Contrast Enhancement on Coronary Computed Tomographic Angiography

Study Overview
=================
Brief Summary
-----------------
Computed tomographic angiography (CTA) is an important prognostic tool with regard to the detection of coronary artery stenoses. Both iodine delivery rate (IDR; the amount of iodine delivered to the patient per second) and iodine concentration are decisive factors in the opacification of arterial vessels. There remains to be some debate in the literature about whether the use of high iodine concentration contrast media is beneficial compared to lower iodine concentrations. To date, there have not been any studies comparing intracoronary attenuation using concentrated contrast media lower than 300 mg I/ml at coronary CTA. For a reliable comparison of CM with different iodine concentrations, adapted injection protocols insuring an identical IDR (in g iodine per second) are mandatory. The investigators hypothesize that usage of lower iodine concentrations, while maintaining identical IDR and total iodine load, will result in comparable diagnostical intra-vascular attenuation in CTA.

Detailed Description
-----------------
To evaluate intravascular contrast enhancement and image quality in coronary CTA using different iodine concentrations ranging from 240 to 370 mg iodine per ml, administered with an identical IDR and total iodine load. To describe the effect of iodine concentration and flow rates on contrast bolus characteristics, eg time to peak, bolus homogeneity, injection pressure and patient comfort.

Official Title
-----------------
Contrast Enhancement on Coronary Computed Tomographic Angiography : Effects on Intra-Coronary Attenuation Using Low Iodine Concentrations While Maintaining Identical IDR (EICAR-Trial)

Conditions
-----------------
Coronary Artery Disease, Coronary Stenosis

Intervention / Treatment
-----------------
* Drug: 240 mg Iodine
* Drug: 300 mg Iodine
* Drug: 370 mg Iodine


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Atypical or typical chest pain Exclusion Criteria: Unstable angina Hemodynamic instability History of CAD Pregnancy Renal insufficiency (defined as glomerular filtration rate (GFR) <45ml/min or <60ml +diabetes HR > 90 bpm and the inability to receive beta-blockers and iodine allergy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 240<br>Group 240 will receive CM with 240 mg Iodine/ml IDR 2.0 gI/s | Drug: 240 mg Iodine<br> <br> * Other names: 240 mg Iodine/ml IDR 2.0 gI/s;|
| Experimental: 300<br>Group 300 will receive CM with 300 mg Iodine/ml IDR 2.0 gI/s | Drug: 300 mg Iodine<br> <br> * Other names: 300 mg Iodine/ml IDR 2.0 gI/s;|
| Experimental: 370<br>Group 370 will receive CM with 370 mg Iodine/ml IDR 2.0 gI/s | Drug: 370 mg Iodine<br> <br> * Other names: 240 mg Iodine/ml IDR 2.0 gI/s;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| intravascular contrast enhancement | intravascular contrast enhancement and image quality based on different contrast media (240, 300, 370) as measured by circular ROI in the target vessels using dedicated post processing. | two years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time to peak | Effect of iodine concentration - as measured by dedicated contrast monitoring software. | two years | 
| bolus homogeneity | Effect on contrast bolus characteristics and injection pressure - as measured by dedicated contrast monitoring software. | two years | 
| patient comfort | Effect on patient comfort. As assessed by patient questionnaire. | two years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Computed tomography, Coronary CTA, Contrast media