T-Cell-Specific CerS4 Depletion Prolonged Inflammation and Enhanced Tumor Burden in the AOM/DSS-Induced CAC Model.

To better understand the role of sphingolipids in the multifactorial process of inflammatory bowel disease (IBD), we elucidated the role of CerS4 in colitis and colitis-associated cancer (CAC). For this, we utilized the azoxymethane/dextran sodium sulphate (AOM/DSS)-induced colitis model in global CerS4 knockout (CerS4 KO), intestinal epithelial (CerS4 Vil/Cre), or T-cell restricted knockout (CerS4 LCK/Cre) mice. CerS4 KO mice were highly sensitive to the toxic effect of AOM/DSS, leading to a high mortality rate. CerS4 Vil/Cre mice had smaller tumors than WT mice. In contrast, CerS4 LCK/Cre mice frequently suffered from pancolitis and developed more colon tumors. In vitro, CerS4-depleted CD8+ T-cells isolated from the thymi of CerS4 LCK/Cre mice showed impaired proliferation and prolonged cytokine production after stimulation in comparison with T-cells from WT mice. Depletion of CerS4 in human Jurkat T-cells led to a constitutively activated T-cell receptor and NF-κB signaling pathway. In conclusion, the deficiency of CerS4 in T-cells led to an enduring active status of these cells and prevents the resolution of inflammation, leading to a higher tumor burden in the CAC mouse model. In contrast, CerS4 deficiency in epithelial cells resulted in smaller colon tumors and seemed to be beneficial. The higher tumor incidence in CerS4 LCK/Cre mice and the toxic effect of AOM/DSS in CerS4 KO mice exhibited the importance of CerS4 in other tissues and revealed the complexity of general targeting CerS4.

[Coronary physiology in the catheter laboratory]. / Koronarphysiologie im Herzkatheterlabor.

The regulation of coronary flow is mainly located in the resistance vessels of the microcirculation, so that the functional relevance of a coronary stenosis arises from the interaction between the epicardial stenosis and the downstream microcirculation. These complex interactions are precisely detectable by physiological measurements, such as the instantaneous wave-free ratio (iwFR) or the fractional flow reserve (FFR). In contrast, the purely visual assessment of the coronary anatomy could lead to misinterpretation and possibly to incorrect revascularization decisions. Consequently, in the current guidelines on myocardial revascularization of the European Society of Cardiology (ESC) the measurement of iwFR and FFR has a class IA indication in intermediate stenoses with unclear hemodynamic relevance. Despite this clear recommendation, physiological measurements are not yet regularly used in the clinical routine. Besides the purely hemodynamic assessment, novel methods such as co-registration and coronary mapping can be used for virtual planning of percutaneous coronary interventions, especially in vessels with diffuse lesions and serial stenoses. Furthermore, invasive flow measurements are also helpful for risk stratification between conservative and interventional treatment of patients with acute coronary syndrome, where additional factors of flow limitation, such as coronary spasm, thrombus and acute disturbance of the microcirculation play an important role.

Transcatheter aortic valve replacement- management of patients with significant coronary artery disease undergoing aortic valve interventions: surgical compared to catheter-based approaches in hybrid procedures.

