Insight into pathogenesis of acute coronary syndrome

Abstract

Over the last several decades, clinical and pathological observations have led us to a better understanding of the pathogenesis of acute coronary syndrome (ACS): coronary artery thrombosis plays a central role in the development of ACS. The three most common plaque morphologies responsible for the development of acute coronary thrombosis are plaque rupture, plaque erosion, and calcified nodules. The majority of these findings come from cross-sectional pathological studies and animal models, which are very different from living patients. In vivo investigation of underlying pathophysiology of ACS is of vital importance. However this has been greatly challenged by the lack of an appropriate intravascular imaging modality for studying coronary plaque morphologies in vivo. To date, a variety of diagnostic tools to detect underlying plaque morphology in the setting of ACS has been developed, including angiography and intravascular ultrasound (IVUS). However, an angiogram only provides a luminal outline and is not able to visualize intravascular structure, while IVUS has inadequate resolution to characterize subtle changes in the vascular wall. Optical coherence tomography (OCT), on the other hand, is an ideal intravascular imaging modality which enables us to accurately evaluate these plaque morphologies, specifically, thin fibrous cap, macrophages, and intracoronary thrombus. More importantly, OCT can potentially help us understand the underlying mechanism behind the abrupt transition from stable atherosclerotic disease to ACS by investigating the natural evolution of coronary atherosclerotic plaques, which may ultimately allow us to discover new diagnostic algorithms and therapeutic targets.