Antithrombotic Treatment for Stroke Prevention in Cervical Artery Dissection: The STOP-CAD Study.

BACKGROUND: Small, randomized trials of patients with cervical artery dissection showed conflicting results regarding optimal stroke prevention strategies. We aimed to compare outcomes in patients with cervical artery dissection treated with antiplatelets versus anticoagulation. METHODS: This is a multicenter observational retrospective international study (16 countries, 63 sites) that included patients with cervical artery dissection without major trauma. The exposure was antithrombotic treatment type (anticoagulation versus antiplatelets), and outcomes were subsequent ischemic stroke and major hemorrhage (intracranial or extracranial hemorrhage). We used adjusted Cox regression with inverse probability of treatment weighting to determine associations between anticoagulation and study outcomes within 30 and 180 days. The main analysis used an as-treated crossover approach and only included outcomes occurring with the above treatments. RESULTS: The study included 3636 patients (402 [11.1%] received exclusively anticoagulation and 2453 [67.5%] received exclusively antiplatelets). By day 180, there were 162 new ischemic strokes (4.4%) and 28 major hemorrhages (0.8%); 87.0% of ischemic strokes occurred by day 30. In adjusted Cox regression with inverse probability of treatment weighting, compared with antiplatelet therapy, anticoagulation was associated with a nonsignificantly lower risk of subsequent ischemic stroke by day 30 (adjusted hazard ratio [HR], 0.71 [95% CI, 0.45-1.12]; P=0.145) and by day 180 (adjusted HR, 0.80 [95% CI, 0.28-2.24]; P=0.670). Anticoagulation therapy was not associated with a higher risk of major hemorrhage by day 30 (adjusted HR, 1.39 [95% CI, 0.35-5.45]; P=0.637) but was by day 180 (adjusted HR, 5.56 [95% CI, 1.53-20.13]; P=0.009). In interaction analyses, patients with occlusive dissection had significantly lower ischemic stroke risk with anticoagulation (adjusted HR, 0.40 [95% CI, 0.18-0.88]; Pinteraction=0.009). CONCLUSIONS: Our study does not rule out the benefit of anticoagulation in reducing ischemic stroke risk, particularly in patients with occlusive dissection. If anticoagulation is chosen, it seems reasonable to switch to antiplatelet therapy before 180 days to lower the risk of major bleeding. Large prospective studies are needed to validate our findings.

A 4-Variable Model to Predict Cardio-Kidney Events and Mortality in Chronic Kidney Disease: The Chronic Renal Insufficiency Cohort (CRIC) Study.

INTRODUCTION: Current prognostic models for chronic kidney disease (CKD) are complex and were designed to predict a single outcome. We aimed to develop and validate a simple and parsimonious prognostic model to predict cardio-kidney events and mortality. METHODS: Patients from the CRIC Study (n = 3,718) were randomly divided into derivation (n = 2,478) and validation (n = 1,240) cohorts. Twenty-nine candidate variables were preselected. Multivariable Cox regression models were developed using stepwise selection for various cardio-kidney endpoints, namely, (i) the primary composite outcome of 50% decline in estimated glomerular filtration rate (eGFR) from baseline, end-stage renal disease, or cardiovascular (CV) mortality; (ii) hospitalization for heart failure (HHF) or CV mortality; (iii) 3-point major CV endpoints (3P-MACE); (iv) all-cause death. RESULTS: During a median follow-up of 9 years, the primary outcome occurred in 977 patients of the derivation cohort and 501 patients of the validation cohort. Log-transformed N-terminal pro-B-type natriuretic peptide (NT-proBNP), log-transformed high-sensitive cardiac troponin T (hs-cTnT), log-transformed albuminuria, and eGFR were the dominant predictors. The primary outcome risk score discriminated well (c-statistic = 0.83) with a proportion of events of 11.4% in the lowest tertile of risk and 91.5% in the highest tertile at 10 years. The risk model presented good discrimination for HHF or CV mortality, 3P-MACE, and all-cause death (c-statistics = 0.80, 0.75, and 0.75, respectively). The 4-variable risk model achieved similar c-statistics for all tested outcomes in the validation cohort. The discrimination of the 4-variable risk model was mostly superior to that of published models. CONCLUSION: The combination of NT-proBNP, hs-cTnT, albuminuria, and eGFR in a single 4-variable model provides a unique individual prognostic assessment of multiple cardio-kidney outcomes in CKD.

Acute Ischemic Stroke Outcome and Preceding Anticoagulation: Direct Oral Anticoagulants Versus Vitamin K Antagonists.

