Among adults who present to the emergency department with acute heart failure, blood glucose levels may predict 30-day mortality, regardless of whether or not the patients have preexisting diabetes.
At ED presentation, patients with acute heart failure syndrome “demonstrate a wide spectrum of physiological and metabolic perturbations.” Hyperglycemia occurs in up to 40% of them, irrespective of their diabetes status. “If blood glucose measurement is prognostically useful, it may be of broad potential utility because it is a rapid, readily available, and inexpensive test that can be used in the acute setting to allow rapid risk stratification for a wide range of potential outcomes,” according to Dr. Maneesh Sud of the University of Toronto and Toronto General Hospital and his associates.
To examine whether initial glucose level correlated with later outcomes, the investigators analyzed data from two large population-based cohorts of patients hospitalized for acute HF during a 3-year period. A total of 9,275 of the 16,524 patients (median age, 79 years) did not have preexisting diabetes (56%), and the remaining 44% did (Eur. Heart J. 2015 [doi:10.1093/eurheartj/ehu462]).
Among patients with diabetes, a blood glucose level exceeding 11.1 mmol/L was associated with significantly increased all-cause 30-day mortality, compared with normal glucose levels, with a hazard ratio (HR) of 1.48. Among patients without diabetes, a blood glucose level exceeding 6.1 mmol/L was associated with significantly increased all-cause 30-day mortality, with an HR of 1.26, and that risk rose with increasing glucose levels to 1.50 at the maximum level of 11.1 mmol/L.
The risk for cardiovascular death within 30 days increased as blood glucose levels rose for both groups of patients, as did the risk for cardiovascular hospitalization. In addition, both patients who had preexisting diabetes and those who did not were at significantly increased risk for diabetes-related hospitalization if their blood glucose level exceeded the normal range at presentation to the ED. And, in patients without diabetes who had elevated blood glucose levels, the risk of developing diabetes was significantly increased, in a dose-dependent fashion. These findings suggest that determining blood glucose levels at ED presentation “may serve as a screen to identify high-risk patients who warrant formal testing for diabetes, allowing for prompt referral to prevent further morbidity and mortality,” Dr. Sud and his associates said.