Intensive care unit

Proportional hazards model

Risk of mortality

Coronary care unit

Anion gap

Quartile

Myocardial infarction

Internal medicine

Confidence interval

Hazard ratio

Medicine

Acidosis

Mortality rate

International Journal of General Medicine

Anion gap (AG) is a valuable and easily obtained clinical tool for differentially diagnosis of acid-base disorders. Current understanding of the prognostic impact of AG on mortality after acute myocardial infarction (AMI) is limited. We aimed to investigate whether AG is a predictor of short-term and long-term all-cause mortality after AMI.We examined 1806 patients diagnosed with AMI in intensive care unit from the Medical Information Mart for Intensive Care III (MIMIC-III) database. We analyzed the association of AG with 30-day, 180-day and 1-year all-cause mortality on a continuous scale and in categories, using multivariable Cox regression. We utilized restricted cubic splines to evaluate the linearity between hazard ratio (HR) and AG concentrations.AG was associated with a higher risk of 30-day, 180-day and 1-year all-cause mortality, with adjusted HRs of 1.083 (95% CI 1.051 to 1.117), 1.077 (95% CI 1.049 to 1.105), and 1.074 (95% CI 1.047 to 1.101), respectively. The results were consistent in subgroup analyses. The association between AG and all-cause mortality was linear for 180-day and 1-year mortality, and near linear for 30-day mortality, as higher concentrations were associated with high all-cause mortality. When stratified according to quartiles, AG was associated with 30-day mortality (HR[95% CI]: second quartile, 2.243[1.273, 3.955]; third quartile, 3.026[1.763, 5.194]; top quartile, 4.402[2.573, 7.531]), 180-day mortality (HR[95% CI]: second quartile, 1.719[1.118, 2.645]; third quartile, 2.362[1.575, 3.542]; top quartile, 3.116[2.077, 4.676]), and 1-year mortality (HR[95% CI]: second quartile, 1.700[1.143, 2.528]; third quartile, 2.239[1.536, 3.264]; top quartile, 2.876[1.969, 4.201]) using bottom quartile as reference.We firstly demonstrated that higher AG was significantly associated with increased 30-day, 180-day and 1-year all-cause mortality in AMI patients. AG as an easily obtained marker is of strong and reliable predictive value for AMI mortality during follow-up.

Serum Anion Gap is Associated with Risk of All-Cause Mortality in Critically Ill Patients with Acute Myocardial Infarction