CD163+ Macrophages Induce Endothelial-to-Mesenchymal Transition in Atheroma.

BACKGROUND: Cell phenotype switching is increasingly being recognized in atherosclerosis. However, our understanding of the exact stimuli for such cellular transformations and their significance for human atherosclerosis is still evolving. Intraplaque hemorrhage is thought to be a major contributor to plaque progression in part by stimulating the influx of CD163+ macrophages. Here, we explored the hypothesis that CD163 macrophages cause plaque progression through the induction of proapoptotic endothelial-to-mesenchymal transition (EndMT) within the fibrous cap. METHODS: Human coronary artery sections from CVPath's autopsy registry were selected for pathological analysis. Athero-prone ApoE-/- and ApoE-/-/CD163-/- mice were used for in vivo studies. Human peripheral blood mononuclear cell-induced macrophages and human aortic endothelial cells were used for in vitro experiments. RESULTS: In 107 lesions with acute coronary plaque rupture, 55% had pathological evidence of intraplaque hemorrhage in nonculprit vessels/lesions. Thinner fibrous cap, greater CD163+ macrophage accumulation, and a larger number of CD31/FSP-1 (fibroblast specific protein-1) double-positive cells and TUNEL positive cells in the fibrous cap were observed in nonculprit intraplaque hemorrhage lesions, as well as in culprit rupture sections versus nonculprit fibroatheroma sections. Human aortic endothelial cells cultured with supernatants from hemoglobin/haptoglobin-exposed macrophages showed that increased mesenchymal marker proteins (transgelin and FSP-1) while endothelial markers (VE-cadherin and CD31) were reduced, suggesting EndMT induction. Activation of NF-κB (nuclear factor kappa ß) signaling by proinflammatory cytokines released from CD163+ macrophages directly regulated the expression of Snail, a critical transcription factor during EndMT induction. Western blot analysis for cleaved caspase 3 and microarray analysis of human aortic endothelial cells indicated that apoptosis was stimulated during CD163+ macrophage-induced EndMT. Additionally, CD163 deletion in athero-prone mice suggested that CD163 is required for EndMT and plaque progression. Using single-cell RNA sequencing from human carotid endarterectomy lesions, a population of EndMT was detected, which demonstrated significant upregulation of apoptosis-related genes. CONCLUSIONS: CD163+ macrophages provoke EndMT, which may promote plaque progression through fibrous cap thinning.

Polygenic Risk Score Associates With Atherosclerotic Plaque Characteristics at Autopsy.

BACKGROUND: Polygenic risk scores (PRSs) for coronary artery disease (CAD) potentially improve cardiovascular risk prediction. However, their relationship with histopathologic features of CAD has never been examined systematically. METHODS: From 4327 subjects referred to CVPath by the State of Maryland Office Chief Medical Examiner for sudden death between 1994 and 2015, 2455 cases were randomly selected for genotyping. We generated PRS from 291 known CAD risk loci. Detailed histopathologic examination of the coronary arteries was performed in all subjects. The primary study outcome measurements were histopathologic plaque features determining severity of atherosclerosis, including %stenosis, calcification, thin-cap fibroatheromas, and thrombotic CAD. RESULTS: After exclusion of cases with insufficient DNA sample quality or with missing data, 954 cases (mean age, 48.8±14.7 years; 75.7% men) remained in the final study cohort. Subjects in the highest PRS quintile exhibited more severe atherosclerosis compared with subjects in the lowest quintile, with greater %stenosis (80.3%±27.0% versus 50.4%±38.7%; adjusted P<0.001) and a higher frequency of calcification (69.6% versus 35.8%; adjusted P=0.004) and thin-cap fibroatheroma (26.7% versus 9.5%; adjusted P=0.007). Even after adjustment for traditional CAD risk factors, subjects within the highest PRS quintile had higher odds of severe atherosclerosis (ie, ≥75% stenosis; adjusted odds ratio, 3.77 [95% CI, 2.10-6.78]; P<0.001) and plaque rupture (adjusted odds ratio, 4.05 [95% CI, 2.26-7.24]; P<0.001). Moreover, subjects within the highest quintile had higher odds of CAD-associated cause of death, especially among those aged ≤50 years (adjusted odds ratio, 4.08 [95% CI, 2.01-8.30]; P<0.001). No statistically significant associations were observed with plaque erosion after adjusting for covariates. CONCLUSIONS: This is the first autopsy study investigating associations between PRS and atherosclerosis severity at the histopathologic level in subjects with sudden death. Our pathological analysis suggests PRS correlates with plaque burden and features of advanced atherosclerosis and may be useful as a method for CAD risk stratification, especially in younger subjects.

