Vago-splenic signal transduction of cardioprotection in humans.

BACKGROUND AND AIMS: The spleen serves as an important relay organ that releases cardioprotective factor(s) upon vagal activation during remote ischaemic conditioning (RIC) in rats and pigs. The translation of these findings to humans was attempted. METHODS: Remote ischaemic conditioning or electrical auricular tragus stimulation (ATS) were performed in 10 healthy young volunteers, 10 volunteers with splenectomy, and 20 matched controls. Venous blood samples were taken before and after RIC/ATS or placebo, and a plasma dialysate was infused into isolated perfused rat hearts subjected to global ischaemia/reperfusion. RESULTS: Neither left nor right RIC or ATS altered heart rate and heart rate variability in the study cohorts. With the plasma dialysate prepared before RIC or ATS, respectively, infarct size (% ventricular mass) in the recipient rat heart was 36 ± 6% (left RIC), 34 ± 3% (right RIC) or 31 ± 5% (left ATS), 35 ± 5% (right ATS), and decreased with the plasma dialysate from healthy volunteers after RIC or ATS to 20 ± 4% (left RIC), 23 ± 6% (right RIC) or to 19 ± 4% (left ATS), 26 ± 9% (right ATS); infarct size was still reduced with plasma dialysate 4 days after ATS and 9 days after RIC. In a subgroup of six healthy volunteers, such infarct size reduction was abrogated by intravenous atropine. Infarct size reduction by RIC or ATS was also abrogated in 10 volunteers with splenectomy, but not in their 20 matched controls. CONCLUSIONS: In humans, vagal innervation and the spleen as a relay organ are decisive for the cardioprotective signal transduction of RIC and ATS.

Liver Diseases: Science, Fiction and the Foreseeable Future.

This Editorial precedes the Special Issue entitled "Novel Challenges and Therapeutic Options for Liver Diseases". Following a historical outline of the roots of hepatology, we provide a brief insight into our colleagues' contributions in this issue on the current developments in this discipline related to the prevention of liver diseases, the metabolic dysfunction-associated steatotic liver disease (or non-alcoholic fatty liver disease, respectively), liver cirrhosis, chronic viral hepatitides, acute-on-chronic liver failure, liver transplantation, the liver-microbiome axis and microbiome transplantation, and telemedicine. We further add some topics not covered by the contributions herein that will likely impact future hepatology. Clinically, these comprise the predictive potential of organokine crosstalk and treatment options for liver fibrosis. With regard to promising developments in basic research, some current findings on the genetic basis of metabolism-associated chronic liver diseases, chronobiology, metabolic zonation of the liver, aspects of the aging liver against the background of demography, and liver regeneration will be presented. We expect machine learning to thrive as an overarching topic throughout hepatology. The largest study to date on the early detection of liver damage-which has been kicked off on 1 March 2024-is highlighted, too.

l-Ornithine-l-Aspartate (LOLA) Normalizes Metabolic Parameters in Models of Steatosis, Insulin Resistance and Metabolic Syndrome.

l-Ornithine- l-aspartate (LOLA) reduces toxic ammonium (NH3) plasma levels in hepatic encephalopathy. NH3 detoxification/excretion is achieved by its incorporation into urea and glutamine via activation of carbamoyl phosphate synthetase 1 (CSP1) by l-ornithine and stimulation of arginase by l-aspartate. We aimed at identifying additional molecular targets of LOLA as a potential treatment option for non-alcoholic fatty liver disease (NAFLD). In primary hepatocytes from NAFLD patients, urea cycle enzymes CSP1 and ornithine transcarbamylase (OTC) increase, while the catabolism of branched-chain amino acids (BCAAs) decreases with disease severity. In contrast, LOLA increased the expression rates of the BCAA enzyme transcripts bcat2, bckdha, and bckdk. In untreated HepG2 hepatoblastoma cells and HepG2-based models of steatosis, insulin resistance, and metabolic syndrome (the latter for the first time established herein), LOLA reduced the release of NH3; beneficially modulated the expression of genes related to fatty acid import/transport (cd36, cpt1), synthesis (fasn, scd1, ACC1), and regulation (srbf1); reduced cellular ATP and acetyl-CoA; and favorably modulated the expression of master regulators/genes of energy balance/mitochondrial biogenesis (AMPK-α, pgc1α). Moreover, LOLA reconstituted the depolarized mitochondrial membrane potential, while retaining mitochondrial integrity and avoiding induction of superoxide production. Most effects were concentration-dependent at ≤40 mM LOLA. We demonstrate for l-ornithine-l-aspartate a broad range of reconstituting effects on metabolic carriers and targets of catabolism/energy metabolism impaired in NAFLD. These findings strongly advocate further investigations to establish LOLA as a safe, efficacious, and cost-effective basic medication for preventing and/or alleviating NAFLD.

[Intersectoral management of patients with abnormal liver enzymes and non-alcoholic fatty liver disease (NAFLD)]. / Intersektorales Management von Patienten mit unklarer Leberwerterhöhung und nichtalkoholischer Fettlebererkrankung (NAFLD).

The prevalence of fatty liver disease has increased significantly in Germany in recent years. With an estimated 18 million German citizens being affected, it is now among the most prevalent diseases. Furthermore, it is also considered a relevant and independent risk factor for other common cardiovascular diseases such as heart attack or stroke. Finally, diabetes mellitus promotes the development of and an unfavorable course of fatty liver disease. Given the high prevalence and complications, the German healthcare system is reaching its limits.Therefore, close coordination of all healthcare providers and specialists involved in the treatment of these patients is essential. In an expert consensus involving private practice and hospital doctors from the fields of gastroenterology, endocrinology, cardiology, general practitioners and laboratory physicians, as well as in close coordination with patient representatives, we have designed a concept for the care of these patients in the German healthcare system. Necessary developments are also addressed. In addition to being useful as a practical guideline, this should also support health policy work, especially in the development of practical care solutions at the medical level.

Patients with NAFLD exhibit more advanced fibrosis in liver biopsy than patients with other chronic liver diseases.

INTRODUCTION: Despite extremely high and seemingly rising prevalence of non-alcoholic fatty liver disease (NAFLD), awareness for this health condition is still low. In the present study we analyzed, if this is reflected in clinical routine for advanced diagnostic measures. METHODS: Retrospective data of 93 patients with histologically determined fibrosis stage and confirmed etiology was analyzed. Patients were grouped according to chronic liver disease alone (n=40), concomitant chronic liver disease and NAFLD (n=29), or NAFLD alone (n=24). Fibrosis stage and presence of cirrhosis were main outcome measures. RESULTS: Patients with NAFLD were significantly older and had significantly higher body mass index and CAP-values than patients with chronic liver disease. Significantly higher fibrosis stages were observed in patients with NAFLD than in those with chronic liver disease alone (p=0.003). Presence of cirrhosis was significantly higher in patients with NAFLD than in patients with chronic liver disease (p=0.01). This was not associated with a significantly different age distribution over fibrosis stages between chronic liver disease and NAFLD. Undergoing liver biopsy 10 years earlier could have possibly prevented progression to cirrhosis in up to 7 patients with NAFLD. This could have potentially saved 35,000 € yearly health care resources. CONCLUSION: These findings suggest that the time course for development of liver fibrosis and cirrhosis is not fundamentally different between patients with NAFLD or with other chronic liver diseases. Higher rates of cirrhosis observed in patients with NAFLD could potentially be ameliorated by earlier diagnostic work-up and improved monitoring.

Towards harnessing the value of organokine crosstalk to predict the risk for cardiovascular disease in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Importantly, NAFLD increases the risk for cardiovascular disease (CVD). A causal relationship has been substantiated. Given the pandemic proportions of NAFLD, a reliable scoring system for predicting the risk of NAFLD-associated CVD is an urgent medical need. We here review cumulative evidence suggesting that systemically released organokines - especially certain adipokines, hepatokines, and cardiokines - may serve this purpose. The underlying rationale is that these signalers directly communicate between white adipose tissue, liver, and heart as key players in the pathogenesis of NAFLD and resultant CVD events. Moreover, evidence suggests that these organ-specific cytokines are secreted in a biologically predetermined, cascade-like pattern. Consequently, upon pinpointing organokines of relevance, we sketch requirements to establish an algorithm predictive of the CVD risk in patients with NAFLD. Such an algorithm, as to be consolidated in the form of an applicable equation, may be improved continuously by machine learning. To the best of our knowledge, such an option has not yet been considered. Establishing and implementing a reliable algorithm for determining the NAFLD-associated CVD risk has the potential to save many NAFLD patients from life-threatening CVD events.