BACKGROUND AND PURPOSE: Acute ischemic stroke (AIS) severity and clinical course are less known in direct oral anticoagulants (DOAC) users. We aimed to explore the outcome of AIS in patients pretreated with vitamin-K-antagonists (VKA) and DOAC. METHODS: A retrospective study was performed. Patients pretreated with oral anticoagulants (OAC) for nonvalvular atrial fibrillation admitted for AIS in a stroke unit between 2016-01-01 and 2018-08-31 were included. The primary endpoint was mortality during the hospital stay, and secondary endpoints were neurologic improvement at stroke unit discharge and good functional outcome 90 days after AIS. RESULTS: A total of 156 patients were included (83 on VKA and 73 on DOAC). Stroke severity (defined by NIHSS on admission) was comparable in both groups (AVK 13.0 [4.0-20.0] versus DOAC 11.0 [4.0-17.0], P = .435). Infratherapeutic levels and/or inappropriate low dose of OAC was also similar between groups (P = .152) and was not associated with stroke severity (P = .631) or mortality (P = .788). VKA (OR 12.616, P = .035, 95%CI 1.19-133.64) and PH2 hemorrhagic transformation (OR 7.516, P = .024, 95%CI 1.31-43.20) were associated with higher mortality in multivariate analysis. Higher stroke severity (OR .101, P < .001, 95%CI .037-.279) and VKA usage (OR .212, P = .003, 95%CI .08-.58) were associated with worse functional outcome at 3 months. Reperfusion therapy was significantly associated with neurologic improvement during stroke unit stay (OR 3.969, P = .009, 95%CI 1.42-11.11) but not with the functional outcome (P = .063). CONCLUSIONS: Nonvalvular atrial fibrillation patients pretreated with DOAC admitted for AIS had a better outcome when compared to VKA, although stroke severity was similar between groups.

Original Intracerebral Hemorrhage Score for the Prediction of Short-Term Mortality in Cerebral Hemorrhage: Systematic Review and Meta-Analysis.

OBJECTIVES: To systematically assess the discrimination and calibration of the Intracerebral Hemorrhage score for prediction of short-term mortality in intracerebral hemorrhage patients and to study its determinants using heterogeneity analysis. DATA SOURCES: PubMed, ISI Web of Knowledge, Scopus, and CENTRAL from inception to September 15, 2018. STUDY SELECTION: Adult studies validating the Intracerebral Hemorrhage score for mortality prediction in nontraumatic intracerebral hemorrhage at 1 month/discharge or sooner. DATA EXTRACTION: Data were collected on the following aspects of study design: population studied, level of care, timing of outcome measurement, mean study year, and mean cohort Intracerebral Hemorrhage score. The summary measures of interest were discrimination as assessed by the C-statistic and calibration as assessed by the standardized mortality ratio (observed:expected mortality ratio). Random effect models were used to pool both measures. Heterogeneity was measured using the I statistic and explored using subgroup analysis and meta-regression. DATA SYNTHESIS: Fifty-five studies provided data on discrimination, and 35 studies provided data on calibration. Overall, the Intracerebral Hemorrhage score discriminated well (pooled C-statistic 0.84; 95% CI, 0.82-0.85) but overestimated mortality (pooled observed:expected mortality ratio = 0.87; 95% CI, 0.78-0.97), with high heterogeneity for both estimates (I 80% and 84%, respectively). Discrimination was affected by study mean Intracerebral Hemorrhage score (ß = -0.05), and calibration was affected by disease severity, with the score overestimating mortality for patients with an Intracerebral Hemorrhage score greater than 3 (observed:expected mortality ratio = 0.84; 95% CI, 0.78-0.91). Mortality rates were reproducible across cohorts for patients with an Intracerebral Hemorrhage score 0-1 (I = 15%). CONCLUSIONS: The Intracerebral Hemorrhage score is a valid clinical prediction rule for short-term mortality in intracerebral hemorrhage patients but discriminated mortality worse in more severe cohorts. It also overestimated mortality in the highest Intracerebral Hemorrhage score patients, with significant inconsistency between cohorts. These results suggest that mortality for these patients is dependent on factors not included in the score. Further studies are needed to determine these factors.

MicroRNA-155 Amplifies Nitric Oxide/cGMP Signaling and Impairs Vascular Angiotensin II Reactivity in Septic Shock.

