28-07-2025
What is Coronary Calcium Scan? A simple heart test that could save your life
When we think about a cardiac arrest, we usually imagine dramatic scenes - chest pain, ambulances, and emergency surgeries. However, the truth is, for most people, heart disease is quietly brewing long before any symptoms actually show exactly where a test called the Coronary Artery Calcium (CAC) scan comes in. It's quick, non-invasive, and surprisingly underused, especially considering how much life-saving information it can traditional blood tests and stress tests are useful, but they don't actually show the disease. CAC scanning does,' says Dr. Dinesh Narang, a senior interventional cardiologist at the Lilavati Hospital. 'It's one of the few tools we have that can spot a heart attack risk that's otherwise invisible.'WHAT IS A CALCIUM SCORE?
It is a CT scan with a very specific goal: checking for calcium deposits in the arteries that feed our heart. These deposits are early warning signs of plaque build-up (known as atherosclerosis) which can eventually lead to cardiac arrest. The test gives you a 'calcium score' which speaks volumes about your heart health and whether you need to heed warning signs.A score of 0 translates to Zero Plaque, which means you're in the clear. No visible heart disease. Similarly, a calcium score between 1–100 is Mild Plaque, which shows some build-up, but it is usually manageable with lifestyle changes. A score on the scan that reads between 101–400 is Moderate Plaque. That means it is time to get proactive. Medications like statins may be recommended for such patients. A score of 401+ is known as Extensive Plaque. This simply means you're at high risk; immediate action is non-negotiable for these Aakruti Mehta, a preventive cardiologist and faculty member, believes, 'a CAC score of zero is the most powerful negative predictor we have in cardiology. It's like getting a clean bill of health for your arteries.' And 401 plus is also an assurance that your heart is at risk. SHOULD YOU TAKE THIS TEST? There's a caveat here that experts want you to be mindful of. The CAC isn't a scan for everyone. It is for those patients who fall somewhere 'in-between' — when you're not low-risk, but not high-risk are three typical conditions that one may need to consider before opting for such a scan. "I would recommend it for a man over 40 or a woman over 50 with one or more heart risk factors (like high blood pressure, diabetes, or smoking history). You may also consider it if the cholesterol numbers are borderline, and you're not sure whether you really need to be on medication. The scan is also recommended for someone who has a family history of heart disease, even though your own test results seem fine," adds Dr Narang. advertisement'For patients unsure about starting lifelong medications, a CAC score can settle the debate,' says Dr. Mehta. 'If it's zero, great—you may be able to delay. But if it's 250? That's not something you ignore.'On the flip side, the scan isn't really necessary if you're in your 20s or 30s, healthy, and with no family history. HOW DOES IT COMPARE TO OTHER HEART TESTSPeople often confuse the CAC scan with stress tests or cholesterol checks, but each test tells a different part of the story. While a cholesterol test shows risk factors, they don't tell you if you actually have heart disease. A 'Stress' tests, on the other hand, checks how well blood flows to your heart when you exercise. But they can miss smaller plaques, the ones that often rupture and cause sudden heart attacks.A CAC scan goes straight to the point. It shows actual plaque in your arteries, even before you feel a thing. As Dr. Mehta puts it: 'Most heart attacks are caused by soft plaques that rupture, not always the big blockages we usually look for in most of the cardiac tests. That's why someone can pass a stress test today and still have a heart attack next week.'advertisementLike any test, it has limitations too, but they're pretty minor in most cases. There's a little radiation exposure, but it's about the same as a mammogram or a couple of cross-country flights! CAC is not always covered by insurance, though many clinics offer it for Rs 5,000 – Rs 15,000. The scan may not show soft plaque, but calcified plaque is still a strong indicator of overall plaque burden in one's Dheeraj Kapoor, a Bengaluru-based radiologist who's overseen more than 2,000 CAC scans, says it best: 'The radiation is minimal, and the value of what you learn? It's immense. The test can absolutely change how someone approaches their heart health.'Here's the big picture: for decades, our approach to preventing heart disease has been based on stats and probabilities. The CAC scan offers something better: It shows you what exactly is inside your own arteries.'More than anything,' says Dr. Narang, 'the CAC scan helps people take action before something happens. That's powerful.'So if you're unsure where you stand—or you're simply tired of guessing—talk to your doctor. Ask about the CAC scan. It might just give you the clearest picture yet of your heart's future. And sometimes, knowing is everything.- Ends
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