Checking calcium levels of arteries which surround and supply blood to the heart could better predict the risk for a heart attack than standard risk-assessment equations used in medical practice, according to a study.

The findings showed that coronary artery calcium measurements were better able to predict the presence of symptomatic coronary artery disease requiring revascularisation (a coronary stent or bypass surgery) than the pooled cohort equation, which relies only on standard risk factors such as age, gender, blood pressure and cholesterol measurements.

The calcium tests will not only get high-risk patients into treatment earlier, but also keep patients who aren't truly at risk from being overtreated, the researchers said. "Calcium in the artery doesn't tell you the extent of soft plaque, but it does mark that disease is present," said Jeffrey L. Anderson, MD, a cardiologist and researcher at the Intermountain Medical Centre Heart Institute in Salt Lake City. 

"These results tell us that coronary calcium adds importantly to probability estimates," he added. The study was presented at the American Heart Association Scientific Session conference in Chicago. Noting that the cost of coronary calcium screening is low, in the range of $100 or less than mammograms and colonoscopies, Anderson said that it should be considered in the future as part of routine medical care after age 50 for men and 55-60 for women.

The team identified 1,107 symptomatic patients who presented to the healthcare system without any known coronary artery disease and who had a PET-stress test to measure coronary flow, conducted as part of their diagnostic evaluation.

While calcium measurements were better able to predict the presence of symptomatic coronary artery disease, they were only moderately successful in determining who over two years of follow-up would go on to die or have a heart attack. "With coronary calcium, we're looking at a marker indicating the actual presence of anatomic disease -- we're not just looking at probabilities of disease based on a patient's standard risk factors," Anderson said.