Disconnect between the effects of serelaxin on renal function and outcome in acute heart failure

BACKGROUND

We aimed to study whether improvement in renal function by serelaxin in patients who were hospitalized for acute heart failure (HF) might explain any potential effect on clinical outcomes.

METHODS

We included 6318 patients from the RELAXin in AHF-2 (RELAX-AHF2) study. Improvement in renal function was defined as a decrease in serum creatinine of ≥ 0.3 mg/dL and ≥ 25%, or increase in estimated glomerular filtration rate of ≥ 25% between baseline and day 2. Worsening renal function (WRF) was defined as the reverse. We performed causal mediation analyses regarding 180-day all-cause mortality (ACM), cardiovascular death (CVD), and hospitalization for HF/renal failure.

RESULTS

Improvement in renal function was more frequently observed with serelaxin when compared with placebo [OR 1.88 (95% CI 1.64-2.15, p < 0.0001)], but was not associated with subsequent clinical outcomes. WRF occurred less frequent with serelaxin [OR 0.70 (95% CI 0.60-0.83, p < 0.0001)] and was associated with increased risk of ACM, worsening HF and the composite of CVD and HF or renal failure hospitalization. Improvement in renal function did not mediate the treatment effect of serelaxin [CVD HR 1.01 (0.99-1.04), ACM HR 1.01 (0.99-1.03), HF/renal failure hospitalization HR 0.99 (0.97-1.00)].

CONCLUSIONS

Despite the significant improvement in renal function by serelaxin in patients with acute HF, the potential beneficial treatment effect was not mediated by improvement in renal function. These data suggest that improvement in renal function might not be a suitable surrogate marker for potential treatment efficacy in future studies with novel relaxin agents in acute HF. Central illustration. Conceptual model explaining mediation analysis; treatment efficacy of heart failure therapies mediated by renal function.

P5005Diagnostic and prognostic utilities of insulin-like growth factor-binding protein-7 in patients presenting to the emergency department with dyspnea: results from the ICON-RELOADED study

Background

Increased activity of insulin-like growth factor–binding protein-7 (IGFBP7) is associated with cellular senescence, tissue aging, and obesity. Prior studies in chronic heart failure (HF) have linked IGFBP7 to impaired myocardial relaxation. The role of IGFBP7 measurement in acute HF remains unclear.

Purpose

To examine whether concentrations of IGFBP7 in patients presenting with dyspnea to the emergency department (ED) will aid in the diagnosis and prognosis of acute HF beyond N-terminal pro- B type natriuretic peptide (NT-proBNP).

Methods

The ICON-RELOADED (International Collaborative of NT-proBNP- Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department) study was a prospective, multicenter clinical trial conducted at 19 sites in North America that enrolled subjects ≥22 years of age presenting to ED with complaints of dyspnea. Subjects were blindly adjudicated for the diagnosis of acute HF. A blood sample was taken at enrollment. Six-month prognosis for death/repeat hospitalization was obtained. IGFBP7 was measured using a pre-clinical research use only assay.

Results

Among 1449 patients (n=274 with acute HF), those with IGFBP7 concentrations in the highest quartile (>123.7 ng/mL) were older, more likely to be male and to have a history of hypertension and HF (all p<0.001). They also had lower estimated glomerular filtration rate (eGFR) and the lowest left ventricular ejection fraction (41% ± 21%) prior to study enrollment (all p<0.001). Independent predictors of IGFBP7 included age, male sex, history of diabetes, history of HF, and eGFR (all p<0.001). Median concentrations of NT-proBNP (2844 vs. 99 ng/mL) and IGFBP7 (146.1 vs. 86.1 ng/mL) were significantly higher in those with acute HF (both p<0.001); addition of IGFBP7 to NT-proBNP concentrations improved discrimination, increasing the area under the receiver operating curve for diagnosis of acute HF (from 0.91 to 0.94; p<0.001) (Figure 1). Addition of IGFBP7 to a complete model of independent predictors of acute HF (including NT-proBNP) improved model calibration; IGFBP7 also significantly re-classified acute HF diagnosis beyond NT-proBNP alone (net reclassification improvement +0.25; p<0.001). Higher log2-IGFBP7 concentrations predicted death/rehospitalization at 6 months (hazard ratio 1.74 per log2-standard deviation, 95% confidence interval 1.26–2.40, p=0.001). In Kaplan-Meier analyses, supramedian concentrations of IGFBP7 were associated with shorter event-free survival (log-rank p<0.001).