Comparison of thrombogenicity in different types of drug-eluting stents during transition from DAPT to SAPT.

BACKGROUND: During the transition from dual antiplatelet therapy (DAPT) to single antiplatelet therapy (SAPT), previous studies have raised concerns about a rebound effect. We compared platelet and inflammatory cell adhesion on different types of stents in the setting of clopidogrel presence and withdrawal. METHODS: In Experiment 1, three pigs were administered with DAPT, that is, clopidogrel and acetylsalicylic acid (ASA), for 7 days. Each animal underwent an extracorporeal carotid arteriovenous shunt model implanted with fluoropolymer-coated everolimus-eluting stent (FP-EES), biodegradable-polymer sirolimus-eluting stent (BP-SES), and biodegradable-polymer everolimus-eluting stents (BP-EES). In Experiment 2, two pigs were administered DAPT, clopidogrel was then withdrawn at day 7, and SAPT with ASA was continued for next 21 days. Then flow-loop experiments with the drawn blood from each time point were performed for FP-EES, BioLinx-polymer zotarolimus-eluting stents (BL-ZES), and BP-EES. The rebound effect was defined as the statistical increase of inflammation and platelet adhesion assessed with immunohistochemistry on the stent-strut level basis from baseline to day-14 or 28. RESULTS: Both experiments showed platelet adhesion value was highest in BP-EES, while the least in FP-EES during DAPT therapy. There was no increase in platelet or inflammatory cell adhesion above baseline values (i.e., no therapy) due to the cessation of clopidogrel on the stent-strut level. Monocyte adhesion was the least for FP-EES with the same trend observed for neutrophil adhesion. CONCLUSIONS: No evidence of rebound effect was seen after the transition from DAPT to SAPT. FP-EES demonstrated the most favorable antithrombotic and anti-inflammatory profile regardless of the different experimental designs.

Clonal Proliferation Within Smooth Muscle Cells in Unstable Human Atherosclerotic Lesions.

BACKGROUND: Studies in humans and mice using the expression of an X-linked gene or lineage tracing, respectively, have suggested that clones of smooth muscle cells (SMCs) exist in human atherosclerotic lesions but are limited by either spatial resolution or translatability of the model. METHODS: Phenotypic clonality can be detected by X-chromosome inactivation patterns. We investigated whether clones of SMCs exist in unstable human atheroma using RNA in situ hybridization (BaseScope) to identify a naturally occurring 24-nucleotide deletion in the 3'UTR of the X-linked BGN (biglycan) gene, a proteoglycan highly expressed by SMCs. BGN-specific BaseScope probes were designed to target the wild-type or deletion mRNA. Three different coronary artery plaque types (erosion, rupture, and adaptive intimal thickening) were selected from heterozygous females for the deletion BGN. Hybridization of target RNA-specific probes was used to visualize the spatial distribution of mutants. A clonality index was calculated from the percentage of each probe in each region of interest. Spatial transcriptomics were used to identify differentially expressed transcripts within clonal and nonclonal regions. RESULTS: Less than one-half of regions of interest in the intimal plaque were considered clonal with the mean percent regions of interest with clonality higher in the intimal plaque than in the media. This was consistent for all plaque types. The relationship of the dominant clone in the intimal plaque and media showed significant concordance. In comparison with the nonclonal lesions, the regions with SMC clonality had lower expression of genes encoding cell growth suppressors such as CD74, SERF-2 (small EDRK-rich factor 2), CTSB (cathepsin B), and HLA-DPA1 (major histocompatibility complex, class II, DP alpha 1), among others. CONCLUSIONS: Our novel approach to examine clonality suggests atherosclerosis is primarily a disease of polyclonally and to a lesser extent clonally expanded SMCs and may have implications for the development of antiatherosclerotic therapies.

