease and provides predictive information beyond that provided by standard risk factors in four major racial and ethnic groups in the United States. No major differences among racial and ethnic groups in the predictive value of calcium…N Engl J Med.
A review that pooled 6 studies (17,961 people) found that adding the score to standard risk calculators improved prediction only a little. Most people moved to a higher or lower risk group by the score did not have an event during follow-up2Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med. The authors found no evidence yet that adding the score improves health outcomes2Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med.
A study of 1,312 adults with at least one risk factor, followed a median 7 years, found the score mattered most for people at intermediate risk. It did not add much for those at low risk11Observational study · 2004 · 1,312 peopleCoronary artery calcium score combined with Framingham score for risk prediction in asymptomatic individuals.These data support the hypothesis that high CACS can modify predicted risk obtained from FRS alone, especially among patients in the intermediate-risk category in whom clinical decision making is most uncertain.JAMA.
A review that pooled 19 studies of 34,041 people with chest symptoms found any calcium was linked to about 5.7 times the risk of heart events compared with none6Meta-analysis · 2020 · 34,041 peoplePrognostic value of coronary artery calcium score in symptomatic individuals: A meta-analysis of 34,000 subjects.This meta-analysis demonstrated that increased levels of CAC are strongly and independently associated with increased risk for MACE in stable, symptomatic patients with suspected CAD, showing increasing risk with greater CAC scores. Application of CAC scanning as a prediction method could be useful for a considerable…Int J Cardiol. The comparison is between groups, so one person's gain depends on their starting risk.
Key studies
Study
Who
What it found
Study following people, 20189Observational study · 2018 · 6,814 peopleTen-year association of coronary artery calcium with atherosclerotic cardiovascular disease (ASCVD) events: the multi-ethnic study of atherosclerosis (MESA).Coronary artery calcium is associated strongly and in a graded fashion with 10-year risk of incident ASCVD as it is for CHD, independent of standard risk factors, and similarly by age, gender, and ethnicity. While 10-year event rates in those with CAC = 0 were almost exclusively below 5%, those with CAC ≥ 100 were…Eur Heart J
6,814 adults, 45 to 84
Risk rose with score; zero scores mostly under 5% over 10 years
Study following people, 20088Observational study · 2008 · 6,722 peopleCoronary calcium as a predictor of coronary events in four racial or ethnic groups.The coronary calcium score is a strong predictor of incident coronary heart disease and provides predictive information beyond that provided by standard risk factors in four major racial and ethnic groups in the United States. No major differences among racial and ethnic groups in the predictive value of calcium…N Engl J Med
6,722 adults, four ethnic groups
High scores linked to far more heart events
Review of 6 studies, 20222Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med
17,961 adults without heart disease
Modest prediction gain; no proven health benefit
Study following people, 200411Observational study · 2004 · 1,312 peopleCoronary artery calcium score combined with Framingham score for risk prediction in asymptomatic individuals.These data support the hypothesis that high CACS can modify predicted risk obtained from FRS alone, especially among patients in the intermediate-risk category in whom clinical decision making is most uncertain.JAMA
1,312 adults with risk factors
Most useful at intermediate risk
Review of 19 studies, 20206Meta-analysis · 2020 · 34,041 peoplePrognostic value of coronary artery calcium score in symptomatic individuals: A meta-analysis of 34,000 subjects.This meta-analysis demonstrated that increased levels of CAC are strongly and independently associated with increased risk for MACE in stable, symptomatic patients with suspected CAD, showing increasing risk with greater CAC scores. Application of CAC scanning as a prediction method could be useful for a considerable…Int J Cardiol
34,041 people with chest symptoms
Any calcium linked to higher risk of heart events
Safety
The scan uses a small dose of radiation, and it can turn up incidental findings that lead to further testing2Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med. Costs may outweigh the modest gain in some people2Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med.
What we don't know
Which patients gain real health benefit from knowing their score is unclear2Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med.
Whether scoring changes outcomes such as heart attacks has not been shown in the pooled evidence2Meta-analysis · 2022 · 5,185 peopleEvaluation of the Incremental Value of a Coronary Artery Calcium Score Beyond Traditional Cardiovascular Risk Assessment: A Systematic Review and Meta-analysis.This systematic review and meta-analysis found that the CACS appears to add some further discrimination to the traditional CVD risk assessment equations used in these studies, which appears to be relatively consistent across studies. However, the modest gain may often be outweighed by costs, rates of incidental…JAMA Intern Med.
Written by AI from the studies listed, without review by a clinician, and graded with the GRADE method. It can be wrong, so check the studies it cites. Education, not medical advice.