The Physiological Impact of CTO PCI on Coronary Pressure Measurements and Correlation in Donor Vessel

Study Overview
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Brief Summary
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This study will be recording pressure wire readings from both blocked and narrowed arteries, to better guide treatment options; medications, stents or potentially bypass surgery, for patients with Chronic Total Occlusion (CTO).

Detailed Description
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The patients in this study are planned to have a Percutaneous Coronary Intervention (PCI) with recanalization of Chronic Total Occlusion (CTO) on clinical grounds alone. This study will be recording pressure wire readings from both blocked and narrowed arteries, to better guide treatment option. To date there is no data available on instantaneous wave free ratio (iFR) measurement (a pressure derived assessment of flow limitation) in patients with blocked arteries.

Official Title
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The Physiological IMPACT of Coronary Chronic Total Occlusion (CTO) Percutaneous Coronary Intervention (PCI) on Coronary Pressure --Derived Measurements, Its Correlation in the Donor Vessel and the Influence of Collateral Circulation

Conditions
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Acute Coronary Syndrome, Coronary Artery Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >18 years of age Stable angina / ischaemic symptoms Evidence of viability and / or ischaemia in the chronic total occlusion (CTO) territory Participant is willing and able to give informed consent for participation in the study Presence of a chronic total occlusion (CTO) in RCA: Duration of the occlusion > 3 months; Thrombolysis In Myocardial Infarction (TIMI) (50) coronary flow grade 0; Spontaneously visible collaterals, Rentrop classification grade 1 or 2 or 3 from contralateral donor artery Presence of minor to intermediate coronary stenosis (1-70 %) in the contralateral donor artery Eligible for PCI to a chronic total occlusion (CTO) Exclusion Criteria: Previous CABG with patent grafts to the interrogated donor artery Left main stenosis of > 40 % Presence of severe flow limiting stenosis in the contralateral donor artery (typically > 70 % stenosis) Haemodynamic instability at the time of intervention (heart rate <40 beats per minute, systolic blood pressure <90mmHg), balloon pump) Significant contraindication to adenosine administration (e.g. heart block, severe asthma) Contraindications to PCI Severe hepatic or lung disease (chronic pulmonary obstructive disease) Pregnancy ACS within 48 hours of procedure Severe valvular heart disease Severe cardiomyopathy / Infiltrative heart disease eGFR < 40

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coronary pressure changes | Changes in coronary pressure - derived measurements (resting Pd/Pa, iFR and FFR) in donor artery pre and post RCA CTO PCI | 5 Minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Population correlation | Correlation between coronary pressure---derived measurements in this population. | 5 minutes | 
| Donor artery correlation | Correlation between collateral circulation function on coronary pressure - derived measurements in donor artery pre and post RCA CTO PCI. | 5 minutes | 
| Cardiac MRI correlation | Correlation between baseline coronary pressure - derived measurements in donor artery pre RCA CTO PCI, collateral circulation indices and baseline non-invasive functional assessment /Cardiac MRI (CMR) | 5 minutes | 
| Effects of stenosis severity (QCA) | Effects of stenosis severity (QCA) in donor artery on coronary pressure-derived measurements | 5 minutes | 
| Collateral circulation characteristics | Influence of collateral circulation characteristics on coronary pressure-derived measurements | 5 minutes | 
| Coronary pressure and jeopardy scores correlation | Correlation between coronary pressure-derived measurements in the donor artery and myocardial jeopardy scores in the donor artery | 5 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Percutaneous Coronary Intervention (PCI), Chronic Total Occlusion (CTO), Cardiac MRI, Instantaneous wave-free ratio (iFR)