The Power of Zero, When Zero is Hero
A 5-Minute CT Calcium Score for Smarter Heart Prevention
By Dr Anup Taksande, Clinical Director - Cardiology & Interventional Cardiology
For decades, heart disease prevention has leaned on the risk factors we all know well — cholesterol, blood pressure, diabetes, smoking, obesity and family history. These are still essential building blocks of any prevention plan. But here's the catch: they only estimate the probability of a future cardiac event. They don't actually tell us whether plaque has already started forming inside the coronary arteries. That's where CT Coronary Artery Calcium (CAC) scoring comes in — it helps close this gap by picking up silent, subclinical coronary atherosclerosis long before it turns into chest pain, a heart attack, or worse.
The test itself is refreshingly simple. It's a quick, non-invasive, ECG-gated CT scan that usually needs no injection, no contrast dye, and no treadmill exercise. It measures the calcium sitting within coronary plaques and reports it as an Agatston score. A score of zero means no calcified plaque was found. Anything above that, and the higher the number climbs, the greater the burden of established coronary atherosclerosis. It's worth being clear about what this test isn't: it doesn't tell you whether a specific artery has a severe blockage, and it should never replace a proper work-up for chest pain or other cardiac symptoms.
The latest 2026 ACC/AHA Multisociety Guideline on the Management of Dyslipidaemia has actually expanded the role of CAC scoring for adults sitting in that borderline or intermediate cardiovascular risk zone — the ones where doctors genuinely aren't sure whether to start or step up cholesterol-lowering treatment. The guideline is fairly direct on this point: any detectable coronary calcium means atherosclerosis is already present, and that alone supports active LDL-cholesterol lowering. It also recommends scaling up LDL reduction as the calcium burden rises. As an example, a CAC score between 300 and 999 calls for LDL-lowering treatment, typically starting with a statin, while very high calcium scores flag people who need particularly aggressive preventive care. (American Heart Association)
European guidelines echo much the same philosophy. The 2021 ESC Cardiovascular Prevention Guideline notes that CAC scoring can be considered around treatment-decision thresholds to sharpen cardiovascular risk classification. In plain terms, it's most valuable exactly when standard risk assessment leaves both doctor and patient unsure how aggressively to treat. Think of it as a risk modifier rather than a blanket screening test for everyone. (Escardio)
What Does the Number Mean?
CAC 0 — The Power of Zero No detectable calcified plaque. In the right asymptomatic adult, this points to a low near-term risk of a coronary event and can support holding off on statin therapy when overall clinical risk is otherwise uncertain.
CAC 1–99 — The Power of One Even a small amount of calcium tells us that coronary atherosclerosis has already begun. From here, age, percentile, risk factors and the broader clinical picture decide how aggressively to treat.
CAC ≥100 or ≥75th percentile for age and sex This meaningfully strengthens the case for statin therapy, along with tighter control of LDL cholesterol, blood pressure, diabetes, weight, smoking and lifestyle habits.
CAC ≥300 This signals a high plaque burden and marks out patients who need aggressive cardiovascular prevention and much lower LDL-cholesterol targets. (JACC)
Perhaps the real strength of calcium scoring lies in how it personalises prevention. Picture two people of the same age, with near-identical cholesterol numbers and blood pressure readings. One could have a CAC score of zero; the other, a score above 300. Their arteries are ageing very differently, their future cardiovascular risk isn't the same, and neither is the intensity of treatment they need. This is exactly why CAC scoring is nudging preventive cardiology away from population-wide averages and toward genuinely precision-based prevention.
That said, zero doesn't always mean zero risk. Calcium scoring can be less reassuring in younger patients, since early plaques are often still non-calcified and simply won't show up. A zero score also shouldn't be used to automatically delay treatment in people with diabetes, active smoking, severe hypercholesterolaemia, chronic inflammatory disease, or a strong family history of early coronary disease. The number always needs to be read alongside the patient's age, symptoms and complete risk profile — never in isolation.
CAC scoring isn't meant to become indiscriminate, age-based mass screening. It delivers the most value in carefully chosen asymptomatic adults — typically those above 40 with borderline or intermediate estimated risk, several risk enhancers, a strong family history, or genuine uncertainty about starting lifelong preventive medication. For people already diagnosed with coronary artery disease, or those experiencing symptoms suggestive of angina, a different diagnostic pathway altogether is needed.
Modern cardiology is steadily shifting focus — from treating heart attacks after they happen, to catching atherosclerosis while there's still time to change its course. CT Calcium Scoring offers a short, objective, and remarkably powerful conversation between a patient and their own future cardiovascular risk.
If you're looking for the best cardiologist in Thane to help you understand whether CAC scoring is right for you, or to discuss your heart risk profile in detail, the cardiology team at KIMS Hospitals, Thane offers comprehensive heart care — from 2 dedicated cath labs and a 24/7 cardiac ICU to advanced treatment for angioplasty, bypass surgery and arrhythmia management.
The Power of Zero is not about doing less. It's about making smarter, more personalised decisions.
Because the best heart attack is the one that never happens.