Daniel R. Wagner

Supported High-Risk Percutaneous Coronary Intervention With the Impella 2.5 Device: The Europella Registry

OBJECTIVESnThis retrospective multicenter registry evaluated the safety and feasibility of left ventricular (LV) support with the Impella 2.5 (Abiomed Europe GmbH, Aachen, Germany) during high-risk percutaneous coronary intervention (PCI).nnnBACKGROUNDnPatients with complex or high-risk coronary lesions, such as last remaining vessel or left main lesions, are increasingly being treated with PCI. Because periprocedural hemodynamic compromise and complications might occur rapidly, many of these high-risk procedures are being performed with mechanical cardiac assistance, particularly in patients with poor LV function. The Impella 2.5, a percutaneous implantable LV assist device, might be a superior alternative to the traditionally used intra-aortic balloon pump.nnnMETHODSnThe Europella registry included 144 consecutive patients who underwent a high-risk PCI. Safety and feasibility end points included incidence of 30-day adverse events and successful device function.nnnRESULTSnPatients were older (62% >70 years of age), 54% had an LV ejection fraction < or = 30%, and the prevalence of comorbid conditions was high. Mean European System for Cardiac Operative Risk Evaluation score was 8.2 (SD 3.4), and 43% of the patients were refused for coronary artery bypass grafting. A PCI was considered high-risk due to left main disease, last remaining vessel disease, multivessel coronary artery disease, and low LV function in 53%, 17%, 81%, and 35% of the cases, respectively. Mortality at 30 days was 5.5%. Rates of myocardial infarction, stroke, bleeding requiring transfusion/surgery, and vascular complications at 30 days were 0%, 0.7%, 6.2%, and 4.0%, respectively.nnnCONCLUSIONSnThis large multicenter registry supports the safety, feasibility, and potential usefulness of hemodynamic support with Impella 2.5 in high-risk PCI.

Use of Circulating MicroRNAs to Diagnose Acute Myocardial Infarction

BACKGROUNDnRapid and correct diagnosis of acute myocardial infarction (MI) has an important impact on patient treatment and prognosis. We compared the diagnostic performance of high-sensitivity cardiac troponin T (hs-cTnT) and cardiac enriched microRNAs (miRNAs) in patients with MI.nnnMETHODSnCirculating concentrations of cardiac-enriched miR-208b and miR-499 were measured by quantitative PCR in a case-control study of 510 MI patients referred for primary mechanical reperfusion and 87 healthy controls.nnnRESULTSnmiRNA-208b and miR-499 were highly increased in MI patients (>10(5)-fold, P < 0.001) and nearly undetectable in healthy controls. Patients with ST-elevation MI (n= 397) had higher miRNA concentrations than patients with non-ST-elevation MI (n = 113) (P < 0.001). Both miRNAs correlated with peak concentrations of creatine kinase and cTnT (P < 10(-9)). miRNAs and hs-cTnT were already detectable in the plasma 1 h after onset of chest pain. In patients who presented <3 h after onset of pain, miR-499 was positive in 93% of patients and hs-cTnT in 88% of patients (P= 0.78). Overall, miR-499 and hs-cTnT provided comparable diagnostic value with areas under the ROC curves of 0.97. The reclassification index of miR-499 to a clinical model including several risk factors and hs-cTnT was not significant (P = 0.15).nnnCONCLUSIONnCirculating miRNAs are powerful markers of acute MI. Their usefulness in the establishment of a rapid and accurate diagnosis of acute MI remains to be determined in unselected populations of patients with acute chest pain.

MicroRNA-150: A Novel Marker of Left Ventricular Remodeling After Acute Myocardial Infarction

