Studies based on histology and intracoronary imaging modalities demonstrated that plaques prone to rupture are typically characterized by a large superficial lipid pool, that is delimited by a thin fibrous cap and often exhibit local signs of inflammation (superficial macrophages). Intravascular imaging techniques proved to be effective solutions to detect high-risk plaque, shedding light on the role of large lipid pool, plaque burden, and reduced lumen area for promoting acute coronary syndromes (ACS).
Optical coherence tomography (OCT), with its capability of visualizing superficial plaque components at a high resolution is potentially capable of identifying high-risk plaques.
The CLIMA study prospectively explored the correlation between the simultaneous presence of four optical coherence tomography (OCT) plaque vulnerability features and an increased risk of future major acute coronary events [i.e. cardiac death and myocardial infarction (MI)]. A total of 1,003 patients undergoing OCT evaluation of the untreated proximal left anterior descending coronary artery in the context of clinically indicated coronary angiogram were prospectively enrolled at 11 independent centres.
The study demonstrated the negative impact of OCT-defined high-risk intermediate lesions of the proximal left anterior descending artery on following clinical outcome (HR 7.54 at 1-year follow-up). Thus, these data seemed to confirm OCT as potential tool to assess ‘in vivo’ the risk profile of coronary plaques and help identify patients at high risk of future coronary events.
The results confirm that the simultaneous presence of four high-risk OCT plaque features is associated with a higher risk of major coronary events.