The power of a zero CAC score is facing fresh scrutiny after new plaque analysis data presented at SCCT 2026 shows just how much noncalcified plaque confers its own cardiovascular risk, despite the software’s financial barriers.
- Current U.S. dyslipidemia guidelines stratify risk using CAC scoring and total plaque volume, but they don’t address the zero-CAC score group.
- Unfortunately, young symptomatic patients with a zero calcium score still go on to have heart attacks, potentially missed by the reassurance zero CAC provides.
To test whether quantitative plaque assessment can address this, researchers analyzed 3.7k PROMISE patients who were evaluated with CCTA and Cleerly’s qualitative plaque analysis (QPA) software, 40% of whom had a CAC score of zero.
- Among zero-CAC patients, the 12% with noncalcified plaque were slightly older, more often male, and more often non-white than those without plaque.
- The rate of significant stenosis (≥50%) was far higher in patients with noncalcified plaque, at 22% versus 9%, regardless of CAC status.
Extending these results into risk stratification yielded some shocking trends.
- MACE rates were similar for patients with noncalcified plaque regardless of CAC status (4.5% vs 3.9%).
- Meanwhile MACE fell to just 0.8% for those with neither CAC nor plaque.
- Zero-CAC patients with noncalcified plaque were nearly six times more likely to experience MACE than those without (HR: 5.93).
- Noncalcified plaque volume predicted MACE about as well as total plaque volume.
That’s a big win for proponents of CCTA and plaque analysis, but it’s not likely to convince everyone, especially with a separate SCCT presentation questioning PROMISE’s economics of QPA vs. CAC.
- Per an analysis by Dr. Khurram Nasir, CCTA costs roughly 3.83x more ($24.5k) than CAC scoring to find one patient who will experience a CV event.
- Beyond that, adding QPA (about $1,000 on top of $400 for CCTA) theoretically pushes the cost of detecting a single MACE-bound patient to $280k.
The Takeaway
PROMISE’s results re-ignite the question of what to do with patients who have zero CAC. While CCTA paired with QPA is the current best clinical option, it’s clear that financial hurdles are what prevent us from using plaque analysis instead of CAC as the go-to diagnostic modality.