Relationships between neighborhood disadvantage and cardiovascular findings at autopsy in subjects with sudden death.

BACKGROUND: Neighborhood disadvantage is associated with a higher risk of sudden cardiac death. However, autopsy findings have never been investigated in this context. Here, we sought to explore associations between neighborhood disadvantage and cardiovascular findings at autopsy in cases of sudden death in the State of Maryland. METHODS: State of Maryland investigation reports from 2,278 subjects within the CVPath Sudden Death Registry were screened for street addresses and 9-digit zip codes. Area deprivation index (ADI), used as metric for neighborhood disadvantage, was available for 1,464 subjects; 650 of whom self-identified as Black and 814 as White. The primary study outcome measurements were causes of death and gross and histopathologic findings of the heart. RESULTS: Subjects from most disadvantaged neighborhoods (i.e., ADI ≥ 8; n = 607) died at younger age compared with subjects from less disadvantaged neighborhoods (i.e., ADI ≤ 7; n = 857; 46.07 ± 14.10 vs 47.78 ± 13.86 years; P = 0.02) and were more likely Black or women. They were less likely to die from cardiac causes of death (61.8% vs 67.7%; P = 0.02) and had less severe atherosclerotic plaque features, including plaque burden, calcification, intraplaque hemorrhage, and thin-cap fibroatheromas. In addition, subjects from most disadvantaged neighborhoods had lower frequencies of plaque rupture (18.8% vs 25.1%, P = 0.004). However, these associations were omitted after adjustment for traditional risk factors and race. CONCLUSION: Neighborhood disadvantage did not associate with cause of death or coronary histopathology after adjustment for cardiovascular risk factors and race, implying that social determinants of health other than neighborhood disadvantage play a more prominent role in sudden cardiac death.

Microthrombi as a Major Cause of Cardiac Injury in COVID-19: A Pathologic Study.

BACKGROUND: Cardiac injury is common in patients who are hospitalized with coronavirus disease 2019 (COVID-19) and portends poorer prognosis. However, the mechanism and the type of myocardial damage associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain uncertain. METHODS: We conducted a systematic pathological analysis of 40 hearts from hospitalized patients dying of COVID-19 in Bergamo, Italy, to determine the pathological mechanisms of cardiac injury. We divided the hearts according to presence or absence of acute myocyte necrosis and then determined the underlying mechanisms of cardiac injury. RESULTS: Of the 40 hearts examined, 14 (35%) had evidence of myocyte necrosis, predominantly of the left ventricle. Compared with subjects without necrosis, subjects with necrosis tended to be female, have chronic kidney disease, and have shorter symptom onset to admission. The incidence of severe coronary artery disease (ie, >75% cross-sectional narrowing) was not significantly different between those with and without necrosis. Three of 14 (21.4%) subjects with myocyte necrosis showed evidence of acute myocardial infarction, defined as ≥1 cm2 area of necrosis, whereas 11 of 14 (78.6%) showed evidence of focal (>20 necrotic myocytes with an area of ≥0.05 mm2 but <1 cm2) myocyte necrosis. Cardiac thrombi were present in 11 of 14 (78.6%) cases with necrosis, with 2 of 14 (14.2%) having epicardial coronary artery thrombi, whereas 9 of 14 (64.3%) had microthrombi in myocardial capillaries, arterioles, and small muscular arteries. We compared cardiac microthrombi from COVID-19-positive autopsy cases to intramyocardial thromboemboli from COVID-19 cases as well as to aspirated thrombi obtained during primary percutaneous coronary intervention from uninfected and COVID-19-infected patients presenting with ST-segment-elevation myocardial infarction. Microthrombi had significantly greater fibrin and terminal complement C5b-9 immunostaining compared with intramyocardial thromboemboli from COVID-19-negative subjects and with aspirated thrombi. There were no significant differences between the constituents of thrombi aspirated from COVID-19-positive and -negative patients with ST-segment-elevation myocardial infarction. CONCLUSIONS: The most common pathological cause of myocyte necrosis was microthrombi. Microthrombi were different in composition from intramyocardial thromboemboli from COVID-19-negative subjects and from coronary thrombi retrieved from COVID-19-positive and -negative patients with ST-segment-elevation myocardial infarction. Tailored antithrombotic strategies may be useful to counteract the cardiac effects of COVID-19 infection.

