Health News : Risk assessments needed before calcium scores introduced to CVD risk factor analysis

Risk assessments needed before calcium scores introduced to CVD risk factor
analysis
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admin on 28/04/2010 18:04:00
 
A US study addressing coronary artery calcium score (CACS) as a predictor of
coronary artery disease (CAD), published in JAMA 28 April 2010 (1), has found
that the addition of calcium scores to traditional risk factors significantly
improved the classification of risk and placed more individuals in the most
extreme risk categories.
Philip Greenland and colleagues, from Northwestern University  (Chicago,
Illinois), undertook a prospective cohort study of 6,814  people, aged 45 to 84
without known cardiovascular disease. The analysis  was part of the Multi-Ethnic
Study of Atherosclerosis (MESA), a  longitudinal study initiated in 2000 to
explore characteristics of sub  clinical cardiovascular disease in people of
White, African American,  Hispanic and Chinese origin. The study set out to
consider whether new  measures of cardiovascular disease (CVD), including
carotid ultrasound,  cardiac MRI and arterial compliance benefited different
racial groups.
In the current analysis coronary artery calcium was assessed by chest  computed
tomography (CT), with the clinical teams also collecting  information on
traditional cardiovascular risk factors. The five year  estimated incidence of
CAD was calculated for each participant using a  Cox proportional hazards model,
with model 1 using the standard  Framingham risk factors of age, sex, smoking,
systolic blood pressure,  use of antihypertensive medications and HDL and total
cholesterol and  race/ethnicity; and model 2 used these standard risk factors
plus CACS.  At a median follow up of 5.8 years, the results showed that adding
CACS  led to significant improvements in risk prediction (with a net 
reclassification improvement of 0.25, 95 % confidence interval,  0.16-0.34; P
AUTHORS:
European Society of Cardiology - Press Office
Tel: +33 (0)4 92 94 86 27
press@escardio.org
NOTES TO EDITOR
A cardiac CT scan for coronary calcium is a non invasive way of  obtaining
information about the presence, location and extent of  calcified plaque in the
coronary arteries. The amount of calcium inside  the walls of the coronary
arteries is considered a good predictor of  future cardiovascular events.
* The European Society of Cardiology (ESC) represents more than  62,000
cardiology professionals across Europe and the Mediterranean. Its  mission is to
reduce the burden of cardiovascular disease in Europe.
REFERENCES
1. TS Polonsky, RL McClelland, NW Jorgensen et al. Coronary Artery  Calcium
Score and Risk Classification for Coronary Heart Disease  Prediction. JAMA, 28
April, 2010, 303: 1610-1616.
2. JP Ioannidis, I Tzoulaki. What Makes a Good Predictor? The Evidence  Applied
to Coronary Artery Calcium Score. Ibid pp 1646-1647.