Coronary Calcium Scans May Predict a Heart Attack

Medically Reviewed

People with a family history of early heart disease are at increased risk of suffering a heart attack. But coronary artery calcium scans might help pinpoint those who are most vulnerable.

In a 2015 study in the journal Circulation: Cardiovascular Imaging, researchers looked at nearly 1,300 people with a first-degree relative who developed heart disease before age 55 (for male relatives) or 65 (for females). Coronary calcium scans, which detect calcium deposits in the heart arteries, helped predict which of those individuals were at greatest risk of suffering a heart attack or cardiac arrest or dying of cardiovascular causes, over the next decade. People with coronary calcium scores of 100 or higher had a two- to threefold higher risk, versus those with no calcium buildup in their arteries.

The findings add to evidence that calcium scores can give a clearer picture of a person’s future heart attack and stroke risk. The scans are not for everyone. But for people who are neither clearly low-risk nor clearly high-risk, a coronary calcium scan might clarify their outlook. From there, decisions can be made about whether they need a daily aspirin or a statin, for example.

What is a coronary calcium scan?

Coronary calcium scanning is a way to evaluate the health of the coronary arteries. Also known as electron-beam computed tomography or multidetector computed tomography, coronary calcium scans measure the amount of calcium in the coronary arteries. Calcium is often a component of plaques and is not present in healthy arteries. In a middle-aged or older individual, about one-quarter of the area of an atherosclerotic plaque is calcified.

A coronary calcium scan is painless and noninvasive and takes less than 10 minutes. It uses a rapid computed tomography (CT) imaging system that is at least 20 times faster than a normal CT scan. During the test, you will lie face up on an examination table while X-rays are passed through your body. Calcium in the artery walls appears as whitish spots or streaks on the X-rays. A computer program is then used to calculate a calcium score that reflects the total calcium buildup in the coronary arteries.

What the scores mean

Scores of 1 to 10 indicate arteries with very mild buildup of calcium-containing plaque; scores of 11 to 100 signify mild buildup of this type of plaque; and scores of 101 to 400 indicate moderate calcium-containing plaque formation. People with higher calcium scores have a greater risk of heart attack and stroke over the next decade than those with lower scores.

The American Heart Association considers coronary calcium scanning a reasonable option for people who have no symptoms of coronary heart disease but are at intermediate risk for the disease and are uncertain about whether to go on a statin and/or aspirin. The test is generally unnecessary for people at very low or high risk because the results would likely not lead their doctor to reconsider their risk category or treatment plan.

For those at intermediate risk (an estimated risk of a heart attack or stroke of 5 to 20 percent over the next decade using the 2013 ASCVD risk estimator), however, a coronary calcium scan may be helpful in further defining risk and deciding on the intensity of measures to be taken to reduce the likelihood of coronary heart disease and its complications.

For example, a doctor would want a person at intermediate risk who has a high calcium score to begin taking a lipid-lowering medication to further lower LDL cholesterol levels and to start taking low dose aspirin to lower the risk of a heart attack and stroke.

Not just a cardiovascular red flag

Coronary calcium deposits may also be a harbinger of lung disease, kidney dysfunction, or cancer, according to recent research.

The findings, published in the May 2016 issue of the Journal of the American College of Cardiology: Cardiovascular Imaging, come from a 10-year study of more than 6,000 people who underwent CT scans to detect coronary artery calcium.

In the study, calcium scores were linked to disease risks beyond the cardiovascular system. People with high scores (above 400) were 53 percent more likely to develop cancer over the next decade, versus those with no detectable coronary calcium. They were also 70 percent more likely to be diagnosed with chronic kidney disease, and 2.7 times more likely to develop chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis.

The study does not prove that a high coronary calcium score directly causes any of those diseases. Instead, it may indicate that a person is at risk. The score is essentially a marker of arterial aging and may reflect the cumulative damage from a host of risk factors, including high blood pressure, obesity, or smoking.

The bottom line

Talk to your doctor about whether a coronary calcium scan might be appropriate for you in refining your estimated risk of cardiovascular disease.

Read more about calcium and heart woes.