Predictors of Coronary Plaque Vulnerability in Patients with Stable Coronary Artery Disease

Aim To identify new predictors for vulnerability of atherosclerotic coronary plaques in patients with stable ischemic heart disease (sIHD). Material and methods This prospective, single-center study included 58 patients with sIHD. Unstable plaques were detected with virtual histology intravascular ultrasound of proximal and medium segments of a coronary artery without significant lesions according to coronarography data. Indexes of inflammation, dyslipidemia and carbohydrate metabolism were considered as candidate predictors for coronary plaque vulnerability. Results In 56 coronary arteries, 58 plaques were detected, 12 of which (20.7 %) were unstable. Vulnerable plaques differed morphologically from stable ones by a greater size of the necrotic core (35.1±8.5 % vs . 24.0±13.2 %; р=0.008), calcified nodules (2.0 [1.0; 5.0] % vs . 1.0 [0; 2.0] %; р=0.006), and a lower content of fibrous components (54.9±10.2 % vs . 66.4±15.8 %; р=0.02). In addition, vulnerable plaques more frequently narrowed the arterial lumen by >70 % of the lumen area (33.3 % vs . 2.2 %; р=0.0006). Correlation analysis showed a negative correlation between the level of high-density lipoproteins (HDL) and calcium volume (r= –0.4104; р=0.023); a positive correlation between the blood glucose level as determined by the oral glucose tolerance test and the lipid component (r=0.48198; р=0.033); and a negative correlation between the apolipoprotein A level and the calcium volume (r= –0.4297; р=0.008). Conclusion The study demonstrated a high prevalence of vulnerable plaques in nontarget coronary arteries in patients with sIHD. In this process, dyslipidemia indexes (LDL, apolipoproteins A) correlate with the calcium volume whereas blood glucose, as measured in the oral glucose tolerance test, correlates with the lipid component of coronary plaque.