OBJECTIVES: Septic shock is a life-threatening clinical situation associated with acute myocardial and vascular dysfunction, whose pathophysiology is still poorly understood. Herein, we investigated microRNA-155-dependent mechanisms of myocardial and vascular dysfunction in septic shock. DESIGN: Prospective, randomized controlled experimental murine study and clinical cohort analysis. SETTING: University research laboratory and ICU at a tertiary-care center. PATIENTS: Septic patients, ICU controls, and healthy controls. Postmortem myocardial samples from septic and nonseptic patients. Ex vivo evaluation of arterial rings from patients undergoing coronary artery bypass grafting. SUBJECTS: C57Bl/6J and genetic background-matched microRNA-155 knockout mice. INTERVENTIONS: Two mouse models of septic shock were used. Genetic deletion and pharmacologic inhibition of microRNA-155 were performed. Ex vivo myographic studies were performed using mouse and human arterial rings. MEASUREMENTS AND MAIN RESULTS: We identified microRNA-155 as a highly up-regulated multifunctional mediator of sepsis-associated cardiovascular dysfunction. In humans, plasma and myocardial microRNA-155 levels correlate with sepsis-related mortality and cardiac injury, respectively, whereas in murine models, microRNA-155 deletion and pharmacologic inhibition attenuate sepsis-associated cardiovascular dysfunction and mortality. MicroRNA-155 up-regulation in septic myocardium was found to be mostly supported by microvascular endothelial cells. This promoted myocardial microvascular permeability and edema, bioenergetic deterioration, contractile dysfunction, proinflammatory, and nitric oxide-cGMP-protein kinase G signaling overactivation. In isolate cardiac microvascular endothelial cells, microRNA-155 up-regulation significantly contributes to LPS-induced proinflammatory cytokine up-regulation, leukocyte adhesion, and nitric oxide overproduction. Furthermore, we identified direct targeting of CD47 by microRNA-155 as a novel mechanism of myocardial and vascular contractile depression in sepsis, promoting microvascular endothelial cell and vascular insensitivity to thrombospondin-1-mediated inhibition of nitric oxide production and nitric oxide-mediated vasorelaxation, respectively. Additionally, microRNA-155 directly targets angiotensin type 1 receptor, decreasing vascular angiotensin II reactivity. Deletion of microRNA-155 restored angiotensin II and thrombospondin-1 vascular reactivity in LPS-exposed arterial rings. CONCLUSIONS: Our study demonstrates multiple new microRNA-155-mediated mechanisms of sepsis-associated cardiovascular dysfunction, supporting the translational potential of microRNA-155 inhibition in human septic shock.

Angiotensin-(1-7) modulates angiotensin II-induced vasoconstriction in human mammary artery.

PURPOSE: The renin-angiotensin system plays a key role in cardiovascular pathophysiology and one of its members, angiotensin-(1-7) (ANG-(1-7)), is now recognized as a peptide with the ability to counter-regulate angiotensin II (ANGII) effects. We sought to investigate ANG-(1-7) actions in human vessels, particularly its effect on ANGII-induced vasoconstriction in human mammary arteries (HMA). METHODS: Samples of HMA from patients submitted to coronary revascularization (22 patients, mean age 67 years) were cut into small rings, mounted in a myograph bath system, normalized and allowed to contract and dilate isometrically. In baseline experiments, the rings were incubated with ANG-(1-7) or vehicle, followed by increasing concentrations of ANGII. This protocol was repeated in the presence of A-779, PD123177, losartan and after mechanical endothelium removal. Western blot analysis and immunofluorescence were also performed in order to verify the presence of Mas receptor in HMA. RESULTS: ANG-(1-7) significantly attenuated ANGII-induced contraction, producing a maximal inhibition of approximately 65.2%. This effect was not abolished by A-779, PD123177 or endothelium removal. In the presence of losartan, ANGII response was attenuated and no differences were observed between ANG-(1-7) and vehicle treated rings. Finally, we observed, for the first time, that the Mas receptor is expressed in HMA endothelium. CONCLUSIONS: ANG-(1-7) significantly attenuates ANGII-induced vasoconstriction and, although the Mas receptor is expressed in HMA, this effect seems to be independent of its activation. Additionally, AT2 receptor and endothelium are not involved in this mechanism, which suggests a direct effect on smooth muscle cells.

Prognostic association of circulating relaxin-2 in acute heart failure.

