Calcium score of Zero: Reassuring, but not the whole story
- Saneka Chakravarty, MD, FACC
- Apr 14
- 4 min read
A coronary artery calcium (CAC) score of zero is reassuring, but it’s not the full story.
CAC = 0 means no calcified plaque. It does NOT mean no plaque at all.
Early plaque can still be present in some people, and it matters.
The Key Insight
CAC detects late-stage (calcified) plaque.
Early plaque is non-calcified and invisible on these non-contrast enhanced CT scans done to detect calcium.
About 6-16% of patients with symptoms of heart disease and ~10% of those without any symptoms may still have plaque buildup, despite CAC = 0.
Prevalence of Non-Calcified Plaques
The occurrence of non-calcified plaques varies quite a bit among different groups of patients:
In people who don't have symptoms, a review of 37,808 individuals found that 10% had non-calcified plaques, with only 1.1% showing significant blockage of blood flow.
For those with symptoms, the prevalence is higher, ranging from 6% to 16% depending on the specific group studied. For example, in a varied group from the Montefiore Healthcare System, 7% had plaque even though they had no calcium buildup. In contrast, a rural group in Appalachia showed a much higher rate of 26%.
Other large studies provide additional insights:
The Swedish SCAPIS study found that among asymptomatic adults aged 50-64 years with no calcium buildup, 5.5% had non-calcified atherosclerosis.
The Miami Heart Study reported that 16% of individuals without calcium buildup had identifiable non-calcified plaques.
The Reassuring Part
CAC = 0 has a 98-99% negative predictive value, i.e.,
Very low chance of blocked arteries.
Very low short-term event risk.
For most people, this is excellent news.
When CAC = 0 Needs a Second Look
You may still be at risk if you have:
Chest symptoms (pain, tightness, shortness of breath).
Diabetes.
High blood pressure.
Smoking history.
High LDL cholesterol.
Male sex.
HIV.
Multiple risk factors.
Younger age (<45, where plaque is often non-calcified).
Why This Matters
Non-calcified plaque is active and potentially unstable.
Associated with ~2x higher risk of future cardiac events.
Seen in up to 23% of heart attack patients with CAC = 0.
Translation: “Zero calcium” ≠ zero biology.
When to Consider Different Testing
A coronary CT angiogram (CCTA) may help if:
You have symptoms + risk factors.
You’re younger with elevated LDL.
There’s uncertainty about your risk.
It detects both calcified and non-calcified plaque, but:
Overall chance of finding dangerous blockage is still low (~1-2%).
Testing should be selective, not routine, at least at this time, till more data emerges.
What You Should Do (Regardless of Score)
Get earlier screening, even in your 20s or 30s.
Pay attention to lifestyle.
At Preventiononly, we don’t wait for plaque to appear; we work to identify risk before the first calcium deposit or even the earliest non-calcified plaque, using a comprehensive approach that combines lifestyle pattern identification from wearable technology, family history, and advanced biomarkers.
Go Beyond a Single Number
With the PreventionPlus app, you can:
Track true cardiovascular risk markers.
Monitor LDL, ApoB, metabolic health.
Get personalized prevention plans.
Identify when advanced testing may help.
Because prevention is continuous, not a one-time test.
Key Evidence
~10% of asymptomatic patients have non-calcified plaque.
6–16% in symptomatic populations (up to 26% in high-risk groups).
~2x increased risk with non-calcified plaque.
98–99% reassurance for major events with CAC = 0.
References
1. Non-Calcified Plaque in Asymptomatic Patients With Zero Coronary Artery Calcium Score: A Systematic Review and Meta-Analysis. Sama C, Abdelhaleem A, Velu D, et al. Journal of Cardiovascular Computed Tomography. 2024 Jan-Feb;18(1):43-49. doi:10.1016/j.jcct.2023.10.002.
2. Interplay Between Zero CAC, Quantitative Plaque Analysis, and Adverse Events in a Diverse Patient Cohort. Fattouh M, Kuno T, Pina P, et al. Circulation. Cardiovascular Imaging. 2023;16(8):e015236. doi:10.1161/CIRCIMAGING.123.015236.
3. Prevalence of Noncalcified Plaques and Coronary Artery Stenosis in Patients With Coronary Calcium Scores of Zero. Al-Muhaidb SM, Aljebreen AMM, AlZamel ZA, Fathala A. Coronary Artery Disease. 2021;32(3):179-183. doi:10.1097/MCA.0000000000000937.
4. Predictors of Non-Calcified Plaque Presence and Future Adverse Cardiovascular Events in Symptomatic Rural Appalachian Patients With a Zero Coronary Artery Calcium Score. Miller T, Hana D, Patel B, et al. Journal of Cardiovascular Computed Tomography. 2023 Sep-Oct;17(5):302-309. doi:10.1016/j.jcct.2023.07.003.
5. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Dyslipidemia: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Blumenthal RS, Morris PB, Gaudino M, et al. Journal of the American College of Cardiology. 2026;:S0735-1097(25)10254-4. doi:10.1016/j.jacc.2025.11.016.
6. Low-Density Lipoprotein Cholesterol and Cardiovascular Risk in the Absence of Calcifications on Computed Tomography: The Western Denmark Heart Registry. Andersen MH, Jensen JM, Kanstrup H, et al. European Heart Journal. 2025;:ehaf497. doi:10.1093/eurheartj/ehaf497.
7. Influence of Age on the Diagnostic Value of Coronary Artery Calcium Score for Ruling Out Obstructive Coronary Disease in Symptomatic Patients. Albuquerque F, Lopes PM, Freitas P, et al. The American Journal of Cardiology. 2023;205:35-39. doi:10.1016/j.amjcard.2023.07.115.
8. Coronary Calcium Score in the Initial Evaluation of Suspected Coronary Artery Disease. Pedersen ER, Hovland S, Karaji I, et al. Heart (British Cardiac Society). 2023;109(9):695-701. doi:10.1136/heartjnl-2022-321682.
9. CTA-Derived Plaque Characteristics and Risk of Acute Coronary Syndrome in Patients With Coronary Artery Calcium Score of Zero: Insights From the ICONIC Trial. Jonas RA, Nurmohamed NS, Crabtree TR, et al. AJR. American Journal of Roentgenology. 2025;. doi:10.2214/AJR.24.31476.
Comments