Association Between the Admission Serum Bicarbonate and Short-Term and Long-Term Mortality in Acute Aortic Dissection Patients Admitted to the Intensive Care Unit

Abstract

Objective Serum bicarbonate (HCO3−) level is strongly related to multiple cardiovascular complications. Currently, there is no study evaluating the prognostic ability of serum HCO3− level in intensive care unit (ICU) patients with acute aortic dissection (AAD). Hence, this study was to assess the relationship between admission serum HCO3− level and clinical outcomes in patients with AAD. Design, Settings and Participants Clinical data were extracted from the MIMIC-III database. Cox proportional hazards models and Kaplan–Meier (KM) survival curve were used to evaluate the association between serum HCO3− levels and short- and long-term mortality in ICU patients with AAD. The subgroup analysis and the receiver operating characteristic (ROC) curve analysis and further KM survival curve based on best cut-off value were applied to assessment of the performance of HCO3− in predicting the mortality in each period (30 days, 90 days, 1 year and 5 years). Main Results Firstly, 336 eligible patients were trisected to low-HCO3− level group (<22 mmol/L), mid-HCO3− level group (22–24 mmol/L) and high-HCO3− level group (>24 mmol/L). Then, in multivariate analysis, the serum HCO3− of low levels (<22 mmol/L) was a significant risk predictor of all-cause mortality in 30 days, 90 days, 1 year and 5 years. Subgroup analyses indicated that there is no interaction in most strata. Finally, areas under ROC curve ranged from 0.60 to 0.69. Conclusion The low HCO3− serum level measured at ICU admission significantly predicts short-term and long-term mortality in AAD patients.