Optimal carbohydrate antigen 125 cutpoint for identifying low-risk patients after admission for acute heart failure.

INTRODUCTION AND OBJECTIVES Carbohydrate antigen 125 (CA125) has been shown to be useful for risk stratification in patients admitted with acute heart failure (AHF). We sought to determine a CA125 cutpoint for identifying patients at low risk of 1-month death or the composite of death/HF readmission following admission for AHF. METHODS The derivation cohort included 3231 consecutive patients with AHF. CA125 cutoff values with 90% negative predictive value (NPV) and sensitivity up to 85% were identified. The adequacy of these cutpoints and the risk of 1-month death/HF readmission was then tested using the Royston-Parmar method. The best cutpoint was selected and externally validated in a cohort of patients hospitalized from BIOSTAT-CHF (n=1583). RESULTS In the derivation cohort, the median [IQR] CA125 was 57 [25.3-157] U/mL. The optimal cutoff value was <23 U/mL (21.5% of patients), with NPVs of 99.3% and 94.1% for death and the composite endpoint, respectively. On multivariate survival analyses, CA125 <23 U/mL was independently associated with a lower risk of death (HR, 0.20; 95%CI, 0.08-0.50; P <.001), and the combined endpoint (HR, 0.63; 95%CI, 950.45-0.90; P=.009). The ability of this cutpoint to discriminate patients at a low 1-month risk was confirmed in the validation cohort (NPVs of 98.6% and 96.6% for death and the composite endpoint). The predicted ability of this cutoff remained significant at 6 months of follow-up. CONCLUSIONS In patients admitted with AHF, CA125 <23 U/mL identified a subgroup at low risk of short-term adverse events, a population that may not require intense postdischarge monitoring.