Comparison of Photon-Counting and Energy-Integrating Computed Coronary Tomography Angiography for Coronary Artery...

Photon-counting detector (PCD)-computed tomography (CT) offers higher spatial resolution and spectral capability compared with energy-integrating (EID)-CT. In coronary computed tomography angiography (CTA), these features may mitigate calcium blooming, enhance stenosis quantification, limit stenosis overestimation, and reduce low-yield referrals to invasive coronary angiography (ICA).

This meta-analysis compared diagnostic outcomes between PCD-CT and EID-CT in adults with stable coronary artery disease undergoing coronary CTA.

The authors' protocol was preregistered and followed the PRISMA 2020 guidelines. Primary outcomes were vessel-level stenosis reclassification, downstream ICA referral, and revascularization rates among those referred. Where multiple studies with compatible definitions were available, random-effects meta-analysis was performed; otherwise, results were described narratively.

Fifteen studies (N = 11,350) met inclusion criteria. At the vessel level, PCD-CT down-classified stenosis severity in a pooled absolute proportion of 34.2% of vessels compared with EID-CT (95% CI: 27.3-41.9; P < 0.0001). This was associated with fewer downstream ICA referrals (pooled OR: 0.71; 95% CI; 0.63-0.79; P < 0.0001) and higher rates of revascularization among those undergoing ICA (OR: 1.43; 95% CI: 1.14-1.79; P = 0.0017). Stratified by coronary artery calcium score (CACS), ICA referrals were lower with PCD-CT when CACS was <400 (OR: 0.62; 95% CI: 0.52-0.75; P < 0.0001) and trended lower when CACS ≥400 (OR: 0.42; 95% CI: 0.16-1.11; P = 0.08).

Compared against conventional EID-CT, PCD-CT was associated with down-classification of stenosis severity, translating to fewer referrals for ICA and a greater rate of revascularization when angiography is undertaken.