Total Plaque Volume Indicates Patients With 0 CAC May Still be at Risk

Despite presenting with a coronary artery calcium (CAC) score of 0, symptomatic patients can remain at significant risk from non-calcified plaque that cannot be detected with standard calcium scoring, according to a recent substudy of the DECIDE registry.1

This analysis was presented at the 21st Annual Scientific Meeting of the Society of Cardiovascular Computed Tomography (SCCT) in San Diego, California, by Ron Blankstein, MD, the associate director of the cardiovascular imaging program, director of cardiac computed tomography, and co-director of the cardiovascular imaging training program at Brigham and Women’s Hospital, as well as a professor of medicine at Harvard Medical School.1

“Of course, when you look at total plaque volume, we’re now looking at the overall amount of plaque, not just calcified plaque,” Blankstein told HCPLive in an exclusive interview. “A particular patient may have a small amount of calcified plaque, but when you consider the overall amount, they move to a higher risk category, and that could have implications about treating that patient more aggressively.”

The DECIDE registry, initially conducted by HeartFlow, aimed to collate observational data regarding the management of patients before and after HeartFlow Artificial Intelligence-Quantitative Coronary Plaque Analysis (AI-QCPA). The registry itself is a post-market, multi-center, data collection study assessing the change in management of clinically stable patients with plaque detected after coronary computed tomography angiography (CCTA).2

Investigators for the DECIDE registry collected data immediately after the CCTA was completed, with analyses conducted 90 days, 180 days, and 365 days post-scan. Patient data were organized into 6 groups, the details of which are as follows:

• Group 1: No AI-QCPA – symptomatic patients who were scanned with plaque detected and no prior revascularization
• Group 2: Delayed AI-QCPA – previously scanned, symptomatic patients with plaque detected and no prior revascularization. AI-QCPA provided 90 days after CCTA
• Group 3: Stress Test Only – symptomatic patients with prior non-invasive stress testing without CCTA and no prior revascularization
• Group 4: Prospective AI-QCPA, symptomatic with no prior revascularization – newly scanned symptomatic patients with plaque
• Group 5: Prospective AI-QCPA, prior PCI – newly scanned patients with plaque, asymptomatic or symptomatic, with prior PCI in 1 vessel territory
• Group 6: Prospective AI-QCPA, asymptomatic without prior revascularization – newly scanned, asymptomatic patients with plaque and no current symptoms or prior revascularization.2

The primary endpoint of the registry was change in medical management after AI-QCPA at 90 days versus following CCTA alone. This endpoint was only assessed in group 2 patients. Secondary outcomes included changes in LDL-C, HbA1c, non-HDL-C, HDL-C, and triglyceride levels across all groups, among others.2

The present analysis included 11,792 symptomatic patients of the roughly 20,000 enrolled in the DECIDE registry. After analysis and accounting for total plaque volume, investigators found that 50% of all patients with a CAC score of 0 were reclassified into higher-risk categories, as were 30% of those with CAC scores 1-99 or 100-299. Conversely, patients with high calcium but modest total plaque volume were reclassified downwards.1

These data reflect existing publications indicating that HeartFlow Plaque Staging substantially changed management in >50% of patients. The current analysis of this dataset effectively provides a model for the intensification of preventive therapy in patients with high total plaque volume despite a CAC score of 0, as well as for deescalating in patients with high CAC but lower total plaque volume.1

“Perhaps some patients’ risk is not very high based on a calcium score, and if we had the overall plaque burden, that might reclassify them into a higher risk group, and we may treat them a little differently,” Blankstein said. “I think that’s what this latest study is trying to get at – after all, most of that reclassification occurred in patients who had a mild amount of plaque.”

Editors’ Note: Blankstein reports disclosures with Amgen, Heartflow, Nanox AI, Novartis, Caristo Diagnostics, Siemens, and others.

References

1. HeartFlow. New Data at SCCT 2026 Reinforce Heartflow Plaque Analysis as the Standard for AI-Powered Coronary Artery Disease Management. GlobeNewswire. July 9, 2026. Accessed July 20, 2026. https://www.globenewswire.com/fr/news-release/2026/07/09/3324747/0/en/index.html

2. HeartFlow. AI DErived Plaque Quantification: CCTA and AI-QCPA for Determining Effective CAD Management (DECIDE). ClinicalTrials.gov Identifier: NCT06376851. Updated October 14, 2025. Accessed July 20, 2026. https://clinicaltrials.gov/study/NCT06376851