Trial Outcomes & Findings for Ultra Low Dose CT for CACS and AC of SPECT (NCT NCT02458352)

Results Overview

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.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

105 participants

Primary outcome timeframe

1 days

Results posted on

2019-10-18

Participant Flow

Participant milestones

Participant milestones
Measure	Standard Dose CT, Ultra-low Dose CT Standard dose and ultra-low 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 Ultra-low dose non-contrast enhanced CT: Additional scan as part of the trial
Overall Study STARTED	105
Overall Study COMPLETED	105
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Standard Dose CT, Ultra-low Dose CT n=105 Participants 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
Age, Categorical <=18 years	0 Participants n=105 Participants
Age, Categorical Between 18 and 65 years	37 Participants n=105 Participants
Age, Categorical >=65 years	68 Participants n=105 Participants
Sex: Female, Male Female	33 Participants n=105 Participants
Sex: Female, Male Male	72 Participants n=105 Participants

PRIMARY outcome

Timeframe: 1 days

Population: 2/105 participants were not analyzed due to corrupt datasets.

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.

Outcome measures

Outcome measures
Measure	Standard Dose CT n=103 Participants 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	Ultra-low Dose CT n=103 Participants Ultra low dose non-contrast enhanced CT Ultra 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
Agreement and Correlation of Coronary Artery Calcium Score Obtained From Ultra-low-dose and Standard CT	212 Agatston score Interval 25.0 to 901.0	178 Agatston score Interval 22.0 to 764.0

PRIMARY outcome

Timeframe: 1 day

Population: 2/105 participants were not analyzed due to corrupt datasets.

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.

Outcome measures

Outcome measures
Measure	Standard Dose CT n=103 Participants 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	Ultra-low Dose CT n=103 Participants Ultra low dose non-contrast enhanced CT Ultra 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
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	0.987 Intraclass correlation coefficient

Adverse Events

Standard Dose CT

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Ultra-low Dose CT

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Ronny Buechel

University Hospital Zurich

Phone: 0041442551059

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place