BACKGROUND: Despite the increasing interest in the study of the endogenous relaxin system in heart failure (HF), its role as a prognostic marker in acute HF remains unclear. We aimed to evaluate the association of relaxin-2 circulating levels with 6 months' mortality in acute HF. METHODS: We evaluated relaxin-2 serum levels at admission in a cohort of patients with acute HF (n = 202) using an enzyme immunoassay. The ability of relaxin-2 to predict all-cause death (primary outcome) and HF-specific death (secondary outcome) at 6 months was assessed using Cox-regression analysis. RESULTS: The median age was 79 (70-85) years old, 44% of the patients were male, and 43% had preserved ejection fraction (≥50%). Median serum relaxin-2 level was 25 pg/mL. Patients with higher relaxin-2 levels had more peripheral oedemas, higher sodium retention score, higher pulmonary artery pressures, higher prevalence of right ventricle dysfunction and lower inferior vena cava collapse at inspiration. Conversely, there was no association with left chambers parameters or with B-type natriuretic peptide (BNP). Higher relaxin-2 concentrations were associated with a higher risk of all-cause death [HR 1.15; 95%CI 1.01,1.30; P = 0.030] and HF-specific death [HR 1.21; 95% CI 1.03-1.42; P = 0.018], after adjustment for classical prognostic factors such as age, sex and BNP. CONCLUSIONS: In our acute HF population, relaxin-2 circulating levels were associated with clinical and echocardiographic markers of systemic congestion and with 6-months' mortality, independently of BNP. These results lay the groundwork for future investigations on the potential of relaxin-2 as an auxiliary biomarker in HF.

Intravenous Thrombolysis in Patients With Cervical Artery Dissection: A Secondary Analysis of the STOP-CAD Study.

OBJECTIVES: Cervical artery dissection (CeAD) accounts for 25% of ischemic strokes in young adults. This study evaluated the benefits and harms of intravenous thrombolysis (IVT) in patients presenting with spontaneous CeAD and acute ischemic stroke symptoms. METHODS: This analysis used data from the retrospective STOP-CAD study and included patients with spontaneous CeAD who presented within 1 day of acute ischemic stroke symptoms. Patients were dichotomized into those who received IVT and those managed without IVT. We assessed the association between IVT and 90-day functional independence (modified Rankin Scale scores 0-2) and the incidence of symptomatic intracranial hemorrhage (ICH, defined as ICH causing new or worsening neurologic symptoms within 72 hours after CeAD diagnosis). RESULTS: This study included 1,653 patients from the original STOP-CAD cohort of 4,023. The median age was 49 years, and 35.1% were women; 512 (31.0%) received IVT. IVT was associated with 90-day functional independence (adjusted odds ratio [aOR] = 1.67, 95% CI 1.23-2.28, p = 0.001), but not with symptomatic ICH (aOR = 1.52, 95% CI 0.79-2.92, p = 0.215). DISCUSSION: In patients with spontaneous CeAD and suspected ischemic stroke, IVT improved functional outcomes, without increasing symptomatic ICH risk. These findings support current guideline recommendations to consider thrombolysis for otherwise eligible patients with CeAD. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that IVT significantly increases the probability of 90-day functional independence in patients with CeAD.

Association between serum phosphorus and mortality in NHANES 2003-2006: the effect of gender and renal function.

BACKGROUND: The impact of high serum phosphorus in the general population is still debated. Studies are heterogeneous, most lack an adjustment for parathyroid hormone, vitamin D and phosphorus intake and the effect might differ by gender and renal function. We investigated the association between serum phosphorus and mortality in American adults. METHODS: We prospectively analyzed 5698 non-pregnant and non-CKD adults from the National Health and Nutrition Examination Survey (NHANES) 2003-2006. Serum phosphorus and potential confounders including parathyroid hormone, 25(OH)vitamin D and phosphorus intake were evaluated. All-cause, cardiovascular- and cancer-related deaths were recorded through December 31st, 2015. Sex-specific terciles of serum phosphorus were used to fit adjusted Cox proportional hazard models for mortality. Analysis was stratified by gender and renal function. RESULTS: A total of 590 deaths were recorded over a median follow-up of 81 months. Women showed higher serum phosphorus than men. The adjusted hazard ratio (HR) for all-cause mortality was 1.35 (95% CI 1.08-1.58) (p = 0.033) for the third tercile (versus second tercile). This increased risk was present in participants with estimated glomerular filtration rate (eGFR) below 90 ml/min/1.73 m2 but not above, although interaction was not significant (p = 0.12). Interaction by gender, phosphorus intake, PTH and fasting time was also not detected. For cardiovascular and cancer mortality, the adjusted HR was 0.81 (95% CI 0.33-2.00) (p = NS) and 1.45 (95% CI 0.77-2.72) (p = NS), respectively. CONCLUSIONS: We demonstrated that the highest tercile of serum phosphorus is associated with increased all-cause mortality, irrespective of PTH, 25(OH)vitamin D or phosphorus intake. This association may differ by gender and renal function, but larger studies testing for effect modification are needed.

