Closing the Digitalis Divide: Back to the Basics of Randomized Controlled Trials

PURPOSE

Publishe d decades after several randomized controlled trials (RCT) demonstrating decreased hospitalizations and no effect on all-cause mortality with digoxin use, a series of meta-analyses linking digoxin treatment and mortality have contributed to a narrower application of this medication for the management of heart failure (HF) and atrial fibrillation (AF). Given the conflicting data from the earlier RCTs and more recent meta-analyses, there is a growing polarization among providers for and against the use of digoxin in managing these conditions.

METHODS

To help close this divide, we provide a perspective on the literature with special attention to the quality of both older and more recent studies on this subject.

RESULTS

The data from the highest quality studies we have, RCTs, suggest that digoxin use in patients with HF and/or AF is associated with improvement in several areas of outcomes including functional capacity, symptom management, reduced hospitalizations, fewer deaths due to HF, and treatment of refractory chronic heart failure with rEF, and may even have overall mortality benefit when serum digoxin concentrations are within therapeutic range. These effects are more pronounced in patients with EF < 25% and NYHA Class II-IV and at highest risk for hospitalization.

CONCLUSION

As the risk of confounding factors was minimized by the study design, the likelihood that positive outcomes were identified with digoxin use increased. Clinicians and researchers need further adequately designed and powered RCTs exploring the connection between digoxin therapy and mortality, hospitalizations, and symptom management.

A safety and pharmacodynamic study of the highly selective aldosterone synthase inhibitor PB6440 in the cynomolgus monkey

Background

Aldosterone is an important mediator of hypertension, particularly resistant hypertension, heart failure, and chronic kidney disease. PB6440 is a potent inhibitor of aldosterone synthase (CYP11B2) with high selectivity over the closely related enzyme CYP11B1. In previous studies in cynomolgus monkeys, PB6440 exhibited excellent oral bioavailability and a marked suppression of aldosterone synthesis at doses as low as 1 mg/kg/day. Importantly, no effect was observed on cortisol production nor significant changes noted in plasma concentrations of the steroid precursors 11-deoxycortisol or deoxycorticosterone (DOC), which are dependent on CYP11B1 activity. The purpose of the current study was to assess the safety and pharmacodynamics of higher doses of PB6440 in the cynomolgus monkey in order to determine a therapeutic index prior to initiation of studies in humans.

Methods

Male and female cynomolgus monkeys (2/sex/dose group) were administered 0, 10, 30 or 100 mg/kg PB6440 once-daily for 14 days by oral gavage. Assessment of safety was based on mortality, clinical observations, body weights, and clinical and anatomic pathology. Blood samples were also collected for pharmacodynamic analysis, including aldosterone, cortisol, 11-deoxycortisol, DOC, and ACTH.

Results

PB6440 was well tolerated at all doses. There were no deaths and no reports of clinical observations at any dose level. Mild decreases in body weight were observed in PB6440-treated animals, which were likely due to the diuretic effects of the compound. PB6440 caused an increase in adrenal weights which was associated with hypertrophy of the adrenal zona fasciculata, a finding which has previously been observed with other aldosterone synthase inhibitors. PB6440 led to marked declines in basal aldosterone levels of −97%, −97% and −98% from baseline at 10, 30 and 100 mg/kg/day, respectively, at 24-hours following the final dose. Despite these clear declines in circulating aldosterone levels, no meaningful changes in cortisol, 11-deoxycortisol, DOC, or ACTH levels were observed, supporting lack of CYP11B1 inhibition. PB6440 led to expected decreases in plasma sodium (up to 7 nmol/L at the high dose). No effect on plasma potassium levels were observed at any dose level.

Conclusions

PB6440 was well tolerated in the cynomolgus monkey at doses that are much higher than needed for potent aldosterone suppression based on previous studies. At the highest dose level tested (100 mg/kg), which led to a 98% reduction in basal aldosterone levels, no evidence of significant CYP11B1 inhibition was observed. The absence of an increase in plasma potassium in the presence of a plasma sodium decline merits further study. Thus, PB6440 is a highly selective novel aldosterone synthase inhibitor for the potential treatment of hypertension, heart failure, and chronic kidney disease in humans.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): PhaseBio Pharmaceuticals Inc.

In patients with type 2 diabetes chronic kidney disease is a modifiable cardiovascular risk factor

Background/Introduction

Chronic kidney disease (CKD) in patients with type 2 diabetes (T2D) is associated with an increased risk of cardiovascular (CV) events. The modifiability of CKD-associated CV risk in patients with T2D across a spectrum of CKD stages remains unknown.

