Abstract 13482: The Size of Circulating Microparticles and Cardiac Function in Patients With Cardiac Surgery

Abstract

Introduction: We previously demonstrated that circulating microparticles (MPs) from cardiac surgery impaired vasodilation. The usages of positive inotropic drugs and the NT-proBNP levels are the important parameters representing cardiac function after cardiac surgery. However, the relationship between the size of MPs and the usages of positive inotropic drugs and the NT-proBNP levels in patients with cardiac surgery remains unknown. Hypothesize: The size of circulating MPs may correct with the usages of positive inotropic drugs and the NT-proBNP levels in patients with cardiac surgery. Methods: 103 patients undergone cardiac surgery and 56 healthy subjects were enrolled. The blood was collected from healthy subjects and patients before (pre-op) and after operation 12h (post-op 12h) and 72 h (post-op 72h). The MPs were isolated by differential centrifugation. The concentration and size distribution of MPs were detected by nanoparticle tracking analysis system. The clinical data were collected and the correlation was performed between the MPs and the clinical data. Results: The level of MPs was increased in patients compared with healthy subjects. There was no significant difference of MPs concentration among the different time points (per-op, post-op 12h and post-op 72h) in patients. The MPs were divided into four groups according to the size (0-100nm, 100-200nm, 200-300nm and 300-400nm). The levels of “100-200nm” MPs were decreased in post-op 12h and post-op 72h groups compared with per-op group, but the levels of “200-300nm” MPs were increased after operation. In post-op12h group, the concentration of “0-100nm” MPs was negatively correlated with the NT-proBNP levels, the dose of dopamine, norepinephrine and milrinone, and the level of “200-300nm” MPs were positively correlated with NT-proBNP levels. In post-op72h group, the level of “0-100nm” MPs was negatively correlated with NT-proBNP levels, and the concentration of “200-300nm” MPs was negatively correlated with the dose of dobutamine. Conclusion: Our data demonstrated that the size of circulating MPs is corrected with the usages of positive inotropic drugs and the NT-proBNP levels in patients with cardiac surgery, and may predict the cardiac function after cardiac surgery.