This simple scan gives powerful insight into heart risk

Heart disease often develops quietly over decades, long before symptoms appear. A computed tomography (CT) calcium score is one tool cardiologists use to detect early signs of coronary artery disease and better understand a patient's individual risk.

The CT calcium score scan is a quick, noninvasive imaging test that measures the amount of calcium buildup in the coronary arteries, which are the blood vessels that supply the heart. Calcium is a marker of plaque, which forms gradually over time and can narrow arteries, increasing the risk of heart attack and other cardiac events.

"The calcium score is essentially a snapshot of how much atherosclerosis has developed in the heart over the years," says Anas Alani, MD, a noninvasive imaging cardiologist and director of the cardiac CT program at Loma Linda University Health. "It gives us information beyond traditional risk factors like high blood pressure or high cholesterol."

What the numbers mean

Calcium scores are reported as a number, with higher scores reflecting more plaque buildup. A score of zero is considered ideal and is associated with a very low risk of a major cardiac event over the next several years.

"If you have a calcium score of zero, that's the best-case scenario," Alani says. "Studies show that your risk of a major cardiac event over the next five years is extremely low, less than one percent per year."

Scores between 1 and 100 are considered mild, while scores between 100 and 300 indicate moderate plaque buildup. A score above 300 suggests severe coronary calcification and a significantly higher risk for heart events.

"In some studies, patients with a calcium score above 300 had a risk equivalent to someone who already had a heart attack," Alani says. "Scores above 1,000 represent extensive disease and require very close follow-up."

Who benefits most from the scan

Calcium scoring is not meant for everyone. According to Alani, it is most useful for patients at intermediate risk which are typically adults over 40 who may have risk factors such as high blood pressure, diabetes, smoking history, or a family history of heart disease, but no known coronary artery disease.

"If someone already has stents, bypass surgery, or known blockages, the calcium score won't change management," he explains. "On the other end, very young patients with no risk factors are unlikely to benefit either, because calcium takes time to develop."

For certain younger patients with strong family histories of premature heart disease, cardiologists may consider other advanced imaging tests, but calcium scoring is generally guided by age and overall risk profile.

What the scan is like

The test itself is fast and simple. Patients lie on a CT scanner table for just a few minutes, and no contrast dye or IV is required. There is no special preparation beyond avoiding caffeine or smoking beforehand, which can raise heart rate and affect image quality.

"The entire scan takes about five to 10 minutes," Alani says. "It's very low radiation, about one millisievert, which is less than the natural background radiation we're exposed to in a year."

On the images, calcium appears as bright white spots in the coronary arteries. Specialized software calculates the total score by measuring the volume and density of those areas.

A tool for prevention, not prediction

Hearing that calcium is present in the arteries can be alarming, but Alani emphasizes that a high score does not mean a heart attack is inevitable.

"Most people will develop some calcium as they age," he says. "This test doesn't mean something bad is about to happen. It means we now have information we can act on."

Once calcium is present, it cannot be reversed, but treatment focuses on slowing progression and stabilizing plaque through lifestyle changes and medication.

"Our goal is prevention," Alani says. "We use the score to guide how aggressive we need to be with cholesterol management, blood pressure control, diabetes care, and lifestyle changes."

Studies show that patients who see their calcium images are often more motivated to make changes. "When patients see the calcium in their own arteries, they tend to be more compliant with medications, more committed to weight loss, exercise, and quitting smoking," Alani says.

Avoiding common mistakes

Alani says the biggest mistakes patients make after getting their results are either overreacting or ignoring them altogether.

"A low or zero score doesn't mean you can abandon healthy habits," he says. "And a high score doesn't mean this is a terminal diagnosis. There are many effective preventive therapies available."

A more personalized approach to heart care

Calcium scoring has become more widely used in recent years as cardiology shifts toward individualized risk assessment.

"We don't want to treat everyone the same," Alani says. "The calcium score helps us personalize care by deciding who needs aggressive therapy, who can focus primarily on lifestyle, and who needs closer follow-up."

Advances in CT technology have also made scans faster, safer, and more precise, contributing to their growing role in preventive cardiology.

"Knowing your calcium score gives you clarity," Alani says. "And when it comes to heart disease, early knowledge can truly change outcomes."

The CT calcium score testing is widely available as part of routine heart risk assessment and can be ordered by a cardiologist or primary care provider. To learn more about heart disease prevention or to discuss whether a CT calcium score is right for you, schedule an appointment with a cardiologist at Loma Linda University Health.