Background: The relationship between hemoglobin A1c (HbA1c) levels and coronary artery disease (CAD) severity is still a matter of debate in non-diabetic patients. This study aimed to determine the association between HbA1c and the severity of CAD in non-diabetic patients.
Methods: The present cross-sectional study was conducted in 2018-2019 on 133 non-diabetic patients with stable angina, unstable angina, or myocardial infarction (MI). They were selected through systematic random sampling. The data were collected by taking a complete medical history, calculating the SYNTAX score, and measuring HbA1c.
Results: A SYNTAX score of >22 was significantly correlated with age, left ventricular ejection fraction, HbA1c, and total cholesterol. The mean SYNTAX score was higher in male patients, those with HbA1c >5.6, and patients with a primary clinical presentation of MI. The association between the SYNTAX score and HbA1c was found to be statistically significant (r = 0.659; P < .001). The odds of having a SYNTAX score of >22 for those with HbA1c >5.6 was 5.48 times higher than for those with HbA1c ≤ 5.6 (odds ratio [OR], 5.48; P < .001). The odds of three-vessel disease in individuals with an HbA1c level greater than 5.6 were found to be 4.80 times higher than in those with HbA1c levels at or below 5.6 (OR, 4.80; P = 0.002).
Conclusion: The present findings showed that HbA1c has the potential to predict the severity of CAD in non-diabetic individuals. HbA1c, even at levels within the normal range, was significantly correlated with SYNTAX scores.
Keywords: Coronary artery disease; Diabetes mellitus; Glycated hemoglobin; Iran; SYNTAX score.