Culprit plaque morphology determines inflammatory risk and clinical outcomes in acute coronary syndrome.

AIMS: Rupture of the fibrous cap (RFC) and erosion of an intact fibrous cap (IFC) are the two predominant mechanisms causing acute coronary syndromes (ACS). It is uncertain whether clinical outcomes are different following RFC-ACS vs. IFC-ACS and whether this is affected by a specific inflammatory response. The prospective, translational OPTIcal-COherence Tomography in Acute Coronary Syndrome study programme investigates the impact of the culprit lesion phenotype on inflammatory profiles and prognosis in ACS patients. METHODS AND RESULTS: This analysis included 398 consecutive ACS patients, of which 62% had RFC-ACS and 25% had IFC-ACS. The primary endpoint was a composite of cardiac death, recurrent ACS, hospitalization for unstable angina, and target vessel revascularization at 2 years [major adverse cardiovascular events (MACE+)]. Inflammatory profiling was performed at baseline and after 90 days. Patients with IFC-ACS had lower rates of MACE+ than those with RFC-ACS (14.3% vs. 26.7%, P = 0.02). In 368-plex proteomic analyses, patients with IFC-ACS showed lower inflammatory proteome expression compared with those with RFC-ACS, including interleukin-6 and proteins associated with the response to interleukin-1ß. Circulating plasma levels of interleukin-1ß decreased from baseline to 3 months following IFC-ACS (P < 0.001) but remained stable following RFC-ACS (P = 0.25). Interleukin-6 levels decreased in patients with RFC-ACS free of MACE+ (P = 0.01) but persisted high in those with MACE+. CONCLUSION: This study demonstrates a distinct inflammatory response and a lower risk of MACE+ following IFC-ACS. These findings advance our understanding of inflammatory cascades associated with different mechanisms of plaque disruption and provide hypothesis generating data for personalized anti-inflammatory therapeutic allocation to ACS patients, a strategy that merits evaluation in future clinical trials.

Differential immunological signature at the culprit site distinguishes acute coronary syndrome with intact from acute coronary syndrome with ruptured fibrous cap: results from the prospective translational OPTICO-ACS study.

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 < 0.05) as compared with RFC-ACS lesions. T-cell-associated extracellular circulating microvesicles (MV) were more pronounced in IFC-ACS lesions and a significantly higher amount of CD8+ T-lymphocytes was detectable in thrombi aspirated from IFC-culprit sites. Furthermore, IFC-ACS lesions showed increased levels of the T-cell effector molecules granzyme A (+22.4%), perforin (+58.8%), and granulysin (+75.4%) as compared with RFC plaques (P < 0.005). Endothelial cells subjected to culture in disturbed laminar flow conditions, i.e. to simulate coronary flow near a bifurcation, demonstrated an enhanced adhesion of CD8+T cells. Finally, both CD8+T cells and their cytotoxic effector molecules caused endothelial cell death, a key potential pathophysiological mechanism in IFC-ACS. 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).

Coronary microevaginations characterize culprit plaques and their inflammatory microenvironment in a subtype of acute coronary syndrome with intact fibrous cap: results from the prospective translational OPTICO-ACS study.

AIMS: Coronary microevaginations (CMEs) represent an outward bulge of coronary plaques and have been introduced as a sign of adverse vascular remodelling following coronary device implantation. However, their role in atherosclerosis and plaque destabilization in the absence of coronary intervention is unknown. This study aimed to investigate CME as a novel feature of plaque vulnerability and to characterize its associated inflammatory cell-vessel-wall interactions. METHODS AND RESULTS: A total of 557 patients from the translational OPTICO-ACS study programme underwent optical coherence tomography imaging of the culprit vessel and simultaneous immunophenotyping of the culprit lesion (CL). Two hundred and fifty-eight CLs had a ruptured fibrous cap (RFC) and one hundred had intact fibrous cap (IFC) acute coronary syndrome (ACS) as an underlying pathophysiology. CMEs were significantly more frequent in CL when compared with non-CL (25 vs. 4%, P < 0.001) and were more frequently observed in lesions with IFC-ACS when compared with RFC-ACS (55.0 vs. 12.7%, P < 0.001). CMEs were particularly prevalent in IFC-ACS-causing CLs independent of a coronary bifurcation (IFC-ICB) when compared with IFC-ACS with an association to a coronary bifurcation (IFC-ACB, 65.4 vs. 43.7%, P = 0.030). CME emerged as the strongest independent predictor of IFC-ICB (relative risk 3.36, 95% confidence interval 1.67-6.76, P = 0.001) by multivariable regression analysis. IFC-ICB demonstrated an enrichment of monocytes in both culprit blood analysis (culprit ratio: 1.1 ± 0.2 vs. 0.9 ± 0.2, P = 0.048) and aspirated culprit thrombi (326 ± 162 vs. 96 ± 87 cells/mm2, P = 0.017), while IFC-ACB confirmed the accumulation of CD4+ T cells, as recently described. CONCLUSION: This study provides novel evidence for a pathophysiological involvement of CME in the development of IFC-ACS and provides first evidence for a distinct pathophysiological pathway for IFC-ICB, driven by CME-derived flow disturbances and inflammatory activation involving the innate immune system. TRIAL REGISTRATION: Registration of the study at clinicalTrials.gov (NCT03129503).

