CARDIOLOGY INSIGHTS

Know Your Score

A Prevention Guide to CAC Scoring, Risk Categories, and What the Results Should Change

SONAL CHANDRA, MD

Most cardiovascular risk calculators used by physicians are proxies — age, cholesterol, and blood pressure. We use these parameters to estimate a patient’s probability of a future event. Coronary artery calcium scoring does something more direct: it looks inside your arteries and measures whether plaque has already formed. That distinction changes everything about how prevention should be structured.

What CAC Measures — and What It Doesn’t

A CAC scan is a low-dose, non-contrast CT that quantifies calcified plaque in the coronary arteries and expresses the result as an Agatston score. It tells you whether atherosclerosis is present and how much. What it does not capture is soft, non-calcified plaque which can be present in younger patients or those earlier in the disease process. A score of zero is reassuring, but it is not a guarantee of clean arteries. A score above zero is not a diagnosis of imminent danger rather it is a call to precision.

A risk calculator estimates probability. A CAC score reveals biology. They are not the same conversation.

Who Benefits Most From CAC

CAC is most valuable in the intermediate-risk patient: the person whose standard risk calculator places them in a gray zone where the decision to start lipid-lowering therapy is genuinely uncertain. In that group, a CAC score frequently resolves the ambiguity: a score of 0 in a 55-year-old with borderline LDL can support deferring medication with close monitoring; a score of 300 in the same patient accelerates treatment decisively.

It is also valuable in patients who decline statins and need objective plaque data to make an informed decision, and in high-performing individuals who want a baseline measure of vascular age that no standard panel provides.

CAC Score Ranges and What They Imply

Score 0

Absent detectable calcified plaque. Associated with very low 10-year cardiovascular event rates. Can usually support a “guarantee period” approach in low-risk patients, repeat scanning is not needed for five to seven years. This is not permission to ignore risk factors; it is a window to address current and future risk factors still aggressively before calcification begins. Lp(a) and apo B testing can still play a role. Caveat: depending on risk factors and age, a zero is not always a guarantee of low risk.

Score 1– 99

Mild plaque burden. Confirms atherosclerosis or plaque is present and/or active. Risk is elevated above peers with zero scores. Treatment decision depends on lipid targets, and cardiometabolic health: blood pressure, blood glucose, inflammation markers. ApoB and Lp(a) testing are crucial here.

Score 100– 399

Moderate burden. Statin therapy is indicated in virtually all guidelines at this threshold. ApoB and Lp(a) testing becomes essential to understand the full atherogenic picture. Lifestyle intensity matters significantly here.

Score 400+

Extensive calcified plaque. High-intensity prevention is indicated: aggressive lipid lowering, optimization of all modifiable risk factors, and typically coronary CTA or functional imaging to assess for obstructive disease. This is not a routine prevention conversation — it is a highly targeted one.

What We Do Differently at CAC 0 vs. 100+

A CAC of zero and a CAC of 400 in two patients with identical standard risk scores represent entirely different clinical situations and they require entirely different prevention strategies.

At zero, the conversation centers on preserving and/or optimizing status: we continue to take a wholistic approach from optimizing insulin sensitivity to managing emerging inflammatory markers, and importantly, establishing a timeline for reassessment.

At 100 or above, the conversation shifts to active plaque stabilization — moderate to high-intensity statin therapy +/- other lipid lowering medications, ApoB targeting, blood pressure optimization below standard thresholds, and in some cases aspirin consideration. The score does not just confirm risk. It calibrates every intervention that follows.

** When plaque is already present, lifestyle modification stops being a recommendation and becomes a clinical requirement. Exercise, nutrition, sleep, and stress management are not adjuncts to medication at this stage, they are co-equal interventions

If you want a prevention plan that’s calibrated to your plaque burden and risk profile, this is where a deep-dive visit is most valuable.