Sex Differences in Coronary Atherosclerosis.

PURPOSE OF REVIEW: The importance of cardiovascular disease (CVD) in women has long been underestimated. Therefore, we need to understand the impact of sex differences on CVD. RECENT FINDINGS: Traditional risk factors contribute to coronary artery disease (CAD) differently in women and men. There are female-specific risk factors and comorbid conditions that affect the risk of CAD. Plaque erosion is frequently seen in younger women who smoke, while plaque rupture is common in older women and men who have elevated blood cholesterol. Coronary artery calcification is also different in both sexes. Thus, coronary artery calcification score-based risk stratification in women is challenging. A deeper understanding of the sex differences in the risk factors and plaque morphology of coronary atherosclerosis may lead to improved outcomes of CVD in women.

Cell-free DNA levels are increased in acute graft-versus-host disease.

BACKGROUND: Cell-free DNA (cfDNA) and nucleosomes, consisting of cfDNA and histones, are markers of cell activation and damage. In systemic inflammation these markers predict severity and fatality. However, the role of cfDNA in acute Graft-versus-Host Disease (aGvHD), a major complication of allogeneic hematopoietic stem cell transplantation (HSCT), is unknown. OBJECTIVE: The aim of this study is to investigate the role of cfDNA as a marker of aGvHD. METHODS: We followed nucleosome levels in 37 allogeneic HSCT patients and an established xenotransplantation mouse model. We determined the origin of cfDNA with a species-specific polymerase chain reaction. RESULTS: In the plasma of aGvHD patients, nucleosome levels significantly increased around the time of aGvHD diagnosis compared to pretransplant, concurrently with a significant increase of known aGvHD markers ST2 and REG3α. In mice, we confirmed that nucleosomes were elevated during clinically detectable aGvHD. We found cfDNA to be mainly of human origin and to a lesser extent of mouse origin, indicating that cfDNA is released by (proliferating) human xeno-reactive PBMC and damaged mouse cells. CONCLUSION: We show increased cfDNA both in an aGvHD mouse model and in aGvHD patients. We also demonstrate that donor hematopoietic cells and to a lesser degree (damaged) host cells are the cellular source of cfDNA in aGvHD. We propose that nucleosomes and cfDNA might be an additive marker for aGvHD.

Smooth Muscle Cell-Specific PKM2 (Pyruvate Kinase Muscle 2) Promotes Smooth Muscle Cell Phenotypic Switching and Neointimal Hyperplasia.

[Figure: see text].

Endothelial Recovery in Bare Metal Stents and Drug-Eluting Stents on a Single-Cell Level.

