JACC Case Rep. 2026 May 14:108311. doi: 10.1016/j.jaccas.2026.108311. Online ahead of print.
ABSTRACT
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.
PMID:42132727 | DOI:10.1016/j.jaccas.2026.108311