Antigen carbohydrate 125 as a prognostic biomarker in patients with stable chronic heart failure.

Background: Carbohydrate antigen 125 (CA125) has been associated with a higher risk of mortality and readmission after an acute heart failure (HF) episode. However, the utility of CA125 in evaluating prognosis in chronic and stable HF is not yet established. The aim of this prospective study was to assess whether there is prognostic value of plasma CA125 in chronic HF population with reduced ejection fraction (HFrEF) after a long period of clinical stability. Methods: Prospective cohort study that included consecutive patients with stable HFrEF who were followed in the outpatient HF clinic of the General University Hospital of Elche (Alicante, Spain) between July 2018 and January 2019. Stability was defined as the absence of hospital admissions due to HF symptoms or use of intravenous diuretics for at least six months before the inclusion date. The primary outcome was all-cause mortality related to CA125. The secondary endpoints were HF admissions and total cardiovascular (CV) admissions. The association between CA125 and recurrent hospitalizations was evaluated by the Famoye bivariate Poisson regression model. Results: The study included 116 patients [69±12 years, 71.6% males, left ventricular ejection fraction 33.4%±7.1%; 52.6% in New York Heart Association class I (indicating long-term stability)]. The median CA125 value was 9.15 U/mL [interquartile range (IQR), 6.15-14.08 U/mL]. During a median follow-up of 18 months (IQR, 13-19 months), there were 13 deaths, 47 HF admissions, and 60 CV admissions. After multivariate adjustment, patients with CA125 >9.15 U/mL had higher rates of HF admissions [incidence rate ratio (IRR) 2.49; 95% confidence interval (CI): 1.14-5.44; P=0.02] and CV admissions (IRR 1.88; 95% CI: 1.01-3.52; P=0.04) compared with those with lower levels. Higher CA125 values were also associated with an increased risk of mortality in a non-linear fashion (P=0.02). Additionally, CA125 levels correlated with serum sodium (P<0.001), inferior vena cava diameter (P=0.03), and inflammatory status (P=0.01). Conclusions: In patients with stable chronic HFrEF, higher plasma CA125 was associated with an increase in the burden of mid-term morbidity and mortality. CA125 could be a surrogate marker of residual congestion and inflammatory activity in this particular scenario.