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Updated: May 16, 2026

Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
Acute Changes in Coronary Microvascular Physiology After Supersaturated Oxygen Therapy in Anterior STEMI
Guillermo J Velazquez Gutierrez1, Jhonny I Borrallas Lopez1, Jesus G Rodriguez de la Torre1
1Clínic Barcelona, Cardiovascular Clinic Institute, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
Background:
Microvascular dysfunction may persist despite successful primary percutaneous coronary intervention (PCI) in anterior ST-segment elevation myocardial infarction (STEMI). Supersaturated oxygen (SSO2) therapy has been proposed to improve myocardial reperfusion.
Case Summary:
A 74-year-old man presented with anterior STEMI. Primary PCI restored TIMI flow grade 3 after mid-left anterior descending artery occlusion. Post-PCI invasive assessment showed microvascular dysfunction, with hyperemic microvascular resistance of 398 mm Hg/L/min) and index of microcirculatory resistance of 25. After 60 minutes of intracoronary SSO2 therapy, hyperemic microvascular resistance decreased to 89 mmHg/L/min, and index of microcirculatory resistance decreased to 15.
Discussion:
Restoration of TIMI flow grade 3 flow does not necessarily reflect effective microvascular reperfusion. In this case, SSO2 therapy was associated with acute improvement in microvascular indices, supporting further investigation.
Take-Home Messages:
Microvascular dysfunction may persist despite successful PCI in anterior STEMI. Invasive assessment enables real-time evaluation of microvascular function. SSO2 therapy was associated with acute improvement in this case, although clinical impact remains to be established.
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