ackground Healed plaques, morphologically characterized by a layered phenotype, are frequently found in subjects with sudden cardiac death. However, in vivo data are lacking. Objectives The purpose of this study was to determine the prevalence, morphological characteristics, and clinical significance of healed culprit plaques in patients with acute coronary syndromes (ACS) using optical coherence tomography (OCT). Methods A total of 376 ACS patients (252 ST-segment elevation myocardial infarction [MI] and 124 non–ST-segment elevation acute coronary syndrome) who had undergone pre-intervention OCT imaging of the culprit lesion were enrolled. Patients were stratified according to the presence of layered phenotype, defined ...

Background Superficial erosion currently causes at least one-third of acute coronary syndromes (ACS), and its incidence is increasing. Yet, the underlying mechanisms in humans are still largely unknown. Objectives The authors sought to assess the role of hyaluronan (HA) metabolism in ACS. Methods Peripheral blood mononuclear cells were collected from ACS (n = 66), stable angina (SA) (n = 55), and control (CTRL) patients (n = 45). The authors evaluated: 1) gene expression of hyaluronidase 2 (HYAL2) (enzyme degrading high-molecular-weight HA to its proinflammatory 20-kDa isoform) and of CD44v1, CD44v4, and CD44v6 splicing variants of HA receptor; and 2) HYAL2 and CD44 protein ...