Early anticoagulation in atrial fibrillation-related acute ischaemic stroke: efficacy and safety profile.

OBJECTIVES: To evaluate the effects of early anticoagulation on functional outcome, recurrent ischaemic events and haemorrhagic complications in Atrial Fibrillation (AF)-related acute ischaemic strokes (AIS). MATERIALS AND METHODS: We retrospectively evaluated patients hospitalised in a Stroke Unit due to AF-related AIS. Patients were divided according to anticoagulation initiation timing (0-4 days, 5-14 days, no anticoagulation by the 14th day). We assessed the following outcomes at 3 months: favourable functional outcome [modified Rankin Scale (mRS) score 0-2 or equal to pre-stroke], recurrent ischaemic events and haemorrhagic complications after anticoagulation initiation. RESULTS: We included 395 patients. Anticoagulation was initiated at days 0-4 in 33.9% of patients, days 5-14 in 25.3% and not initiated by the day 14 in 40.8%. Factors associated with earlier anticoagulation included lower previous mRS, valvular AF and lower stroke severity. Favourable functional outcome occurred in 40.2% of patients, with lower odds in those anticoagulated at 5-14 versus 0-4 days (OR: 0.47, 95% CI: 0.23-0.94), independently of age, previous mRS and stroke severity. Recurrent ischaemic events occurred in 8.3% of patients, with higher odds in non-anticoagulated patients by the 14th day, compared to the remainder groups (OR: 3.26, 95% CI: 1.29-8.22 vs. 0-4 days and OR: 8.16, 95% CI: 1.76-37.9 vs. 5-14 days). In patients who started anticoagulation (n = 288), haemorrhagic complications occurred in 10.8%, being more frequent in those who started at 0-4 days vs. > 14 days. However, it did not abolish the 0-4-day initiation's benefit on functional outcome. CONCLUSIONS: Early anticoagulation was associated with lower ischaemic recurrence and better functional outcome at 3 months. Additional studies are needed to better clarify its haemorrhagic risk.

Urocortin-2 in Acute Heart Failure: Role as a Marker of Volume Overload and Pulmonary Hypertension.

Urocortin (Ucn)-2 has shown promising therapeutic effects on heart failure (HF). However, there are still significant knowledge gaps regarding the role and modulation of the endogenous Ucn-2 axis in the cardiovascular system and, specifically, in acute HF. We evaluated Ucn-2 levels in admission serum samples of 80 acute HF patients and assessed their association with clinical, analytical and echocardiographic parameters. Median age was 76.5 years, and 37 patients (46%) were male. Median serum Ucn-2 was 2.3ng/mL. Ucn-2 levels were positively associated with peripheral edemas (P = 0.022), hepatomegaly (P = 0.007) and sodium retention score (ρ = 0.37, P = 0.001) and inversely correlated with inferior vena cava collapse at inspiration (ρ = -0.37, P = 0.001). Additionally, patients with higher Ucn-2 levels had a higher prevalence of right atrial dilation (P = 0.027), right ventricle dilation (P = 0.008), and higher systolic pulmonary artery pressure (ρ = 0.34, P = 0.002). Regarding analytical parameters, Ucn-2 correlated positively with log BNP (r = 0.22, P = 0.055) and inversely with uric acid (r = 0.24, P = 0.029) and total (r = -0.30, P = 0.007) and low-density lipoprotein cholesterol (r = -0.23, P = 0.038). No associations were found between Ucn-2 and age, sex or left heart structure or function. In conclusion, Circulating Ucn-2 was associated with clinical and echocardiographic markers of volume overload and pulmonary hypertension in acute HF patients.

Relaxin-2, pathophysiological insights and outcomes in heart failure with preserved ejection fraction: Findings from the NETDiamond cohort.

