Updated project metadata. Objectives: The primary objective of this high-resolution proteomic study was to investigate patients with severe aortic valve stenosis (AVS) to detect novel biomarkers for diagnostic and/or therapeutic purposes. Background: Among patients with severe AVS, some are likely to rapidly progress with a higher mortality and benefit from prompt surgical or interventional care. To select these patients, novel disease-related biomarkers are needed. Methods: We used induced pluripotent stem cell derived cardiomyocytes as a relative quantification standard to profile the proteomes of formalin-fixed paraffin-embedded (FFPE) atria and left ventricles from 30 patients with AVS. Results: In total, 3370 proteins were quantified using high-resolution mass spectrometry. Statistical analysis revealed significant upregulation of 64 proteins in the atria and 27 proteins in the ventricles including several known chamber specific marker-proteins. Atrial upregulation of proteins that belong to the interstitial compartment or contribute to endocrine function was observed. To uncover disease related proteins, we compared our data to similar published datasets from healthy and diseased hearts. We performed gene set enrichment analyses to pinpoint global proteomic characteristics of a decompensated state of AVS with hypertrophy, like the downregulation of ventricular mitochondrial proteins and the development of ventricular fibrosis. Finally, we propose a set of high abundant proteins like LGALS3BP, TUBA4A, TINAGL1 and LAMA2 as well as SRL, FHL1 and ATP2A2 playing a crucial role in AVS-related heart disease. Conclusions: We established a reproducible workflow for high-resolution quantitative proteomics of FFPE myocardial samples and provide interesting candidate proteins with biomarker potential for AVS.