Identification of a DNA methylation signature for worsening of heart failure

Abstract Introduction DNA methylation (DNAm), an epigenetic modification shaped by the exposome, provides a stable and quantifiable readout of long-term exposures. Exposomal factors such as lifestyle habits, psychosocial stress, and ambient environmental exposures are recognized as drivers in the development and progression of heart failure (HF). However, the specific DNAm-related mechanisms contributing to the development and worsening of HF remain unknown. Purpose To identify DNAm changes associated with incident worsening of HF and to investigate the putative underlying pathophysiology leading to the event. Methods Individuals from the MyoVasc study, a prospective cohort on chronic HF with deep clinical phenotyping, were investigated (N=3,289). EDTA plasma and DNA were extracted from peripheral blood and stored at -80°C. DNAm was measured using the Infinium MethylationEPIC methylation array (Illumina, San Diego, USA). Worsening of HF was defined as a composite of cardiac death, hospitalization due to HF or progression to HF stage C/D. Clinical outcome was derived from a structured follow-up with validation and adjudication of endpoints. Regularized cox regression with 10-fold cross validation was used to select CpG sites and subsequently create a methylation signature. Gene analysis was performed using the Gene ontology and ClinVar databases. Results Data from 1,978 individuals (mean age: 69.0 95% CI: 61.0-75.0; women: 30.4%) with HF stage B (19.7%; N=389) and HF stage C/D (80.3%; N=1589) were analysed. In total, N=343 had a worsening of HF event during 4 years of follow-up. A total of 857 CpG sites were associated with worsening of HF (C-index=0.8; 10-fold cross-validated C index=0.64). The methylation signature created from the identified CpGs with adjustment for age and sex was strongly associated with incident worsening of HF (hazard ratio per SD HRSD 3.0 2.7 - 3.3, p 0.0001), outperforming the gold standard biomarker NT-proBNP (HR(SD) 2.3 2.0 - 2.6, p 0.0001). The signature showed the strongest associations with diabetes mellitus (β=0.11 0.06 - 0.15, p 0.0001), chronic kidney disease (β=0.2 0.16 - 0.25, p 0.0001) and global longitudinal strain (β=0.1 0.08 – 0.13, p 0.0001). Components of the signature associated with a higher incidence were enriched in T-cell signalling, cardiac muscle contraction and GABA pathway-related processes. Components associated with lower incidence demonstrated enrichment in DNA-repair, structural integrity, ribosome activity and in mitochondria-related processes. Search in clinical databases yielded enrichment for cardiomyopathy and myocardial infarction. Conclusion This study identified a methylation signature robustly associated with worsening of HF, outperforming NT-proBNP as a predictive biomarker. The signature implicates novel processes related to cardiac, immune and DNA-repair systems into the epigenetic mechanisms driving the development and progression of HF.