A team of scientists from Almazov National Medical Centre and the Pavlov First St. Petersburg Medical University have proposed the use of indocyanine green in the diagnosis of ischemic heart damage in laboratory animals. The intravenous injection of indocyanine green stains only damaged vessels due to their increased permeability, preventing the penetration of the dye into healthy tissues.
Once in the infarction area where there is blood flow, indocyanine green accumulates, allowing scientists to use its fluorescence to identify damaged areas in the heart. In areas with poor blood supply, indocyanine leaks more slowly and accumulates poorly in them. Thus, by differences in fluorescence intensity, scientists can determine the boundaries of the myocardial infarction area with preserved and impaired blood flow.
Indocyanine green is a safe and biocompatible dye that is rapidly taken up by the liver following intravenous injection. Its concentration in the blood significantly decreases within 3-4 minutes, with only trace amounts remaining in 20-30 minutes. This allows for intraoperative fluorescence assessment of areas of damage and inflammation. The authors of the technique believe that indocyanine green can be used in the diagnosis of subepicardial myocardial infarction during open-heart surgery, even if the infarction occurred a day ago.
The authors have used indocyanine green to assess the efficacy of their developing adjuvant therapy for myocardial infarction during primary angioplasty.
Thioflavin is a fluorescent dye that is typically used in the blood flow assessment in experimental studies. However, it is toxic to laboratory animals. Indocyanine green is not only safe for animals and operators, but also has a greater depth of emission in the absence of autofluorescence of surrounding tissues. This will help to improve the quality of images obtained when assessing the efficacy of treatment.
The technique is currently in its experimental phase and has only been tested on rats. Further research is needed to introduce the technology into daily practice. The research was supported by the RSF grant (номер 23-15-00151): https://rscf.ru/project/23-15-00151/