Association of exosomes in patients with compromised myocardial perfusion on functional imaging.

Background: Exosomes are membrane vesicles that are actively secreted in response to microenvironmental stimuli. In this study, we quantified the amount of exosomes in patients with significant coronary artery disease (CAD) and evaluated its relationship with myocardial perfusion imaging (MPI) results.

Methods: Patients who underwent both MPI and coronary angiography were recruited. Plasma was collected during angiography, and exosomes were extracted via the precipitation method. The summed stress scores (SSS), summed difference scores, and ventricular functional parameters were calculated from the MPI and compared with the amounts of exosomes and extracted miRNAs.

Results: In total, 115 patients were enrolled (males: 78 %; mean age: 66.6 ± 10.6 years). Those with abnormal SSS according to the MPI had significantly fewer exosomes (p = 0.032). After multivariate analysis, the SSS remained significantly related to the amount of exosomes (p = 0.035). In forty randomly selected samples, miRNA-432-5p and miRNA-382-3p were upregulated in patients with abnormal SSS.

Conclusion: Patients with compromised poststress myocardial perfusion on MPI tended to have fewer exosomes in association with CAD-related miRNAs. This is the first study to clarify the fundamental and pathophysiological causes of CAD using radiographic examinations.