Total RNA was converted to cDNA using a reverse transcription kit (Universal cDNA Synthesis Kit, Exiqon). Three (unpooled) PF samples of the AVR surgical patient group were randomly selected to be run in a PCR-based miRNA array enabling the profiling of 752 human miRNAs (miRNACURY LNA microRNA PCR human panels I and II; version 3, Exiqon). The miRNA array plates were run using a LightCycler 480 (Roche).