Why the study?
Wire-based IMR is the gold standard for coronary microvascular assessment, but angio-IMR is a novel method that derives IMR without intracoronary instrumentation or adenosine.
Does angiography-based IMR accurately predict wire-based IMR and prognostic risk in patients with coronary lesions?
Does angiography-based IMR accurately predict wire-based IMR and prognostic risk in patients with coronary lesions?
Angiography-based IMR provides a highly sensitive and specific alternative to wire-based IMR for assessing coronary microvascular resistance and predicting MACE without the need for intracoronary instrumentation or adenosine.
Angio-IMR shows acceptable diagnostic accuracy and MACE association; leaves open whether it should replace wire-based IMR in practice.
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.
No takes yet. Share an insight, caveat, or question.
Li et al. (2022) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: