Distinguishing heart failure with preserved ejection fraction from heart failure with reduced ejection fraction using proteomics techniques

Heart failure is the second leading cause of morbidity and mortality in the world after cancer. In the UK, over 500,000 people are living with heart failure of which 30-40% die within 1 year of diagnosis. Some biomarkers for diagnosis and prognosis of heart failure have been established. However, they suffer from poor levels of accuracy and efficacy and their roles in clinical use is poorly understood. Thus, new biomarkers are needed. In this research, mass spectrometry based proteomics was used to profile patients plasma for clinical biomarker discovery due to its ability to perform both quantitative and qualitative protein profiling on clinical samples. Ninety samples from control, heart failure with preserved ejection fraction and heart failure with reduced ejection fraction subjects were used. Plasma protein profiling was performed using an optimised UPLC-IMS-DIA-MSE label free quantitation method. Bioinformatics analysis was used to analyse the changes observed in the protein profiles to identify potential biomarkers of heart failure. A novel method, termed mixed mode matrix was used for pilot study prior to main study with lipid removal agent. Samples were analysed using Waters Synapt G2S HDMS QToF mass spectrometer in triplicate on positive mode electrospray ionisation. Statistical comparisons of protein profiles was carried out using Progenesis LC-MS prior to data mining using SPSS, RapidMiner and SIMCA 14 to identify potential biomarkers. Thirty proteins were identified as potential biomarkers and shown to be involved in various pathophysiological processes leading to heart failure. ASL which plays role in nitrogen oxide production in the epithelium was upregulated in heart failure cohort. Conversely, GPX3 which scavenges free radicals in blood preventing apoptosis and necrosis of cells was downregulated in heart failure cohort. These two proteins were proposed as potential biomarkers for heart failure with preserved ejection fraction. Future studies to validate these biomarkers with the developed targeted LC-MS based MRM assay is needed.