Transaminase Concentrations Cannot Separate Non-Alcoholic Fatty Liver and Non-Alcoholic Steatohepatitis in Morbidly Obese Patients Irrespective of Histological Algorithm.

BACKGROUND: In current general practice, elevated serum concentrations of liver enzymes are still regarded as an indicator of non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH). In this study, we analyzed if an adjustment of the upper limit of normal (ULN) for serum liver enzymes can improve their diagnostic accuracy. METHODS: Data from 363 morbidly obese patients (42.5 ± 10.3 years old; mean BMI: 52 ± 8.5 kg/m2), who underwent bariatric surgery, was retrospectively analyzed. NAFL and NASH were defined histologically according to non-alcoholic fatty liver activity score (NAS) and according to steatosis activity fibrosis (SAF) score for 2 separate analyses, respectively. RESULTS: In 121 women (45%) and 45 men (46%), elevated values for at least one serum parameter (ALT, AST, γGT) were present. The serum concentrations of ALT (p < 0.0001), AST (p < 0.0001) and γGT (p = 0.0023) differed significantly between NAFL and NASH, irrespective of the applied histological classification method. Concentrations of all 3 serum parameters correlated significantly positively with the NAS and the SAF score, with correlation coefficients between 0.33 (ALT/NAS) and 0.40 (γGT/SAF). The area under the curves to separate NAFL and NASH by liver enzymes achieved a maximum of 0.70 (ALT applied to NAS-based classification). For 95% specificity, the ULN for ALT would be 47.5 U/L; for 95% sensitivity, the ULN for ALT would be 17.5 U/L, resulting in 62% uncategorized patients. CONCLUSION: ALT, AST, and γGT are unsuitable for non-invasive screening or diagnosis of NAFL or NASH. Utilizing liver enzymes as an indicator for NAFLD or NASH should generally be questioned.

Association of cell death mechanisms and fibrosis in visceral white adipose tissue with pathological alterations in the liver of morbidly obese patients with NAFLD.

The role of visceral white adipose tissue (vWAT) in the progression of non-alcoholic liver disease (NAFLD) with its sub entities non-alcoholic fatty liver and steatohepatitis (NAFL; NASH) is underinvestigated. We thus explored mechanisms of fibrosis and regulated cell death in vWAT and liver tissue. In NAFLD, women displayed significantly more fibrosis in vWAT than men, and collagen 1α mRNA expression was significantly upregulated. The degrees of fibrosis in vWAT and liver tissue correlated significantly. The size of vWAT-resident adipocytes in NAFLD correlated negatively with the local degree of fibrosis. The extent of apoptosis, as measured by circulating M30, positively correlated with the degree of fibrosis in vWAT; necrosis-associated HMGB1 mRNA expression was significantly downregulated in vWAT and liver tissue; (iii) necroptosis-related RIPK-3 mRNA expression was significantly upregulated in vWAT; and autophagy-related LC3 mRNA expression was significantly downregulated in vWAT, while upregulated in the liver. Thus, the different cell death mechanisms in the vWAT in NAFLD are regulated independently while not ruling out their interaction. Fibrosis in vWAT may be associated with reduced adipocyte size and thus partially protective against NAFLD progression.Abbreviations: ATG5: autophagy related 5; BAS: bariatric surgery; BMI: body mass index; ELISA: enzyme-linked immunosorbent assay; EtOH: ethanol; FFAs: free fatty acids; HCC: hepatocellular carcinoma; HMGB1: high-mobility group box 1 protein; IHC: immunohistochemistry; IL: interleukin; LC3: microtubule-associated proteins 1A/1B light chain 3B; M30: neoepitope K18Asp396-NE displayed on the caspase-cleaved keratin 18 fragment; M65: epitope present on both caspase-cleaved and intact keratin 18; NAFL: non-alcoholic fatty liver; NAFLD: non-alcoholic fatty liver disease; NAS: NAFLD activity score; NASH: non-alcoholic steatohepatitis; NLRP3: nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3; qRT-PCR: quantitative real-time polymerase-chain reaction; r: Pearson's correlation coefficient (r); rs: Spearman's rank correlation coefficient; RIPK3: receptor-interacting serine/threonine-protein kinase 3; T2DM: type 2 diabetes mellitus (T2DM); TUNEL: terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling; vWAT: visceral WAT; WAT: white adipose tissue.