OBJECTIVE: Healing processes, particularly reendothelialization, are essential for vascular homeostasis after plain old balloon angioplasty and stent implantation. Drug-eluting stents (DES) are commonly used for percutaneous coronary intervention because restenosis rates are reduced as compared with bare metal stents (BMS). However, in addition to understanding the nature of regenerated endothelial cells, concerns over incomplete stent healing persist, and the molecular effects of antiproliferative drug coatings on endothelium remain poorly understood. APPROACH AND RESULTS: We used the rabbit iliac artery model to analyze differences in stent endothelialization in BMS and DES. Histology and immunohistochemistry confirmed that stent coverage was significantly greater in BMS than in DES at 30 days after stent implantation. Single-cell RNA sequencing revealed a more immature transcriptomic signature of neointimal endothelial cell harvested from stented arteries in comparison with native and plain old balloon angioplasty­ treated arteries. Whereas the genetic signature of BMS was overall proangiogenic with enrichment of genes involved in endothelial proliferation, sprouting, and migration, as well as extracellular matrix assembly, DES-derived endothelial cell showed upregulation of genes associated with angiogenesis inhibition and endothelial activation. CONCLUSIONS: Single-cell RNA sequencing analysis identified unique transcriptional changes within regenerated endothelium after plain old balloon angioplasty and stent implantation. These data suggest unique endothelial transcriptional differences, which characterize the different response of the endothelium to vascular injury and may help explain why long-term responses in DES remain suboptimal.

APOL1 Genetic Variants Are Associated With Increased Risk of Coronary Atherosclerotic Plaque Rupture in the Black Population.

[Figure: see text].

Histopathologic analysis of extracted thrombi from deep venous thrombosis and pulmonary embolism: Mechanisms and timing.

BACKGROUND: Mechanical thrombectomy is increasingly being used as an alternative to pharmacologic therapies for the treatment of patients with acute deep venous thrombosis (DVT) and pulmonary embolism (PE) and allows direct histopathologic comparison of thrombi extracted from living patients. We performed histopathologic analysis to thrombi extracted from cases of DVT and PE to gain insights into their relative cellular compositions. METHODS: Thrombus retrieved using a catheter-based thrombectomy system (ClotTriever for lower extremity DVT and FlowTriever for PE) from the 17 patients (7 DVT cases and 10 PE cases) were histologically evaluated. Histological features were used to estimate their age and pathological characteristics. RESULTS: The thrombus in all cases were composed of fibrin, platelets, red blood cells, and acute inflammatory cells. The weights of thrombus obtained from DVT versus PE cases were heavier (DVT 7.2 g (g) (5.6-10.2) vs. PE 4.8 g (3.6-6.8), p = .01). Overall thrombus healing (i.e., thrombus composed of smooth muscle cells, endothelial cells, and proteoglycans) was different between DVT and PE cases. 6/7 (86%) with features of late stage healing were from DVT cases while only three of ten (30%) were from PE cases while PE contained more acute thrombi with 7/10 (70%) stage 2 as compared 1/7 (14%) for DVT (p = .0498). CONCLUSION: This study is the first to directly compare the histology of extracted thrombus in DVT versus PE cases from patients with clinical events. Overall PE cases demonstrated significantly earlier stage thrombus with a larger component of red blood cells.

Vascular Response of a Polymer-Free Paclitaxel-Coated Stent (Zilver PTX) versus a Polymer-Coated Paclitaxel-Eluting Stent (Eluvia) in Healthy Swine Femoropopliteal Arteries.

PURPOSE: To compare the long-term vascular healing responses of healthy swine iliofemoral arteries treated with a polymer-free paclitaxel-eluting stent (Z-PES, Zilver PTX) or a fluoropolymer-based paclitaxel-eluting stent (FP-PES, Eluvia). MATERIALS AND METHODS: Bilateral iliofemoral arteries in 20 swine were treated with a Z-PES (n = 16) or a FP-PES (n = 24) and were examined histologically at 1, 3, 6, and 12 months. RESULTS: Morphometric analysis revealed larger external and internal elastic lamina, stent expansion, and lumen area in the FP-PES than in the Z-PES at all timepoints. Luminal narrowing was similar in the 2 groups at 1 month; however, greater stenosis was observed in the Z-PES group at 3 months, with significant regression thereafter, resulting in equivalent stenosis at 6 and 12 months. Greater drug effect and less complete vessel healing were found in the FP-PES group at all timepoints, including greater numbers of malapposed struts with excessive fibrin deposition at 1 and 3 months, than in the Z-PES group. Three of 12 FP-PESs from the 6- and 12-month cohorts also showed circumferential medial disruption with peri-strut inflammation, whereas no abnormal findings were observed in contralateral Z-PESs. CONCLUSIONS: Prolonged paclitaxel release with the presence of a permanent polymer may contribute to the differential vascular responses seen for the Z-PES and FP-PES groups, including medial layer disruption and aneurysmal vessel degeneration that was sometimes observed in the FP-PES group. These distinct features should be confirmed by pathology and in vivo imaging of human superficial femoral arteries to determine their clinical significance.

