Incidental Coronary Artery Calcification and the Risk of Major Adverse Cardiovascular Outcomes

Background Incidental findings of coronary artery calcifications (CACs) are not consistently reported, and the clinical significance relating to cardiovascular outcomes remains to be established. In this single-center cross-sectional study, we assessed the association between incidental coronary artery calcification documented on formal chest CT reports and the incidence of major adverse cardiovascular events (MACE). Methods A MACE was defined as the occurrence of stroke or transient ischemic attack or ST-segment elevation myocardial infarction, non-ST-elevation myocardial infarction, or undergoing coronary artery bypass grafting. A composite endpoint included either MACE or the occurrence of cardiovascular death. We assessed the predictors of the composite outcome and the effect of lipid-lowering therapy on the composite outcome in the studied cohort.  Results The composite outcome occurred in 39.1% of the 1,354 subjects studied. Peripheral arterial disease was the only comorbid condition associated with increased odds (adjusted odds ratio (aOR) 2.6, p < 0.001, 95% CI: 1.9 - 3.56). The average treatment effect of lipid-lowering therapy was 0.11 (p = 0.002, 95% CI: 0.04 - 0.17). At 10 years after the first CAC report, the presence of peripheral artery disease appears to present the lowest odds of survival, which is <50% (hazard ratio (HR) 2.44, p < 0.001, 95% CI: 1.67 - 3.56). Conclusion In patients with CAC on incidental chest CT scans, the presence of peripheral arterial disease is associated with increased odds of MACE and/or cardiovascular death. In those with incidental CAC on non-gated chest CT scans, the residual risk for MACE remains high despite lipid-lowering therapy and antiplatelet agents.