Coronary artery calcium paradox and physical activity

Reducing the risk of plaque rupture events in individuals without a prior myocardial infarction is an imprecise science. To help clarify whether there is evidence of coronary artery disease and avoid ‘medicalisation’ of otherwise healthy individuals, international guidelines recommend incorporating the measurement of coronary artery calcium alongside risk prediction models.1 Coronary artery calcium serves as a surrogate marker of advanced calcified atherosclerosis and can be calculated from a non-contrast ECG-gated CT scan where a score of 1–99 Agatston units represents subclinical atherosclerosis, and a score of 100 or more Agatston units is considered an appropriate threshold for initiating medical therapy.1 At ≥100 Agatston units, the burden of advanced calcified atherosclerosis justifies statin implementation and this has been validated in a real-world cohort study of 16 996 subjects with a 10-year number needed to treat to prevent one cardiovascular event of 12.2 Many clinicians have advocated the benefits of coronary artery calcium in redefining the cardiovascular risk assessment of healthy individuals, as there is a strong link between high burdens of coronary artery calcium, accelerated progression of calcified plaque and the risk of future myocardial infarction. However, if the burden of calcified plaque is an accurate barometer of cardiovascular risk, one would expect an intervention which reduces an individual’s cardiovascular risk to attenuate progression of calcified plaque. And herein lies the coronary artery calcium paradox; both invasive and non-invasive imaging studies have …