Purpose

To test whether CKD, as defined jointly by estimated glomerular filtration rate (eGFR) and albuminuria (urine albumin-to-creatinine ratio [UACR]), is a modifiable CV risk factor in patients with T2D. Furthermore, to estimate the population-wide reduction in first CV events in the US if all eligible patients were treated with finerenone.

Methods

We estimated the incidence rates of CV events (composite of CV death, non-fatal stroke, non-fatal myocardial infarction, or hospitalisation for heart failure) over a median follow-up of 3.0 years in 13,026 patients with CKD and T2D, treated with finerenone or placebo, in a joint analysis by eGFR and UACR categories. Patients were from FIDELITY, a prespecified pooled analysis of two phase III trials, and had an eGFR ≥25 ml/min/1.73 m2 and UACR 30–5000 mg/g at screening.The potential impact of finerenone treatment on the US population was evaluated by simulating the number of first CV events that could be prevented per year with finerenone, using incidence rates from FIDELITY and prevalence rates of CKD in patients with T2D from the National Health and Nutrition Examination Survey (NHANES).

Results

Lower eGFR and higher UACR categories were associated with higher incidences of CV events in finerenone and placebo recipients (Figure). Finerenone reduced CV risk versus placebo (hazard ratio 0.86; 95% CI 0.78–0.95; p=0.0018) without evidence of moderation of risk reduction by combined eGFR and UACR categories (p interaction = 0.66; Figure 1). Using NHANES, a total of 6.4 million treatment-eligible individuals with CKD and T2D were identified; 75% had CKD with an eGFR ≥60 ml/min/1.73 m2 and 25% had CKD with an eGFR &lt;60 ml/min/1.73 m2. Simulations using this NHANES population projected that 1 year of finerenone treatment could prevent 38,359 CV events in US patients with CKD and T2D, with 66% of events prevented in patients with eGFR ≥60 ml/min/1.73 m2.

Conclusions

Higher albuminuria and lower eGFR are associated with increased CV risk in patients with T2D. Across a range of eGFR and albuminuria categories, CV risk is modifiable. Therefore, CKD is a modifiable CV risk factor in part mediated by mineralocorticoid receptor overactivation. UACR screening to identify patients with T2D and albuminuria with an eGFR ≥60 ml/min/1.73 m2 is likely to provide a significant opportunity for population benefits.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bayer AG

Antifibrotic and anti-inflammatory effects of the selective nonsteroidal MR antagonist finerenone in preclinical pulmonary fibrosis

Background

Patients with idiopathic pulmonary fibrosis (IPF) are at increased risk of developing coronary artery disease (CAD) with a median survival of 3.5 years after diagnosis. Cardiac and pulmonary fibrosis share several common signaling pathways including TGF-β-related collagen synthesis. Pirfenidone and nintedanib were the first approved medical antifibrotic IPF therapies that inhibit TGF-β–related collagen synthesis or multiple receptor tyrosine kinases, respectively. However, the role of mineralocorticoid receptor blockade in IPF is less well understood.

Purpose

To test the hypothesis that the selective nonsteroidal MR antagonist finerenone has antifibrotic and anti-inflammatory activity in preclinical IPF.

Methods

Anti-fibrotic/anti-inflammatory efficacy was investigated in two different mouse models of pulmonary fibrosis. Lung fibrosis was induced by either intranasal application of bleomycin (1 mg/kg) or intratracheal application of silica particles (2.5 mg/mouse). Bleomycin-treated C57BL6 mice (8 weeks old male, n=10–15/group) were administered once daily orally from day 7 to 21 with vehicle (ethanol/solutol/water), finerenone (10 mg/kg) or nintedanib (60 mg/kg) in vehicle. Silica-treated C57BL6 mice (8 weeks old male, n=10–12/group) were administered once daily orally from day 7 to 30 with vehicle (ethanol/solutol/water), finerenone (1 or 10 mg/kg) or nintedanib (100 mg/kg) in vehicle, or with pirfenidone (800mg/kg/d) via chow. At day 21 and 30 respectively, histological examination of pulmonary fibrosis using immunohistochemistry (COL1A1 positive tissue area in %) and Ashcroft score as well as profibrotic and pro-inflammatory cytokine and COL1A1 protein level (ELISA) analysis in lung homogenate were performed.

Results

Bleomycin caused a significant increase in lung COL1A1 positive tissue area and Ashcroft Score and silica-induced lung pathology additionally showed elevated IL-1beta, IL-6, IL-10, IL-12p70, TNFalpha and COL1A1 protein levels in lung tissue. Therapeutic treatment with finerenone as well as nintedanib from day 7–21 significantly reduced the percentage of lung COL1A1 positive tissue and Ashcroft score in the bleomycin mice model without a significant difference between treatment groups. Furthermore, finerenone significantly reduced lung COL1A1 as well as IL-1beta, IL-6, IL-10, IL-12p70 and TNFalpha protein levels in lung homogenate after a therapeutic treatment from day 7–30 in the silica mice model, whereas nintedanib showed only a reduction in lung COL1A1 and IL-10 levels and treatment with pirfenidone was without significant effects. There was a significant difference in the reduction of lung IL-12p70 and TNFalpha protein levels between finerenone 10 mg/kg and nintedanib as well as pirfenidone treatment.

