The fundamental aim of this study is to investigate the ability of intracoronary imaging to predict progression of coronary atherosclerosis in patients with acute coronary syndrome. In patients who are indicated for acute coronary angiography and have at least one non-culprit lesion (not indicated for revascularization) identical segment of non-culprit vessel will be analysed and several parameters will be detected by OCT (optical coherence tomography) and NIRS (near-infrared spectroscopy) including the presence of TCFA (thin-cap fibroatheroma) and plaque lipid content quantified by LCBI (lipid core burden index). During follow up visits (1Y, 2Y, 5Y and 10Y) major cardiovascular events will be monitored and the progression of coronary involvement will be estimated at 1Y and 2Y by CCTA (coronary computed angiography).~The second part of the trial is to investigate the ability of NIRS to detect vulnerable plaque characterized by the presence of OCT-defined TCFA.~A further target is to study the influence of gene polymorphisms (in genes playing a role in vessel dilatation) on the progression of coronary atherosclerosis and clinical outcomes. Patient DNA will be isolated from peripheral blood leucocytes, and polymorphisms in genes for Hemoxygenase-1 and endothelial Nitric Oxide Synthase will be analysed.
To predict coronary atherosclerosis progression in patients with acute coronary syndrome by the use of intracoronary imaging methods.~To investigate the ability of NIRS to detect vulnerable plaque characterized by the presence of OCT-defined TCFA To study the influence of gene polymorphisms (in genes playing role in vessel dilatation) on the progression of coronary atherosclerosis and clinical outcomes