Utility of plasma CA125 as a proxy of intra-abdominal pressure in patients with acute heart failure

Aims: Increased intra-abdominal pressure (IAP) is now considered a potential contributor to organ damage and disease progression in acute heart failure (AHF). In this work, we aimed to determine if antigen carbohydrate 125 (CA125) is associated with IAP and to identify a cutpoint of CA125 useful for ruling out intra-abdominal hypertension (defined as IAP ≥ 12 mmHg).

Methods and results: We prospectively evaluated a cohort of 53 patients admitted with AHF in which IAP was measured within the first 24-h of admission. The mean age was 80 ± 8 years, 31 (58.5%) were female, and 31 (58.5%) had left ventricular ejection fraction ≥50%. The median plasma levels of NT-proBNP and CA125 were 3830 pg/mL (2417-8929) and 45.8 U/mL (29.8-114.0), respectively. The median of IAP was 15 mmHg (11-17), and 39 (73%) patients had an IAP ≥ 12 mmHg. The diagnostic performance of CA125 for identifying an IAP ≥ 12 mmHg was tested using the receiving operating characteristic (ROC) curve. The cut-off for CA125 of 17.1 U/mL showed a sensitivity of 92%, a specificity of 50%, and an area under the ROC curve of 0.71. After multivariate adjustment, CA125 remained non-linearly and positively associated with higher IAP (P-value = 0.003), explaining almost 28% of the model's variability (R2: 27.6%).

Conclusions: Patients with AHF and intra-abdominal hypertension had higher CA125 plasma levels. A baseline concentration of CA125 below 17.1 U/mL will increase the odds of identifying a subset of patients with normal IAP.