Diagnostic and Prognostic Value of Angiography-derived IMR

• Conditions: Coronary Microvascular Dysfunction; Myocardial Ischemia
• Interventions: Device: Angiography-drived Index of Microcirculatory Resistance

• Registration Number: NCT04825028
• Lead Sponsor: Shanghai Zhongshan Hospital

Brief Summary

The importance of the microvasculature in determining clinical outcomes has been highlighted in patients with coronary artery disease (CAD). For patients with stable CAD, despite the success of percutaneous coronary intervention (PCI) in relieving a stenosis in the epicardial coronary artery, microvascular dysfunction may preclude sufficient coronary flow and myocardial perfusion, possibly leading to worse clinical outcome. With the technical development of computational fluid dynamics, angiographic derivation of index of Index of Microcirculatory Resistance (IMR) without pressure wire, hyperemic agents, or theromdilution method is available as a potential alternative for pressure wire-derived IMR. In this regard, the current study will evaluate diagnostic implication of angiography-derived IMR and its prognostic implication after PCI in patients with stable CAD.

Detailed Description

The importance of the microvasculature in determining clinical outcomes has been highlighted in patients with coronary artery disease (CAD). For patients with stable CAD, despite the success of percutaneous coronary intervention (PCI) in relieving a stenosis in the epicardial coronary artery, microvascular dysfunction may preclude sufficient coronary flow and myocardial perfusion, possibly leading to worse clinical outcome. With the technical development of computational fluid dynamics, angiographic derivation of IMR without pressure wire, hyperemic agents, or theromdilution method is available as a potential alternative for pressure wire-derived IMR. In this regard, the current study will evaluate diagnostic implication of angiography-derived IMR and its prognostic implication after PCI in patients with stable CAD.

This study cohorts consist with 3 separate cohort: first, internal diagnostic accuracy cohort, which will evaluate correlation between angiography-derived IMR and hyperemic microvascular resistance calculated using Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography (CZT-SPECT)-derived myocardial blood flow and invasively measured pressure data. For this, 53 consecutive patients with available CZT-SPECT within 3 months of measuring FFR in the left anterior descending coronary artery will be evaluated. Second: external diagnostic cohort, in which diagnostic accuracy of angiography-derived IMR will be assessed in patients with ischemia and no obstructive coronary artery disease (INOCA) and normal controls, whose results were previously published (J Nucl Cardiol. 2020 Sep 30. doi: 10.1007/s12350-020-02252-8.) Among this cohort, 45 patients with no obstructive CAD and normal CZT-SPECT perfusion imaging will be regarded as normal controls, in 35 INOCA patients, vessels with normal corresponding perfusion territory will be regarded as internal control. Third, prognosis cohort, in which 138 consecutive CAD patients received PCI with available angiograms and who were suitable for angiographic fractional flow reserve and IMR measurement will be analyzed. Primary clinical outcome will be cardiac death or congestive heart failure at 2 years from index procedure. Secondary outcome will be any myocardial infarction, ischemia-driven revascularization, definite or probable stent thrombosis, congestive heart failure admission and angina pectoris admission at 2 years from index procedure.

Study Timeline

• Status Verified: 2021-03
• Study First Submitted: 2021-03-28
• Study First Submitted QC: 2021-03-28
• Last Update Submitted: 2021-03-28
• Study Start: 2021-04-01
• Study First Posted: 2021-04-01
• Last Update Posted: 2021-04-01
• Primary Completion: 2021-05-01
• Study Completion: 2021-10-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 271

Inclusion Criteria

• CAD patients with available CZT-SPECT within 3 months of measuring FFR in the left anterior descending coronary artery (Cohort 1)
• INOCA patients and normal controls confirmed by CZT-SPECT and angiography (Cohort 2)
• Stable CAD patients received PCI (Cohort 3)
• analyzable angiograms at the index procedure

Exclusion Criteria

• Previous coronary artery bypass grafting
• Chronic total occlusion patients
• limited image quality of coronary angiography
• Insufficient angiographic project for TIMI frame count
• Severe tortuosity of target vessel
• No optimal projection for reconstruction

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
External Diagnostic Accuracy Cohort	Angiography-drived Index of Microcirculatory Resistance	Patients are subgroup of previously published study (J Nucl Cardiol. 2020 Sep 30. doi: 10.1007/s12350-020-02252-8.), INOCA patients and normal controls confirmed by CZT-SPECT and angiography will be included for the assessment of angiography-derived IMR in diagnosing microvascular dysfunction.
Internal Diagnostic Accuracy Cohort	Angiography-drived Index of Microcirculatory Resistance	Consecutive patients with available CZT-SPECT within 3 months of measuring FFR in the left anterior descending coronary artery. In these patients, correlation between angiography-derived IMR and hyperemic microvascular resistance will be assessed.
Prognosis Cohort	Angiography-drived Index of Microcirculatory Resistance	Prognosis cohort, in which angiography-derived IMR will be measured in the target vessel after successful revascularization. Those patients have follow-up data after 2 years from index procedure.

Primary Outcome Measures

Name	Time	Method
Major adverse cardiac events	at 28 months from index procedure	Major adverse cardiac events (MACE), including cardiac death and readmission due to heart failure.
Diagnostic accuracy	at the index procedure	Correlation between angiography-derived IMR and HMR

Secondary Outcome Measures

Name	Time	Method
Spontaneous MI	at 28 months from index procedure	Spontaneous MI
Target vessel revascularization	at 28 months from index procedure	Target vessel revascularization
Readmission due to angina	at 28 months from index procedure	Readmission due to angina
A composite of cardiac death, readmission due to heart failure and angina	at 28 months from index procedure	A composite of cardiac death, readmission due to heart failure and angina
Readmission due to heart failure	at 28 months from index procedure	Readmission due to heart failure
A composite of cardiac death, readmission due to heart failure, spontaneous MI, target vessel revascularization and angina	at 28 months from index procedure	A composite of cardiac death, readmission due to heart failure, spontaneous MI, target vessel revascularization and angina.
Cardiac death	at 28 months from index procedure	Cardiac death

Trial Locations

Locations (1)

Shanghai Tenth People's Hospital; 🇨🇳 Shanghai, China