Liver parameters as part of a non-invasive model for prediction of all-cause mortality after myocardial infarction.

INTRODUCTION: Liver parameters are associated with cardiovascular disease risk and severity of stenosis. It is unclear whether liver parameters could predict the long-term outcome of patients after acute myocardial infarction (AMI). We performed an unbiased analysis of the predictive value of serum parameters for long-term prognosis after AMI. MATERIAL AND METHODS: In a retrospective, observational, single-center, cohort study, 569 patients after AMI were enrolled and followed up until 6 years for major adverse cardiovascular events, including cardiac death. Patients were classified into non-survivors (n = 156) and survivors (n = 413). Demographic and laboratory data were analyzed using ensemble feature selection (EFS) and logistic regression. Correlations were performed for serum parameters. RESULTS: Age (73; 64; p < 0.01), alanine aminotransferase (ALT; 93 U/l; 40 U/l; p < 0.01), aspartate aminotransferase (AST; 162 U/l; 66 U/l; p < 0.01), C-reactive protein (CRP; 4.7 U/l; 1.6 U/l; p < 0.01), creatinine (1.6; 1.3; p < 0.01), γ-glutamyltransferase (GGT; 71 U/l; 46 U/l; p < 0.01), urea (29.5; 20.5; p < 0.01), estimated glomerular filtration rate (eGFR; 49.6; 61.4; p < 0.01), troponin (13.3; 7.6; p < 0.01), myoglobin (639; 302; p < 0.01), and cardiovascular risk factors (hypercholesterolemia p < 0.02, family history p < 0.01, and smoking p < 0.01) differed significantly between non-survivors and survivors. Age, AST, CRP, eGFR, myoglobin, sodium, urea, creatinine, and troponin correlated significantly with death (r = -0.29; 0.14; 0.31; -0.27; 0.20; -0.13; 0.33; 0.24; 0.12). A prediction model was built including age, CRP, eGFR, myoglobin, and urea, achieving an AUROC of 77.6% to predict long-term survival after AMI. CONCLUSIONS: Non-invasive parameters, including liver and renal markers, can predict long-term outcome of patients after AMI.

Comparison of the simple red blood cell adhesiveness/aggregation test with the laser-assisted optical rotational cell analyzer: Red blood cell aggregation in patients with coronary artery disease and a healthy control group.

BACKGROUND: Red blood cell (RBC) aggregation influences blood flow properties, impacts blood microcirculation and consequently oxygen delivery. Different methods are established to determine RBC aggregation: under static conditions (i.e. the RBC adhesiveness/aggregation test (EAAT)) or under shear conditions (i.e. the laser-assisted optical rotational cell analyzer (LORCA)). OBJECTIVE: Comparison of these two different methods in detecting the RBC aggregation of patients with coronary artery disease (CAD) and of healthy controls. METHODS: RBC aggregation was quantified in peripheral venous blood of patients with CAD and healthy controls using EAAT and LORCA. RESULTS: Both methods detected an increased RBC aggregation in patients with CAD compared to the healthy control group: the ratio of clot-free area to whole area (rCFA) detected with EAAT (15.65 vs. 11.30%), and aggregation index (66.33 vs. 53.90%), shear rate of disaggregation (SDA) (105.59 vs. 69.21 s-1), and upstroke/ttop (0.03 vs. 0.02 au/s) detected with LORCA device were increased, aggregation half time (detected with LORCA) was decreased (2.11 vs. 3.60 s). rCFA (EAAT) correlated with SDA (LORCA). CONCLUSIONS: Both methods determine an increased RBC aggregation in patients with CAD. However, only one measurement parameter of the LORCA seems to reflect the same RBC aggregation properties as the EAAT.

Compensation of feature selection biases accompanied with improved predictive performance for binary classification by using a novel ensemble feature selection approach.

