Cardiac Society of Australia and New Zealand position statement executive summary: coronary artery calcium scoring

Summary

Introduction

This article summarises the Cardiac Society of Australia and New Zealand position statement on coronary artery calcium (CAC) scoring. CAC scoring is a non-invasive method for quantifying coronary artery calcification using computed tomography. It is a marker of atherosclerotic plaque burden and the strongest independent predictor of future myocardial infarction and mortality. CAC scoring provides incremental risk information beyond traditional risk calculators such as the Framingham Risk Score. Its use for risk stratification is confined to primary prevention of cardiovascular events, and can be considered as individualised coronary risk scoring for intermediate risk patients, allowing reclassification to low or high risk based on the score. Medical practitioners should carefully counsel patients before CAC testing, which should only be undertaken if an alteration in therapy, including embarking on pharmacotherapy, is being considered based on the test result.

Main recommendations

• CAC scoring should primarily be performed on individuals without coronary disease aged 45–75 years (absolute 5-year cardiovascular risk of 10–15%) who are asymptomatic.
• CAC scoring is also reasonable in lower risk groups (absolute 5-year cardiovascular risk, < 10%) where risk scores traditionally underestimate risk (eg, family history of premature CVD) and in patients with diabetes aged 40–60 years.
• We recommend aspirin and a high efficacy statin in high risk patients, defined as those with a CAC score ≥ 400, or a CAC score of 100–399 and above the 75th percentile for age and sex.
• It is reasonable to treat patients with CAC scores ≥ 100 with aspirin and a statin.
• It is reasonable not to treat asymptomatic patients with a CAC score of zero.

Changes in management as a result of this statement

• Cardiovascular risk is reclassified according to CAC score.
• High risk patients are treated with a high efficacy statin and aspirin.
• Very low risk patients (ie, CAC score of zero) do not benefit from treatment.