Conclusion

Nonsteroidal MR antagonism by finerenone showed anti-fibrotic/anti-inflammatory efficacy in two animal models of pulmonary fibrosis and may impact the progressive course of fibrotic diseases.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): BAYER AG

Non-fatal cardiovascular events preceding sudden cardiac death in patients with an acute myocardial infarction complicated by heart failure: insights from the High-Risk-Myocardial-Infarction database

Background

Sudden cardiac death (SCD) is responsible for 20–40% of mortality following acute myocardial infarction (AMI). The risk of SCD is even higher among patients with AMI complicated by heart failure (HF) (either clinically apparent HF or left ventricular dysfunction). The temporal relationship between an AMI complicated by HF and subsequent SCD and the association of non-fatal cardiovascular (CV) events following AMI with SCD has yet to be described.

Purpose

Among patients with AMI complicated by HF, we evaluated the probability and temporal association of subsequent non-fatal cardiovascular (CV) events (HF hospitalization, recurrent MI, or stroke) and SCD.

Methods

The High-Risk Myocardial Infarction (HRMI) database contains 28,771 patients with signs of HF or reduced LV ejection fraction (&lt;40%) after AMI. Among patients with an AMI complicated by HF, we used adjudicated cause of death from the HRMI Database to identify: 1) the temporal distribution of SCD among patients following an index AMI; 2) the probability of having SCD following a non-fatal CV event following the index AMI.

Results

Median follow-up was 1.9 years. Mean age was 65.0±11.5 years and 70% were male. The incidence of CV death was 7.9 per 100 patient-year [py] and for SCD was 3.1 per 100py (40% of CV deaths). SCD rates were highest in the early period (&lt;90 days) after AMI and decreased over time. Recurrent MI preceded 9.6% of SCD after a median time of 145 days; HF hospitalization preceded 17.0% of SCD after a median 144 days; and stroke preceded 2.7% of SCD after a median of 138 days (vs. non-sudden CV death: MI 46.6% at 1 days, HF hospitalization: 30.9% at 67 days, stroke 12.9% at 9 days). The incidence of SCD preceded by HF hospitalization was significantly higher than SCD without preceding HF hospitalization.

Conclusion

Among patients with AMI complicated by HF, SCD predominantly occurred in the early “high-risk” period after AMI; SCD rates decreased afterwards. Patients with non-fatal HF hospitalizations during follow-up may have a higher subsequent SCD risk. Preventing HF onset after MI may help decreasing SCD.

Proportion of sudden cardiac death

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Lucien Award, McGill University

P6350Impact of diabetes on serum biomarkers in heart failure with preserved ejection fraction: insights from the spironolactone for heart failure with preserved ejection fraction (TOPCAT) trial

Background and purpose

Diabetes mellitus (DM) is common in heart failure with preserved ejection fraction (HFpEF). Patients with DM and HF with reduced ejection fraction have higher levels of prognostic biomarkers relative to non-diabetics. We sought to examine differences in biomarkers at baseline and over time in patients with HFpEF with and without DM (non-DM).

Methods

The Americas cohort of the TOPCAT trial included 248 subjects with baseline measurements of serum biomarkers and follow-up measures 12 months later. Subjects were identified as non-DM or DM at baseline. Baseline values were compared using non-parametric tests and 12-month changes were compared via linear regression after log-transformation and adjustment for baseline biomarker value, age, gender, randomization strata, and randomized treatment.

Results

At baseline, DM patients had significantly lower eGFR and higher hsCRP, PIIINP, TIMP1, and Gal-3 levels versus non-DM patients (Table). In addition, there was a significantly larger increase over time in levels of hs-TnT, a marker of myocyte death, in DM vs. non-DM patients (p=0.016).

