Abstract 13568: Lack of Association between Increasing Levels of Hemoglobin A1c and Coronary Atherosclerosis in Non-Diabetic Acute Myocardial Infarction Patients

Abstract

Background: Analyses of population studies have demonstrated an independent association between hemoglobin A1c (A1C) and cardiovascular risk in non-diabetic patients. Whether this association is related to more extensive atherosclerosis is not known.

Methods: We analyzed data from acute myocardial infarction (AMI) patients free of diabetes (no prior diagnosis, and A1C < 6.5) enrolled 2004-2008 in the multicenter TRIUMPH registry. Associations were analyzed using modified Poisson regression models between A1C, by quartiles and continuously, and the prevalence of multi-vessel coronary disease (MVD), defined as ≥2 vessels with ≥70% stenosis (or ≥50% left main stenosis).

Results: The cohort comprised 1073 patients with mean age 57 years; 28.9% women; 21.8% nonwhite. Subjects were divided into A1C quartiles: Q1: 3.1-<5.4%; Q2: 5.4-<5.6%; Q3: 5.6-<5.9%; and Q4: 5.9-<6.5%. Increasing quartiles of A1C were associated with increasing age, women, body mass index (BMI), hypertension, and dyslipidemia. The crude prevalence of MVD for A1C Q1-Q4 was 39.7%, 43.9%, 40.0%, and 51%, respectively (ptrend=0.023). After adjusting for age, sex, hypertension, smoking, family history of CAD, LDL, HDL, triglyceride, BMI, sedentary lifestyle, insulin resistance (as estimated by homeostasis model assessment), and hs-CRP, A1C was not significantly associated with MVD (figure). Consistent findings were observed when A1c was analyzed as a continuous variable and when vessel disease was defined as ≥20% stenosis.

Conclusions: In a large cohort of non-diabetic AMI patients, A1C was not associated with more advanced coronary atherosclerosis. Increased events associated with higher A1C values may be related to other features of the athero-thrombosis process beyond atherosclerosis itself.