MOTIVATION: Biomarker discovery methods are essential to identify a minimal subset of features (e.g., serum markers in predictive medicine) that are relevant to develop prediction models with high accuracy. By now, there exist diverse feature selection methods, which either are embedded, combined, or independent of predictive learning algorithms. Many preceding studies showed the defectiveness of single feature selection results, which cause difficulties for professionals in a variety of fields (e.g., medical practitioners) to analyze and interpret the obtained feature subsets. Whereas each of these methods is highly biased, an ensemble feature selection has the advantage to alleviate and compensate for such biases. Concerning the reliability, validity, and reproducibility of these methods, we examined eight different feature selection methods for binary classification datasets and developed an ensemble feature selection system. RESULTS: By using an ensemble of feature selection methods, a quantification of the importance of the features could be obtained. The prediction models that have been trained on the selected features showed improved prediction performance.

Influence of stent implantation on erythrocyte aggregation in human native coronary arteries and saphenous vein grafts.

OBJECTIVE: Stent implantation into atherosclerotic coronary vessels induces the release of particulate debris and soluble vasoactive substances, which impair downstream microvascular function. Microvascular perfusion, however, is also determined by hemorheological parameters. We therefore analyzed now changes in erythrocyte (RBC) aggregation in coronary arterial blood during stent implantation. METHODS: Symptomatic male patients with stable angina pectoris and stenosis in their native right coronary artery (RCA) or saphenous vein graft on right coronary artery (SVG-RCA) were enrolled. Coronary arterial blood was taken before and coronary aspirate during stent implantation with a distal occlusion/aspiration device. RBC aggregation was determined using the erythrocyte adhesiveness/aggregation test. The ratio of clot-free area to whole area of a spread blood drop was quantified (rCFA). To evaluate the impact of soluble factors within aspirate plasma on RBC aggregation, separated RBCs of healthy volunteers were exposed to patients' coronary arterial blood and aspirate samples. RESULTS: rCFA was comparably increased in coronary aspirate of RCAs and SVG-RCAs after stent implantation (RCA: 25.7±2.1% vs 32.2±2.1%; SVG-RCA: 28.9±1.9% vs 33.3±2.0%, P<.01). The rCFA of healthy volunteers was increased after adding coronary aspirate plasma. CONCLUSIONS: Stent implantation into atherosclerotic coronary arteries induces an increase in RBC aggregation, potentially contributing to impaired microvascular perfusion.

Aspirate from human stented saphenous vein grafts induces epicardial coronary vasoconstriction and impairs perfusion and left ventricular function in rat bioassay hearts with pharmacologically induced endothelial dysfunction.

Stent implantation into aortocoronary saphenous vein grafts (SVG) releases particulate debris and soluble vasoactive mediators, for example, serotonin. We now analyzed effects of the soluble mediators released into the coronary arterial blood during stent implantation on vasomotion of isolated rat epicardial coronary artery segments and on coronary flow and left ventricular developed pressure in isolated perfused rat hearts. Coronary blood was retrieved during percutaneous SVG intervention using a distal occlusion/aspiration protection device in nine symptomatic patients with stable angina pectoris and a flow-limiting SVG stenosis. The blood was separated into particulate debris and plasma. Responses to coronary plasma were determined in isolated rat epicardial coronary arteries and in isolated, constant pressure-perfused rat hearts (±nitric oxide synthase [NOS] inhibition and ±serotonin receptor blockade, respectively). Coronary aspirate plasma taken after stent implantation induced a stronger vasoconstriction of rat epicardial coronary arteries (52 ± 8% of maximal potassium chloride induced vasoconstriction [% KClmax = 100%]) than plasma taken before stent implantation (12 ± 8% of KClmax); NOS inhibition augmented this vasoconstrictor response (to 110 ± 15% and 24 ± 9% of KClmax). Coronary aspirate plasma taken after stent implantation reduced in isolated perfused rat hearts only under NOS inhibition coronary flow by 17 ± 3% and left ventricular developed pressure by 25 ± 4%. Blockade of serotonin receptors abrogated these effects. Coronary aspirate plasma taken after stent implantation induces vasoconstriction in isolated rat epicardial coronary arteries and reduces coronary flow and left ventricular developed pressure in isolated perfused rat hearts with pharmacologically induced endothelial dysfunction.

In Acute Myocardial Infarction Liver Parameters Are Associated With Stenosis Diameter.