AIMS: The role of relaxin-2 as a circulating marker in heart failure (HF) with preserved ejection fraction (HFpEF) is poorly understood. We aimed to characterize relaxin-2 circulating levels in a population of chronic HFpEF patients and their association with long-term prognosis. METHODS: Relaxin-2 serum levels were measured in 85 chronic HFpEF patients from a prospective cohort study (NETDiamond). Clinical, imaging, and analytical data were compared across relaxin-2 tertiles. The primary outcome was a composite of cardiovascular death, HF hospitalisation, acute HF episode or diuretic intensification and the secondary outcome a composite of cardiovascular death and total HF hospitalisations. Cox regression and negative binomial models were used to assess the relation between relaxin-2 and the outcomes. RESULTS: Relaxin-2 levels were positively associated with left atrial volume, left ventricular mass and peripheral oedema, and negatively associated with ischemic heart disease and statin use. Higher relaxin-2 levels were associated with an increased risk of primary outcome, even after adjustment for age, B-type natriuretic peptide (BNP) and glomerular filtration rate (eGFR) (adjusted HR = 2.80, 95%CI 1.4-7.3, p = 0.034 for tertile 3). They were also associated with the occurrence of the secondary outcome (Incidence Rate Ratio = 5.28, 95%CI 1.2-23.2, p = 0.027), but this significance was lost when simultaneously adjusted for BNP and eGFR. CONCLUSION: In chronic HFpEF patients, higher relaxin-2 circulating levels were associated with left chambers remodelling, congestion, and adverse prognosis. These findings support a potential role for relaxin-2 as a pathophysiological agent and as a circulating biomarker in HFpEF.

Relaxin and the Cardiovascular System: from Basic Science to Clinical Practice.

The peptide hormone relaxin was originally linked to reproductive physiology, where it is believed to mediate systemic and renal hemodynamic adjustments to pregnancy. Recently, its broad range of effects in the cardiovascular system has been the focus of intensive research regarding its implications under pathological conditions and potential therapeutic potential. An understanding of the multitude of cardioprotective actions prompted the study of serelaxin, recombinant human relaxin-2, for the treatment of acute heart failure. Despite early promising results from phase II studies, recently revealed RELAX-AHF-2 outcomes were rather disappointing and the treatment for acute heart failure remains an unmet medical need. This article reviews the physiologic actions of relaxin on the cardiovascular system and its relevance in the pathophysiology of cardiovascular disease. We summarize the most updated clinical data and discuss future directions of serelaxin for the treatment of acute heart failure. This should encourage additional work to determine how can relaxin's beneficial effects be exploited for the treatment of cardiovascular disease.

Angiotensin II-induced increase in myocardial distensibility and its modulation by the endocardial endothelium in the rabbit heart.

As recently demonstrated, angiotensin II (Ang II) induces an increase in myocardial distensibility. Although endothelin-1 and the endocardial endothelium (EE) also modulate myocardial diastolic properties, their interaction with Ang II at this level has not yet been investigated. Increasing concentrations of Ang II (from 10(-8) to 10(-5) M) were studied in rabbit right papillary muscles in the following conditions: (1) baseline; (2) after selective removal of EE with Triton X-100; and (3) with intact EE in presence of a non-selective endothelin receptor antagonist (PD-145065), a selective endothelin type A receptor antagonist (BQ-123), an inhibitor of nitric oxide synthesis (N(G)-nitro-L-arginine (L-NA) or an inhibitor of the NAD(P)H oxidase (apocynin). At baseline, Ang II induced a concentration-dependent positive inotropic effect and an increase in passive muscle length (L) up to 1.020 +/- 0.004 L/L(max). After restoring muscle length to maximal physiological length (L(max)), passive tension decreased by 46.1 +/- 4.0%. When the EE was removed, the effect on myocardial distensibility was abolished. With intact EE in presence of PD-145065, BQ-123 or L-NA, the effects of Ang II on myocardial distensibility were attenuated, with a maximal increase in passive muscle length of 1.0087 +/- 0.0012, 1.0068 +/- 0.0022 and 1.0066 +/- 0.0020 L/L(max) and a decrease in resting tension of 22.6 +/- 3.6, 16.1 +/- 6.0 and 20.4 +/- 5.6%, respectively. In the presence of apocynin, the effect on myocardial distensibility was abolished. In conclusion, the Ang II-dependent acute increase in myocardial distensibility is abolished by the selective removal of the EE and attenuated in the presence of endothelin-1 receptor antagonists, an inhibitor of nitric oxide synthesis or an inhibitor of NAD(P)H oxidase.

Lipid Antigen Presentation by CD1b and CD1d in Lysosomal Storage Disease Patients.