ROC curve for diagnosis of acute HF

Conclusions

Among patients with acute dyspnea, concentrations of IGFBP7 add to NT-proBNP for diagnosis of acute HF and provide added prognostic utility for short-term risk.

Acknowledgement/Funding

Funding for this study was provided by Roche Diagnostics (Risch-Rotkreuz, Switzerland).

Defining early events of Epstein-Barr virus (EBV) infection in immortalized nasopharyngeal epithelial cells using cell-free EBV infection

Epstein-Barr virus (EBV) infection is strongly associated with nasopharyngeal carcinoma, a common cancer in Southeast Asia and certain regions of Africa. However, the dynamics of EBV episome maintenance in infected nasopharyngeal epithelial (NPE) cells remain largely undefined. Here, we report the establishment of a highly efficient cell-free EBV infection method for NPE cells. By using this method, we have defined some of the dynamic events involved in the early stage of EBV infection in NPE cells. We report, for the first time, a rapid loss of EBV copies from infected NPE cells during the first 12-72 h post-infection. The rate of EBV loss slowed at later stages of infection. Live cell imaging revealed that the freshly infected NPE cells were delayed in entry into mitosis compared with uninfected cells. Freshly infected NPE cells transcribed significantly higher levels of lytic EBV genes BZLF1 and BMRF1 yet significantly lower levels of EBER1/2 than stably infected NPE cells. Notably, there were very low or undetectable levels of protein expressions of EBNA1, LMP1, Zta and Rta in freshly infected NPE cells, whereas EBNA1 and LMP1 proteins were readily detected in stable EBV-infected NPE cells. The kinetics of EBV loss and the differential EBV gene expression profiles between freshly and stably infected NPE cells are in line with the suggestion of epigenetic changes in the EBV genome that affect viral gene expression and the adaptation of host cells to EBV infection to maintain persistent EBV infection in NPE cells.

Persistent pulmonary congestion before discharge predicts rehospitalization in heart failure: a lung ultrasound study

Background

B-lines evaluated by lung ultrasound (LUS) are the sonographic sign of pulmonary congestion, a major predictor of morbidity and mortality in patients with heart failure (HF). Our aim was to assess the prognostic value of B-lines at discharge to predict rehospitalization at 6 months in patients with acute HF (AHF).

Methods

A prospective cohort of 100 patients admitted to a Cardiology Department for dyspnea and/or clinical suspicion of AHF were enrolled (mean age 70 ± 11 years). B-lines were evaluated at admission and before discharge. Subjects were followed-up for 6-months after discharge.

Results

Mean B-lines at admission was 48 ± 48 with a statistically significant reduction before discharge (20 ± 23, p < .0001). During follow-up, 14 patients were rehospitalized for decompensated HF. The 6-month event-free survival was highest in patients with less B-lines (≤ 15) and lowest in patients with more B-lines (> 15) (log rank χ² 20.5, p < .0001). On multivariable analysis, B-lines > 15 before discharge (hazard ratio [HR] 11.74; 95 % confidence interval [CI] 1.30–106.16) was an independent predictor of events at 6 months.

Conclusions

Persistent pulmonary congestion before discharge evaluated by ultrasound strongly predicts rehospitalization for HF at 6-months. Absence or a mild degree of B-lines identify a subgroup at extremely low risk to be readmitted for HF decompensation.

Once daily ledipasvir/sofosbuvir fixed-dose combination with ribavirin in patients with inherited bleeding disorders and hepatitis C genotype 1 infection

AIM

People with inherited bleeding disorders have been disproportionally affected by HCV. We assessed the fixed-dose combination of the NS5A inhibitor ledipasvir (LDV) with the NS5B polymerase inhibitor sofosbuvir (SOF) with ribavirin (RBV) in patients with genotype 1 HCV and inherited bleeding disorders.

