Diagnostic performance and prognostic impact of coronary angiography‐based Index of Microcirculatory Resistance assessment: A systematic review and meta‐analysis

Abstract

Background: The Index of Microcirculatory Resistance (IMR), measured with a pressure-thermistor tipped coronary guidewire has been established as a gold standard for coronary microvascular assessment. Angiography-based IMR (angio-IMR) is a novel method to derive IMR without intracoronary instrumentation or the need for adenosine.Methods: PubMed and Embase databases were systemically searched in November 2021 for studies that measured angio-IMR. The primary outcomes were pooled sensitivity and specificity as well as the area under the curve (AUC) of the summary receiver operating characteristic curve using IMR as a reference standard.Results: A total of 129 records were initially identified and 8 studies were included in the final analysis. Overall, 1653 lesions were included in this study, of which 733 were in patients presenting with ST-segment elevation myocardial infarction. Angio-IMR yielded high diagnostic performance predicting wire-based IMR with pooled sensitivity = 0.81 (95% confidence interval: 0.76, 0.85), specificity = 0.80 (0.72, 0.86), and AUC = 0.86 (0.82, 0.88), which was similar irrespective of patient presentation.When the clinical outcome was compared between high versus low angio-IMR in patients presenting with myocardial infarction, high angio-IMR predicted an increased risk of major adverse cardiac events (MACE). Conclusion:Our study found that coronary angio-IMR has relatively high diagnostic performance as well as prognostic values predicting MACE, supporting its use in clinical practice.

Diagnostic and prognostic value of angiography-derived index of microvascular resistance: a systematic review and meta-analysis

“…Previous investigations have encompassed two meta-analyses that evaluated the diagnostic and prognostic value of A-IMR ( 48 , 49 ). Our study aligns with the findings of those two analyses.…”

Angiography-based index of microcirculatory resistance (AccuIMR) for the assessment of microvascular dysfunction in acute coronary syndrome and chronic coronary syndrome

“…However, angiographic modalities have usually been restricted by their qualitative and empirical nature, and Doppler wire-based indexes have been limited by their increased technical complexity and instability. IMR, first described in 2003 ( 7 ), is a highly reproducible, readily available, quantitative method for assessing microvascular function independent of the epicardial arteries, which has been considered the “gold standard” of microcirculatory evaluation ( 19 ). Hemodynamic changes, such as heart rate, blood pressure, and contractility, have not been shown to affect IMR significantly ( 20 ).…”

The Coronary Angiography-Derived Index of Microcirculatory Resistance Predicts Left Ventricular Performance Recovery in Patients with ST-Segment Elevation Myocardial Infarction

“…Similarly, De Maria et al validated that angiography-derived IMR is a promising alternative of invasive IMR to detect CMD in patients with STEMI and stable coronary artery disease [ 9 , 10 ]. As a novel tool for the assessment of CMD, the pooled sensitivity and specificity of angiography-based IMR are 0.81 and 0.80, respectively, regardless of patients' presentation in a meta-analysis [ 11 ].…”