Associations Between Albumin-Corrected Anion Gap and Mortality in Heart Failure Patients with Chronic Obstructive Pulmonary Disease: A Retrospective Cohort Study.

In-hospital and 30-day mortality rates among HF patients with COPD in the ICU were 11.2% and 13.7%, respectively.

• Study included 1283 patients with heart failure and chronic obstructive pulmonary disease from the MIMIC-IV database.
• 54.6% of the cohort were male.
• ACAG levels were assessed within 24 hours of ICU admission.
• This was a retrospective cohort study using the Medical Information Mart for Intensive Care (MIMIC)-IV database.

Kaplan-Meier analysis demonstrated significantly increased mortality risk in patients with higher ACAG levels.

• Log-rank P<0.001 for the association between higher ACAG levels and increased mortality risk.
• Patients were stratified into tertiles (T1, T2, T3) based on ACAG levels.
• The analysis was conducted for both in-hospital and 30-day mortality outcomes.

Higher ACAG levels (T3 vs T1) were independently associated with increased in-hospital mortality in fully adjusted Cox regression models.

• Hazard ratio for in-hospital mortality comparing highest to lowest ACAG tertile: 2.04 (95% CI: 1.18–3.54; p=0.011).
• Multivariate Cox regression models were used with full adjustment for confounders.
• Results were consistent across subgroup analyses.

Higher ACAG levels (T3 vs T1) were independently associated with increased 30-day mortality in fully adjusted Cox regression models.

• Hazard ratio for 30-day mortality comparing highest to lowest ACAG tertile: 1.83 (95% CI: 1.12–2.97; p=0.015).
• Multivariate Cox regression models were used with full adjustment for confounders.
• Results were consistent across subgroup analyses.

Restricted cubic spline (RCS) analysis revealed a linear relationship between ACAG and mortality risk.

• The linear relationship was consistent across subgroups.
• RCS analysis was used to examine the dose-response relationship between ACAG and mortality.
• No nonlinear threshold effect was identified.

ACAG demonstrated superior discriminatory ability for in-hospital mortality compared to anion gap alone and albumin alone.

• AUC for ACAG predicting in-hospital mortality: 0.693.
• AUC for anion gap predicting in-hospital mortality: 0.571.
• AUC for albumin predicting in-hospital mortality: 0.640.
• Similar findings were observed for 30-day mortality.
• ROC curve analysis was used to assess and compare discriminatory performance.