Decreased expression of miR-133a but not of miR-1 is associated with signs of heart failure in patients undergoing coronary bypass surgery.

OBJECTIVES: Coronary artery disease (CAD)-associated ischemic heart failure is characterized by dysregulated gene expression which is partly mediated by microRNAs (miRNAs). While the muscle-specific miR-1 and miR-133 are involved in cardiac development and hypertrophy, their role in heart failure resulting from CAD is unknown. We, therefore, tested the hypothesis that cardiac miR-1 and miR-133 expression is associated with signs of heart failure in patients undergoing coronary artery bypass grafting. METHODS: 83 patients were included in this prospective study. Cardiac index and vascular pressures were measured under general anesthesia and the miRNA expression was quantified (RNase protection assay and real-time PCR) from samples of the right atrial myocardium. RESULTS: miR-133 expression decreased significantly with increased severity of heart failure, as indicated by a greater New York Heart Association (NYHA) functional class (p = 0.014) and increased pulmonary artery occlusion pressure (p = 0.045). Furthermore, patients with NT-proBNP concentrations >1,800 pg/ml showed a 25% decrease in miR-133 expression compared to patients with concentrations <300 pg/ml (p = 0.023). In contrast, no associations were detected for miR-1 expression. CONCLUSIONS: In surgical CAD patients, a decreased miR-133 expression is associated with variables characteristic of heart failure. This supports a role for miR-133 but not miR-1 in the adaption to and/or remodeling of the ischemic heart.

In patients chronically treated with metoprolol, the demand of inotropic catecholamine support after coronary artery bypass grafting is determined by the Arg389Gly-beta 1-adrenoceptor polymorphism.

In vitro, the Arg389Gly-beta(1)-adrenoceptor (AR) polymorphism exhibits decreased receptor signaling. In vivo, dobutamine infusion evoked smaller heart rate and/or contractility increases in subjects carrying Gly389Gly-beta(1)AR vs subjects carrying Arg389Arg-beta(1)AR. The aim of this study was to find out whether the Arg389Gly-beta(1)AR polymorphism might also determine demand of catecholamine-induced inotropic support in patients with low cardiac index (CI) after coronary artery bypass grafting (CABG) surgery with cardiopulmonary bypass (CPB). For this purpose, we assessed in 82 patients, who were preoperatively chronically treated with metoprolol, after CABG surgery with CPB, the dose and duration of adrenaline-induced inotropic support in relation to the Arg389Gly-beta(1)AR genotype. Patients homozygous for the Arg389-beta(1)AR variant (n = 45) required, in comparison to patients homozygous for the Gly389-beta(1)AR variant (n = 9), lower adrenaline doses (53 +/- 24 vs 164 +/- 39 ng/kg body weight/min, p < 0.05) to reach a stable and comparable hemodynamic status and a CI >or= 3.0 l/min/m(2). Moreover, the time necessary for inotropic support tended to be shorter in patients homozygous for the Arg389-beta(1)AR than in patients homozygous for the Gly389-beta(1)AR (10.5 +/- 6 vs 20.5 +/- 12 h). Values for patients heterozygous for the Arg389Gly-beta(1)AR (n = 28) were in between. We conclude that the Arg389Gly-beta(1)AR polymorphism appears to be a determinant of cardiac responses to catecholamine stimulation. Thus, by assessment of the Arg389Gly-beta(1)AR polymorphism, it might be possible to predict demand of and therapeutic responses to beta AR agonist treatment.

No protection of heart, kidneys and brain by remote ischemic preconditioning before transfemoral transcatheter aortic valve implantation: Interim-analysis of a randomized single-blinded, placebo-controlled, single-center trial.

BACKGROUND: Remote ischemic preconditioning (RIPC) reduces myocardial injury and improves clinical outcome in patients undergoing coronary revascularization, but only in the absence of propofol-anesthesia. We investigated whether RIPC provides protection of heart, kidneys and brain and improves outcome in patients undergoing transfemoral transcatheter aortic valve implantation (TF-TAVI). METHODS: Patients undergoing TF-TAVI were randomized to receive RIPC (3cycles of 5min left upper arm ischemia and 5min reperfusion) or placebo. The primary endpoint was myocardial injury, reflected by the area under the curve for serum troponin I concentrations (AUC-TnI) over the first 72h. Secondary endpoints included the incidences of periprocedural myocardial infarction, delayed gadolinium enhancement on postprocedural cardiac MRI, acute kidney injury, periprocedural stroke, and the incidence and volume of new lesions on postprocedural cerebral MRI. All-cause and cardiovascular mortality and major adverse cardiac and cerebrovascular events (MACCE) were assessed over 1-year follow-up. A prespecified interim-analysis was performed after the last patient had completed 1-year follow-up (NCT02080299). RESULTS: 100 consecutive patients were enrolled between September 2013 and June 2015. There were no significant between-group differences in the primary endpoint of peri-interventional myocardial injury (ratio RIPC/placebo AUC-TnI: 0.87, 95% CI: 0.57-1.34, p=0.53) or the secondary endpoints of cardiac, renal and cerebral impairment. There was no significant treatment effect in subgroup-analyses of patients undergoing cardiac or cerebral MRI. Mortality and MACCE did not differ. No RIPC-related adverse events were observed. CONCLUSIONS: RIPC did neither protect heart, kidneys and brain nor improve clinical outcome in patients undergoing TF-TAVI.

