Xenetix® 350: Comparative Assessment of Image Quality for Coronary CT Angiography

Study Overview
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Brief Summary
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The purpose of this study is to demonstrate the (statistical) non-inferiority of iobitridol (Xenetix® 350) when compared to contrast agents with higher iodine concentrations, iopromide (Ultravist® 370) and iomeprol (Iomeron® 400) in terms of coronary CT scan evaluability (quality and interpretability of images).

Detailed Description
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Patients suspected of coronary artery disease were submitted to coronary CT angiography using either iobitridol or contrast agents with higher iodine concentrations (iopromide or iomeprol). Independent off-site readers evaluated image quality regarding the ability to identify coronary artery stenosis (score 0- non evaluable to 4- excellent quality). The study was aimed at showing the non-inferiority of iobitridol in its ability to provide evaluable CT scans for the identification of coronary stenosis.

Official Title
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Xenetix® 350: Comparative Assessment of Image Quality for Coronary CT Angiography (X-ACT Study)

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Drug: iobitridol
* Drug: iopromide
* Drug: iomeprol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female adult patient (having reached legal majority age) Symptomatic patient suspected for coronary artery disease scheduled for a coronary CT angiography Exclusion Criteria: Patient with a heart rate > 65 beats per minute (bpm) and contraindication or intolerance to b-blocker administration Patient with arrhythmia or non-sinus rhythm Patient with decompensated heart failure Patient with evidence of ongoing or active clinical instability (suspected or known acute myocardial infarction, cardiac shock, acute pulmonary oedema) Patient who has previously undergone coronary artery bypass graft Patient who has previously undergone percutaneous transluminal coronary stent placement Patient with artificial heart valve Patient with known moderate to severe aortic stenosis

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Iobitridol<br>Patients were IV injected with a single dose of iobitridol before a coronary CT angiography | Drug: iobitridol<br>* single IV injection<br>* Other names: Xenetix®;|
| Active Comparator: Iopromide<br>Patients were IV injected with a single dose of iopromide before a coronary CT angiography | Drug: iopromide<br>* Single IV injection<br>* Other names: Ultravist®;|
| Active Comparator: Iomeprol<br>Patients were IV injected with a single dose of iomeprol before a coronary CT angiography | Drug: iomeprol<br>* Single IV injection<br>* Other names: Iomeron®;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of Patients With Evaluable CT Scans i.e. Allowing Identification of Coronary Artery Stenosis According to Off-site Reading Assessment | Evaluability was based upon the off-site assessment of 18-coronary segments graded for image quality with a 5-point scale.4= Excellent quality, fully confidence without any doubts concerning the presence/absence of luminal stenosis; 3= Good quality, confidence concerning the presence/absence of luminal stenosis; 2= Moderate quality, relative confidence, with minor doubts concerning the presence/absence of luminal stenosis; 1= Poor quality, some doubts concerning the presence/absence of stenosis; 0= Non diagnostic. A patient's CT scan was considered as evaluable for identification of coronary artery stenosis if none of the 18 coronary segments had a score of 0. | < 24h | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Image Quality According to Off-site Reading | For each patient, all 18 coronary segments were graded for image quality using a 5-point evaluation scale (from 0=non-diagnostic to 4=excellent). The average image quality was evaluated using the off-site readings, by averaging the scores obtained for the 18 segments used to determine the CT evaluability (primary criteria). | <24h | 
| Coronary Track Rate | A post processing software automatically tracked the number of distal segments of the left anterior descending coronary artery, the left circumflex coronary artery and the right coronary artery . The number of segments tracked per patient were assessed by an independent off-site radiologist. | <24h | 
| Average Signal Attenuation After IV Injection of Contrast | Attenuation of signal was measured off-site on post-injection images of four coronary segments, in the ascending aorta and in the left ventricle, then it was averaged at the patient level. | <1h | 
| Average Signal-to-Noise Ratio (Average SNR) | Signal attenuation was measured by off-site radiologists in the lumen of 4 coronary segments, in the ascending aorta and in the left ventricle and was expressed in Hounsfield Unit (HU). Measurements were set in post-injection images for the 6 territories. A measure of noise in CT scans was collected at least in the aorta and if possible in the muscle and/or air. Signal-to-Noise Ratios (SNR) of post-injection images were derived in all territories from attenuation measurements according to the following formula: SNR Territory = Post Attenuation / Image Noise | <1h | 
| Average Contrast-to-noise Ratio (Average CNR) | Signal attenuation was measured by off-site radiologists in the lumen of 4 coronary segments in the ascending aorta and the in left ventricle and expressed in Hounsfield Unit (HU). A measure of noise in CT scans was collected at least in the aorta and if possible in the muscle and/or air. In territories where pre and post signal attenuation measures were both available, the contrast-to-noise ratio was computed according to the following formula: CNR = (Post Att - Baseline Att) / Image Noise | <1h | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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iodinated contrast media, coronary artery disease