Aptamer Proteomics for Biomarker Discovery in Heart Failure With Preserved Ejection Fraction: The PARADIGM-HF Proteomic Sub-Study

Introduction: Prognostic markers and biological pathways linked to detrimental clinical outcomes in heart failure with preserved ejection fraction (HFpEF) remain incompletely defined. Goal: To identify serum proteins associated with risk for HF hospitalization (HFH) and cardiovascular (CV) death in patients with HFpEF, including proteins with differential associations with clinical outcomes in HFpEF compared to HFrEF. Methods: We measured serum levels of 4123 unique proteins in 1117 patients with HFpEF in the PARAGON-HF trial using a modified aptamer proteomic assay. Baseline protein concentrations significantly associated with total HFH and CV death were identified by recurrent events regression, accounting for multiple testing, adjusted for age, sex, treatment, and anticoagulant use, and compared to 2515 patients with HFrEF from the PARADIGM-HF and ATMOSPHERE trials. Results: We identified 288 proteins to be robustly associated with the risk of HFH and CV death (335 events over an average of 2.7 years of follow-up) in a HFpEF trial population. Proteins most strongly related to HFpEF outcomes included B2M, TIMP1, SERPINA4, and SVEP1 ( Figure ). Protein-outcome associations in patients with HFpEF did not markedly differ compared to HFrEF. Just 3 proteins (APOE, RTF1, and VWF) were differentially associated with outcomes between the HF subtypes (FDR <0.05). A proteomic risk score derived in HFpEF patients was not superior to a previous proteomic score derived in HFrEF nor to clinical risk factors, NT-proBNP, or high-sensitivity cardiac troponin. Conclusions: Numerous serum proteins linked to metabolic, coagulation, and extracellular matrix regulatory pathways were associated with worse HFpEF prognosis. SVEP1, a cell adhesion protein recently identified as a HFrEF prognosis biomarker, also strongly predicted risk in HFpEF. Our results demonstrate substantial similarities in serum proteomic risk markers across the EF spectrum.