G-protein-coupled receptor kinase activity in human heart failure: effects of beta-adrenoceptor blockade.

OBJECTIVES: In human end-stage heart failure as well as in experimental animal models of heart failure, G-protein-coupled receptor kinase activity (GRK) is increased while beta-adrenoceptor responsiveness is diminished. In animal studies, beta-adrenoceptor blockers reverse the GRK-mediated desensitization and down-regulation of myocardial beta-adrenoceptors. The aim of this study was to investigate whether alterations in GRK activity are an early or late accompaniment of human heart failure and whether also in humans beta-adrenoceptor blocker treatment is able to influence myocardial GRK activity. METHODS: We assessed in right atria, obtained from patients at different stages of heart failure, treated with or not treated with beta-adrenoceptor blockers, and in the four chambers of explanted hearts, obtained from patients with end-stage heart failure, beta-adrenoceptor density (by (-)-[(125)I]-iodocyanopindolol binding) and GRK activity (by an in vitro rhodopsin phosphorylation assay). RESULTS: With increasing severity of heart failure, plasma noradrenaline levels increased while myocardial beta-adrenoceptor density decreased with a maximum in GRK activity in end-stage heart failure. However, in relation to the progression of heart failure, we found that GRK activity transiently increased at an early stage of heart failure (NYHA I and II) but decreased back to control values in patients at NYHA III and IV. beta-Adrenoceptor blockers were able to reduce the early increase in GRK activity at NYHA I and II to control levels, whereas in those patients who did not have increased GRK activity (NYHA III and IV), they had only a marginal effect. CONCLUSION: According to our results, an increase in GRK activity is an early and transient event in the course of heart failure that can be prevented by beta-adrenoceptor blocker treatment.

Hox genes are involved in vascular wall-resident multipotent stem cell differentiation into smooth muscle cells.

Human vascular wall-resident CD44+ multipotent stem cells (VW-MPSCs) within the vascular adventitia are capable to differentiate into pericytes and smooth muscle cells (SMC). This study demonstrates HOX-dependent differentiation of CD44(+) VW-MPSCs into SMC that involves epigenetic modification of transgelin as a down-stream regulated gene. First, HOXB7, HOXC6 and HOXC8 were identified to be differentially expressed in VW-MPSCs as compared to terminal differentiated human aortic SMC, endothelial cells and undifferentiated pluripotent embryonic stem cells. Silencing these HOX genes in VW-MPSCs significantly reduced their sprouting capacity and increased expression of the SMC markers transgelin and calponin and the histone gene histone H1. Furthermore, the methylation pattern of the TAGLN promoter was altered. In summary, our findings suggest a role for certain HOX genes in regulating differentiation of human VW-MPSC into SMCs that involves epigenetic mechanisms. This is critical for understanding VW-MPSC-dependent vascular disease processes such as neointima formation and tumor vascularization.

Vascular wall-resident CD44+ multipotent stem cells give rise to pericytes and smooth muscle cells and contribute to new vessel maturation.

Here, we identify CD44(+)CD90(+)CD73(+)CD34(-)CD45(-) cells within the adult human arterial adventitia with properties of multipotency which were named vascular wall-resident multipotent stem cells (VW-MPSCs). VW-MPSCs exhibit typical mesenchymal stem cell characteristics including cell surface markers in immunostaining and flow cytometric analyses, and differentiation into adipocytes, chondrocytes and osteocytes under culture conditions. Particularly, TGFß1 stimulation up-regulates smooth muscle cell markers in VW-MPSCs. Using fluorescent cell labelling and co-localisation studies we show that VW-MPSCs differentiate to pericytes/smooth muscle cells which cover the wall of newly formed endothelial capillary-like structures in vitro. Co-implantation of EGFP-labelled VW-MPSCs and human umbilical vein endothelial cells into SCID mice subcutaneously via Matrigel results in new vessels formation which were covered by pericyte- or smooth muscle-like cells generated from implanted VW-MPSCs. Our results suggest that VW-MPSCs are of relevance for vascular morphogenesis, repair and self-renewal of vascular wall cells and for local capacity of neovascularization in disease processes.

