Effects of glycemic control on in-hospital mortality among acute heart failure patients with reduced, mid-range, and preserved ejection fraction

The relationship between glycemic control and outcome in patients with heart failure (HF) remains contentious. A recent study showed that patients with HF with mid-range ejection fraction (HFmrEF) more frequently had comorbid diabetes relative to other patients. Herein, we examined the association between glycosylated hemoglobin (HbA1c) and in-hospital mortality in acute HF patients with reduced, mid-range, and preserved EF. A multicenter retrospective study was conducted on 5205 consecutive patients with acute HF. Potential risk factors for in-hospital mortality were selected by univariate analyses; then, multivariate Cox regression analysis with backward stepwise selection was performed to identify significant factors. Kaplan-Meier survival curves and log-rank testing were used to compare in-hospital mortality between groups. Across the study cohort, 44% (2288 patients) had reduced EF, 20% had mid-range EF, and 36% had preserved EF. The overall in-hospital mortality rate was 4.6%, with no significant differences among the HF patients with reduced, mid-range, and preserved EF groups. For patients with HFmrEF, higher HbA1c level was a significant risk factor for in-hospital mortality (hazard ratio 1.387; 95% confidence interval 1.014-1.899; P = 0.041). In contrast, HbA1c was not an independent risk factor for in-hospital mortality in HF patients with preserved or reduced EF. In conclusion, HbA1c is an independent risk factor for in-hospital mortality in acute HF patients with mid-range EF, but not in those with preserved or reduced EF. Elucidation of the pathophysiological mechanisms behind these findings could facilitate the development of more effective individualized therapies for acute HF.