All patients with heart diseases should undergo risk stratification to predict those who are at high risk for short- and long-term adverse outcomes. Carbohydrate antigen 125 (CA125) is a glycoprotein produced by mesothelium that has clinical role in ovarian cancer monitoring. However, as it is not specific for ovarian cells, CA125 could also be used in heart diseases to monitor congestion and inflammation. Pericarditis, atrial fibrillation, heart failure and coronary artery disease are some scenarios in which this biomarker was studied.CA125 identifies patients at high risk of rehospitalizations and death, in addition to being associated with hemodynamic data (ejection fraction and right atrial pressure). Hence, CA125 is a tool for risk stratification in heart diseases.