Quarterly Focus Issue: Heart Failure
Heart Failure and Diabetes
Relationship of Hemoglobin A1C and Mortality in Heart Failure Patients With Diabetes

https://doi.org/10.1016/j.jacc.2009.04.049Get rights and content
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Objectives

This study was designed to examine the relationship between glycosylated hemoglobin (HbA1C) and adverse outcomes in diabetic patients with established heart failure (HF).

Background

Despite the common coexistence of diabetes and HF, previous studies examining the association between HbA1C and outcomes in this population have been limited and have reported discrepant results.

Methods

We assessed the association between increasing quintiles (Q1 to Q5) of HbA1C and risk of death or risk of HF hospitalization by conducting a retrospective study in a national cohort of 5,815 veterans with HF and diabetes treated in ambulatory clinics at Veterans Affairs medical centers.

Results

At 2 years of follow-up, death occurred in 25% of patients in Q1 (HbA1C ≤6.4%), 23% in Q2 (6.4% < HbA1c ≤7.1%), 17.7% in Q3 (7.1% < HbA1c ≤7.8%), 22.5% in Q4 (7.8% < HbA1c ≤9.0%), and 23.2% in Q5 (HbA1c >9.0%). After adjustment for potential confounders, the middle quintile (Q3) had reduced mortality when compared with the lowest quintile (risk-adjusted hazard ratio: 0.73, 95% confidence interval: 0.61 to 0.88, p = 0.001). Hospitalization rates for HF at 2 years increased with increasing quintiles of HbA1C (Q1: 13.3%, Q2: 13.1%, Q3: 15.5%, Q4: 16.4%, and Q5: 18.2%), but this association was not statistically significant when adjusted for potential confounders.

Conclusions

The association between mortality and HbA1C in diabetic patients with HF appears U-shaped, with the lowest risk of death in those patients with modest glucose control (7.1% < HbA1C ≤7.8%). Future prospective studies are necessary to define optimal treatment goals in these patients.

Key Words

diabetes
heart failure
glycosylated hemoglobin
HbA1C
prognosis

Abbreviations and Acronyms

EPRP
External Peer Review Program
GFR
glomerular filtration rate
HbA1C
glycosylated hemoglobin
HF
heart failure
LVEF
left ventricular ejection fraction
Q
quintile
VA
Veterans Affairs

Cited by (0)

This study was supported in part by VA Health Services Research and Development Service grant # IIR 02-082-1 (to Dr. Deswal). Dr. Aguilar is a recipient of a National Institutes of Health Mentored Career Development Award (5K01-HL092585-02). The views expressed in this article are those of the authors and do not necessarily represent those of the Department of Veteran Affairs.