Comparison of serum KL-6 versus bronchoalveolar lavage neutrophilia for the diagnosis of bronchiolitis obliterans in lung transplantation.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is a life-threatening complication after lung transplantation that is characterized by progressive fibrosis in the small airways. However, little is known about sensitive markers for detecting BOS. Our study compared the clinical utility of serum KL-6 level, a marker for pulmonary fibrosis, with that of neutrophilia in bronchoalveolar lavage fluid (BALF) for detecting BOS. METHODS: Levels of serum KL-6 were evaluated in 152 samples from 53 lung transplant recipients (BOS, 15; non-BOS, 38) and in 27 samples from age- and sex-matched healthy individuals. Pulmonary function tests, arterial blood gas analysis, and BALF cell differentials were simultaneously evaluated. RESULTS: Serum KL-6 levels were significantly increased in the BOS group compared with the non-BOS group and the healthy individuals (p < 0.0001). Receiver operating characteristic curve analysis for detecting BOS showed the largest area under the curve for KL-6 compared with lactate dehydrogenase, C-reactive protein, or neutrophils percentage in BALF. Serum KL-6 correlated with the decline in forced expiratory volume in 1 second (FEV(1)) from post-lung transplant baseline (r = 0.43; p = 0.0001). CONCLUSIONS: Serum KL-6 levels are increased and correlate with the decline from baseline in FEV(1) in lung transplant recipients. The diagnostic accuracy of serum KL-6 level is better than that of BALF neutrophilia for detecting BOS.

Is there a role of the Thr164Ile-beta(2)-adrenoceptor polymorphism for the outcome of chronic heart failure?

OBJECTIVE: The Thr164Ile-beta(2)-adrenoceptor (AR) polymorphism exhibits lower affinities for catecholamines and reduced basal and agonist-stimulated adenylyl cyclase activity in vitro. It has been suggested that patients with chronic heart failure (CHF) due to ischemic or dilated cardiomyopathy carrying the Thr164Ile-beta(2)AR polymorphism exhibit much more rapid progression to death or heart transplantation (HTX) than CHF-patients carrying the homozygous Thr164-beta(2)AR. This study aimed to further evaluate the role of the Thr164Ile-beta(2)AR in CHF. For this we hypothesized that the Thr164Ile-beta(2)AR variant should be more abundant in HTX-patients than in patients with stable CHF or healthy controls. METHODS AND RESULTS: We genotyped 309 HTX-patients, 520 stable CHF-patients and 328 healthy controls for the three beta(2)AR variants Arg16Gly, Gln27Glu and Thr164Ile. The prevalence of the Thr164Ile-beta(2)AR variant was not considerably different in HTX-patients (2.3%) from that in CHF-patients (1.9%) or healthy controls (2.1%). Similarly, the frequency of the minor Ile164-allele was f(-)=0.0106 in HTX-patients, f(-)=0.0096 in CHF-patients and f(-)=0.0113 in healthy controls. CONCLUSIONS: The prevalence of the hypofunctional Thr164Ile-beta(2)AR variant and the frequency of the Ile164-allele were almost identical in CHF-patients, who had undergone HTX, with those in patients with stable CHF or in healthy controls. Thus, the role of the Thr164Ile-beta(2)AR in CHF remains questionable.

Prognostic value of tubular proteinuria and enzymuria in nonoliguric acute tubular necrosis.

BACKGROUND: Acute tubular necrosis (ATN) has high mortality, especially in patients who require renal replacement therapy (RRT). We prospectively studied the diagnostic accuracy of the urinary excretion of low-molecular-weight proteins and enzymes as predictors of a need for RRT in ATN. METHODS: In 73 consecutive patients with initially nonoliguric ATN, we measured urinary excretion of alpha(1)- and beta(2)-microglobulin, cystatin C, retinol-binding protein, alpha-glutathione S-transferase, gamma-glutamyltransferase, lactate dehydrogenase, and N-acetyl-beta-D-glucosaminidase early in the course of ATN. RESULTS: Twenty-six patients (36%) required RRT a median of 4 (interquartile range, 2-6) days after detection of proteinuria and enzymuria. Patients who required RRT had higher urinary cystatin C and alpha(1)-microglobulin [median (interquartile range), 1.7 (1.2-4.1) and 34.5 (26.6-45.1) g/mol of creatinine] than patients who did not require RRT [0.1 (0.02-0.5) and 8.0 (5.0-17.5) g/mol of creatinine]. Urinary excretion of cystatin C and alpha(1)-microglobulin had the highest diagnostic accuracies in identifying patients requiring RRT as indicated by the largest areas under the ROC curves: 0.92 (95% confidence interval, 0.86-0.96) and 0.86 (0.78-0.92), respectively. Sensitivity and specificity were 92% (95% confidence interval, 83-96%) and 83% (73-90%), respectively, for urinary cystatin C >1 g/mol of creatinine, and 88% (78-93%) and 81% (70-88%) for urinary alpha(1)-microglobulin >20 g/mol of creatinine. CONCLUSION: In nonoliguric ATN, increased urinary excretion of cystatin C and alpha(1)-microglobulin may predict an unfavorable outcome, as reflected by the requirement for RRT.