THURSDAY, Aug. 18 (HealthDay News) -- A calcium test performed with the assistance of a CT scanner seems to provide insight into the likelihood that certain patients at moderate risk of heart problems will have a heart attack or stroke, researchers say.

The test to detect coronary calcium can help physicians determine whether the patients should take cholesterol-lowering drugs to reduce their cardiovascular risks, the study authors explained.

At issue are people who fall into the middle area between those who are at high risk of heart problems due to factors like high blood pressure and those who are at low risk. People in the so-called "gray zone" may have risk factors, such as being overweight or having high blood sugar levels, but they aren't considered in great danger.

The question is: Should those in the middle range of risk -- an estimated 6 million people in the United States -- be prescribed the anticholesterol drugs known as statins, which often work well but have side effects?

The study, published in the Aug. 19 issue of The Lancet, sought to determine whether a test of calcium in the arteries is more helpful at estimating risk than a blood test that examines levels of C-reactive protein.

The researchers tracked 2,083 people for six years. They found that 13 percent of those with the highest levels of calcium in their arteries had a heart attack or stroke during that time period. But just 2 percent of those with high levels of C-reactive protein -- and no calcium buildup -- had a heart attack or stroke.

Not everyone needs a calcium test, said lead study author Dr. Michael J. Blaha, a cardiology fellow at the Johns Hopkins University School of Medicine. However, he stated in a Hopkins news release, "we believe looking for calcification in coronary vessels in certain patients makes sense in order to predict who may benefit from statin therapy, because the test gets right to the heart of the disease we want to treat."

"Our data support recent American Heart Association guidelines, which say it is reasonable to order a coronary calcium scan for adults who are considered to be at intermediate risk of a heart attack over the next 10 years. A high coronary calcium score would indicate that statin therapy would likely be a useful strategy to lower that person's cardiovascular risk," study co-investigator Dr. Roger Blumenthal, director of the Ciccarone Center for the Prevention of Heart Disease at Johns Hopkins University, said in the news release.

Commenting on the study, cardiologist Dr. Vijay Nambi, an assistant professor at Baylor College of Medicine, said that most insurance companies don't cover the calcium tests, which cost in the range of $200-$400. "Sometimes people have to pay for it out of pocket," said Nambi, who thinks it's a useful test. "It helps physicians in a lot of respects."

Test results can also help patients make decisions when they're worried about taking anticholesterol drugs, Nambi added.

More information

For more about heart disease, visit the U.S. National Library of Medicine.