HbA1c as an Early Serologic Marker for the Hemodynamic Progression of Stage A Heart

The classic association of glycemic control, as represented by HBa1c, with progression or improvement of microvascular and macrovascular clinical complications has been well documented. Additionally, while the association of HBa1c elevation with a syndrome described as diabetic cardiomyopathy has also been well documented, the use of the advanced glycation end product axis (AGE/sRAGE/esRAGE which includes HBa1c) as markers for the early subclinical hemodynamic changes of diabetic cardiomyopathy has been suggested but less well characterized or utilized. Stage A heart failure is defined as persons with normal cardiac structure and function who have predisposing subclinical risks for cardiovascular disease. Estimates suggest that Stage A heart failure may comprise up to 56% of any community's patient population and are patients most commonly seen in non-specialty primary care clinics. In light of newer cardiometabolic agents which show promise in cardiovascular disease primary prevention, these patients may be an important target for preventative cardiometabolic care. In a retrospective community based cohort study from Pueblo County Colorado which has a higher population proportion of metabolic syndrome and diabetes mellitus, we hope to clarify and quantify an association of the AGE HBa1c elevation with the early subclinical hemodynamic changes of diabetic cardiomyopathy as measured by LAV, LVM, E/A ratio, E/e' ratio and BNP in patients with stage A heart failure.

Methods: Retrospective cohort analysis by chart review of patients presenting to Parkview Medical Center's inpatient service and outpatient clinics who obtained a full resting echo characterized by normal cardiac structure and function in conjunction with HBa1c and BNP levels within a 3 month time window. Using multiple regression analysis of the dependent variables LAV, LVM, E/A ratio, E/e' ratio and BNP, powered to detect a 5% change in LAV in conjunction with rising HBa1c levels characterized as normal (<5.7), metabolic syndrome (5.7-6.4) or diabetic (>6.4) after controlling for the presence of hypertension and coronary artery disease.