Impact of Hyperemic State on Angio-IMR Performance

Summary

The goal of this observational study is to evaluate the diagnostic performance of angiography-derived microcirculatory indices (Angio-IMR) in assessing patients with stable angina or suspected coronary artery disease. The main questions it aims to answer are: How do the numerical values of Angio-IMR from five different software vendors change across three physiological states (resting, sub-hyperemia induced by nitroglycerin, and maximal hyperemia induced by adenosine)? Which physiological state and software algorithm provide the highest diagnostic accuracy (Area Under the Curve, AUC) for diagnosing Coronary Microvascular Disease (CMD) when compared to the gold standard wire-based IMR? Researchers will compare the Angio-IMR results calculated under the three different physiological conditions within the same patient to see how the hyperemic state impacts the performance and consistency of these non-invasive indices. Participants will: Undergo standard-of-care coronary angiography and physiological assessment using a pressure wire for index of microvascular resistance (Wire-IMR) as part of their clinical management. Have their angiographic images captured at three specific time points: at rest, after intracoronary nitroglycerin, and during adenosine-induced maximal hyperemia. Allow their de-identified imaging and clinical data to be analyzed by an independent core laboratory using five different Angio-IMR software platforms to evaluate microvascular function.

Eligibility

Inclusion Criteria:

* Stable angina or suspected coronary heart disease.
* Scheduled for coronary angiography and physiological assessment.
* Target vessel with stenosis \< 50% or 50%-90% with fractional flow reserve (FFR) \> 0.80.
* Provided informed consent.

Exclusion Criteria:

* Hemodynamic instability (acute myocardial infarction, cardiogenic shock, severe arrhythmia).
* Contraindications to angiography (e.g., end-stage renal disease).
* Contraindications to adenosine (e.g., severe asthma, high-degree atrial-ventricular block).
* Life expectancy \< 1 year or pregnancy.
* Target vessel unsuitable for wire operation (left main lesion, severe tortuosity) or stenosis \> 90%.

Conditions3

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