Coronary Artery Calcium Score

Coronary artery calcium scoring is an X-ray test that looks for specks of calcium in the coronary arteries. This calcification is an early sign of coronary artery disease. This test is currently the most sensitive measure of determining the future risk of developing coronary artery disease in individuals and therefore it has been increasingly been used as a screening test.

Coronary artery disease (CAD) is still a leading cause of morbidity and mortality in Europe. Consequently there has been much interest in developing screening methods to identify those at risk of having a primary cardiac event. The presence of calcium in coronary arteries is almost always indicative of atherosclerotic plaque (furring of the arteries) and evidence suggests that an increased coronary calcium score predicts an increased risk of developing significant coronary artery disease and correlates with cardiovascular survival.

Coronary artery calcium scanning as a screening test

Coronary artery calcium scanning is not useful in those at very low or very high risk, or in those with known coronary artery disease (CAD). It is unclear at present as to who should be offered coronary artery calcium (CAC) scanning but the following possibilities have been proposed:

  • Screening those with an intermediate risk of coronary artery disease based on risk factors
  • Presence of just one risk factor, eg high blood pressure
  • Presence of a strong family history of premature CAD
  • Screening patients without symptoms who are anxious.

Cardiac risk factors (high blood pressure, high cholesterol, smoking, family history) and insulin resistance lead to early development and progression of coronary artery calcification. Early diagnosis and aggressive treatment of risk factors may reduce the future risk in these patients although specific guidelines for treatment are still widely debated and await further evidence from clinical studies.

The main benefit of CACS is its high negative predictive value, reported as high as 98% in some studies.