The lysosome has a key role in the presentation of lipid antigens by CD1 molecules. While defects in lipid antigen presentation and in invariant Natural Killer T (iNKT) cell response were detected in several mouse models of lysosomal storage diseases (LSD), the impact of lysosomal engorgement in human lipid antigen presentation is poorly characterized. Here, we analyzed the capacity of monocyte-derived dendritic cells (Mo-DCs) from Fabry, Gaucher, Niemann Pick type C and Mucopolysaccharidosis type VI disease patients to present exogenous antigens to lipid-specific T cells. The CD1b- and CD1d-restricted presentation of lipid antigens by Mo-DCs revealed an ability of LSD patients to induce CD1-restricted T cell responses within the control range. Similarly, freshly isolated monocytes from Fabry and Gaucher disease patients had a normal ability to present α-Galactosylceramide (α-GalCer) antigen by CD1d. Gaucher disease patients' monocytes had an increased capacity to present α-Gal-(1-2)-αGalCer, an antigen that needs internalization and processing to become antigenic. In summary, our results show that Fabry, Gaucher, Niemann Pick type C, and Mucopolysaccharidosis type VI disease patients do not present a decreased capacity to present CD1d-restricted lipid antigens. These observations are in contrast to what was observed in mouse models of LSD. The percentage of total iNKT cells in the peripheral blood of these patients is also similar to control individuals. In addition, we show that the presentation of exogenous lipids that directly bind CD1b, the human CD1 isoform with an intracellular trafficking to the lysosome, is normal in these patients.

Negative inotropic effect of selective AT2 receptor stimulation and its modulation by the endocardial endothelium.

Angiotensin II is an octapeptide whose effects are mediated by two types of receptors. AT(1) receptors are responsible for the vasoconstrictor, positive inotropic and growth promoting properties, while AT(2) receptors have been linked to vasodilator and anti-mitogenic properties. In this study we investigated the effects of selective AT(2) receptor stimulation on myocardial contractility and lusitropy. Effects of selective AT(2) receptor activation were evaluated in rabbit right papillary muscles (n=96) by adding increasing concentrations of H-9395, an AT(2) receptor agonist, alone or in presence of a selective AT(1) receptor antagonist (ZD-7155), or alternatively, by adding increasing concentrations of angiotensin II in presence of ZD-7155. In the latter conditions, selective AT(2) receptor activation was also performed in presence of NG-nitro-L-Arginine, indomethacin, proadifen, hydroxocobalamin, apamin plus charybdotoxin, Hoe-140 or PD-123,319, as well as, after endocardial endothelium removal. Selective AT(2) stimulation induced a negative inotropic and lusitropic effect in the first three protocols. This effect was completely abolished after selective removal of the endocardial endothelium and blunted in presence of Hoe-140, hydroxocobalamin, apamin plus charybdotoxin and PD-123,319, but maintained in presence of NG-nitro-L-Arginine, indomethacin or proadifen. Selective AT(2) receptor stimulation induces a negative inotropic and lusitropic effect, which is modulated by endocardial endothelium and mediated by bradykinin B(2) receptors through NO release and calcium dependent potassium channels activation. Such findings may help to better understand the therapeutic effects of selective AT(1) antagonists, which are increasingly used for treating cardiovascular diseases.

Relaxin serum levels in acute heart failure are associated with pulmonary hypertension and right heart overload.

AIMS: Despite the promising results of serelaxin as a new potential acute heart failure (HF) therapy, its clinical use preceded the understanding of the endogenous relaxin system in HF. We aimed to evaluate relaxin circulating levels in a population of acute HF and their association with clinical and echocardiographic parameters. METHODS AND RESULTS: We included 117 patients from a registry of acute HF. Admission serum relaxin was measured using an enzyme-linked immunosorbent assay (ELISA) kit. Clinical, analytical, and echocardiographic parameters were compared between patients with relaxin levels above and below the median. Median age was 82 years [interquartile range (IQR) 72-87], 41% of the patients were male, and 63% had systolic dysfunction. Median serum relaxin was 31.4 pg/mL (IQR 0.6-89.8). Patients with relaxin levels above the median had more peripheral oedema (89.8% vs. 68.4%, P = 0.004) and a significantly higher sodium retention score (mean 4.8 ± 1.5 vs. 3.6 ± 2.0, P < 0.001). These patients also had significantly higher systolic pulmonary arterial pressure [median 47.0 (IQR 36.0-61.0) vs. 34.5 (IQR 25.0-51.0) mmHg, P = 0.002], higher prevalence of right ventricular (RV) systolic dysfunction (28.1% vs. 10.3%, P = 0.02), RV dilation (31.0% vs. 5.3%, P < 0.001), and right atrial dilation (66.1% vs. 36.5%, P = 0.002), and less inferior vena cava diameter variability (40% vs. 60%, P = 0.009). No differences were noted regarding admission blood pressure, left chamber dimensions, or LV function. CONCLUSION: In our population of acute HF patients, admission relaxin serum levels were associated with clinical and echocardiographic markers of pulmonary hypertension, RV dysfunction, and overload, suggesting a role for circulating relaxin as a biomarker in this setting.

