Abstract 15734: Glucose Variability and Mortality in Patients Hospitalized with Acute Myocardial Infarction
Background: Mean blood glucose (BG) during acute myocardial infarction (AMI) is an important predictor of inpatient mortality but does not capture glycemic lability, which has been postulated to affect clinical outcomes. Whether glucose variability (GV) is associated with in-hospital mortality during AMI, after accounting for mean BG, is unknown.
Methods: Using Cerner Corporation' Health Facts database, we identified consecutive AMI patients admitted to 61 U.S. hospitals between 2000–2008. Five different GV metrics were compared for their ability to predict in-hospital mortality (range, standard deviation [SD], mean amplitude of glycemic excursions [MAGE], mean absolute glucose change [MAG], and average daily risk range [ADRR]) in 18,563 patients with ≥3 BGs within the first 48 hrs of hospitalization. Hierarchical multivariable logistic regression models adjusted for mean BG, hypoglycemia (<70 mg/dl), and multiple patient and site characteristics. Furthermore, sensitivity analyses were performed by excluding hypoglycemia from the models and by analyzing 4,396 patients with ≥6 BGs during the first 48 hrs.
Results: Overall, hospital mortality was 7%. In unadjusted analyses, greater GV was associated with higher mortality (e.g., OR 1.16 [95% CI 1.14–1.19] per 50 mg/dl increase in range); this association was stronger in patients without diabetes. There were small, but significant differences in C-indices between the GV metrics (range 0.62; SD 0.62; MAGE 0.59; MAG 0.62; ADRR 0.65 [p<0.0001]). However, the association between GV and mortality for each metric was not statistically significant after multivariable adjustment. In contrast, mean BG remained an important predictor of survival (p<0.001 in all models). Sensitivity analyses as well as multivariable models stratified by diabetes status produced similar results.
Conclusions: In our study, GV metrics were not independently associated with in-hospital mortality in patients with AMI. In contrast, mean BG remained an important predictor of hospital survival even after adjustment for GV. These findings suggest that GV does not provide additional prognostic value above and beyond mean BG in AMI, at least as estimated from routinely collected BG data in the hospital setting.
- © 2010 by American Heart Association, Inc.