Clinical Predictors of Coronary Artery Plaque Progression by Quantitative Serial Assessment Using 320-Row Computed Tomography Coronary Angiography in Asymptomatic Patients with Type 2 Diabetes Mellitus.

Background: Natural history of coronary plaque progression (PP) in patients with diabetes mellitus (DM) remains unclear. This study aimed to investigate the clinical predictors of coronary PP in patients with DM.

Methods: In this prospective observational study, we analyzed 70 asymptomatic patients (age, 64.4 years; male, 67%) with type 2 DM without prior history of coronary artery disease who underwent serial 320-row computed tomography coronary angiography with an interscan interval of more than 24 months (median 37.7 months). Study endpoint was PP, which was defined if coronary plaque volumes (PVs) at follow-up minus PVs at baseline was >0. We evaluated plaque composition using the Hounsfield Unit thresholds and insulin resistance estimated by the homeostasis model assessment of insulin resistance (HOMA-IR).

Results: Thirty-nine patients who showed PP had a higher increase in hemoglobin A1c (⊿HbA1c) from baseline to follow-up than those without PP (0.3% ± 0.8% vs -0.4% ± 1.1%; p = 0.01), although there was no statistical difference in HbA1c at baseline (7.1 ± 0.5% vs. 7.3 ± 1.4%; p = 0.24). In multivariable analysis, ⊿HbA1c [odds ratio (OR): 3.05; 95% confidence interval (CI): 1.39-6.67; p = 0.001] was an independent predictor for PP. Increase in low-density lipoprotein cholesterol (⊿LDL-C), not ⊿HbA1c, was significantly correlated to percent change in necrotic core (NC) volume (β-coefficients: 0.04; 95% CI: 0.004 - 0.08; p = 0.03). Among 48 patients without insulin therapy, patients with PP (n = 28) had a higher increase in HOMA-IR than those without PP (n = 20) (0.95 ± 2.00 vs. -0.63 ± 1.31; p = 0.003).

Conclusions: Increase in HbA1c and HOMA-IR was associated with PP in asymptomatic patients with type 2 DM, whereas increase in LDL-C was correlated to increase in NC.