Coronary Artery Calcium-Guided Antiplatelet Therapy: What Does the Evidence Show?

Coronary artery calcium (CAC) scoring has become an important tool for cardiovascular risk refinement in primary prevention and is increasingly used in both internal medicine and cardiology practice. By quantifying subclinical coronary atherosclerosis, CAC improves risk estimation beyond traditional risk factors and can help guide preventive strategies. Indeed, CAC tracks with actual risk more precisely than pooled equations and is a superior risk categorization tool. However, a growing clinical challenge is the tendency to use CAC score alone to support initiation of aspirin therapy. Although a high CAC score identifies patients with greater atherosclerotic burden and elevated long-term atherosclerotic cardiovascular disease (ASCVD) risk, it does not directly determine whether an individual patient is likely to derive net clinical benefit from aspirin. Contemporary primary prevention trials have demonstrated that aspirin provides only modest reductions in cardiovascular events while consistently increasing bleeding risk, resulting in a narrow therapeutic margin that is highly dependent on overall cardiovascular risk, bleeding susceptibility, and concomitant preventive therapies such as statins. In this focused review, we examine the available evidence linking CAC burden to aspirin benefit, discuss the limitations of CAC-guided treatment decisions, and propose a practical framework that integrates ASCVD risk, bleeding risk, and patient-specific clinical factors. We also identify key evidence gaps requiring prospective study. A more individualized approach to aspirin allocation may help clinicians avoid reflexive score-driven prescribing and better align preventive therapy with expected net benefit.