Association Between Elevated Blood Glucose and Outcome in Acute Heart Failure

Abstract

The aim of this analysis was to assess the association between elevated blood glucose level and mortality in acute heart failure (AHF). Elevated blood glucose has been reported to be prognostically meaningful in patients with cardiac diagnoses, such as coronary artery disease. The short-term prognostic impact of hyperglycemia in AHF is unknown, however. In a multinational cohort of AHF, we examined the ability of blood glucose concentrations at presentation to predict all-cause mortality by 30 days. Fully adjusted models for prognosis included a previous diagnosis of diabetes mellitus as a covariate. A total of 6,212 subjects with AHF (mean age, 72 years; 52.5% male) were studied; the median blood glucose concentration on arrival at the hospital was 7.5 mmol/l (135 mg/dl), and 41% had a previous diagnosis of diabetes mellitus (DM). After 30 days, 618 patients (10%) had died. Compared with survivors, decedents had significantly higher median blood glucose concentrations (8.9 mmol/l vs. 7.4 mmol/l; p < 0.0001). In the fully adjusted model, an elevated blood glucose level was an independent predictor of 30-day mortality in AHF (odds ratio: 2.19; 95% confidence interval: 1.69 to 2.83; p < 0.001). The risk associated with an elevated blood glucose level appeared consistent across all subgroups of patients, including patients with preserved (hazard ratio: 5.41; 95% confidence interval: 2.44 to 12.0; p < 0.0001) and impaired systolic function (hazard ratio: 2.37; 95% confidence interval: 1.57 to 3.59; p < 0.0001). Furthermore, in reclassification analyses, elevated blood glucose added significant prognostic information to clinical parameters alone (4.4% net reclassification improvement; p = 0.01). Among patients with AHF, blood glucose concentrations at presentation are powerfully prognostic for 30-day mortality, independent of a diagnosis of diabetes mellitus or other clinical variables. Because blood glucose is easily modifiable, it may represent a valid target for therapeutic intervention.