Detection of high-risk subjects in acute myocardial infarction (AMI) by noninvasive means would reduce the need for intracardiac catheterization and associated complications. Liver enzymes are associated with cardiovascular disease risk. A potential predictive value for liver serum markers for the severity of stenosis in AMI was analyzed.Patients with AMI undergoing percutaneous coronary intervention (PCI; n = 437) were retrospectively evaluated. Minimal lumen diameter (MLD) and percent stenosis diameter (SD) were determined from quantitative coronary angiography. Patients were classified according to the severity of stenosis (SD ≥ 50%, n = 357; SD < 50%, n = 80). Routine heart and liver parameters were associated with SD using random forests (RF). A prediction model (M10) was developed based on parameter importance analysis in RF.Age, alkaline phosphatase (AP), aspartate aminotransferase (AST), and MLD differed significantly between SD ≥ 50 and SD < 50. Age, AST, alanine aminotransferase (ALT), and troponin correlated significantly with SD, whereas MLD correlated inversely with SD. M10 (age, BMI, AP, AST, ALT, gamma-glutamyltransferase, creatinine, troponin) reached an AUC of 69.7% (CI 63.8-75.5%, P < 0.0001).Routine liver parameters are associated with SD in AMI. A small set of noninvasively determined parameters can identify SD in AMI, and might avoid unnecessary coronary angiography in patients with low risk. The model can be accessed via http://stenosis.heiderlab.de.

Myocardial injury during transfemoral transcatheter aortic valve implantation: an intracoronary Doppler and cardiac magnetic resonance imaging study.

AIMS: Myocardial injury reflected by a post-procedural increase of serum troponin I (TnI) occurs frequently during transcatheter aortic valve implantation (TAVI). It is potentially caused by intraprocedural hypotension, periprocedural coronary microembolisation and post-procedural (para)valvular leakages (PVLs). We invasively assessed coronary flow dynamics including coronary flow velocity reserve (CFVR), embolic high-intensity transient signals (HITS) as well as rapid pacing induced hypotension and post-procedural PVLs to determine their contribution to post-procedural TnI increases. METHODS AND RESULTS: In 15 transfemoral TAVI patients, TnI was measured serially, and cardiac MRIs with late gadolinium enhancement (LGE) were performed pre- and post-interventionally. There were no significant correlations between coronary flow dynamics, CFVR and the area under the curve (AUC) of TnI over 72 hours. Despite the detection of HITS in all patients and during all procedural steps, there was also no correlation between the amount of HITS and the AUC of TnI. However, there were positive correlations between the duration of rapid pacing as well as the time of subsequent blood pressure recovery and the AUC of TnI. Both LGE and more than mild PVL were observed in a single case only. CONCLUSIONS: Myocardial injury after TAVI appears to be related more to hypoperfusion-induced ischaemia than to periprocedural microembolisation.

Release of Intracoronary Microparticles during Stent Implantation into Stable Atherosclerotic Lesions under Protection with an Aspiration Device.

OBJECTIVE: Stent implantation into atherosclerotic coronary vessels impacts on downstream microvascular function and induces the release of particulate debris and soluble substances, which differs qualitatively and quantitatively between native right coronary arteries (RCAs) and saphenous vein grafts on right coronary arteries (SVG-RCAs). We have now quantified the release of microparticles (MPs) during stent implantation into stable atherosclerotic lesions and compared the release between RCAs and SVG-RCAs. METHODS: In symptomatic, male patients with stable angina and a stenosis in their RCA or SVG-RCA, respectively (n = 14/14), plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation with a distal occlusion/aspiration device and divided into particulate debris and plasma. Particulate debris was weighed. Platelet-derived MPs (PMPs) were distinguished by flow cytometry as CD41+, endothelium-derived MPs (EMPs) as CD144+, CD62E+ and CD31+/CD41-, leukocyte-derived MPs as CD45+, and erythrocyte-derived MPs as CD235+. RESULTS: In patients with comparable plaque volume and composition in RCAs and SVG-RCAs, intracoronary PMPs and EMPs were increased after stent implantation into their RCAs and SVG-RCAs (CD41+: 2729.6 ± 645.6 vs. 4208.7 ± 679.4 and 2355.9 ± 503.9 vs. 3285.8 ± 733.2 nr/µL; CD144+: 451.5 ± 87.9 vs. 861.7 ± 147.0 and 444.6 ± 74.8 vs. 726.5 ± 136.4 nr/µL; CD62E+: 1404.1 ± 247.7 vs. 1844.3 ± 378.6 and 1084.6 ± 211.0 vs. 1783.8 ± 384.3 nr/µL, P < 0.05), but not different between RCAs and SVG-RCAs. CONCLUSION: Stenting in stable atherosclerotic lesions is associated with a substantial release not only of PMPs, but also of EMPs in RCAs and SVG-RCAs. Their release does not differ between RCAs and SVG-RCAs. TRIAL REGISTRATION: ClinicalTrials.gov NCT01430884.