METHODS

To be eligible, patients had to be over 18 years of age and have an inherited bleeding disorder. HCV treatment-naïve and -experienced patients could enrol. All patients received LDV 90 mg per SOF 400 mg once daily and weight-based RBV in a divided dose for 12 weeks. The primary efficacy endpoint was sustained virologic response (SVR), defined as HCV RNA below the limit of detection (15 IU mL^-1 ) 12 weeks after the end of treatment (SVR12).

RESULTS

Of the 14 patients enrolled, 8 (57%) had haemophilia A, 3 (21%) had haemophilia B and 2 (14%) had von Willebrand disease, and 1 (7%) had factor XIII deficiency. All 14 patients (100%, 95% CI: 77-100%) achieved SVR12. Treatment was well tolerated: all patients completed therapy, with mostly mild adverse events. No specific safety concerns associated with the patient's underlying bleeding disorders were noted.

CONCLUSION

These results appear to suggest that people with HCV and inherited bleeding disorders can be safely and effectively treated with 12 weeks of LDV/SOF plus RBV.

Etiological factors of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common disease among southern Chinese. The major etiological factors proposed for NPC pathogenesis include genetic susceptibility, environment factors and EBV infection. In the high risk population, genetic susceptibility to NPC has been mapped to the HLA loci and adjacent genes in MHC region on chromosome 6p21. Consumption of preserved food including salted fish has been implicated in its etiology in earlier studies. Its contribution to pathogenesis of NPC remains to be determined. A decreasing trend of NPC incidence was observed in Hong Kong, Taiwan and Singapore in recent years which may be accounted by a change of dietary habits. A comprehensive epidemiological study will help to elucidate the relative importance of various risk factors in the pathogenesis of NPC. Despite the close association of EBV infection with NPC, the etiological role of EBV in NPC pathogenesis remains enigmatic. EBV infection in primary nasopharyngeal epithelial cells is uncommon and difficult to achieve. EBV does not transform primary nasopharyngeal epithelial cells into proliferative clones, which contrasts greatly with the well-documented ability of EBV to transform and immortalize primary B cells. Genetic alterations identified in premalignant nasopharyngeal epithelium may play crucial roles to support stable EBV infection. Subsequently, latent and lytic EBV gene products may drive clonal expansion and transformation of premalignant nasopharyngeal epithelial cells into cancer cells. Stromal inflammation in nasopharyngeal mucosa is believed to play an important role in modulating the growth and possibly drive the malignant transformation of EBV-infected nasopharyngeal epithelial cells. Furthermore, there are increasing evidences supporting a role of EBV infection to evade host immune surveillance. EBV-infected cells may have selective growth advantages in vivo by acquiring a stress-resistance phenotype. Understanding the etiological factors and pathogenesis of NPC will contribute effectively to the prevention and treatment of this disease.

Epstein-Barr virus-encoded latent membrane protein 1 impairs G2 checkpoint in human nasopharyngeal epithelial cells through defective Chk1 activation

Nasopharyngeal carcinoma (NPC) is a common cancer in Southeast Asia, particularly in southern regions of China. EBV infection is closely associated with NPC and has long been postulated to play an etiological role in the development of NPC. However, the role of EBV in malignant transformation of nasopharyngeal epithelial cells remains enigmatic. The current hypothesis of NPC development is that premalignant nasopharyngeal epithelial cells harboring genetic alterations support EBV infection and expression of EBV genes induces further genomic instability to facilitate the development of NPC. The latent membrane protein 1 (LMP1) is a well-documented EBV-encoded oncogene. The involvement of LMP1 in human epithelial malignancies has been implicated, but the mechanisms of oncogenic actions of LMP1, particularly in nasopharyngeal cells, are unclear. Here we observed that LMP1 expression in nasopharyngeal epithelial cells impaired G2 checkpoint, leading to formation of unrepaired chromatid breaks in metaphases after γ-ray irradiation. We further found that defective Chk1 activation was involved in the induction of G2 checkpoint defect in LMP1-expressing nasopharyngeal epithelial cells. Impairment of G2 checkpoint could result in loss of the acentrically broken chromatids and propagation of broken centric chromatids in daughter cells exiting mitosis, which facilitates chromosome instability. Our findings suggest that LMP1 expression facilitates genomic instability in cells under genotoxic stress. Elucidation of the mechanisms involved in LMP1-induced genomic instability in nasopharyngeal epithelial cells will shed lights on the understanding of role of EBV infection in NPC development.