Coronary Artery DiseaseULDCACSLARGENCT03637231
Ultra-low-dose CACS in a Large Population
A study testing Ultra low-dose CTAC in people with Coronary Artery Disease, run by University of Zurich at 1 site in Switzerland.
Trial summary
Radiation exposure to patients from CT for CAC scoring has steadily decreased in recent years. This is mainly achieved through lowering tube currents alongside with the introduction of iterative reconstruction algorithms which allow compensating for increased image noise. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Coronary Artery Disease
- What is being tested?
- Ultra low-dose CTAC
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 301 participants
- Where
- 1 siteSwitzerland
- Study dates
- 5 Jul 2018to 25 Oct 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients referred for a non-contrast enhanced CT scan for CAC scoring
- Male and Female subjects ≥18 years of age,
- Written informed consent
Who cannot join
- Pregnancy or breast-feeding
- CACS of 0 after inclusion of 50 patients with CACS 0 (as assessed visually after the first CT scan, prior to performing the 3 additional study scans)
- History of coronary artery stenting, coronary artery bypass grafting, of implantation of cardiac devices (e.g. valve prosthesis, pacemaker, implantable cardioverter defibrillator etc.)
- Enrolment of the investigator, his/her family members, employees and other dependent persons
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
Department of Nuclear Medicine, University Hospital Zurich
Zurich, 8091
About this study
Official title: Ultra-low-dose Coronary Artery Calcium Scoring: Evaluation of Prognostic Performance and Impact of Physiological Factors on Quantification in a Large Population
Radiation exposure to patients from CT for CAC scoring has steadily decreased in recent years. This is mainly achieved through lowering tube currents alongside with the introduction of iterative reconstruction algorithms which allow compensating for increased image noise. However, the greatest radiation dose reduction can be obtained by reducing peak tube voltage. Yet lowering peak tube voltage remains challenging because tissue attenuation is closely related to photon energy, thus rendering the established thresholds for calculating CAC scores (i.e. Agatston scores) incomparable if peak tube voltages other than the standard 120 kilovolt peak (kVp) are applied. The investigators have developed novel tube-adapted thresholds for CAC scoring by CT at 80 kVp and 70-kVp tube voltage and have shown that these novel thresholds are valid, yielding results closely comparable to the standard 120-kVp protocol. The present study aims to optimize application of such low-dose scans in a general population through assessment of the impact of physiological patient parameters on image parameters such as image noise which per se may impact the accuracy and feasibility of ultra-low-dose CAC scoring with reduced tube voltage. Furthermore, the prognostic performance of such low-dose CAC scoring will be elucidated.
- Conditions
- Coronary Artery Disease
- Being tested
- Ultra low-dose CTAC
- Medical subject headings
- Coronary Artery Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultra low-dose CTACDiagnostic test
All patients undergo two non-contrast enhanced CT scans with standard dose (i.e. 120 kVp), one with 80 kVp and one with 70 kVp.
| Study group | Role | What they receive |
|---|---|---|
| Standard and ultra-low-dose CAC scoring | Other | Not described Receives: Diagnostic Test: Ultra low-dose CTAC |
What is being measured
The primary outcome is the main question the study is designed to answer.
Impact of BMI on CAC scores derived from low-dose versus standard-dose CT
Assessment of deviation of CAC scores derived from low-dose CT versus standard-dose CT (i.e. standard of reference) by calculating bias and Bland-Altmann limits of agreement as well as intraclass correlation in different subgroups of patients, stratified by body mass index.
Measured: 2 years
Secondary outcomes (1)
Prognostic value of CAC scores derived from CT scans with varying tube voltages
Assessment of sensitivity and specificity CAC scores derived from low-dose CT versus standard-dose CT (i.e. standard of reference) to predict future cardiovascular events (i.e. myocardial infarction, revascularisation, death) over a short to mid-term follow-up period (i.e. 2 years).
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Aug 2018
- Study start5 Jul 2018
- Primary completion25 Oct 2021
- Study completion25 Oct 2021
Why it stopped: The preliminary findings render it very unlikely that the methodology can be refined further in order to yield more accurate results even if more patients would be included and the study would be continued.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Coronary Artery DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 301 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03637231
- Sponsor's protocol ID
- USZ-2017-01158
- Acronym
- ULDCACSLARGE
- Status last verified
- Nov 2022
- First submitted
- 26 Jul 2018
- Last updated
- 14 Nov 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Grani C, Vontobel J, Benz DC, Bacanovic S, Giannopoulos AA, Messerli M, Grossmann M, Gebhard C, Pazhenkottil AP, Gaemperli O, Kaufmann PA, Buechel RR. Ultra-low-dose coronary artery calcium scoring using novel scoring thresholds for low tube voltage protocols-a pilot study. Eur Heart J Cardiovasc Imaging. 2018 Dec 1;19(12):1362-1371. doi: 10.1093/ehjci/jey019.
PubMed 29432592Bechtiger FA, Grossmann M, Bakula A, Patriki D, von Felten E, Fuchs TA, Gebhard C, Pazhenkottil AP, Kaufmann PA, Buechel RR. Risk stratification using coronary artery calcium scoring based on low tube voltage computed tomography. Int J Cardiovasc Imaging. 2022 Oct;38(10):2227-2234. doi: 10.1007/s10554-022-02615-x. Epub 2022 Apr 23.