Cholesterol crystals at the culprit lesion in patients with acute coronary syndrome are associated with worse cardiovascular outcomes at two years follow up - results from the translational OPTICO-ACS study program.

BACKGROUND: Cholesterol crystals (CCs) represent a feature of advanced atherosclerotic plaque and may be assessed by optical coherence tomography (OCT). Their impact on cardiovascular outcomes in patients presenting with acute coronary syndromes (ACS) is yet unknown. METHODS: The culprit lesion (CL) of 346 ACS-patients undergoing preintervention OCT imaging were screened for the presence of CCs and divided into two groups accordingly. The primary end-point was the rate of major adverse cardiac events plus (MACE+) consisting of cardiac death, myocardial infarction, target vessel revascularization and re-hospitalization due to unstable or progressive angina at two years. RESULTS: Among 346 patients, 57.2% presented with CCs at the CL. Patients with CCs exhibited a higher prevalence of ruptured fibrous caps (RFC-ACS) (79.8% vs. 56.8%; p < 0.001) and other high-risk features such as thin cap fibroatheroma (80.8% vs. 64.9%; p = 0.001), presence of macrophages (99.0% vs. 85.1%; p < 0.001) as well as a greater maximum lipid arc (294.0° vs. 259.3°; p < 0.001) at the CL as compared to patients without CCs. MACE+ at two years follow-up occurred more often in CC-patients (29.2% vs. 16.1%; p = 0.006) as compared to patients without CCs at the culprit site. Multivariable cox regression analysis identified CCs as independent predictor of MACE+ (HR 1.705; 1.025-2.838 CI, p = 0.040). CONCLUSIONS: CCs were associated with conventional high-risk plaque features and associated with increased MACE+-rates at two years follow up. The identification of CCs might be useful as prognostic marker in patients with ACS and assist "precision prevention" in the future.

Spotty calcium deposits within acute coronary syndrome (ACS)-causing culprit lesions impact inflammatory vessel-wall interactions and are associated with higher cardiovascular event rates at one year follow-up: Results from the prospective translational OPTICO-ACS study program.

BACKGROUND AND AIMS: Spotty calcium deposits (SCD) represent a vulnerable plaque feature which seems to result - as based on recent invitro studies - from inflammatory vessel-wall interactions. SCD can be reliably assessed by optical coherence tomography (OCT). Their prognostic impact is yet unknown. Therefore, the aims of this translational study were to comprehensively characterize different plaque calcification patterns, to analyze the associated inflammatory mechanisms in the microenvironment of acute coronary syndrome (ACS)-causing culprit lesions (CL) and to investigate the prognostic significance of SCD in a large cohort of ACS-patients. METHODS: CL of the first 155 consecutive ACS-patients from the translational OPTICO-ACS-study program were investigated by OCT-characterization of the calcium phenotype at ACS-causing culprit lesions. Simultaneous immunophenotyping by flow-cytometric analysis and cytokine bead array technique across the CL gradient (ratio local/systemic levels) was performed and incidental major adverse cardiovascular events plus (MACE+) at 12 months after ACS were assessed. RESULTS: SCD were observed within 45.2% of all analyzed ACS-causing culprit lesions (CL). Culprits containing spotty calcium were characterized by an increased culprit ratio of innate effector cytokines interleukin (IL)-8 [2.04 (1.24) vs. 1.37 (1.10) p < 0.05], as well as TNF (tumor necrosis factor)-α [1.17 (0.93) vs. 1.06 (0.89); p < 0.05)] and an increased ratio of circulating neutrophils [0.96 (0.85) vs. 0.91 (0.77); p < 0.05] as compared to culprit plaques without SCD. Total monocyte levels did not differ between the two groups (p = n.s.). However, SCD-containing CLs were characterized by an increased culprit ratio of intermediate monocytes [(1.15 (0.81) vs. 0.96 (0.84); p < 0.05)] with an enhanced surface expression of the integrin receptor CD49d as compared to intermediate monocytes derived from SCD-free CLs [(1.06 (0.94) vs. 0.97 (0.91)] p < 0.05. Finally, 12 months rates of MACE+ were higher in patients with, as compared to patients without SCD at CL (16.4% vs. 5.3%; p < 0.05). CONCLUSIONS: This study for the first time identified a specific inflammatory profile of CL with SCD, with a predominance of neutrophils, intermediate monocytes and their corresponding effector molecules. Hence, this study advances our understanding of ACS-causing CL and provides the basis for future personalized anti-inflammatory, therapeutic approaches to ACS.