Antigen carbohydrate 125 as a biomarker in heart failure: a narrative review.

Congestion explains many of the signs and symptoms of acute heart failure (AHF) and disease progression. However, accurate quantification of congestion is challenging in daily practice. Antigen carbohydrate 125 (CA125) or mucin 16 (MUC16), a large glycoprotein synthesized by mesothelial cells, has emerged as a reliable proxy of congestion and inflammation in patients with heart failure (HF). In AHF syndromes, CA125 is strongly associated with right-sided HF parameters and a higher risk of adverse clinical events beyond standard prognostic factors, including natriuretic peptides. Furthermore, CA125 has the potential for both monitoring and guide HF treatment following a decompensated HF event. The wide availability of CA125 in most clinical laboratories, together with its standardized measurement and reduced cost, makes this marker attractive for routine use in decompensated HF. Further research is required to understand better its biological role and its promising utility as a tool to guide decongestive therapy in HF.