The performance of angiography-derived index of microcirculatory resistance for ischemia in angina with non-obstructive coronary artery disease: Validated by wire-based IMR and SPECT-MPI

Jingpu Wang; Chenguang Li; Mingyou Zhang; Jinying Zhou; Qiyu Zhang; Weifeng Guo; Congcong Pan; Haojun Yu; Shufu Chang; Hao Lu; Zhangwei Chen; Hongcheng Shi; Feng Zhang; Juying Qian; Junbo Ge

doi:10.1016/j.ijcard.2025.133236

The performance of angiography-derived index of microcirculatory resistance for ischemia in angina with non-obstructive coronary artery disease: Validated by wire-based IMR and SPECT-MPI

Int J Cardiol. 2025 Jul 15:431:133236. doi: 10.1016/j.ijcard.2025.133236. Epub 2025 Apr 2.

Authors

Jingpu Wang¹, Chenguang Li¹, Mingyou Zhang², Jinying Zhou¹, Qiyu Zhang¹, Weifeng Guo³, Congcong Pan¹, Haojun Yu⁴, Shufu Chang¹, Hao Lu¹, Zhangwei Chen¹, Hongcheng Shi⁴, Feng Zhang⁵, Juying Qian¹, Junbo Ge⁶

Affiliations

¹ Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China; National Clinical Research Center for Interventional Medicine, Shanghai, China; State Key Laboratory of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China; NHC Key Laboratory of Ischemia Heart Disease, Shanghai, China; Key Laboratory of Viral Heart Disease, Chinese Academy of Medical Science, Shanghai, China.
² Department of Cardiology, The first Hospital of Jilin University, Changchun, China.
³ Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Institute of Medical Imaging, Shanghai, China.
⁴ Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai, China.
⁵ Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China; National Clinical Research Center for Interventional Medicine, Shanghai, China; State Key Laboratory of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China; NHC Key Laboratory of Ischemia Heart Disease, Shanghai, China; Key Laboratory of Viral Heart Disease, Chinese Academy of Medical Science, Shanghai, China. Electronic address: zhang.feng@zs-hospital.sh.cn.
⁶ Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China; National Clinical Research Center for Interventional Medicine, Shanghai, China; State Key Laboratory of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China; NHC Key Laboratory of Ischemia Heart Disease, Shanghai, China; Key Laboratory of Viral Heart Disease, Chinese Academy of Medical Science, Shanghai, China. Electronic address: jbge@zs-hospital.sh.cn.

PMID: 40185371
DOI: 10.1016/j.ijcard.2025.133236

Abstract

Background: Coronary microvascular dysfunction (CMD) accounts for a significant part of angina with non-obstructive coronary artery (ANOCA). Angiography-derived index of microcirculatory resistance (angio-IMR) has been developed for the evaluation of CMD but not yet validated sufficiently in ANOCA.

Aims: To validate angio-IMR against wire-based IMR and to investigate its diagnostic performance for ischemia in ANOCA patients.

Methods: This study included two independent cohorts. The angio-IMR and wire-based IMR were measured in 74 patients (74 vessels) in the wire-based IMR validation cohort. The angio-IMR and single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) were successfully completed in 136 patients (408 vessels) in the SPECT-MPI validation cohort. The ischemia was defined as the myocardial perfusion defect on SPECT-MPI and a summed difference score (SDS) ≥ 2.

Results: In the wire-based IMR validation cohort, the angio-IMR ≥ 25 had the high diagnostic efficiency (area under the receiver-operating characteristics curve (AUC): 0.917, 95 %CI: 0.843-0.922; p < 0.001) and classification agreement (CA) (91.9 %) with the referenced wire-based IMR ≥ 25. In the SPECT-MPI validation cohort, more ischemia was observed in the high angio-IMR group (angio-IMR ≥ 25) compared to the low angio-IMR group (angio-IMR < 25) (55.2 % vs 10.4 %, p < 0.001). The angio-IMR ≥ 25 had a moderate diagnostic performance for ischemia (AUC: 0.759, 95 %CI: 0.670-0.849; p < 0.001), and it could improve the ability to discriminate ischemia in ANOAC patients (integrated discrimination improvement (IDI): 0.184; p < 0.001; net reclassification improvement (NRI): 0.217; p < 0.001).

Conclusion: The study demonstrates that angio-IMR, validated through both wire-based IMR and SPECT-MPI, presents a promising and convenient diagnostic approach for identifying ischemia in patients with ANOCA.

Keywords: Angina with non-obstructive coronary artery; Angiography-derived index of coronary microcirculatory resistance; Coronary microvascular dysfunction; Ischemia; Single photon emission computed tomography imaging.

Publication types

Validation Study

MeSH terms

Aged
Angina Pectoris* / diagnostic imaging
Angina Pectoris* / physiopathology
Cohort Studies
Coronary Angiography* / methods
Coronary Angiography* / standards
Coronary Artery Disease* / diagnostic imaging
Coronary Artery Disease* / physiopathology
Coronary Circulation* / physiology
Female
Humans
Male
Microcirculation* / physiology
Middle Aged
Myocardial Ischemia* / diagnostic imaging
Myocardial Ischemia* / physiopathology
Myocardial Perfusion Imaging* / methods
Myocardial Perfusion Imaging* / standards
Tomography, Emission-Computed, Single-Photon* / methods
Tomography, Emission-Computed, Single-Photon* / standards
Vascular Resistance* / physiology