Co-Registration of Peripheral Atherosclerotic Plaques Assessed by Conventional CT Angiography, MicroCT and Histology in Patients with Chronic Limb Threatening Ischaemia.

OBJECTIVE: To co-register conventional computed tomography angiography (CTA), with ex vivo micro-computed tomography (microCT) and histology of popliteal atherosclerotic plaques. Improving the non-invasive imaging capabilities may be valuable to advance patient care with peripheral arterial obstructive disease towards lesion and individual based treatment. METHODS: In this prospective observational study, 12 popliteal arteries from 11 symptomatic patients who had undergone transfemoral amputations for chronic limb threatening ischaemia and who had pre-operative CTA, were analysed ex vivo by microCT and histology. A total of 353 histological cross sections were co-registered with microCT and CTA, and classified as: lipid rich (LP, n = 26), fibrous (FP, n = 80), or calcific (CP, n = 247) plaques. CTA and microCT plaque density was calculated in 791 regions of interest as Hounsfield units (HU). RESULTS: CTA and microCT could identify plaque components that were confirmed by histology such as fibrous tissue (FP), lipid pool/core (LP), and calcification (CP). MicroCT densities were 77.8 HU for FP (IQR 52.8, 129.5 HU), -28.4 HU for LP (IQR -87.1, 13.2 HU), and 3826.0 HU for CP (IQR 2989.0, 4501.0 HU). CTA densities of the three components of the plaque were: 78.0 HU for FP (IQR 59.5, 119.8 HU), 32.5 HU for LP (IQR 15.0, 42 HU), and 641.5 HU for CP (IQR 425.8, 1135 HU). The differences were statistically significant between the HU densitometric characteristics among the three groups (p < .0001) for both imaging modalities. Overall, microCT performed better diagnostically than conventional CTA for the three types of plaques: areas under the receiving operator characteristics curve were greater for microCT than CTA for FP (0.97 vs. 0.90), for LP (0.88 vs. 0.67), and for CP (0.97 vs. 0.90). CONCLUSION: CTA and microCT can be used to identify histological atherosclerotic plaque components, with better diagnostic performance for microCT. This study demonstrates the feasibility of using microCT to assess plaque morphology lesions in a manner that approaches histology thus becoming a useful tool for ex vivo assessment of atherosclerosis and towards lesion based treatment.

Clinical usefulness of drug-laboratory test interaction alerts: a multicentre survey.

OBJECTIVES: Knowledge of possible drug-laboratory test interactions (DLTIs) is important for the interpretation of laboratory test results. Failure to recognize these interactions may lead to misinterpretation, a delayed or erroneous diagnosis, or unnecessary extra diagnostic tests or therapy, which may harm patients. The aim of this multicentre survey was to evaluate the clinical value of DLTI alerts. METHODS: A survey was designed with six predefined clinical cases selected from the clinical laboratory practice with a potential DLTI. Physicians from several departments, including internal medicine, cardiology, intensive care, surgery and geriatrics in six participating hospitals were recruited to fill in the survey. The survey addressed their knowledge of DLTIs, motivation to receive an alert and opinion on the potential influence on medical decision making. RESULTS: A total of 210 physicians completed the survey. Of these respondents 93% had a positive attitude towards receiving DLTI alerts; however, the reported value differed per case and per respondent's background. In each clinical case, medical decision making was influenced as a consequence of the reported DLTI message (ranging from 3 to 45% of respondents per case). CONCLUSIONS: In this multicentre survey, most physicians stated DLTI messages to be useful in laboratory test interpretation. Medical decision making was influenced by reporting DLTI alerts in each case. Alerts should be adjusted according to the needs and preferences of the receiving physicians.

