The cardiac blood transcriptome predicts de novo onset of atrial fibrillation in heart failure

Heart failure (HF) increases the risk of developing atrial fibrillation (AF), leading to increased morbidity and mortality. Therefore, better prediction of this risk may improve treatment strategies. Although several predictors based on clinical data have been developed, the establishment of a transcriptome-based predictor of AF incidence in HF has proven to be more problematic. We hypothesized that the transcriptome profile of coronary sinus blood samples of HF patients is associated with AF incidence. We therefore enrolled 192 HF patients who were selected for biventricular cardioverter defibrillator implantation. Both coronary sinus and peripheral blood samples were obtained during the procedure. Patients were followed-up during two years and AF occurrence was based on interrogation of the defibrillator. A total of 96 patients stayed in sinus rhythm (SR) during follow-up, 13 patients developed AF within 1 year and 10 patients developed AF during the second year of follow up. Gene expression profiling of coronary sinus samples led to the identification of 321 AF predictor genes based on their differential expression between patients developing AF within 1 year of blood sampling and patients remaining in SR. The expression levels of these genes were combined to obtain a molecular atrial fibrillation prediction score for each patient which was significantly different between both patient groups (Mann-Whitney, p = 0.00018). We conclude that the cardiac blood transcriptome of HF patients should be further investigated as a potential AF risk prediction tool.