OCT-Features Of moRphology, coMposItion anD instABility of Culprit and Not Culprit Coronary pLaquE in ACS Patients

INTRODUCTION. Pathophysiology of Acute Coronary Syndrome (ACS) deeply differs from those of stable patients, mainly due to peculiar features of plaque. Interestingly, most of the lesions triggering an acute ischemic event, usually defined "culprit lesions" are not angiographically severe, but present with mild stenosis. However, when evaluated at autopsy or with intracoronary imaging, they show often a pro-thrombotic pattern, with thin cap fibroatheroma, soft plaques and thrombus, prone to rupture.

Patients without culprit plaque rupture (CPR) exhibit different mechanisms of instability including thrombus at the site of plaque erosion, or intense vasoconstriction of epicardial arteries or coronary microcirculation disfunction.

In this setting, in the last years Optical Coherence Tomography (OCT) has emerged as the most accurate instrument for intracoronary evaluation. Due to a resolution of approximately 10-20 µm it has been largely exploited in the evaluation and characterization of plaque features, both in stable and acute coronary artery disease.

On the other hand, despite recent evidences, characteristics of culprit plaque in different subset of patients are not well defined. Moreover clinical significance of plaque characteristics is unknown.

METHODS The OCT-FORMIDABLE register will include with a retrospective fashion all consecutive patients that perform OCT on culprit and not culprit plaque in any subset in patients with ACS. Clinical and OCT data will be included in the register according to the dataset.