Glycaemic Variability Heavily Affects Outcomes of Diabetic Patients Hospitalized for Acute Heart Failure

Background: Acute glucose fluctuations are associated with hypoglycaemia and are emerging risk factors for cardiovascular outcomes. However, the relationship between glycaemic variability (GV) and the occurrence of mid-term major cardiovascular events (MACE) in diabetic patients remains unclear. This study investigates the prognostic value of GV in diabetic patients with acute heart failure (AHF). Methods: This was an observational study including consecutive patients with diabetes and AHF between January 2015 and November 2016. GV was assessed using standard deviation of glycaemia values during initial hospitalization in intensive cardiac care unit. MACE, including recurrent AHF, new-onset myocardial infarction, ischemic stroke and cardiac death, were recorded. The predictive effects of GV on patient outcomes were analysed with respect to baseline characteristics and cardiac status. Results: A total of 392 patients with diabetes and AHF were enrolled. During follow-up median [(interquartile range) 29 (6-51) months], MACE occurred in 227 patients (57.9%). 92 patients died (23.5%) of cardiac causes, 107 were hospitalized for heart failure (27.3%), 19 had new-onset myocardial infarction (4.8%), and 9 (2.3%) had an ischemic stroke. Multivariable logistic regression analysis showed that GV >50 mg/dL (2.70 mmol/L), Age >75 years, reduced left ventricular ejection fraction (LVEF <30%) and female gender were independent predictors of MACE: Hazard Ratios (HR) of 3.16 [2.25-4.43; p<0.001], 1.54 [1.14-2.08; p=0.005], 1.47 [1.06-2.07; p=0.02] and 1.43 [1.05-1.94; p=0.03], respectively. Conclusions: Among other well-known factors of HF, a GV cut-off value of >50 mg/dL was the strongest independent predictive factor for mid-term MACE in patients with diabetes and AHF.