BACKGROUND: Coronary artery disease (CAD) is associated with poorer outcomes after aortic valve replacement (AVR). For high-risk patients with complex CAD, combined transcatheter aortic valve replacement (TAVR) plus off-pump/minimally-invasive coronary artery bypass (OPCAB/MIDCAB) has been proposed. METHODS: A prospective registry analysis was performed to compare the characteristics and outcomes of patients undergoing TAVR+OP/MIDCAB with those undergoing TAVR plus percutaneous coronary intervention (PCI) and surgical AVR plus coronary artery bypass grafting (CABG) between 2008 and 2015 at a single site in Germany. RESULTS: 464 patients underwent SAVR+CABG, 50 underwent TAVR+OP/MIDCAB, and 112 underwent TAVR+PCI. The mean ages (p < 0.001) and logistic EuroSCOREs (p < 0.001) were similarly higher in TAVR+OP/MIDCAB and TAVR+PCI patients compared to SAVR+CABG patients. Prior cardiac surgery was more common in TAVR+PCI than in TAVR+OP/MIDCAB and SAVR+CABG patients (p < 0.001). Procedural times were shortest (p < 0.001), creatine kinase (muscle brain) levels least elevated (p < 0.001), pericardial tamponade least common (p = 0.027), and length of hospital stay shortest (p = 0.011) in TAVR+PCI, followed by TAVR+OP/MIDCAB and SAVR+CABG patients. In-hospital mortality was highest for TAVR+OP/MIDCAB patients (18.0%) with comparable rates for TAVR+PCI and SAVR+CABG groups (9.0 and 6.9%; p = 0.009). Mortality by 12 months was more probable after TAVR+OP/MIDCAB (HR: 2.17, p = 0.002) and TAVR/PCI (HR: 1.63, p = 0.010) than after SAVR+CABG, with the same true of rehospitalisation (HR: 2.39, p = 0.003 and HR: 1.63, p = 0.033). CONCLUSIONS: TAVR+OP/MIDCAB patients share many characteristics with TAVR+PCI patients, with only slightly poorer long-term outcomes. In patients ineligible for SAVR+CABG and TAVR+PCI, hybrid interventions are reasonable second-line options.

Cerebral Embolic Protection Devices During Transcatheter Aortic Valve Implantation: Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Silent ischemic embolic lesions are common after transcatheter aortic valve implantation (TAVI). The use of embolic protection devices (EPD) may reduce the occurrence of these embolic lesions. Thus, a quantitative overview and credibility assessment of the literature was necessary to draw a robust message about EPD. Therefore, the aim of this meta-analysis was to study whether the use of EPD reduces silent ischemic and clinically evident cerebrovascular events associated with TAVI. METHODS: We conducted a comprehensive search to identify studies that evaluated patients undergoing TAVI with or without EPD. Random-effects meta-analyses were performed to estimate the effect of EPD compared with no-EPD during TAVI using aggregate data. RESULTS: Sixteen studies involving 1170 patients (865/305 with/without EPD) fulfilled the inclusion criteria. The EPD delivery success rate was reported in all studies and was achieved in 94.5% of patients. Meta-analyses evaluating EPD versus without EPD strategies could not confirm or exclude any differences in terms of clinically evident stroke (relative risk, 0.70; 95% confidence interval [CI], 0.38-1.29; P=0.26) or 30-day mortality (relative risk, 0.58; 95% CI, 0.20-1.64; P=0.30). There were no significant differences in new-single, multiple, or total number of lesions. The use of EPD was associated with a significantly smaller ischemic volume per lesion (standardized mean difference, -0.52; 95% CI, -0.85 to -0.20; P=0.002) and smaller total volume of lesions (standardized mean difference, -0.23; 95% CI, -0.42 to -0.03; P=0.02). Subgroup analysis by type of valve showed an overall trend toward significant reduction in new lesions per patient using EPD (standardized mean difference, -0.41; 95% CI, -0.82 to 0.00; P=0.05), driven by self-expanding devices. CONCLUSIONS: The use of EPD during TAVI may be associated with smaller volume of silent ischemic lesions and smaller total volume of silent ischemic lesions. However, EPD may not reduce the number of new-single, multiple, or total number of lesions. There was only very low quality of evidence showing no significant differences between patients undergoing TAVI with or without EPD with respect to clinically evident stroke and mortality.

Conventional versus Transapical Aortic Valve Replacement: Is It Time for Shift in Indications?

