Relationship between the albumin-corrected anion gap and short-term prognosis among patients with cardiogenic shock: a retrospective analysis of the MIMIC-IV and eICU databases

Abstract

Objectives We aimed to investigate the association between the albumin-corrected anion gap (ACAG) and the prognosis of cardiogenic shock (CS).Design A multicentre retrospective cohort study.Setting Data were collected from the Medical Information Mart for Intensive Care (MIMIC-IV) and eICU Collaborative Research Database (eICU-CRD) datasets.Participants 808 and 700 individuals from the MIMIC-IV and eICU-CRD, respectively, who were diagnosed with CS.Primary and secondary outcomes The primary endpoint was short-term all-cause mortality, including intensive care unit (ICU), in-hospital and 28-day mortality. The secondary endpoints were the 28-day free from the ICU duration and the length of ICU stay.Results CS patients were divided into two groups according to the admission ACAG value: the normal ACAG group (≤20 mmol/L) and the high ACAG group (> 20 mmol/L). CS patients with higher ACAG values exhibited increased short-term all-cause mortality rates, including ICU mortality (MIMIC-IV cohort: adjusted HR: 1.43, 95% CI=1.05–1.93, p=0.022; eICU-CRD cohort: adjusted HR: 1.38, 95% CI=1.02–1.86, p=0.036), in-hospital mortality (MIMIC-IV cohort: adjusted HR: 1.31, 95% CI=1.01–1.71, p=0.03; eICU-CRD cohort: adjusted HR: 1.47, 95% CI=1.12–1.94, p=0.006) and 28-day mortality (adjusted HR: 1.42, 95% CI: 1.11 to 1.83, p=0.007). A positive linear correlation was observed between the ACAG value and short-term mortality rates via restricted cubic splines. Compared with the AG, the ACAG presented a larger area under the curve for short-term mortality prediction. In addition, the duration of intensive care was longer, whereas the 28-day free from the ICU duration was shorter in patients with a higher ACAG value in both cohorts.Conclusion The ACAG value was independently and strongly associated with the prognosis of patients with CS, indicating that the ACAG value is superior to the conventional AG value.