PubMed 37726457Sartoretti T, Gennari AG, Sartoretti E, Skawran S, Maurer A, Buechel RR, Messerli M. Fully automated deep learning powered calcium scoring in patients undergoing myocardial perfusion imaging. J Nucl Cardiol. 2023 Feb;30(1):313-320. doi: 10.1007/s12350-022-02940-7. Epub 2022 Mar 17.
PubMed 35301677
Study at a glance
From the registry record, last updated by the sponsor on 14 Nov 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ultra-low-dose Coronary Artery Calcium Scoring: Evaluation of Prognostic Performance and Impact of Physiological Factors on Quantification in a Large Population
- ClinicalTrials.gov ID
- NCT03637231
- Acronym / sponsor ID
- ULDCACSLARGE / USZ-2017-01158
- Conditions
- Coronary Artery Disease
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: The preliminary findings render it very unlikely that the methodology can be refined further in order to yield more accurate results even if more patients would be included and the study would be continued.
- Enrolment
- 301 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Study start
- 5 Jul 2018 (actual)
- Primary completion
- 25 Oct 2021 (actual)
- Study completion
- 25 Oct 2021 (actual)
- First posted
- 17 Aug 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Radiation exposure to patients from CT for CAC scoring has steadily decreased in recent years. This is mainly achieved through lowering tube currents alongside with the introduction of iterative reconstruction algorithms which allow compensating for increased image noise. However, the greatest radiation dose reduction can be obtained by reducing peak tube voltage. Yet lowering peak tube voltage remains challenging because tissue attenuation is closely related to photon energy, thus rendering the established thresholds for calculating CAC scores (i.e. Agatston scores) incomparable if peak tube voltages other than the standard 120 kilovolt peak (kVp) are applied. The investigators have developed novel tube-adapted thresholds for CAC scoring by CT at 80 kVp and 70-kVp tube voltage and have shown that these novel thresholds are valid, yielding results closely comparable to the standard 120-kVp protocol. The present study aims to optimize application of such low-dose scans in a general population through assessment of the impact of physiological patient parameters on image parameters such as image noise which per se may impact the accuracy and feasibility of ultra-low-dose CAC scoring with reduced tube voltage. Furthermore, the prognostic performance of such low-dose CAC scoring will be elucidated.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Standard and ultra-low-dose CAC scoring | Other | Diagnostic Test: Ultra low-dose CTAC |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients referred for a non-contrast enhanced CT scan for CAC scoring
- Male and Female subjects ≥18 years of age,
- Written informed consent
Key exclusion criteria (4 listed)
- Pregnancy or breast-feeding
- CACS of 0 after inclusion of 50 patients with CACS 0 (as assessed visually after the first CT scan, prior to performing the 3 additional study scans)
- History of coronary artery stenting, coronary artery bypass grafting, of implantation of cardiac devices (e.g. valve prosthesis, pacemaker, implantable cardioverter defibrillator etc.)
- Enrolment of the investigator, his/her family members, employees and other dependent persons
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ultra low-dose CTACAll patients undergo two non-contrast enhanced CT scans with standard dose (i.e. 120 kVp), one with 80 kVp and one with 70 kVp. | Diagnostic test | Standard and ultra-low-dose CAC scoring |
Primary outcome
Impact of BMI on CAC scores derived from low-dose versus standard-dose CT
Time frame: 2 years
Assessment of deviation of CAC scores derived from low-dose CT versus standard-dose CT (i.e. standard of reference) by calculating bias and Bland-Altmann limits of agreement as well as intraclass correlation in different subgroups of patients, stratified by body mass index.
1 secondary outcome
Prognostic value of CAC scores derived from CT scans with varying tube voltages
Time frame: 2 years
Results and safety
The study was stopped early (reason given: The preliminary findings render it very unlikely that the methodology can be refined further in order to yield more accurate results even if more patients would be included and the study would be continued.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Nov 2022.
- Background: PubMed 29432592Grani C, Vontobel J, Benz DC, Bacanovic S, Giannopoulos AA, Messerli M, Grossmann M, Gebhard C, Pazhenkottil AP, Gaemperli O, Kaufmann PA, Buechel RR. Ultra-low-dose coronary artery calcium scoring using novel scoring thresholds for low tube voltage protocols-a pilot study. Eur Heart J Cardiovasc Imaging. 2018 Dec 1;19(12):1362-1371. doi: 10.1093/ehjci/jey019.
- Derived from this study: PubMed 37726457Bechtiger FA, Grossmann M, Bakula A, Patriki D, von Felten E, Fuchs TA, Gebhard C, Pazhenkottil AP, Kaufmann PA, Buechel RR. Risk stratification using coronary artery calcium scoring based on low tube voltage computed tomography. Int J Cardiovasc Imaging. 2022 Oct;38(10):2227-2234. doi: 10.1007/s10554-022-02615-x. Epub 2022 Apr 23.
- Derived from this study: PubMed 35301677Sartoretti T, Gennari AG, Sartoretti E, Skawran S, Maurer A, Buechel RR, Messerli M. Fully automated deep learning powered calcium scoring in patients undergoing myocardial perfusion imaging. J Nucl Cardiol. 2023 Feb;30(1):313-320. doi: 10.1007/s12350-022-02940-7. Epub 2022 Mar 17.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultra low-dose CTAC in people with Coronary Artery Disease, run by University of Zurich at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 14 Nov 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: The preliminary findings render it very unlikely that the methodology can be refined further in order to yield more accurate results even if more patients would be included and the study would be continued.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Impact of BMI on CAC scores derived from low-dose versus standard-dose CT (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03637231, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Nov 2022; AzTrials last refreshed its copy on 31 Oct 2026.