Role of coronary artery calcium score in the primary prevention of cardiovascular disease.

First developed in 1990, the Agatston coronary artery calcium (CAC) score is an international guideline-endorsed decision aid for further risk assessment and personalized management in the primary prevention of atherosclerotic cardiovascular disease. This review discusses key international studies that have informed this 30 year journey, from an initial coronary plaque screening paradigm to its current role informing personalized shared decision making. Special attention is paid to the prognostic value of a CAC score of zero (the so called "power of zero"), which, in a context of low estimated risk thresholds for the consideration of preventive therapy with statins in current guidelines, may be used to de-risk individuals and thereby inform the safe delay or avoidance of certain preventive therapies. We also evaluate current recommendations for CAC scoring in clinical practice guidelines around the world, and past and prevailing barriers for its use in routine patient care. Finally, we discuss emerging approaches in this field, with a focus on the potential role of CAC informing not only the personalized allocation of statins and aspirin in the general population, but also of other risk-reduction therapies in special populations, such as individuals with diabetes and people with severe hypercholesterolemia.