Early Assessment of QFR in STEMI-II

Study Overview
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Brief Summary
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The study intends to provide new data on whether the noval method using quantitative flow ratio could assess microvascular dysfunction based on the previous study EARLY-MYO-QFR-I.

Detailed Description
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Microvascular dysfunction (MVD) is a serious complication of PCI, which happens frequently after STEMI and always correlates with a poor prognosis. However, precise and simplified assessment of MVD is difficult, especially in the acute phase of STEMI patients. Resent studies suggested that FFR could be overestimated when MVD exists. But whether the overestimated value of FFR caused by CMR defined microvascular obstruction (MVO) could reflect microvascular function is still unclear. In the previous study EARLY-MYO-QFR-I, we have demonstrated that the relationship between Contrast-enhanced CMR defined MVO and QFR. While angiography images were collected on a retrospectively manner, and the study population were selected (STEMI patients with spontaneously recanalized culprit vessel before PCI) to verify our hypothesis. This phase of study would be a prospective study. We tend to created a new study population by a temporary artificial stenosis inside the stent by partially inflating a balloon catheter during pharmacologic hyperemia in STEMI patients.

Official Title
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EARLY Microvascular Dysfunction Assessment Using Quantitative Flow Ratio After ST-segment Elevation MYOcardial Infarction (EARLY-MYO-QFR II)

Conditions
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ST Segment Elevation Myocardial Infarction

Intervention / Treatment
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* Diagnostic Test: Computation of quantitative flow ratio


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: STEMI patients treated with revasculation within 12 hours from onset of symptoms to PCI time and received CMR 5 days afterwards. STEMI was defined as a combination of the following: chest pain for more than 30min, electrocardiographic (ECG) changing with ST segment elevation of >2 mm in at least 2 precordial leads and >1 mm in limb leads, and abnormal troponin levels or CKMB levels higher than twice the upper limit of normal. Stents were implanted whenever technically possible. TFG 2/3 after PCI. Exclusion Criteria: Patients with left bundle branch block in the presenting ECG, cardiogenic shock, previous PCI or bypass surgery, previous AMI history. Patients with trouble in partially inflating a balloon catheter during pharmacologic hyperemia. Patients with unqualified coronary angiographic images with problems such as ostial lesion, severe vessel tortuosity and diffuse long lesions.
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: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MVO group<br>CMR was performed in all the cases. According to the results of CMR, we divided the study population into MVO group and Non-MVO group. | Diagnostic Test: Computation of quantitative flow ratio<br>* After stents were implanted whenever technically possible in the STEMI patients, the investigators created a temporary artificial stenosis inside the stent by partially inflating a balloon catheter during pharmacologic hyperemia. Computation of QFR was performed offline, using AngioPlus system(Pluse medical imaging technology, Shanghai, China). In the first step, 2 diagnostic angiographic projections with the artifical stenosis, at least 25° apart, were selected and 3D reconstruction of the interrogated vessel without its side branches was performed. Then, the software computed the QFR.<br>|
| Experimental: Non-MVO group<br>CMR was performed in all the cases. According to the results of CMR, we divided the study population into MVO group and Non-MVO group. | Diagnostic Test: Computation of quantitative flow ratio<br>* After stents were implanted whenever technically possible in the STEMI patients, the investigators created a temporary artificial stenosis inside the stent by partially inflating a balloon catheter during pharmacologic hyperemia. Computation of QFR was performed offline, using AngioPlus system(Pluse medical imaging technology, Shanghai, China). In the first step, 2 diagnostic angiographic projections with the artifical stenosis, at least 25° apart, were selected and 3D reconstruction of the interrogated vessel without its side branches was performed. Then, the software computed the QFR.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac magnetic resonance (CMR) | Cardiac magnetic resonance (CMR) is a non-invasive test for MVO assessing | Five days after PCI | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| TIMI Flow Grade (TFG) | TIMI Flow Grade (TFG) assesses flow in the epicardial arteries. Type zero perfusion expressed not antegrade movement away the occlusion; type two is a minimum, inadequate perfusion of contrast average round the mass; type three (partial perfusion) is a perfect just limited perfusion from the distal coronary bed by contrast element; and type three (complete perfusion) is an antegrade movement to the whole distal artery at a regular flow. | One minutes after PCI | 
| TIMI Myocardial Perfusion Grade (TMPG) | TIMI Myocardial Perfusion Grade (TMPG) assesses flow in the microvessels. TMPG0: no or minimal blush; TMPG1: Stain present Blush persists on next injection; TMPG2: Dye strongly persistent at end of washout Gone by next injection; TMPG3: normal ground glass appearance of blush Dye mildly persistent at end of washout. | One minutes after PCI | 
| ST-segment resolution (STR) | The ST-segment resolution (STR) was measured after the end of the QRS complex J point in leads I, aVL, and V1 to V6 for anterior MI, and leads II, III, aVF, V5, and V6 for nonanterior MI. | 90 minutes after PCI | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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STEMI, Cardiac magnetic resonance, balloon catheter