Related Experiment Video
Updated: Sep 27, 2026
Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Angiography-derived index of microcirculatory resistance in older patients with acute coronary syndrome undergoing
Martina Magistri1, Carlos Collet2, Flavio Luciano Ribichini3
1Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom; Division of Cardiology, Department of Medicine, University of Verona, Verona, Italy.
Background:
Coronary microvascular dysfunction (CMD) plays a significant role in the prognosis of patients with ischaemic heart disease.
Aims:
In this analysis of the study to Improve Clinical Outcomes in high-risk patieNts with acute coronary syndrome (ICON1), we investigated the association between CMD and long-term outcomes in older patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI).
Methods:
Patients aged ≥75 years with NSTE-ACS undergoing PCI were included. Post-PCI angiography-derived index of microcirculatory resistance (IMRangio) was assessed. The primary endpoint was a composite of all-cause death, myocardial infarction, any revascularisation, any hospital readmission, or heart failure events.
Results:
A total of 152 patients with post-PCI IMRangio assessment were included. The receiver-operating characteristics (ROC)-defined cut-off for predicting the primary endpoint was 40 U. High post-PCI IMRangio (≥40 U) was observed in 38 patients and was independently associated with the primary endpoint at both 1- and 5-year follow-up (hazard ratio [HR] 4.82, 95% confidence interval [CI] 2.02-11.51, p < 0.01 and HR 4.18, 95% CI 2.20-7.95, p < 0.01; respectively). A multivariate model was developed to predict the primary endpoint at 1 and 5 years. The inclusion of high post-PCI IMRangio significantly improved its discriminatory ability for the primary endpoint at 1 year (area under the curve [AUC] 0.74 vs. 0.85, p = 0.04) and 5 years (AUC 0.74 vs. 0.84, p = 0.03).
Conclusion:
Older NSTE-ACS patients with high post-PCI IMRangio have worse long-term clinical outcomes. In this clinical setting, post-PCI IMRangio, together with conventional risk factors and angiographic variables, may help identifying a higher-risk phenotype.
Study Registration:
NCT01933581, https://clinicaltrials.gov/study/NCT01933581.
