Abstract 436: Gender-based Differences in Preoperative Levels of Circulating MicroRNA in Patients Who Developed Postoperative Atrial Fibrillation

Abstract

Background: Circulating microRNAs have recently been identified as biomarkers predicting A-Fib and heart failure. Yet, their role in identifying those at risk for postoperative atrial fibrillation (PoAF) in a gender-specific manner has not been studied. Methods: Preoperative blood from patients undergoing cardiac surgery with no prior history of AF, supraventricular/ventricular tachycardia was used for RNA isolation. Differences in the relative levels of miRNA between those who did/did not develop PoAF were assessed using qPCR. Principal component analysis and receiver operative characteristics were performed to predict miRNA associated with PoAF. Results: Out of 56 patients, 29 developed PoAF (52%, mean age 70.4± 9y, 51% males), while 27 (mean age 63y ± 10) remained free of AF. Patients who developed PoAF were older (P<0.01). There were no differences in the prevalence of hypertension, diabetes, dyslipidemia, prior myocardial infarction, heart failure, stroke, COPD, or cardiac medications. Out of 13 miRNAs analyzed, differential levels of miR423 (AUC83.7%, CL 72.4% - 93.3%), miR187 (AUC 76.8%, CL 63.4% - 90.2%) and miR34a2 (AUC 67.7%, CL53%-82.4%) were associated with PoAF. Gender-specific analysis showed a different set of circulating miRNAs (miR-187,-34a2,-25) in male vs. female (miR-29a1, -21,-126,-15b) patients with miR423 common in both as an independent predictor of PoAF. Conclusion: This indicates the existence of different substrate/precipitating factors reflected in miRNAs profile in male and female patients who developed PoAF. Gender differences exist in circulatory miRNA levels can help in predicting the development of new-onset AF after cardiac surgery.