Research report: Longitudinal trends in cardiac CT utilization by institutional academic status: insights from the MR/CT registry

Coronary CT angiography has become one of the most widely used tools in modern cardiology, but a new analysis of more than 236,000 cardiac CT examinations suggests that the way the test is deployed depends heavily on the type of institution performing it. The study, drawn from the MR/CT Registry of the European Society of Cardiovascular Radiology, tracked cardiac CT practice from January 2011 to June 2025 and compared referral patterns, pre-test probability profiles, and the use of functional testing before scanning at academic versus non-academic centers.

The registry, a federated multicenter repository of real-world cardiac imaging practice, contributed 236,432 cardiac CT examinations from 306 participating sites across 26 countries. Of these, 44.8 percent came from academic centers and 55.2 percent from non-academic centers. Within the total, 155,975 examinations were coronary CT angiography, the non-invasive technique that has emerged as a cornerstone in the evaluation of coronary artery disease. The retrospective observational study was approved by an institutional review board at Leipzig University and analyzed anonymized case-level data submitted through a standardized online interface with uniform variable definitions held constant throughout the study period.

The researchers classified centers as academic only if they satisfied three criteria: formal affiliation with a university medical center, participation in formal radiology or cardiology residency programs, and a demonstrated research track record in cardiac imaging. Independent teaching hospitals, municipal institutions with contractual academic ties, and centers hosting postgraduate trainees without academic governance were excluded from the academic category. Outcomes were evaluated on a semi-annual basis and modeled with joinpoint regression, a statistical technique that identifies points in time where linear trends shift, estimating segment-specific and average annual percent changes with 95 percent confidence intervals.

The headline finding concerns indications. At academic centers, suspected coronary artery disease remained the leading reason for cardiac CT, but its share showed an initial proportionate decrease, with an annual percent change of minus 18.7 percent, followed by gradual growth of plus 2.6 percent per year, resulting in no overall change across the study period, from 65.6 percent in 2011 to 51.2 percent in 2025. Non-academic centers told a different story: suspected CAD consistently accounted for a greater proportion of referrals and rose modestly but significantly over time, from 74.6 percent to 80.9 percent. In other words, academic institutions diversified their cardiac CT portfolio while non-academic sites stayed firmly focused on coronary artery assessment.

That diversification shows up in the details. At academic centers, the proportion of scans performed for transcatheter aortic valve replacement planning rose sharply in the early years, with an annual percent change of plus 31.6 percent, before settling into a mild decline. Scans for known coronary artery disease fell steadily at both settings, from 6.5 percent to 2.8 percent at academic sites and from 17.5 percent to 5.7 percent at non-academic sites. Pulmonary vein visualization and known cardiac valve disease contributed relatively small shares throughout. The authors note that because these outcomes are proportions, compositional effects matter: growth in structural indications can reduce the relative share of suspected CAD even when absolute volumes increase.

Perhaps the most striking divergence concerns functional testing performed before coronary CT angiography. At academic centers, pre-CCTA functional testing remained low throughout the entire period, ending at just 2.3 percent after a brief early uptick and a steady subsequent decline. At non-academic centers, the prevalence of functional testing before CCTA fell consistently but remained substantially higher, dropping from 63.0 percent to 39.5 percent. The authors caution that persistently higher rates of functional testing in some settings may reflect access constraints rather than guideline non-adherence, pointing to the need for infrastructure and workforce expansion alongside pathway refinement.

Pre-test probability profiles shifted in ways that also separated the two settings. Patients were stratified into low, intermediate, and high pre-test probability of obstructive coronary artery disease using a categorical framework integrating age, sex, and angina type, applied uniformly across all 15 years to preserve longitudinal comparability. At academic centers, intermediate-risk patients rose from 40.4 percent to 87.1 percent of those undergoing CCTA, driven by an early marked increase followed by a slower sustained rise, while the low-risk share collapsed from 57.6 percent to 9.9 percent. At non-academic centers, intermediate-risk patients remained the predominant group but showed no significant net change, moving from 47.0 percent to 57.0 percent. High-risk referrals stayed consistently lower at academic centers, at 2.0 percent versus 3.0 percent, than at non-academic sites, where they ranged from 16.7 percent to 12.9 percent without significant overall change.

The authors interpret these patterns as evidence of a diffusion process. Academic centers adopted a broader range of cardiac CT use cases, whereas non-academic centers maintained a steadier, CAD-focused trajectory likely shaped by throughput demands and access constraints. Joinpoint-localized changes suggest a maturation curve at both settings, with significant shifts occurring before the publication of the landmark randomized trials SCOT-HEART and PROMISE, followed by subsequent consolidation. The analysis also annotated the timing of the 2016 NICE guideline and the 2019 ESC guideline on the trend plots. In line with a previous UK analysis of more than 1.9 million CCTAs, the registry data show a higher proportion of CCTA indications following the first landmark trials and the NICE guideline, along with a swift decrease in pre-CCTA functional testing, but no additional inflection points around the later trials and updated ESC guidelines, suggesting those consolidated existing trends rather than redirecting them.

The study builds on earlier registry work. Foldyna and colleagues previously examined 64,317 CCTA entries from the same registry and found comparable patient risk profiles across academic status but higher rates of recommended downstream testing at non-academic sites. The current analysis nearly doubles that sample size and adds longitudinal context, allowing a clearer distinction in referral patterns between the two settings. The authors suggest that continuing to align referrals toward intermediate pre-test probability could optimize diagnostic yield while avoiding overuse in very low or very high probability cohorts, and that streamlining pre-CCTA functional testing, with clear triggers for when it remains warranted, could reduce time to diagnosis and duplicative testing.

The findings come with important caveats. This was a retrospective, descriptive study in which direct analysis of source imaging data was not possible. The pre-test probability framework reflects an older guideline era, and the authors note that applying more recent European Society of Cardiology models from 2019 and 2024 retrospectively would compromise longitudinal comparability. Academic status classification relied on a strict three-criterion framework, leaving room for misclassification in hybrid institutions. Downstream testing and management decisions after CCTA were not captured, so post-CCTA functional imaging use could not be assessed. Although the registry is a European initiative, some contributing sites are located outside Europe, and voluntary reporting bias may affect the completeness of submitted data. Within those limits, the study offers a 15-year, setting-stratified portrait of how coronary CT angiography has matured differently in academic and community practice, and a foundation for targeted strategies to optimize its global implementation.

Subject of Research: Longitudinal trends in coronary CT angiography utilization, referral profiles, and pre-scan functional testing at academic versus non-academic centers in the ESCR MR/CT Registry from 2011 to 2025.

Article Title: Longitudinal trends in cardiac CT utilization by institutional academic status: insights from the MR/CT registry

Article References: Vecsey-Nagy, M., Moser, L. J., Budde, R. P. J., Francone, M., Gutberlet, M., Paar, M. H., Loewe, C., Muscogiuri, G., Nikolaou, K., Pirnat, M., Pontana, F., Salgado, R., Vliegenthart, R., Williams, M. C., Wintersperger, B. J., & Alkadhi, H. (2026). Longitudinal trends in cardiac CT utilization by institutional academic status: insights from the MR/CT registry. European Radiology Cardiovascular and Thoracic, 1(1), Article 2. https://doi.org/10.1007/s44449-026-00002-5

Image Credits: AI Generated

DOI: 10.1007/s44449-026-00002-5

Keywords: coronary CT angiography, cardiac CT, pre-test probability, functional testing, academic centers, non-academic centers, ESCR MR/CT Registry, joinpoint regression, coronary artery disease, referral patterns, guidelines, TAVR planning