Background—Left ventricular (LV) remodeling after acute myocardial infarction is associated with adverse prognosis. MicroRNAs (miRNAs) regulate the expression of several genes involved in LV remodeling. Our aim was to identify miRNAs associated with LV remodeling after acute myocardial infarction. Methods and Results—We studied 90 patients after first ST-segment–elevation acute myocardial infarction. A derivation cohort consisted of 60 patients characterized by echocardiography predischarge and at 6-month follow-up. Thirty patients characterized by magnetic resonance imaging predischarge and at 4-month follow-up were the validation cohort. Remodeling was defined as an increase in LV end-diastolic volume (&Dgr;EDV>0) between discharge and follow-up. Circulating miRNAs were measured by microarrays and polymerase chain reaction. Using a systems-based approach, we identified several miRNAs potentially involved in LV remodeling. In the derivation cohort, one of these miRNAs, miR-150, was downregulated in patients with remodeling (&Dgr;EDV>0) compared with patients without remodeling (&Dgr;EDV⩽0). In the validation cohort, patients with remodeling had 2-fold lower levels of miR-150 than those without (P=0.03). miR-150 outperformed N-terminal pro-brain natriuretic peptide to predict remodeling (area under the receiver-operating characteristic curve of 0.74 and 0.60, respectively). miR-150 reclassified 54% (95% confidence interval, 5–102; P=0.03) of patients misclassified by N-terminal pro-brain natriuretic peptide and 59% (95% confidence interval, 9–108; P=0.02) of patients misclassified by a multiparameter clinical model, including age, sex, and admission levels of troponin I, creatine kinase, and N-terminal pro-brain natriuretic peptide. Conclusions—Low circulating levels of miR-150 are associated with LV remodeling after first ST-segment–elevation acute myocardial infarction. miR-150 has potential as a novel biomarker in this setting.Background— Left ventricular (LV) remodeling after acute myocardial infarction is associated with adverse prognosis. MicroRNAs (miRNAs) regulate the expression of several genes involved in LV remodeling. Our aim was to identify miRNAs associated with LV remodeling after acute myocardial infarction.nnMethods and Results— We studied 90 patients after first ST-segment–elevation acute myocardial infarction. A derivation cohort consisted of 60 patients characterized by echocardiography predischarge and at 6-month follow-up. Thirty patients characterized by magnetic resonance imaging predischarge and at 4-month follow-up were the validation cohort. Remodeling was defined as an increase in LV end-diastolic volume (ΔEDV>0) between discharge and follow-up. Circulating miRNAs were measured by microarrays and polymerase chain reaction. Using a systems-based approach, we identified several miRNAs potentially involved in LV remodeling. In the derivation cohort, one of these miRNAs, miR-150, was downregulated in patients with remodeling (ΔEDV>0) compared with patients without remodeling (ΔEDV≤0). In the validation cohort, patients with remodeling had 2-fold lower levels of miR-150 than those without ( P =0.03). miR-150 outperformed N-terminal pro-brain natriuretic peptide to predict remodeling (area under the receiver-operating characteristic curve of 0.74 and 0.60, respectively). miR-150 reclassified 54% (95% confidence interval, 5–102; P =0.03) of patients misclassified by N-terminal pro-brain natriuretic peptide and 59% (95% confidence interval, 9–108; P =0.02) of patients misclassified by a multiparameter clinical model, including age, sex, and admission levels of troponin I, creatine kinase, and N-terminal pro-brain natriuretic peptide.nnConclusions— Low circulating levels of miR-150 are associated with LV remodeling after first ST-segment–elevation acute myocardial infarction. miR-150 has potential as a novel biomarker in this setting.

A panel of 4 microRNAs facilitates the prediction of left ventricular contractility after acute myocardial infarction.

Background Prediction of clinical outcome after acute myocardial infarction (AMI) is challenging and would benefit from new biomarkers. We investigated the prognostic value of 4 circulating microRNAs (miRNAs) after AMI. Methods We enrolled 150 patients after AMI. Blood samples were obtained at discharge for determination of N-terminal pro-brain natriuretic peptide (Nt-proBNP) and levels of miR-16, miR-27a, miR-101 and miR-150. Patients were assessed by echocardiography at 6 months follow-up and the wall motion index score (WMIS) was used as an indicator of left ventricular (LV) contractility. We assessed the added predictive value of miRNAs against a multi-parameter clinical model including Nt-proBNP. Results Patients with anterior AMI and elevated Nt-proBNP levels at discharge from the hospital were at high risk of subsequent impaired LV contractility (follow-up WMIS>1.2, nu200a=u200a71). A combination of the 4 miRNAs (miR-16/27a/101/150) improved the prediction of LV contractility based on clinical variables (Pu200a=u200a0.005). Patients with low levels of miR-150 (odds ratio [95% confidence interval] 0.08 [0.01–0.48]) or miR-101 (0.19 [0.04–0.97]) and elevated levels of miR-16 (15.9 [2.63–95.91]) or miR-27a (4.18 [1.36–12.83]) were at high risk of impaired LV contractility. The 4 miRNA panel reclassified a significant proportion of patients with a net reclassification improvement of 66% (Pu200a=u200a0.00005) and an integrated discrimination improvement of 0.08 (Pu200a=u200a0.001). Conclusion Our results indicate that panels of miRNAs may aid in prognostication of outcome after AMI.

