Introduction: Post-operative atrial fibrillation (POAF) is a common complication following coronary artery bypass grafting (CABG) contributing to increased morbidity and healthcare costs. MicroRNA are non-coding RNA that regulate gene expression and can be measured in serum. MicroRNA are emerging as biomarkers with potential for predicting disease onset. This study aimed to demonstrate that microRNA biomarkers can be used to identify high risk patients for development of POAF.
Methods: Patients undergoing CABG were identified and screened for participation. A blood sample was collected within 24 hours prior to surgery. Incidence of POAF was tracked with inpatient records and phone calls at 30 and 60 days post-CABG. Cases of POAF and controls were matched as closely as possible based on POAF risk. Samples were tested with microRNA transcriptome assay using 96 wells. Values were reported as threshold cycles. The threshold cycle considered positive for each well was 35. The miRNA levels in cases and controls were compared using T statistics.
Results: A total of 164 patients were screened and 26 enrolled in the study. Atrial fibrillation was identified in nine patients. One patient was excluded due to atrial flutter. A total of 8 cases and 8 controls were matched. The mean positive wells for cases was 5.1(+/-7.4) and for controls was 24.8 (+/-15.7) (p = 0.0099).
Conclusions: Results indicate a significant difference in microRNA expression among patients who develop POAF following CABG and those who do not. No prior study has demonstrated expression patterns of microRNA in the context of POAF. These outcomes should be used as preliminary data for a larger future study.