Coronary Artery Disease
Conditions
Brief summary
The aim of the study is to compare the CACS obtained from standard dose CT to the CACS obtained from ultra-low-dose scans. Additionally, the usefulness of ultra-low-dose CT for AC of myocardial perfusion SPECT will be assessed.
Interventions
DEVICEUltra low dose non-contrast enhanced CT
Non-contrast enhanced CT for CACS and AC using a novel protocol for ultra low dose radiation dose exposure
DEVICEStandard dose non-contrast enhanced CT
Clinically indicated non-contrast enhanced CT for CACS and AC according to routine protocol
Sponsors
University of Zurich
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients referred for myocardial perfusion SPECT * Male and Female subjects ≥18 years of age, * Written informed consent
Exclusion criteria
* Pregnancy or breast-feeding * CACS of 0 after inclusion of 10 patients with CACS 0 * Stents or implanted cardiac devices (valves, pace makers, ICD) * Coronary artery bypass grafts
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Agreement and Correlation of Coronary Artery Calcium Score Obtained From Ultra-low-dose and Standard CT | 1 days | CAC and BA limits of agreement between coronary artery calcium score obtained from ultra-low-dose and standard CT. Coronary artery calcium (CAC) is a measure for quantification of coronary artery calcification based on non-contrast enhanced CT, ranging from 0 (no calcifications) to infinite. It is an arbitrary unit. Increasing CAC means higher amounts of coronary artery calcifications and is associated with worse prognosis. Bland-Altman (BA) analysis is a statistical method to compare two modalities or techniques assessing the same measure. Limits of agreement is defined as +/- twice the standard deviation of the differences between the reference method and the new modality/technique. Broader limits of agreement mean less accurate results obtained by the new modality/techniqe, while a 0 BA limit of agreement would theoretically reflect perfect agreement. |
| Intra-class Correlation Coefficient Between Segmental Relative Tracer Uptake From SPECT Datasets Reconstructed With AC Maps Based on Ultra-Low-Dose and Standard Dose CT | 1 day | For every patient, the CT images from 120 and 70 kVp-CT scans were used to create CTAC maps which were then used to reconstruct SPECT images, displayed as a 17-segment model polar plot with normalized percent tracer uptake given for every segment. Intra-class correlation was then applied to compare segmental relative tracer uptake. Analysis and the resulting correlation coefficient of 0.987 basically demonstrates interchangeability between the two datasets. |
Countries
Switzerland
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Standard Dose CT, Ultra-low Dose CT Standard dose non-contrast enhanced CT
Standard dose non-contrast enhanced CT: Clinically indicated non-contrast enhanced CT for CACS and AC according to routine protocol | 105 |
| Total | 105 |
Baseline characteristics
| Characteristic | Standard Dose CT, Ultra-low Dose CT | — |
|---|---|---|
| Age, Categorical <=18 years | 0 Participants | — |
| Age, Categorical >=65 years | 68 Participants | — |
| Age, Categorical Between 18 and 65 years | 37 Participants | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Sex: Female, Male Female | 33 Participants | — |
| Sex: Female, Male Male | 72 Participants | — |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 105 | 0 / 105 |
| other Total, other adverse events | 0 / 105 | 0 / 105 |
| serious Total, serious adverse events | 0 / 105 | 0 / 105 |
Outcome results
Primary
Agreement and Correlation of Coronary Artery Calcium Score Obtained From Ultra-low-dose and Standard CT
CAC and BA limits of agreement between coronary artery calcium score obtained from ultra-low-dose and standard CT. Coronary artery calcium (CAC) is a measure for quantification of coronary artery calcification based on non-contrast enhanced CT, ranging from 0 (no calcifications) to infinite. It is an arbitrary unit. Increasing CAC means higher amounts of coronary artery calcifications and is associated with worse prognosis. Bland-Altman (BA) analysis is a statistical method to compare two modalities or techniques assessing the same measure. Limits of agreement is defined as +/- twice the standard deviation of the differences between the reference method and the new modality/technique. Broader limits of agreement mean less accurate results obtained by the new modality/techniqe, while a 0 BA limit of agreement would theoretically reflect perfect agreement.
Time frame: 1 days
Population: 2/105 participants were not analyzed due to corrupt datasets.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Standard Dose CT | Agreement and Correlation of Coronary Artery Calcium Score Obtained From Ultra-low-dose and Standard CT | 212 Agatston score |
| Ultra-low Dose CT | Agreement and Correlation of Coronary Artery Calcium Score Obtained From Ultra-low-dose and Standard CT | 178 Agatston score |
Primary
Intra-class Correlation Coefficient Between Segmental Relative Tracer Uptake From SPECT Datasets Reconstructed With AC Maps Based on Ultra-Low-Dose and Standard Dose CT
For every patient, the CT images from 120 and 70 kVp-CT scans were used to create CTAC maps which were then used to reconstruct SPECT images, displayed as a 17-segment model polar plot with normalized percent tracer uptake given for every segment. Intra-class correlation was then applied to compare segmental relative tracer uptake. Analysis and the resulting correlation coefficient of 0.987 basically demonstrates interchangeability between the two datasets.
Time frame: 1 day
Population: 2/105 participants were not analyzed due to corrupt datasets.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Standard Dose CT | Intra-class Correlation Coefficient Between Segmental Relative Tracer Uptake From SPECT Datasets Reconstructed With AC Maps Based on Ultra-Low-Dose and Standard Dose CT | 1 Intraclass correlation coefficient |
| Ultra-low Dose CT | Intra-class Correlation Coefficient Between Segmental Relative Tracer Uptake From SPECT Datasets Reconstructed With AC Maps Based on Ultra-Low-Dose and Standard Dose CT | 0.987 Intraclass correlation coefficient |