Hba1c variability is associated with adverse outcomes in heart failure patients with and without diabetes

Abstract Funding Acknowledgements Type of funding sources: None. Background Glycemic control is an important clinical issue in the management of patients with heart failure (HF). Variability of Glycated hemoglobin A1c (HbA1c) has been proven to be a predictor of cardiovascular events. However, previous studies mainly focused on general population and patients with coronary artery disease, while less is known about the effect of long-term HbA1c variability on clinical outcomes in HF patients. Purpose To evaluate the association of HbA1c variability and the risk of all-cause mortality and rehospitalization in patients with HF irrespective of their diabetic status. Methods By using the data from the well-validated Clinical Data Analysis Reporting System (CDARS), HF patients from 2003-2020 who had more than 3 times HbA1c measurements after the diagnosis of HF were included (N=65950, mean age was 66.5±12.0 years and 39409 (52.9%) were male). Average successive variability (ASV) ( average absolute difference between successive values), standard deviation (SD) of HbA1c were calculated. Hazard ratio (HR) of all-cause mortality and HF rehospitalization were estimated using competing risk regression with Cox proportional-hazard model. Results During a median follow-up of 7.2 years, 52446 (79.5%) patients developed HF rehospitalization and 34508 (52.3%) died. After adjusting for confounders, each unit change of HbA1c ASV or SD was significantly associated with higher risk of all-cause mortality, as well as higher risk of HF-rehospitalization (Figure 1). Among the study population, 48673 (73.8%) was diabetic while the remaining 17277 (26.2%) were non-diabetic. Interestingly, HbA1c variability had a stronger impact to non-diabetic compared to diabetic patients (P for interaction <0.001) in predicting all-cause mortality and HF rehospitalization (Table 1). Conclusion In patients with HF, a greater HbA1c variability was associated with an increased risk of HF rehospitalization and all-cause mortality. Such effect was stronger in non-diabetic compared with diabetic. HbA1c variability, irrespective of baseline diabetic status, should be evaluated in HF patients for better risk-stratification.