microRNA expression and its potential role in cardioprotection by ischemic postconditioning in pigs.

Ischemic postconditioning (PoCo) reduces infarct size following myocardial ischemia/reperfusion. To protect, PoCo must be performed early during reperfusion, and causal cardioprotective signaling must occur then. The role of microRNA (miRNA) in PoCo is unclear. Anesthetized pigs were subjected to 60 min left anterior descending coronary artery (LAD) occlusion and 180 min reperfusion. Immediate full reperfusion (IFR, n = 5) was compared to PoCo (four cycles of 60 s/60 s reperfusion/reocclusion, n = 5). Transmural myocardial biopsies from the LAD territory were sampled at baseline, 60 min ischemia, 10 and 180 min reperfusion. RNA was isolated. The expression of 11 miRNAs, including muscle-specific (miRNA-1, -133a, -206, -208b, -214, and -499), fibrosis- (miRNA-21, -24, and -29b), neovascularization- (miRNA-92a), and inflammation-associated (miRNA-146b) candidates, was quantified using real-time PCR (RT-PCR). mRNA expression at baseline and 180 min reperfusion was quantified and validated (microarray and RT-PCR). PoCo reduced infarct size from 44.9 ± 7.7 to 34.8 ± 5.3% of the area at risk. The expression of miRNA-1, -24, -29b, -133a, -146b, -208b, and -499 was increased at 10 min reperfusion with PoCo vs. IFR; however, that of miRNA-1, -24, -208b, and -499 was already increased at 60 min ischemia and probably reflects falsely positive results. Five mRNAs were different with PoCo vs. IFR. In silico analysis identified a tentative connection between three miRNAs and five mRNAs with the biological functions "cell death", "inflammatory response" and/or "glucose metabolism". If at all, only miRNA-29b, -133a, and -146b fulfill the minimal temporal requirements for a potential causal involvement in cardioprotection by PoCo.

Aspirate from human stented native coronary arteries vs. saphenous vein grafts: more endothelin but less particulate debris.

Stent implantation into atherosclerotic coronary arteries releases particulate debris and soluble substances that contribute to impaired microvascular perfusion. Here we addressed the potential for microvascular obstruction in patients with stenotic native right coronary arteries (nRCA) compared with saphenous vein grafts on right coronary arteries (SVG-RCA). We enrolled symptomatic, male patients with stable angina pectoris and a flow-limiting stenosis in their nRCA or SVG-RCA (n = 18/18). Plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation under protection with a distal occlusion/aspiration device and divided into particulate debris and plasma. The release of catecholamines, endothelin, serotonin, thromboxane B2, and tumor necrosis factor-α was measured. The response of rat mesenteric arteries with intact (+E) and denuded (-E) endothelium to aspirate plasma (without and with selective endothelin receptor blockade) was normalized to that by potassium chloride (KClmax = 100%). Plaque volume and composition were not different between nRCA and SVG-RCA. There was less particulate debris (65 ± 8 vs. 146 ± 23 mg; P < 0.05) and more endothelin release (5.8 ± 0.8 vs. 1.3 ± 0.7 pg/ml; P < 0.05) in nRCA than in SVG-RCA, whereas the release of the other mediators was not different. Aspirate from nRCA induced stronger vasoconstriction than that from SVG-RCA [nRCA, 78 ± 6% (+E)/84 ± 5% (-E); SVG-RCA, 59 ± 6% (+E)/68 ± 3% (-E); P < 0.05 nRCA vs. SVG-RCA], which was attenuated by a nonspecific endothelin and a specific endothelin receptor A antagonist. Thus coronary aspirate from stented nRCA is characterized by less debris but more endothelin and stronger vasoconstrictor response than that from SVG-RCA.