Glycosylated haemoglobin and coronary atherosclerosis in non-diabetic patients: is it a prognostic factor?

Background: Some studies aimed to evaluate the relationship between HbA1c and coronary artery disease (CAD). However, it is well known that long-term glycometabolic disorders put the heart at risk for CAD. Considering the inconsistencies between previous studies, this study aimed to investigate the relationship between HbA1c and coronary artery atherosclerosis. Methods: A cross-sectional study was conducted on 411 non-diabetic patients who underwent their first coronary angiography between November 2013 and December 2014 in Baqiyatallah Hospital. Blood samples were taken before angiography. Coronary angiograms were reported and reviewed by two cardiologists according to the Gensini score. They were not aware about the patients' HbA1c level. Severity of CAD was determined through ascertaining the prevalence of multi-vessel disease, extent of CAD (single-, two-or three-vessel disease or left main stem stenosis (> 50%)). Data analysis was performed by using SPSS software. Results: A total of 411 patients (252 men and 159 women) were evaluated. Angiography was normal in 67 patients (16.3%), 30.7% had single-vessel disease (SVD), and 29.1%, 20.7% and 3.2% had two-, three- and multivessel disease, respectively. Based on the ROC curve, the HbA1c was able to differentiate between patients with and without coronary atherosclerosis (p < .001, cutoff point = 5.45). The cut-off points for differentiation of severe CAD and patients with 75-100% stenosis of coronary artery were 5.55 (p < .001) and 5.65 (p < .001), respectively. Conclusions: The present study demonstrated that HbA1c might be an independent diagnostic factor in non-diabetic patients with severe coronary atherosclerosis.