Diversity of macrophage phenotypes and responses in atherosclerosis.

The presence of macrophages within the plaque is a defining hallmark of atherosclerosis. Macrophages are exposed to various microenvironments such as oxidized lipids and cytokines which effect their phenotypic differentiation and activation. Classically, macrophages have been divided into two groups: M1 and M2 macrophages induced by T-helper 1 and T-helper 2 cytokines, respectively. However, for a decade, greater phenotypic heterogeneity and plasticity of these cells have since been reported in various models. In addition to M1 and M2 macrophage phenotypes, the concept of additional macrophage phenotypes such as M (Hb), Mox, and M4 has emerged. Understanding the mechanisms and functions of distinct phenotype of macrophages can lead to determination of their potential role in atherosclerotic plaque pathogenesis. However, there are still many unresolved controversies regarding their phenotype and function with respect to atherosclerosis. Here, we summarize and focus on the differential subtypes of macrophages in atherosclerotic plaques and their differing functional roles based upon microenvironments such as lipid, intraplaque hemorrhage, and plaque regression.

Vascular responses to coronary calcification following implantation of newer-generation drug-eluting stents in humans: impact on healing.

AIMS: Vascular calcification is routinely encountered in percutaneous coronary intervention (PCI) and severe coronary calcification is a known predictor of in-stent restenosis and stent thrombosis. However, the histopathologic mechanisms behind such events have not been systematically described. METHODS AND RESULTS: From our registry of 1211 stents, a total of 134 newer-generation drug-eluting stents (DES) (Xience, Resolute-Integrity, PROMUS-Element, and Synergy) with duration of implant ≥30 days were histologically analysed. The extent of calcification of the stented lesions was evaluated radiographically and divided into severe (SC, n = 46) and non-severely calcified lesions (NC, n = 88). The percent-uncovered struts per section {SC vs. NC; median 2.4 [interquartile range (IQR) 0.0-19.0] % vs. 0.0 (IQR 0.0-4.6) %, P = 0.02} and the presence of severe medial tears (MTs) (59% vs. 44%, respectively, P = 0.03) were greater in SC than NC. In addition, SC had a higher prevalence of ≥3 consecutive struts lying directly in contact with surface calcified area (3SC) (52% vs. 8%, respectively, P < 0.0001). Multivariate analysis demonstrated that sections with duration of implantation ≤6 months [odds ratio (OR): 7.7, P < 0.0001], 3SC (OR: 6.5, P < 0.0001), strut malapposition (OR: 5.0, P < 0.0001), and lack of MTs (OR: 2.5, P = 0.0005) were independent predictors of uncovered struts. Prevalence of neoatherosclerosis was significantly lower in SC than that of NC (24% vs. 44%, P = 0.02). CONCLUSION: Severe calcification, especially surface calcified area is an independent predictor of uncovered struts and delayed healing after newer-generation DES implantation. These data expand of knowledge of the vascular responses of stenting of calcified arteries and suggests further understand of how best to deal with calcification in patients undergoing PCI.

Apolipoprotein E4 Is Associated with Right Ventricular Dysfunction in Dilated Cardiomyopathy-An Animal and In-Human Comparative Study.

