High levels of coronary calcium can lead to an elevated risk of heart attacks, says a report in the January 16th issue of the Journal of the American College of Cardiology.
The amount of coronary calcium is known to have a direct relationship with the total plaque burden, but some researchers have argued that increased levels stabilise the heart and reduce the chance of an attack.
The new research from a team led by Dr. Paolo Raggi from Tulane University School of Medicine in New Orleans, assessed the coronary-related outcomes of 98 asymptomatic subjects who had calcium scores of at least 1000 on screening electron beam tomography. The subjects were followed for a mean of 17 months and underwent no further testing after the initial screen.
The researchers found that just over a third of the subjects experienced myocardial infarction or coronary death during the study period, all of which occurred within 28 months of follow-up. The subjects affected had significantly higher calcium scores than those who did not.
Furthermore, the researchers found that the annual coronary event rate for subjects in the study was 25%, significantly higher than the 7.4% rate reported in a historical control group of patients.