Angiotensin II acutely decreases myocardial stiffness: a novel AT1, PKC and Na+/H+ exchanger-mediated effect.

Acute effects of angiotensin II (AngII) on diastolic properties of the myocardium were investigated. Increasing concentrations of AngII (10(-9) to 10(-5) M) were added to rabbit papillary muscles in the absence (n=11) or presence of: (i) AT1 receptor antagonists, losartan (10(-6) M; n=7) or ZD-7155 (10(-7) M; n=8); (ii) ZD-7155 (10(-7) M) plus AT2 receptor antagonist PD-123,319 (2 x 10(-6) M; n=6); (iii) PKC inhibitor, chelerythrine (10(-5) M; n=8); or (iv) Na(+)/H(+) exchanger (NHE) inhibitor, 5-(N-methyl-N-isobutyl)-amiloride (10(-6) M; n=10). Passive length-tension relations were constructed before and after a single concentration of AngII (10(-5) M, n=6). Effects of AngII infusion (10 microg kg(-1) min(-1)) were evaluated in in situ rabbit hearts. AngII concentration dependently increased inotropy and resting muscle length (RL). At 10(-5) M, active tension increased 43.3+/-6.25% and RL 1.96+/-0.4%. Correcting RL to its initial value resulted in a 46+/-4% decrease of resting tension, indicating decreased muscle stiffness, as confirmed by the right and downward shift of the passive length-tension relation promoted by AngII. In the intact heart, at matched systolic pressures of 112 mmHg, AngII decreased end-diastolic pressures from 10.3+/-0.3 to 5.9+/-0.5 mmHg, and minimal diastolic pressures from 8.4+/-0.5 to 4.6+/-0.6 mmHg. AT1 blockade inhibited AngII effects on myocardial inotropy and stiffness, while PKC or NHE inhibition only significantly attenuated its effects on resting length and tension. In conclusion, AngII decreases myocardial stiffness, an effect that requires AT1 receptor activation and is mediated by PKC and NHE. This represents a novel mechanism of acute neurohumoral modulation of diastolic function, suggesting that AngII is a powerful regulator of cardiac filling.

Inotropic and lusitropic effects of ghrelin and their modulation by the endocardial endothelium, NO, prostaglandins, GHS-R1a and KCa channels.

Contractile effects of ghrelin (10(-9) to 10(-6) M) were tested in rat papillary muscles of normal (n = 50) and hypertrophic (n = 16) right ventricles (RV). RV hypertrophy was induced by pulmonary hypertension using monocrotaline. In normal muscles, ghrelin was added either alone (n = 9) or after pre-treatment with indomethacin (cycloxygenase inhibitor, 10(-5) M; n = 10), L-nitro-L-arginin (NO synthase inhibitor, 10(-4) M; n = 9), D-Lys(3)-GHRP-6 (GHS-R1a antagonist; 10(-4) M; n = 8) or apamin+charybdotoxin (KCa channels blockers; 10(-6) M, n =7 ), as well as after damaging the endocardial endothelium (n = 7). In hypertrophic muscles, ghrelin was added either alone (n = 9) or after pre-treatment with apamin+charybdotoxin (10(-6 M, n=7). Ghrelin concentration-dependently decreased active tension (AT) and maximal velocity of tension rise (negative inotropic effect), as well as, maximal velocity of tension decay (negative lusitropic effect) and time to AT (onset of relaxation). These effects were maximal at 10(-6) M, similar in normal and hypertrophic muscles and were significantly altered only by apamin+charybdotoxin, indomethacin and L-nitro-L-arginin. Apamin+charybdotoxin attenuated the negative inotropic effect, while indomethacin and L-nitro-L-arginin, respectively, blunted and exacerbated the premature onset of relaxation. In conclusion, ghrelin induces negative inotropic and lusitropic effects and an earlier onset of relaxation in normal and hypertrophic myocardium, which are independent of GHS-R1a, since they were not affected by D-Lys(3)-GHRP-6. The negative inotropic effect is partly mediated by KCa channels, while the earlier onset of relaxation is modulated by prostaglandins and NO.