The coronary calcium score is a more accurate predictor of significant coronary stenosis than conventional risk factors in symptomatic patients: Euro-CCAD study

Abstract

Aims: In this retrospective study we assessed the predictive value of the coronary calcium score for significant (>50%) stenosis relative to conventional risk factors.

Methods and results: We investigated 5515 symptomatic patients from Denmark, France, Germany, Italy, Spain and the USA. All had risk factor assessment, computed tomographic coronary angiogram (CTCA) or conventional angiography and a CT scan for coronary artery calcium (CAC) scoring. 1539 (27.9%) patients had significant stenosis, 5.5% of whom had zero CAC. In 5074 patients, multiple binary regression showed the most important predictor of significant stenosis to be male gender (B=1.07) followed by diabetes mellitus (B=0.70) smoking, hypercholesterolaemia, hypertension, family history of CAD and age but not obesity. When the log transformed CAC score was included, it became the most powerful predictor (B=1.25), followed by male gender (B=0.48), diabetes, smoking, family history and age but hypercholesterolaemia and hypertension lost significance. The CAC score is a more accurate predictor of >50% stenosis than risk factors regardless of the means of assessment of stenosis. The sensitivity of risk factors, CAC score and the combination for prediction of >50% stenosis when measured by conventional angiogram was considerably higher than when assessed by CTCA but the specificity was considerably higher when assessed by CTCA. The accuracy of CTCA for predicting >50% stenosis using the CAC score alone was higher (AUC=0.85) than using a combination of the CAC score and risk factors with conventional angiography (AUC=0.81).

Conclusion: In symptomatic patients, the CAC score is a more accurate predictor of significant coronary stenosis than conventional risk factors.

Keywords: Atherosclerosis; Coronary calcification; Risk factors.