Serum anion gap at admission predicts all-cause mortality in critically ill patients with cerebral infarction: evidence from the MIMIC-III database

Abstract

Background

Recent studies reported that serum anion gap could be regarded as a prognostic biomarker for patients admitted to intensive care units. However, the association between AG and mortality in cerebral infarction patients remained largely unknown.

Methods

Relevant clinical data were collected from Medical Information Mart for Intensive Care III. Patients were divided into three groups according to tertiles of AG. Kaplan–Meier curve and Cox proportional hazards models were used to evaluate the association between AG levels and all-cause mortality. Subgroup analyses were performed to verify the predictive role of AG on mortality.

Results

Kaplan–Meier analysis showed that patients with higher AG had shorter survival time. Cox regression model indicated high AG as an independent risk factor of 30-day, 60-day and 180-day all-cause mortality (30-day: HR = 2.45, 95% CI = 1.21–4.97, 60-day: HR = 2.04, 95% CI = 1.07–3.89, and 180-day: HR = 1.85, 95% CI = 1.02–3.36). However, no significance was observed between AG and 365-day all-cause mortality (HR = 1.56, 95% CI = 0.87–2.78).

Conclusions

High AG was associated with increased risk of all-cause mortality, and AG could be an independent short-term prognostic factor for cerebral infarction.

Keywords:

• Biomarker
• anion gap
• cerebral infarction
• mortality
• intensive care units
• MIMIC-III

Acknowledgements

The authors declare that there are no sources of funding to be acknowledged.

Ethics approval and consent to participate

The MIMIC III database has received ethical approval from the Institutional Review Boards of both Beth Israel Deaconess Medical Centre (Boston, MA) and the Massachusetts Institute of Technology (Cambridge, MA). All data are de-identified in this database by removing patients’ information, and the requirement for individual patient consent is not indispensable.

Disclosure statement

The authors report no conflict of interest.

Data availability statement

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.