Background The incidence of degenerative aortic valve diseases has increased along with the life expectancy of our population. Although conventional aortic valve replacement (AVR) is the gold standard for symptomatic aortic stenosis, transcatheter procedures have proven to be a valid therapeutic option in high-risk patients. The aim of this study was to compare these procedures in a high-risk cohort. Methods We retrospectively analyzed all symptomatic (dyspnea or angina) high-risk patients (logistic EuroSCORE ≥ 15%) fulfilling the transcatheter aortic valve implantation (TAVI) indications. Most of the AVR patients (n = 180) were operated on before the implementation of TAVI. All TAVI procedures (n = 127) were performed transapically (TA). After matching for age, logistic EuroSCORE, and left ventricular ejection fraction, 82 pairs of patients were evaluated. Results When comparing AVR with TA-TAVI, there was no difference between groups in survival after 1 year (Kaplan-Meier analysis, 81.1% [95% CI: 72.5-89.7%] vs. 75.8% [95% CI: 66.2-75.9%], Log tank p = 0.660) and the complication rates (n for AVR vs. TA-TAVI: stroke, 2 vs. 0, p = 0.580; acute renal insufficiency, 8 vs. 12, p = 0.340; atrial fibrillation, 24 vs. 26, p = 0.813; pacemaker implantation, 4 vs. 4, p > 0.999). In addition, quality of life did not differ between groups. Patients in the TA-TAVI group had lower mean valvular gradients postoperatively compared with the AVR group (14.6 ± 6.6 vs. 10.2 ± 4.9 mm Hg, p < 0.001). Conclusion For high-risk patients, the TAVI procedure is comparable with conventional AVR, but is not advantageous. These results do not support the expansion of TAVI to low- or intermediate-risk patients.

Testing in Patients With Stable Coronary Artery Disease　- The Debate Continues.

The major guidelines on stable coronary artery disease recommend revascularizing patients with large areas of myocardium at risk. The algorithms on how to prove that such high risk is present differ considerably. The opinions on the use of coronary CT (calcium scoring and angiography) vary widely. This review aims to summarize the recommendations of the major guidelines, commenting on differences between the guidelines and discussing whether extending the role of coronary CT angiography should be considered in the light of new CT data.

Clinical usefulness, angiographic characteristics, and safety evaluation of intracoronary acetylcholine provocation testing among 921 consecutive white patients with unobstructed coronary arteries.

BACKGROUND: Coronary spasm can cause myocardial ischemia and angina in patients with and those without obstructive coronary artery disease. However, provocation tests using intracoronary acetylcholine administration are rarely performed in clinical routine in the United States and Europe. Thus, we assessed the clinical usefulness, angiographic characteristics, and safety of intracoronary acetylcholine provocation testing in white patients with unobstructed coronary arteries. METHODS AND RESULTS: From September 2007 to June 2010, a total of 921 consecutive patients (362 men, mean age 62±12years) who underwent diagnostic angiography for suspected myocardial ischemia and were found to have unobstructed coronary arteries (no stenosis ≥50%) were enrolled. The intracoronary acetylcholine provocation testing was performed directly after angiography according to a standardized protocol. Three hundred forty-six patients (35%) reported chest pain at rest, 222 (22%) reported chest pain on exertion, 238 (24%) reported a combination of effort and resting chest pain, and 41 (4%) presented with troponin-positive acute coronary syndrome. The overall frequency of epicardial spasm (>75% diameter reduction with angina and ischemic ECG shifts) was 33.4%, and the overall frequency of microvascular spasm (angina and ischemic ECG shifts without epicardial spasm) was 24.2%. Epicardial spasm was most often diffuse and located in the distal coronary segments (P<0.01). No fatal or irreversible nonfatal complications occurred. However, 9 patients (1%) had minor complications (nonsustained ventricular tachycardia [n=1], fast paroxysmal atrial fibrillation [n=1], symptomatic bradycardia [n=6], and catheter-induced spasm [n=1]). CONCLUSIONS: Epicardial and microvascular spasm are frequently found in white patients with unobstructed coronary arteries. Epicardial spasm is most often diffuse and located in the distal coronary segments. The intracoronary acetylcholine provocation test is a safe technique to assess coronary vasomotor function.

Meloxicam treatment disrupts the regional structure of innate inflammation sites by targeting the pro-inflammatory effects of prostanoids.

