Advanced technique of myocardial no-reflow quantification using indocyanine green

Area of Science:

• Cardiovascular Research
• Experimental Myocardial Infarction Models
• Microvascular Physiology

Background:

• The no-reflow phenomenon, characterized by impaired blood flow post-reperfusion, affects over half of patients undergoing primary percutaneous coronary intervention (PCI).
• Current methods for assessing no-reflow, such as thioflavin S (ThS) staining, primarily estimate microvascular obstruction size.

Purpose of the Study:

• To investigate the potential of indocyanine green (ICG) for visualizing no-reflow zones in a rat model of myocardial ischemia-reperfusion injury.
• To evaluate ICG's ability to assess both microvascular obstruction and vascular permeability in myocardial infarction zones.

Main Methods:

• Utilized dual staining with ICG and ThS in a rat myocardium ischemia-reperfusion model.
• Employed a FLUM multispectral fluorescence organoscope for simultaneous fluorescence recording.
• Correlated ICG fluorescence patterns with ThS-identified no-reflow zones.

Main Results:

• Identified ICG-negative zones that directly correlated in size with ThS-detected no-reflow areas.
• Demonstrated that contrast changes between no-reflow and healthy myocardium reflect the severity of blood stasis.
• Confirmed ICG-negative zones represent no-reflow regions.

Conclusions:

• Indocyanine green (ICG) effectively visualizes no-reflow zones in experimental myocardial infarction.
• The ICG method provides a viable alternative or adjunct to traditional ThS staining for assessing no-reflow.
• ICG's retention in tissues with increased vascular permeability aids in evaluating infarction severity.