Introduction
atrial inflammation, inflammation, POAF, fibrosis, pericarditis, hypertrophy, Pericarditis
INFILTRATION, ATRIAL FIBRILLATION (AF), PROLIFERATION, INFLAMMATION, FIBROSIS, STERILE, PERICARDITIS, HYPERTROPHY, PERICARDITIS
Almost half of patients recovering from open-chest surgery experience atrial fibrillation (AF) that results principally from inflammation in the pericardial space surrounding the heart. Given that postoperative AF is associated with increased mortality, effective measures to prevent AF after open-chest surgery are highly desirable. In this study, we tested the concept that extracellular vesicles (EVs) isolated from human atrial explant-derived cells can prevent postoperative AF. Middle-aged female and male rats were randomized to undergo sham operation or induction of sterile pericarditis followed by trans-epicardial injection of human EVs or vehicle into the atrial tissue. Pericarditis increased the probability of inducing AF while EV treatment abrogated this effect in a sex-independent manner. EV treatment reduced infiltration of inflammatory cells and production of pro-inflammatory cytokines. Atrial fibrosis and hypertrophy seen after pericarditis were markedly attenuated by EV pretreatment, an effect attributable to suppression of fibroblast proliferation by EVs. Our study demonstrates that injection of EVs at the time of open-chest surgery shows prominent antiinflammatory effects and prevents AF due to sterile pericarditis. Translation of this finding to patients might provide an effective new strategy to prevent postoperative AF by reducing atrial inflammation and fibrosis.
Atrial fibrillation (AF) is the most common heart rhythm disturbance in the world — afflicting almost 38 million patients worldwide (There is at present no effective solution to prevent POAF (Accordingly, we built on previous work from our group using human heart explant-derived cells (EDCs) (