Pilot Trial: Comparison of Flow Patterns

Study Overview
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Brief Summary
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The purpose of this study is to determine why sutureless aortic bioprostheses apparently offer better haemodynamic properties compared to sewed-in aortic bioprostheses in patients who underwent aortic valve replacement. Our approach to address this question is the combination of clinical data with the application of specifically validated experimental and computer based analyses to compare the performance of these valves under patient-specific conditions.

Official Title
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Pilot Trial: Comparison of Flow Patterns. Is There a Difference Between sewed-in and Sutureless Bioprosthetic Aortic Heart Valves?

Conditions
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Aortic Valve Stenosis, Aortic Valve Insufficiency

Intervention / Treatment
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* Radiation: Cardiac CT-scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient underwent open aortic valve replacement with either an Edwards Magna Ease or an Edwards Intuity valve Implanted valve size 23mm Surgical access via full sternotomy or hemisternotomy Intuity Valve System implanted by one of the clinical investigators of the TRITON trial (http://clinicaltrials.gov/show/NCT01445171) at the Medical University of Vienna Post-operative ejection fraction ≥50% Sinus-Rhythm Ability to understand and comply with study procedures Signed informed consent Exclusion Criteria: Under 18 years of age Emergency surgery Pregnancy Previous aortic root replacement Previous aortic valve replacement Previous or concomitant root enlargement Previous or concomitant repair of the ascending aorta Paravalvular leakage Ectasia of the ascending aorta Previous or concomitant myomectomy Concomitant replacement or repair of valves other than aortic Usage of more than 3 sutures for implantation of the Intuity Valve System Heavily calcified aortic root Glomerular filtration rate (GFR) < 30 ml/min Inability to understand or comply with study procedures Known allergic reaction to iodinated, non-ionic contrast agents

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: Other
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Sutureless valve<br>Patients who underwent aortic valve replacement with a sutureless aortic valve. An echocardiogram and a cardiac CT-scan will be conducted. | Radiation: Cardiac CT-scan<br>* ECG gated CT angiography of the heart will be performed on a 128-slice dual-source and two Stellar detectors CT system with retrospective ECG-gating (Siemens/SOMATOM Definition Flash - Siemens, Germany, 100kV, 395.75 mAs). In details, multi-phase images will be acquired to reconstruct between 10 and 100% of the cardiac cycle (10% increments) with a slice thickness of 1 mm. Examination will include left ventricular outflow tract, aortic root, coronary sinus, ascending aorta together with the prosthetic valves.<br>|
| Other: Sewed-in valve<br>Patients who underwent aortic valve replacement with a sewed-in aortic valve. An echocardiogram and a cardiac CT-scan will be conducted. | Radiation: Cardiac CT-scan<br>* ECG gated CT angiography of the heart will be performed on a 128-slice dual-source and two Stellar detectors CT system with retrospective ECG-gating (Siemens/SOMATOM Definition Flash - Siemens, Germany, 100kV, 395.75 mAs). In details, multi-phase images will be acquired to reconstruct between 10 and 100% of the cardiac cycle (10% increments) with a slice thickness of 1 mm. Examination will include left ventricular outflow tract, aortic root, coronary sinus, ascending aorta together with the prosthetic valves.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of maximum and minimum velocity under patient specific conditions |  | between 6 months and 4 years after aortic valve replacement | 
| Comparison of the effective orifice area under patient specific conditions |  | between 6 months and 4 years after aortic valve replacement | 
| Comparison of the percentage of turbulent flow under patient specific conditions |  | between 6 months and 4 years after aortic valve replacement | 
| Comparison of the pressure drop under patient specific conditions |  | between 6 months and 4 years after aortic valve replacement | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient-specific, computer simulated pressure gradients compared to echocardiographically obtained pressure gradients. | The first secondary outcome measure is the comparison of -pressure gradients as computed by the model against the same data collected standardly with echocardiographic technique. Differences will be quantified. If positive (< 10%), this assessment would enhance the use of patient-specific models in clinics as a predictive tool for detailed haemodynamics. | between 6 months and 4 years after aortic valve replacement | 
| Patient-specific, computer simulated peak velocity compared to echocardiographically obtained peak velocity. | The second secondary outcome measure is the comparison of -peak velocity as computed by the model against the same data collected standardly with echocardiographic technique. Differences will be quantified. If positive (< 10%), this assessment would enhance the use of patient-specific models in clinics as a predictive tool for detailed haemodynamics. | between 6 months and 4 years after aortic valve replacement | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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aortic valve replacement, aortic valve bioprosthesis, hemodynamics