HF Mortality Linked to Glucose Levels

Action Points

• Note that, among patients with acute heat failure, an elevated admission blood glucose level was associated with 30-day mortality in this prospective observational cohort study.

• Be aware that serial glucose measurements were not available, limiting the ability to understand any potential effects of hyperglycemia treatment.
  

Serum glucose measured at the time of hospital admission predicted 30-day mortality in acute heart failure patients, researchers reported.

In a multi-national heart failure cohort, patients who died over a 30-day period had a significantly higher median blood glucose on admission compared with survivors (8.9 versus 7.4 mmol/L, P<0.0001), Alexandre Mebazaa, MD, of Lariboisiere University Hospital in Paris, and colleagues reported online in the Journal of the American College of Cardiology.

“Our results are consistent with basic and clinical science data linking an elevated blood glucose level with myocardial injury, impaired myocardial performance, arrhythmia, and risk of ventricular remodeling,” they wrote.

Elevated glucose has also been associated with worse outcomes for patients with stroke and other critical illnesses, the researchers said, but its short-term prognostic impact in acute heart failure isn’t known.

Mebazaa and colleagues analyzed data from a multi-national cohort of 6,212 acute heart failure patients who had a mean age of 72, and 41% of whom had a previous diagnosis of diabetes.

The mean blood glucose concentration on arrival at the hospital was 7.5 mmol/L (135 mg/dL), and after 30 days, 10% of the patients had died.

Mebazaa and colleagues found that patients who died had a significantly higher median blood glucose concentration at admission compared with survivors (8.9 versus 7.4 mmol/L, P<0.0001).

In a fully adjusted model, elevated blood sugar was an independent predictor of 30-day death in acute heart failure (OR 2.19, 95% CI 1.69 to 2.83, P<0.001).

The risk between blood sugar levels and 30-day mortality was consistent across all subgroups of patients, the researchers reported, including those with:

• Preserved systolic function (HR 5.41, 95% CI 2.44 to 12.0, P<0.0001)
• Impaired systolic function (HR 2.37, 95% CI 1.57 to 3.59, P<0.0001)

 

They also emphasized that the relationship between blood sugar and death was seen in patients both with and without a previous diagnosis of diabetes.

In sensitivity analyses, adjusting for factors such as left ventricular ejection fraction (LVEF) and plasma natriuretic peptides, as well as excluding patients from the largest cohort, didn’t significantly alter any of the findings.

The analyses revealed a 9% absolute increase in 30-day mortality for each 1-mmol/L increase in blood glucose (OR 1.09, 95% CI 1.05 to 1.12, P<0.0001).

The researchers said it was not clear whether elevated blood sugar in acute heart failure is “a marker for risk or a mediator of adverse outcomes” — but since serum glucose is “widely measured, easily interpreted, and inexpensive to measure,” using it in risk assessment is “worthy of consideration.”

The study was limited by a lack of data on glycated hemoglobin (HbA1c) at admission and by the absence of serial measurements of glucose during the hospital stay.

Further work is needed to better understand the pathophysiology and complete trajectory of hyperglycemia in acute heart failure, they concluded.

Further reading :
Mebazaa A, et al “Association between elevated blood glucose and outcome in acute heart failure” J Am Coll Cardiol 2013; DOI: 10.1016/j.jacc.2012.11.054.