Coronary Revascularization Based on CMR Viability Study Vs Direct Revascularization in Ischemic Cardiomyopathy Patients

Study Overview
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Brief Summary
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The study aiming to demonstrate the baseline characteristics and outcomes of patients undergoing revascularization by PCI vs those kept only on medical treatment, based on CMR viability assessment.

Detailed Description
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Cardiac magnetic resonance (CMR) has an ever-increasing role in the assessment and management of patients with coronary artery disease (CAD). Advantages of CMR include the lack of ionizing radiation and its flexibility, high spatial resolution, and three-dimensional capabilities that enable imaging in any desired plane. In the evaluation of patients with ischemic cardiomyopathy, CMR is primarily used in the setting of chronic CAD for the evaluation of myocardial ischemia and viability. Left ventricular systolic dysfunction, resulting from coronary artery disease is reversible with revascularization in cases of hibernation and stunned myocardium. Revascularization is dependent not only on the presence but also the extent of viability, and a viable myocardium is necessary for functional recovery. In a CMR study, in areas with dysfunctional myocardium as detected in cine sequences, the end diastolic wall thinning >5.5 mm, the extent of subendocardial fibrosis together with response to low dose dobutamine were shown to predict functional recovery. However, in the famous viability sub study of the STICH (Surgical Treatment for Ischemic Heart Failure) trial, there was a significant association between myocardial viability and outcome by univariate analysis, but not on multivariable analysis. Thereby, the value of CMR in this regards is still debatable. So, according to the recent state of art paper from the American Heart Association, data is still limited regarding CMR use to guide revascularization strategies or predict outcomes in patients with severe LV dysfunction. The statement recommended that future trials should continue to address the clinical impact of specific modality-based strategies or multimodality strategies in guiding treatment in terms of patient outcomes. On the other hand, appropriately guided coronary revascularization may go beyond providing recovery of myocardial systolic contractility by improving patient's functional class and heart failure symptoms, enhancing diastolic relaxation, reducing the burden of rhythm abnormalities, or decreasing the burden of polypharmacy, thereby reducing the risk of drug toxicity and improving quality of life. These additional benefits need also to be explored in clinical trials.

Official Title
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Comparison Between Coronary Revascularization Based on CMR Viability Study Vs Direct Revascularization in Patients With Ischemic Cardiomyopathy

Conditions
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Ischemic Cardiomyopathy

Intervention / Treatment
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* Device: cardiac MRI
* Procedure: Percutaneous coronary intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients >18 years of age, with LVEF<40%. Patients presenting for viability assessment to Assiut university Heart Hospital, starting from October 2020 till September 2021, will be retrospectively recruited. Patients with a coronary angiography that is amenable for revascularization. The decision and type of revascularization will be determined by the treating physicians. Exclusion Criteria: Classic CMR and gadolinium-based dye contraindications including non-MRI compatible implants/foreign bodies (e.g. non-MRI compatible pacemaker, large pieces of shrapnel) and patients with eGFR<30 ml/min/1.73 m2. Patients with non-ischemic cardiomyopathy confirmed by both CMR and coronary angiography.

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CMR viability study group<br>Diagnostic Test: CMR Basic CMR data including LV and RV volumes, SWMA reported, EF and wall thinning will be collected. SWMA from SSFP sequences will be reported and numbered according to the usual (1 normal, 2 hypokinetic, 3 akinetic, 4 dyskinetic, 5 aneurysmal). Data of viability assessed with LGE imaging with scar measurement using standard deviation method with SD of 4-5 will be used. AHA 17 segment model will be used as a reference for LV segmentation. Viability scoring will be calculated for each segment based on the transmurality index, in a semiautomated method, with no scar given 0, 1-25% subendocardial scar given score 1, 25-50% given 2, 50-75% given 3, >75% as 4. Wall thinning will be given 0 or 1 score for each segment, with 1 given for <6 mm thickness. | Device: cardiac MRI<br>* assessment of the viability using CMR<br>* Other names: CMR;|
| direct revascularization group<br>Direct Coronary revascularization | Procedure: Percutaneous coronary intervention<br>* direct revascularization using PCI<br>* Other names: PCI;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Detection of death, myocardial infarction , arrhythmia and hospitalization for HF | Detection of death, myocardial infarction (not related to index procedure) and hospitalization for heart failure or arrhythmia at 6-12 months after revascularization or medical treatment based on CMR viability testing. | 6-12 months after revascularization or medical treatment based on CMR viability testing. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| - Quality of life assessment using Kansas Qol questionnaire. |  | 6-12 months after revascularization or medical treatment based on CMR viability testing. | 
| - Improvement of echocardiography measured LVEF at 6-12 months after revascularization. |  | 6-12 months after revascularization or medical treatment based on CMR viability testing. | 
| - Detection of the effect of delayed revascularization after the CMR viability study on the outcome. |  | 6-12 months after revascularization or medical treatment based on CMR viability testing. |