ACC/AHA March 2026 Guidelines Assign CAC Central Role for Intermediate-Risk Adults

The guidelines update follows 35 years of data showing CAC superior to pooled cohort equations for reclassifying risk. A zero score downgrades statin eligibility; scores above 100 trigger therapy. Medicare reimbursement for acute myocardial infarction averages $50,000 while CAC scans cost $100 and deliver 0.1 mSv radiation. Current coverage leaves the test cash-only for most patients outside trial settings.

Three randomized cohorts and the MESA registry demonstrate CAC improves net reclassification by 15-25 percent over cholesterol-based calculators. AI tools now extract CAC from 12 million annual chest CTs performed for non-cardiac indications, surfacing disease without new radiation or appointments. This opportunistic route reaches populations excluded by out-of-pocket requirements.

Policy remains anchored in treatment reimbursement. Shifting 5 percent of post-MI spend to CAC eligibility for the 30 million intermediate-risk adults would alter downstream statin and revascularization volumes. Guideline committees and CMS coverage determinations now face simultaneous pressure from imaging economics and AI standardization.

CMS draft coverage for AI-CAC on existing chest CTs is scheduled for 2027 comment. Threshold adoption requires documented 10 percent reduction in first-event MI among newly identified high-CAC patients within two years of implementation.