ApoE abnormality represents a well-known risk factor for cardiovascular diseases. Beyond its role in lipid metabolism, novel studies demonstrate a complex involvement of apoE in membrane homeostasis and signaling as well as in nuclear transcription. Due to the large spread of apoE isoforms in the human population, there is a need to understand the apoE's role in pathological processes. Our study aims to dissect the involvement of apoE in heart failure. We showed that apoE-deficient rats present multiple organ damages (kidney, liver, lung and spleen) besides the known predisposition for obesity and affected lipid metabolism (two-fold increase in tissular damages in liver and one-fold increase in kidney, lung and spleen). Heart tissue also showed significant morphological changes in apoE-/- rats, mostly after a high-fat diet. Interestingly, the right ventricle of apoE-/- rats fed a high-fat diet showed more damage and affected collagen content (~60% less total collagen content and double increase in collagen1/collagen3 ratio) compared with the left ventricle (no significant differences in total collagen content or collagen1/collagen3 ratio). In patients, we were able to find a correlation between the presence of ε4 allele and cardiomyopathy (χ2 = 10.244; p = 0.001), but also with right ventricle dysfunction with decreased TAPSE (15.3 ± 2.63 mm in ε4-allele-presenting patients vs. 19.8 ± 3.58 mm if the ε4 allele is absent, p < 0.0001*) and increased in systolic pulmonary artery pressure (50.44 ± 16.47 mmHg in ε4-allele-presenting patients vs. 40.68 ± 15.94 mmHg if the ε4 allele is absent, p = 0.0019). Our results confirm that the presence of the ε4 allele is a lipid-metabolism-independent risk factor for heart failure. Moreover, we show for the first time that the presence of the ε4 allele is associated with right ventricle dysfunction, implying different regulatory mechanisms of fibroblasts and the extracellular matrix in both ventricles. This is essential to be considered and thoroughly investigated before the design of therapeutical strategies for patients with heart failure.

Mesenchymal Stromal Cells Stimulate the Proliferation and IL-22 Production of Group 3 Innate Lymphoid Cells.

Infusion of mesenchymal stromal cells (MSCs) is a promising and increasingly applied therapy for patients who suffer from a variety of inflammatory diseases, including graft-versus-host disease (GvHD), a common and life-threatening complication after allogeneic hematopoietic stem cell transplantation. The therapeutic effect of MSCs is mainly ascribed to their ability to suppress T cells and to support tissue repair. However, clinical response rates in patients with GvHD are limited to 50%, and the determinants for MSC responsiveness are unknown. We recently reported that high frequencies of activated group 3 innate lymphoid cells (ILC3s) before and after allogeneic hematopoietic stem cell transplantation were associated with a lower risk of GvHD. This may be related to IL-22 production by ILC3s, a cytokine important for intestinal epithelial cell homeostasis. In this study, we investigated whether ILC3s may contribute to the therapeutic effect of MSCs by studying the interaction between MSCs and ILC3s in vitro. ILC3s isolated from human tonsils were cocultured with human bone marrow-derived MSCs for 5 d in the presence of IL-2. Coculture with MSCs enhanced the proliferation and IL-22 production of ILC3s. Reciprocally, ILC3s promoted ICAM-1 and VCAM-1 expression on MSCs. For both directions, the activation was mainly mediated by cell-cell contact and by MSC-derived IL-7 and likely by aryl hydrocarbon receptor ligands. Thus, in addition to inhibiting the proliferation of alloreactive T cells, MSCs also promote the expansion and IL-22 production of ILC3s, which may contribute to healthy homeostasis and wound repair in the treatment of various inflammatory conditions in the intestine, including GvHD.

The effects of stenting on coronary endothelium from a molecular biological view: Time for improvement?

Coronary artery stenting following balloon angioplasty represents the gold standard in revascularization of coronary artery stenoses. However, stent deployment as well as percutaneous transluminal coronary angioplasty (PTCA) alone causes severe injury of vascular endothelium. The damaged endothelium is intrinsically repaired by locally derived endothelial cells and by circulating endothelial progenitor cells from the blood, leading to re-population of the denuded regions within several weeks to months. However, the process of re-endothelialization is often incomplete or dysfunctional, promoting in-stent thrombosis and restenosis. The molecular and biomechanical mechanisms that influence the process of re-endothelialization in stented segments are incompletely understood. Once the endothelium is restored, endothelial function might still be impaired. Several strategies have been followed to improve endothelial function after coronary stenting. In this review, the effects of stenting on coronary endothelium are outlined and current and future strategies to improve endothelial function after stent deployment are discussed.