Abstract: Background: Aortic valve stenosis (AS) promotes a progressive remodelling of the left ventricle (LV) characterised by cardiomyocyte hypertrophy and increased deposition of extracellular matrix elements. These adaptive plastic changes may evolve towards heart failure over time. The extent of LV remodelling and its persistence after valve replacement are significant prognostic factors for the long-term outcome of AS patients. The biological processes that determine the reverse remodelling rate after surgery of AS patients are unknown. Purpose: To ascertain preoperative LV transcriptomic determinants of favourable reverse remodelling one year after surgery in AS patients. To this end, a genome-wide transcriptomic analysis was performed in LV biopsies from AS patients and surgical controls. Methods and Results: The study was performed in AS (n=24) and control patients (n=12) (age and sex matched) followed up for one year after surgery. RNA-seq was performed on LV biopsies obtained during surgery. AS patients were stratified according to the quality of the reverse remodelling at one year in good (LV mass index ?51 g/m2.7, n=12) or poor (LV mass index >51 g/m2.7, n=12) performers. RNA-seq libraries were prepared and sequenced using an Illumina Next Seq Unit. Resulting reads were mapped against GRCh38.99 version of the human transcriptome. The results from the principal component analysis revealed a distinctive expression gene pattern for the AS condition, accounting for 60.1 % of the variance, with no difference for the sex condition (8.7 %). Differential gene expression was considered significant when yielding a Benjamini-Hochberg adjusted p-value < 0.05. Compared to controls, 339 and 443 genes were differentially expressed in AS with good and poor reverse remodelling, respectively, with 509 overlapping. Gene Set Enrichment Analysis (GSEA) of differentially expressed genes in patients with poor reverse remodelling compared to control patients, showed a significant enrichment (NES > 1.5) in genes associated with angiogenesis, epithelial-mesenchymal transition (EMT), and heart growth. The down-regulated genes (NES < 0) were associated with transcription processes, such as histone modification and RNA processing-related genes, highlighting the significance of epigenetic mechanisms in AS patients exhibiting poor reverse remodelling. In contrast, such transcriptomic profile patterns were not observed in AS with good-reverse remodelling. Conclusion: Aortic stenosis patients with good or poor reverse remodelling one year after aortic valve replacement exhibited distinct preoperative LV transcriptome profile. Gene ontology enrichment analysis revealed angiogenesis, EMT, and epigenetic processes as critical biological functions associated with poor reverse remodelling in AS patients.

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