Ultra-low-dose CACS in a Large Population

Coronary Artery Disease Clinical Trial

— ULDCACSLARGE  

Official title:

Ultra-low-dose Coronary Artery Calcium Scoring: Evaluation of Prognostic Performance and Impact of Physiological Factors on Quantification in a Large Population

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT03637231
• Other study ID #: USZ-2017-01158
• Status: Terminated
• Phase: N/A
• Start date: July 5, 2018
• Est. completion date: October 25, 2021

Study information

• Verified date: November 2022
• Source: University of Zurich
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical 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. 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.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 301
• Est. completion date: October 25, 2021
• Est. primary completion date: October 25, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Patients referred for a non-contrast enhanced CT scan for CAC scoring
• Male and Female subjects =18 years of age,
• Written informed consent

Exclusion Criteria:

• 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

Related Conditions & MeSH terms

• Coronary Artery Disease

Intervention

Diagnostic Test:
• Ultra low-dose CTAC
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.

Locations

Country	Name	City	State
Switzerland	Department of Nuclear Medicine, University Hospital Zurich	Zurich

Sponsors (1)

Lead Sponsor	Collaborator
University of Zurich

Country where clinical trial is conducted

Switzerland, 

References & Publications (1)

Gräni 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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.	2 years
Secondary	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).	2 years