High calcium scores in patients with a low Framingham risk of cardiovascular (CVS) disease: implications for more accurate CVS risk assessment in New Zealand
Chris J Ellis, Malcolm E Legget, Colin Edwards, Niels Van Pelt, John A Ormiston, Jonathan Christiansen, Helen Winch, Mark Osborne, Greg Gamble
Trying to predict who is at higher risk of a heart attack or stroke is not easy for doctors. The currently used method is quite inaccurate, and relies on 'risk factors' such as a high cholesterol level and advancing age, to try to calculate who is more at risk. A calcium score test, which involves having a low dose of X-ray via a 'CT' scan, helps to improve this assessment, by measuring who actually has more calcified arteries than would be expected for their age. These patients are at higher risk. Hence a calcium score test can detect some of those people who may be best advised to take preventative medicines to protect their arteries at an earlier age, than would otherwise be suggested, using currently used methods. Of 942 patients in Auckland, we found that 27% of patients who were calculated to be at low risk, using the standard method, in fact had a markedly increased 'calcium score', meaning that they were actually at a much higher risk than had been calculated. These patients were then able to be more vigorously managed, rather than (inadvertently) falsely reassured.
