Predictors of in-hospital mortality in diabetic patients with non-ST-elevation myocardial infarction

Background: There have been little data about the additive effects of coronary risk factors on mortality in diabetic patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI). This study aimed to evaluate the predictors of mortality in diabetic patients presenting with NSTEMI. All patients admitted to Tehran Heart Center (THC) with a confirmed diagnosis of NSTEMI and a history of diabetes mellitus (DM) type 2 between September 2003 and April 2017 were included. Clinical characteristics and paraclinical data such as lipid profiles, creatinine, hemoglobin, and hemoglobin A1C (HbA1C) were evaluated in these patients to predict in-hospital mortality. The approach for model calibration was a logistic regression with the backward elimination method. Results: Of a total of 9158 patients with non-ST-segment elevation myocardial infarction, 3133 had diabetes mellitus type 2 and met our criteria to enter the final analysis. In the multivariable analysis, age, chronic obstructive pulmonary disease, and a severely reduced left ventricular ejection fraction (LVEF) significantly increased the rate of in-hospital mortality, whereas mildly and moderately reduced left ventricular ejection fraction did not increase the rate of mortality. Conclusions: Age, chronic obstructive pulmonary disease (COPD), and severely reduced LVEF (<30%) independently increased in-hospital mortality in our diabetic patients with a confirmed diagnosis of NSTEMI. Severely reduced LVEF had the strongest relationship with in-hospital mortality, whereas the mean HbA1C level and the type of DM management exerted no significant effect on in-hospital mortality.