Modeling Serum Level of S100β and Bispectral Index to Predict Outcome After Cardiac Arrest

OBJECTIVESnThis study was designed to evaluate multimodal prognostication in patients after cardiac arrest (CA).nnnBACKGROUNDnAccurate methods to predict outcome after CA are lacking.nnnMETHODSnSeventy-five patients with CA treated with therapeutic hypothermia after cardiac resuscitation were enrolled in this prospective observational study. Serum levels of neuron-specific enolase (NSE) and neuron-enriched S100 beta (S100β) were measured 48 h after CA. Bispectral index (BIS) was continuously monitored during the first 48 h after CA. The primary endpoint was neurological outcome, as defined by the cerebral performance category (CPC) at 6-month follow-up: scores 1 or 2 indicated good outcome, and scores 3 to 5, poor outcome. The secondary endpoint was survival.nnnRESULTSnA total of 46 (61%) patients survived at 6 months and 41 (55%) patients had CPC 1 or 2. Levels of NSE and S100β were higher in patients with poor outcomes compared with patients with good outcomes (4-fold and 10-fold, respectively; p < 0.001). BIS was lower in patients with poor outcomes (10-fold; p < 0.001). NSE, S100β, or BIS alone predicted neurological outcome, with areas under the receiver-operating characteristic curve (AUC) above 0.80. Combined determination of S100β and BIS had an incremental predictive value (AUC: 0.95). S100β improved discriminations based on BIS (p = 0.0008), and BIS improved discriminations based on S100β (p < 10(-5)). Patients with S100β level above 0.03 μg/l and BIS below 5.5 had a 3.6-fold higher risk of poor neurological outcome (p < 0.0001). S100β and BIS predicted 6-month mortality (log-rank statistic: 50.41; p < 0.001).nnnCONCLUSIONSnCombined determination of serum level of S100β and BIS monitoring accurately predicts outcome after CA.

Identification of candidate long non-coding RNAs in response to myocardial infarction

BackgroundLong non-coding RNAs (lncRNAs) constitute a novel class of non-coding RNAs. LncRNAs regulate gene expression, thus having the possibility to modulate disease progression. In this study, we investigated the changes of lncRNAs expression in the heart after myocardial infarction (MI).ResultsAdult male C57/BL6 mice were subjected to coronary ligation or sham operation. In a derivation group of 4 MI and 4 sham-operated mice sacrificed 24xa0hours after surgery, microarray analysis showed that MI was associated with up-regulation of 20 lncRNAs and down-regulation of 10 lncRNAs (fold-change >2). Among these, 2 lncRNAs, called myocardial infarction-associated transcript 1 (MIRT1) and 2 (MIRT2), showed robust up-regulation in the MI group: 5-fold and 13-fold, respectively. Up-regulation of these 2 lncRNAs after MI was confirmed by quantitative PCR in an independent validation group of 8 MI and 8 sham-operated mice (9-fold and 16-fold for MIRT1 and MIRT2, Pu2009<u20090.001). In a time-course analysis involving 21 additional MI mice, the expression of both lncRNAs peaked 24xa0hours after MI and returned to baseline after 2xa0days. In situ hybridization revealed an up-regulation of MIRT1 expression in the left ventricle of MI mice. Expression of MIRT1 and MIRT2 correlated with the expression of multiple genes known to be involved in left ventricular remodeling. Mice with high level of expression of MIRT1 and MIRT2 had a preserved ejection fraction.ConclusionMyocardial infarction induces important changes in the expression of lncRNAs in the heart. This study motivates further investigation of the role of lncRNAs in left ventricular remodeling.

Adenosine up-regulates vascular endothelial growth factor in human macrophages

It is known from animal models that the cardioprotective nucleoside adenosine stimulates angiogenesis mainly through up-regulation of vascular endothelial growth factor (VEGF). Since macrophages infiltrate the heart after infarction and because adenosine receptors behave differently across species, we evaluated the effect of adenosine on VEGF in human macrophages. Adenosine dose-dependently up-regulated VEGF expression and secretion by macrophages from healthy volunteers. VEGF production was also increased by blockade of extracellular adenosine uptake with dipyridamole. This effect was exacerbated by the toll-like receptor-4 ligands heparan sulfate, hyaluronic acid and lipopolysaccharide, and was associated with an increase of hypoxia inducible factor-1alpha expression, the main transcriptional inducer of VEGF in hypoxic conditions. The agonist of the adenosine A2A receptor CGS21680 reproduced the increase of VEGF and the antagonist SCH58261 blunted it. In conclusion, these results provide evidence that activation of adenosine A2A receptor stimulates VEGF production in human macrophages. This study suggests that adenosine is a unique pro-angiogenic molecule that may be used to stimulate cardiac repair.

