Dysregulation of Autophagy in Circulating Platelets Is Associated with Platelet Dysfunction During Cardiopulmonary Bypass.

OBJECTIVES: To investigate whether cardiopulmonary bypass (CPB)-induced platelet dysfunction is associated with dysregulated autophagic flux in patients undergoing cardiac surgery. DESIGN: Prospective, single-center observational study. SETTING: A tertiary university hospital cardiac operating room. PARTICIPANTS: Forty adult patients undergoing cardiac surgery with CPB. INTERVENTIONS: No therapeutic intervention was applied. Blood samples were collected at 3 perioperative time points for platelet function and autophagy assessment. MEASUREMENTS AND MAIN RESULTS: Platelet count (PLT) significantly decreased after CPB, whereas mean platelet volume (MPV) was lower at T3 than at T1. Flow cytometry showed a marked increase in CD62P expression, and thromboelastography revealed a significant reduction in maximum amplitude, indicating impaired platelet function. Western blotting and immunofluorescence demonstrated blocked autophagic flux, characterized by abnormal accumulation of both LC3-II and p62 in platelets. CONCLUSION: Cardiac surgery with CPB is associated with platelet activation and functional decline, which are correlated with blocked autophagic flux.