Prognostic Implication of Angiography-Derived IMR in STEMI Patients

Study Overview
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Brief Summary
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Coronary microcirculatory dysfunction has been known to be prevalent even after successful revascularization of STEMI patients. Previous study presented that index of microcirculatory resistance (IMR) in culprit vessel of STEMI patients showed significant association with the risk of cardiac death or heart failure admission. Recent technical development enabled angiographic derivation of IMR without pressure wire, hyperemic agents, or theromdilution method. In this regard, the current study will evaluate prognostic implication of angiography-derived IMR in STEMI patients who were successfully revascularized.

Detailed Description
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Coronary microcirculatory dysfunction has been known to be prevalent even after successful revascularization of STEMI patients. Previous study presented that index of microcirculatory resistance (IMR) in culprit vessel of STEMI patients showed significant association with the risk of cardiac death or heart failure admission. Recent technical development enabled angiographic derivation of IMR without pressure wire, hyperemic agents, or theromdilution method. In this regard, the current study will evaluate prognostic implication of angiography-derived IMR in STEMI patients who were successfully revascularized. The study cohorts consist with 2 separate cohort: first, diagnostic accuracy cohort, which will evaluate diagnostic accuracy of angiography-derived IMR for invasive IMR. For this, 31 patients with culprit vessel IMR measurement at the time of primary PCI will be evaluated. The patients cohort is the subgroup of previous registry (NCT02186093). Second, prognosis cohort, in which angiography-derived IMR will be measured in the culprit vessel after successful revascularization. Those patients have follow-up data after 10 years from index procedure. This cohort is STEMI subgroup derived from Institutional registry of Samsung Medical Center, whose results were previously published (JACC Cardiovascular Intervention. 2019 Apr 8;12(7):607-620.) Among 490 STEMI patients from the overall study cohorts, 309 patients with available angiograms and who were suitable for angiographic FFR and IMR measurement will be analyzed. Primary clinical outcome will be cardiac death at 10 years from index procedure. Secondary outcome will be any myocardial infarction, ischemia-driven revascularization, definite or probable stent thrombosis, congestive heart failure admission at 10 years from index procedure.

Official Title
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Prognostic Implication of Angiography-Derived Index of Microcirculatory Resistance in Successfully Reperfused STEMI Patients

Conditions
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Acute ST-segment Elevation Myocardial Infarction

Intervention / Treatment
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* Device: Angiography-drived Index of Microcirculatory Resistance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: STEMI patients who were successfully revascularized for culprit vessel analyzable angiograms at the index procedure Exclusion Criteria: Previous coronary artery bypass grafting Coronary bypass graft as culprit vessel Patients with unclear culprit vessel limited image quality of coronary angiography Insufficient angiographic project for TIMI frame count Severe tortuosity of culprit vessel No optimal projection for reconstruction

Ages Eligible for Study
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Minimum Age: 19 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 |
| --- | --- |
| Diagnostic Accuracy Cohort<br>Patients are subgroup of previously published study (JACC Cardiovascular Intervention 2020;13:1155-67), which evaluated invasive physiologic indices from culprit and non-culprit vessels of acute myocardial infarction patients. From the study cohort, 31 STEMI patients who underwent IMR measurement in culprit vessel after successful revascularization will be analyzed. In these patients, diagnostic accuracy of angiography-derived IMR will be compared with invasive IMR. | Device: Angiography-drived Index of Microcirculatory Resistance<br>* From coronary angiographic images, angiography-derived IMR will be calculated based on mathematical calculation. Angiography-derived IMR = (hyperemic Pa x angiography-derived FFR) x (vessel length / {K x V diastole}). Hyperemic Pa will be estimated from resting Pa according to prespecified equation.<br>* Other names: Angiography-derived IMR;|
| Prognosis Cohort<br>Prognosis cohort, in which angiography-derived IMR will be measured in the culprit vessel after successful revascularization. Those patients have follow-up data after 10 years from index procedure. This cohort is STEMI subgroup derived from Institutional registry of Samsung Medical Center, whose results were previously published (JACC Cardiovascular Intervention. 2019 Apr 8;12(7):607-620.) Among 490 STEMI patients from the overall study cohorts, 309 patients with available angiograms and who were suitable for angiographic FFR and IMR measurement will be analyzed. Primary clinical outcome will be cardiac death at 10 years from index procedure. Secondary outcome will be any myocardial infarction, ischemia-driven revascularization, definite or probable stent thrombosis, congestive heart failure admission at 10 years from index procedure. | Device: Angiography-drived Index of Microcirculatory Resistance<br>* From coronary angiographic images, angiography-derived IMR will be calculated based on mathematical calculation. Angiography-derived IMR = (hyperemic Pa x angiography-derived FFR) x (vessel length / {K x V diastole}). Hyperemic Pa will be estimated from resting Pa according to prespecified equation.<br>* Other names: Angiography-derived IMR;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic accuracy | Diagnostic accuracy of angiography-derived IMR to predict invasive IMR | at the index procedure | 
| Cardiac death or heart failure admission | Cardiac death or heart failure admission | at 10 years from index procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Any myocardial infarction | Any myocardial infarction | at 10 years from index procedure | 
| Ischemia-driven revascularization | Ischemia-driven revascularization | at 10 years from index procedure | 
| Stent thrombosis | Definite or probable stent thrombosis according to ARC definition | at 10 years from index procedure | 
| Congestive heart failure admission | Admission for congestive heart failure | at 10 years from index procedure | 
| Major adverse cardiac events | a composite of cardiac death, any myocardial infarction, ischemia-driven revascularization, definite or probable stent thrombosis, or congestive heart failure admission | at 10 years from index procedure | 
| Cardiac death | Cardiac death | at 10 years from index procedure | 
| All-cause death | All-cause death | at 10 years from index procedure | 
| Heart failure admission | Heart failure admission | at 10 years from index procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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STEMI, Index of microcirculatory resistance, Quantitative flow ratio, Fractional flow reserve, Prognosis, Angiography-derived IMR