Nature and prognostic importance of abnormal glucose tolerance and diabetes in acute heart failure.

Abstract

To investigate the nature and importance of blood glucose abnormalities in an unselected heart failure (HF) population. Cohort study. Urban University hospital. All index emergency HF admissions to one University hospital during the year 2000 were studied. 454 consecutive index admissions had blood chemistry, diabetic status and follow-up information recorded. 390 (86%) patients had an echocardiogram, of whom 117 (30%) had preserved left ventricular systolic function and 110 (24%) had diabetes. Sixty (13%) patients had abnormal glucose tolerance (8.0-10.99 mmol/l), and 284 (63%) patients had a normal admission blood glucose (<8 mmol/l). 51 (11.2%) patients died in hospital. After adjustment for other prognostic attributes, abnormal glucose tolerance (Cox hazard ratio HR, 95% CI: 5.920, 1.03 to 34.00; p = 0.046) but not diabetes (HR 3.46, 0.75 to 16.02; p = 0.112) predicted in-hospital mortality. During follow-up (median 812 (range 632-978) days), 104 (36.6%), 30 (50.0%) and 55 (50%) patients with a normal admission blood glucose concentration, abnormal glucose tolerance and diabetes, respectively, died (log rank test p = 0.0037, adjusted p = 0.075). Compared with patients with normal admission blood glucose, abnormal glucose tolerance (adjusted HR: 1.41 (0.92 to 2.16); p = 0.12) and diabetes (adjusted HR: 2.02 (1.41 to 2.88); p = 0.0001) predicted mortality. Considering glucose on admission as a continuous covariate, a 2 mmol/l increase was associated with a HR of 1.08 (1.03 to 1.13), p = 0.0010, which after adjustment for the above covariates became 1.08 (1.03 to 1.13), p = 0.0023. Admission blood glucose concentration and diabetes are prognostically important in HF and could help target some patients for more intensive therapy.