Adenosine Stimulates the Migration of Human Endothelial Progenitor Cells. Role ofCXCR4 and MicroRNA-150

Background Administration of endothelial progenitor cells (EPC) represents a promising option to regenerate the heart after myocardial infarction, but is limited because of low recruitment and engraftment in the myocardium. Mobilization and migration of EPC are mainly controlled by stromal cell-derived factor 1α (SDF-1α) and its receptor CXCR4. We hypothesized that adenosine, a cardioprotective molecule, may improve the recruitment of EPC to the heart. Methods EPC were obtained from peripheral blood mononuclear cells of healthy volunteers. Expression of chemokines and their receptors was evaluated using microarrays, quantitative PCR, and flow cytometry. A Boyden chamber assay was used to assess chemotaxis. Recruitment of EPC to the infarcted heart was evaluated in rats after permanent occlusion of the left anterior descending coronary artery. Results Microarray analysis revealed that adenosine modulates the expression of several members of the chemokine family in EPC. Among these, CXCR4 was up-regulated by adenosine, and this result was confirmed by quantitative PCR (3-fold increase, P<0.001). CXCR4 expression at the cell surface was also increased. This effect involved the A2B receptor. Pretreatment of EPC with adenosine amplified their migration towards recombinant SDF-1α or conditioned medium from cardiac fibroblasts. Both effects were abolished by CXCR4 blocking antibodies. Adenosine also increased CXCR4 under ischemic conditions, and decreased miR-150 expression. Binding of miR-150 to the 3′ untranslated region of CXCR4 was verified by luciferase assay. Addition of pre-miR-150 blunted the effect of adenosine on CXCR4. Administration of adenosine to rats after induction of myocardial infarction stimulated EPC recruitment to the heart and enhanced angiogenesis. Conclusion Adenosine increases the migration of EPC. The mechanism involves A2B receptor activation, decreased expression of miR-150 and increased expression of CXCR4. These results suggest that adenosine may be used to enhance the capacity of EPC to revascularize the ischemic heart.

Systems-Based Approaches to Cardiovascular Biomarker Discovery

The pace of discovery of cardiovascular biomarkers seems to be slowing. Although important advances in the identification of molecular biomarkers have been made during the past decade, it is becoming apparent that their clinical relevance is limited and that advanced discovery methods are needed.nnThere are >27 000 articles on cardiac biomarkers in PubMed. However, only a small number of these biomarkers are in clinical use. In patients with heart failure (HF), numerous biomarkers have been evaluated (Table), but only brain natriuretic peptide and its precursor molecules have been widely applied.1 In patients with stable coronary artery disease, C-reactive protein (CRP) is a potential prognostic biomarker. Although there is conflicting evidence about the ability of CRP to augment the predictive accuracy of traditional clinical risk factors,2,3 targeting patients with elevated CRP for lipid lowering therapy with rosuvastatin was associated with improved cardiovascular outcomes in 1 randomized controlled trial.4 However, a recent meta-analysis of 83 studies including >60 000 patients has questioned its value.5 The key hurdle to the introduction of new “omic” biomarkers has been the inability to demonstrate their clinical relevance and validity. This refers not only to meeting analytic validity and independent evaluation criteria, but also to the biomarkers capacity to guide the improvement of patient outcomes. We believe that a more integrated, unbiased approach is essential to discover novel diagnostic and prognostic models of heart disease.nnView this table:nnTable. nExamples of Biomarkers in Heart FailurennnnBiomarker discovery research has traditionally emphasized the study of individual molecular indicators of clinical condition. A major limitation of this approach is that the informational complexity underpinning many clinical states are not adequately taken into account.nnThe relevance of hypothesis-driven, reductionist approaches to biomarker discovery is indisputable. However, an overreliance on this strategy may limit the translation of fundamental …

Proteomic analysis of plasma samples from patients with acute myocardial infarction identifies haptoglobin as a potential prognostic biomarker

Prognosis of clinical outcome following myocardial infarction is variable and difficult to predict. We have analyzed the plasma proteome of thirty patients with acute myocardial infarction to search for new prognostic biomarkers. Proteomic analyses of blood samples were performed by 2-D-DiGE after plasma depletion of albumin and immunoglobulins G. New York Heart Association (NYHA) class determined at 1-year follow-up was used to identify patients with heart failure. Principal component analysis and hierarchical clustering of proteomic data revealed that patients could be separated into 3 groups. The 22 differentially expressed proteins involved in this grouping were identified as haptoglobin (Hp) and respective isoforms. The 3 groups of patients had distinct Hp isoforms: patients from group 1 had the α1-α1, patients from group 2 the α2-α1, and patients from group 3 the α2-α2 genotype. This classification was also associated with different total plasma levels of Hp. The presence of the α2 genotype and low plasma levels of Hp was associated with a higher NYHA class and therefore with a detrimental functional outcome after myocardial infarction. A plasma level of Hp below 1.4g/L predicted the occurrence of heart failure (NYHA 2, 3, 4) at 1-year with 100% sensitivity.