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Aims Acute coronary syndromes with intact fibrous cap (IFC-ACS), i.e. caused by coronary plaque erosion, account for approximately one-third of ACS. However, the underlying pathophysiological mechanisms as compared with ACS caused by plaque rupture (RFC-ACS) remain largely undefined. The prospective translational OPTICO-ACS study programme investigates for the first time the microenvironment of ACS-causing culprit lesions (CL) with intact fibrous cap by molecular high-resolution intracoronary imaging and simultaneous local immunological phenotyping. Methods and results The CL of 170 consecutive ACS patients were investigated by optical coherence tomography (OCT) and simultaneous immunophenotyping by flow cytometric analysis as well as by effector molecule concentration measurements across the culprit lesion gradient (ratio local/systemic levels). Within the study cohort, IFC caused 24.6% of ACS while RFC-ACS caused 75.4% as determined and validated by two independent OCT core laboratories. The IFC-CL were characterized by lower lipid content, less calcification, a thicker overlying fibrous cap, and largely localized near a coronary bifurcation as compared with RFC-CL. The microenvironment of IFC-ACS lesions demonstrated selective enrichment in both CD4+ and CD8+ T-lymphocytes (+8.1% and +11.2%, respectively, both P Conclusions The OPTICO-ACS study emphasizes a novel mechanism in the pathogenesis of IFC-ACS, favouring participation of the adaptive immune system, particularly CD4+ and CD8+ T-cells and their effector molecules. The different immune signatures identified in this study advance the understanding of coronary plaque progression and may provide a basis for future development of personalized therapeutic approaches to ACS with IFC. Trial registration The study was registered at clinicalTrials.gov (NCT03129503).

Aims Cardiovascular events remain the leading cause of death in Western world. Atherosclerosis is the most common underlying complication driven by low-density lipoproteins (LDL) disturbing vascular integrity. Carbamylation of lysine residues, occurring primarily in the presence of chronic kidney disease (CKD), may affect functional properties of lipoproteins; however, its effect on endothelial function is unknown. Methods and results Low-density lipoprotein from healthy donors was isolated and carbamylated. Vascular reactivity after treatment with native LDL (nLDL) or carbamylated LDL (cLDL) was examined in organ chambers for isometric tension recording using aortic rings of wild-type or lectin-like-oxidized LDL receptor-1 (LOX-1) transgenic mice. Reactive oxygen species (ROS) and nitric oxide (NO) production were determined using electron spin resonance spectroscopy. The effect of LDL-carbamyl-lysine levels on cardiovascular outcomes was determined in patients with CKD during a median follow-up of 4.7 years. Carbamylated LDL impaired endothelium-dependent relaxation to acetylcholine or calcium-ionophore A23187, but not endothelium-independent relaxation to sodium nitroprusside. In contrast, nLDL had no effect. Carbamylated LDL enhanced aortic ROS production by activating NADPH-oxidase. Carbamylated LDL stimulated endothelial NO synthase (eNOS) uncoupling at least partially by promoting S -glutathionylation of eNOS. Carbamylated LDL-induced endothelial dysfunction was enhanced in LOX-1 transgenic mice. In patients with CKD, LDL-carbamyl-lysine levels were significant predictors for cardiovascular events and all-cause mortality. Conclusions Carbamylation of LDL induces endothelial dysfunction via LOX-1 activation and increased ROS production leading to eNOS uncoupling. This indicates a novel mechanism in the pathogenesis of atherosclerotic disease which may be pathogenic and prognostic in patients with CKD and high plasma levels of cLDL.

Aims MicroRNAs (miRNA) are important non-coding modulators controlling patterns of gene expression. However, profiling and validation of circulating miRNA levels related to adverse cardiovascular outcome has not been performed in patients with an acute coronary syndrome (ACS). Methods and results In a multicentre, prospective ACS cohort, 1002 out of 2168 patients presented with ST-segment elevation myocardial infarction (STEMI). Sixty-three STEMI patients experienced an adjudicated major cardiovascular event (MACE, defined as cardiac death or recurrent myocardial infarction) within 1 year of follow-up. From a miRNA profiling in a matched derivation case–control cohort, 14 miRNAs were selected for validation. Comparing 63 cases vs. 126 controls, 3 miRNAs were significantly differentially abundant. In patients with MACE, miR-26b-5p levels ( P = 0.038) were decreased, whereas miR-320a ( P = 0.047) and miR-660-5p ( P = 0.01) levels were increased. MiR-26b-5p has been suggested to prevent adverse cardiomyocyte hypertrophy, whereas miR-320a promotes cardiomyocyte death and apoptosis, and miR-660-5p has been related to active platelet production. This suggests that miR-26b-5p, miR-320a, and miR-660-5p may reflect alterations of different pathophysiological pathways involved in clinical outcome after ACS. Consistently, these three miRNAs reliably discriminated cases from controls [area under the receiver-operating characteristic curve (AUC) in age- and sex-adjusted Cox regression for miR-26b-5p = 0.707, miR-660-5p = 0.683, and miR-320a =0.672]. Combination of the three miRNAs further increased AUC to 0.718. Importantly, addition of the three miRNAs to both, the Global Registry of Acute Coronary Events (GRACE) score and a clinical model increased AUC from 0.679 to 0.720 and 0.722 to 0.732, respectively, with a net reclassification improvement of 0.20 in both cases. Conclusion This is the first study performing profiling and validation of miRNAs that are associated with adverse cardiovascular outcome in patients with STEMI. MiR-26b-5p, miR-320a, and miR-660-5p discriminated for MACE and increased risk prediction when added to the GRACE score and a clinical model. These findings suggest that the release of specific miRNAs into circulation may reflect the activation of molecular pathways that impact on clinical outcome after STEMI.