Abstract Aims The human epididymis protein 4 (HE4), a novel fibrosis marker, is expressed only in activated fibroblasts and is thought to reflect ongoing left ventricular (LV) fibrosis. LV fibrosis is a feature of severe aortic stenosis (AS) and is related to the post‐operative outcome of patients with AS. We investigated the relationship between serum levels of HE4 and the post‐operative prognosis of patients with severe AS. Methods and results We measured the serum HE4 levels of 55 participants (80.8 ± 8.0 years old, male n = 26, 46%) with severe AS prior to surgical aortic valve replacement ( n = 31, 56%) or transcatheter aortic valve implantation ( n = 24, 44%) at Kumamoto University Hospital in 2018. We followed them for cardiovascular (CV) death or hospitalization for heart failure (HF) for 3 years. Serum HE4 levels were positively correlated with computed tomography–extracellular volume (CT‐ECV) values ( r = 0.53, P = 0.004). Kaplan–Meier curves demonstrated a significantly higher probability of hospitalization for HF or CV‐related death in the patients with high HE4 (greater than the median HE4 value) compared with the patients with low HE4 (lower than the median HE4 value) (log‐rank P = 0.003). Multivariate analysis showed HE4 (log(HE4)) to be an independent prognostic factor [hazard ratio (HR): 7.50; 95% confidence interval (CI): 1.81–31.1; P = 0.005]. Receiver operating characteristic (ROC) curve analysis suggested that HE4 is a marker of increased risk of CV‐related death or hospitalization for HF at 3 years after surgery, with an area under the curve (AUC) of 0.76 (95% CI: 0.62–0.90; P = 0.003). Conclusions We found that HE4 is a potentially useful biomarker for predicting future CV events in patients scheduled for AS surgery. Measuring serum HE4 values could help consider AS surgery.

Human epididymis protein 4 is a useful predictor of post‐operative prognosis in patients with severe aortic stenosis