BACKGROUND AND PURPOSE: Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely prescribed drugs in the world due to their analgesic, antipyretic and anti-inflammatory effects. However, NSAIDs inhibit prostanoid synthesis, interfering with their pro-inflammatory and anti-inflammatory functions and potentially prolonging acute inflammation. EXPERIMENTAL APPROACH: We used high-content immunohistochemistry to define the impact of meloxicam treatment on spatially separated pro-inflammatory and anti-inflammatory processes during innate inflammation in mice induced by zymosan. This allowed us to determine the effect of meloxicam treatment on the organization of pro-inflammatory and anti-inflammatory microenvironments, thereby identifying relevant changes in immune cell localization, recruitment and activation. KEY RESULTS: Meloxicam treatment reduced zymosan-induced thermal hypersensitivity at early time points but delayed its resolution. High-content immunohistochemistry revealed that the pro-inflammatory area was smaller after treatment, diminishing neutrophil recruitment, M1-like macrophage polarization, and especially phagocytosis by neutrophils and macrophages. The polarization of macrophages towards the M2-like anti-inflammatory phenotype was unaffected, and the number of anti-inflammatory eosinophils actually increased. CONCLUSION AND IMPLICATIONS: High-content immunohistochemistry was able to identify relevant meloxicam-mediated effects on inflammatory processes based on alterations in the regional structure of inflammation sites. Meloxicam delayed the clearance of pathogens by inhibiting pro-inflammatory processes, causing prolonged inflammation. Our data suggest that the prescription of NSAIDs as a treatment during an acute pathogen-driven inflammation should be reconsidered in patients with compromised immune systems.

Mast cell-derived interleukin-4 mediates activation of dendritic cell during toll-like receptor 2-mediated inflammation.

Introduction: During an innate inflammation, immune cells form distinct pro- and anti-inflammatory regions around pathogen-containing core-regions. Mast cells are localized in an anti-inflammatory microenvironment during the resolution of an innate inflammation, suggesting antiinflammatory roles of these cells. Methods: High-content imaging was used to investigated mast cell-dependent changes in the regional distribution of immune cells during an inflammation, induced by the toll-like receptor (TLR)-2 agonist zymosan. Results: The distance between the zymosan-containing core-region and the anti-inflammatory region, described by M2-like macrophages, increased in mast cell-deficient mice. Absence of mast cells abolished dendritic cell (DC) activation, as determined by CD86-expression and localized the DCs in greater distance to zymosan particles. The CD86- DCs had a higher expression of the pro-inflammatory interleukins (IL)-1ß and IL-12/23p40 as compared to activated CD86+ DCs. IL-4 administration restored CD86 expression, cytokine expression profile and localization of the DCs in mast cell-deficient mice. The IL-4 effects were mast cell-specific, since IL-4 reduction by eosinophil depletion did not affect activation of DCs. Discussion: We found that mast cells induce DC activation selectively at the site of inflammation and thereby determine their localization within the inflammation. Overall, mast cells have antiinflammatory functions in this inflammation model and limit the size of the pro-inflammatory region surrounding the zymosan-containing core region.

Eosinophil-derived IL-4 is necessary to establish the inflammatory structure in innate inflammation.

Pathogen-induced inflammation comprises pro- and anti-inflammatory processes, which ensure pathogen removal and containment of the proinflammatory activities. Here, we aimed to identify the development of inflammatory microenvironments and their maintenance throughout the course of a toll-like receptor 2-mediated paw inflammation. Within 24 h after pathogen-injection, the immune cells were organized in three zones, which comprised a pathogen-containing "core-region", a bordering proinflammatory (PI)-region and an outer anti-inflammatory (AI)-region. Eosinophils were present in all three inflammatory regions and adapted their cytokine profile according to their localization. Eosinophil depletion reduced IL-4 levels and increased edema formation as well as mechanical and thermal hypersensitivities during resolution of inflammation. Also, in the absence of eosinophils PI- and AI-regions could not be determined anymore, neutrophil numbers increased, and efferocytosis as well as M2-macrophage polarization were reduced. IL-4 administration restored in eosinophil-depleted mice PI- and AI-regions, normalized neutrophil numbers, efferocytosis, M2-macrophage polarization as well as resolution of zymosan-induced hypersensitivity. In conclusion, IL-4-expressing eosinophils support the resolution of inflammation by enabling the development of an anti-inflammatory framework, which encloses proinflammatory regions.