Baseline and 12-Month Biomarkers Baseline % Change at 12 Months Non-DM (n=132) DM (n=116) p Non-DM (n=110) DM (n=94) p eGFR (mL/min/1.73m2) 67 [57, 77] 57 [46, 73] 0.003 −14% (−17, −10) −14% (−18, −10) 0.34 hsCRP (mg/L) 2.4 [1.1, 5.6] 3.1 [1.6, 7.5] 0.046 1% (−5, 3) −11% (−27, 7) 0.54 NT-proBNP (pg/mL) 624 [338, 1235] 629 [278, 1429] 0.80 −2% (−12, 10) −5% (−21, 13) 0.48 hs-TNT (ng/mL) 5.7 [3.1, 12.4] 7.1 [3.7, 14.2] 0.17 −1% (−14, 13) 11% (−3, 27) 0.016 Soluble ST2 (ng/mL) 28 [22, 32] 28 [21, 35] 0.36 −1% (−7, 5) −4% (−9, 2) 0.60 Aldosterone (ng/L) 149 [120, 202] 142 [113, 174] 0.09 17% (9, 26) 23% (14, 33) 0.76 PICP (ng/mL) 137 [101, 169] 127 [102, 155] 0.29 5% (−5, 17) 1% (−9, 12) 0.07 CITP (ng/mL) 1.6 [1.0, 2.8] 1.6 [0.9, 3.0] 0.93 −25% (−37, 10) −23% (−36, −8) 0.87 PIIINP (ng/mL) 23 [16, 30] 28 [21, 36] <0.001 5% (−4, 15) 5% (−3, 14) 0.12 TIMP-1 (ng/mL) 188 [170, 212] 212 [183, 245] <0.001 −1% (−4, 2) −2% (−5, 2) 0.59 Galectin-3 (ng/mL) 20 [16, 23] 22 [18, 28] <0.001 6% (3, 10) 9% (4, 14) 0.52 eGFR, estimated glomerular filtration rate; hsCRP, high-sensitivity CRP; NT-proBNP, N-terminal pro-B-type natriuretic peptide; hs-TnT, high-sensitivity troponin T; PICP, pro-collagen type I carboxy-terminal peptide; CITP, collage type I; PIIINP=pro-collagen type III amino-terminal peptide; TIMP-1=tissue inhibitor of MMP-1.

Conclusions

In comparison to patients without DM, those with DM had poorer renal function and higher baseline levels of markers of myocardial stretch, myocyte death, and pro-fibrotic biomarkers. Further, hs-TnT increased over 12 months only in patients with DM.

"Only a Life Lived for Others Is Worth Living": Redox Signaling by Oxygenated Phospholipids in Cell Fate Decisions

SIGNIFICANCE

Oxygenated polyunsaturated lipids are known to play multi-functional roles as essential signals coordinating metabolism and physiology. Among them are well-studied eicosanoids and docosanoids that are generated via phospholipase A2 hydrolysis of membrane phospholipids and subsequent oxygenation of free polyunsaturated fatty acids (PUFA) by cyclooxygenases and lipoxygenases. Recent Advances: There is an emerging understanding that oxygenated PUFA-phospholipids also represent a rich signaling language with yet-to-be-deciphered details of the execution machinery-oxygenating enzymes, regulators, and receptors. Both free and esterified oxygenated PUFA signals are generated in cells, and their cross-talk and inter-conversion through the de-acylation/re-acylation reactions is not sufficiently explored.

CRITICAL ISSUES

Here, we review recent data related to oxygenated phospholipids as important damage signals that trigger programmed cell death pathways to eliminate irreparably injured cells and preserve the health of multicellular environments. We discuss the mechanisms underlying the trans-membrane redistribution and generation of oxygenated cardiolipins in mitochondria by cytochrome c as pro-apoptotic signals. We also consider the role of oxygenated phosphatidylethanolamines as proximate pro-ferroptotic signals.

FUTURE DIRECTIONS

We highlight the importance of sequential processes of phospholipid oxygenation and signaling in disease contexts as opportunities to use their regulatory mechanisms for the identification of new therapeutic targets.

Depressive symptoms and hazardous/harmful alcohol use are prevalent and correlate with stigma among TB-HIV patients in Lesotho

SETTING

Limited data exist on the prevalence and correlates, including stigma, of mental health conditions, including depressive symptoms and alcohol use, among patients co-infected with tuberculosis (TB) and the human immunodeficiency virus (HIV) in sub-Saharan Africa, despite their negative impact on health outcomes.

OBJECTIVE

To assess the prevalence and correlates of depressive symptoms and hazardous/harmful alcohol use among TB-HIV patients in the Start TB patients on ART and Retain on Treatment (START) study.

DESIGN

START, a mixed-methods cluster-randomized trial, evaluated a combination intervention package vs. standard of care (SOC) to improve treatment outcomes in TB-HIV co-infected patients in Lesotho. Moderate/severe depressive symptoms and hazardous/harmful alcohol use were measured using baseline questionnaire data collected from April 2013 to March 2015. Demographic, psychosocial, and TB- and HIV-related knowledge and attitudes, including stigma, were assessed for association with both conditions using generalized linear mixed models.

RESULTS

Among 371 participants, 29.8% reported moderate/severe depressive symptoms, and 24.7% reported hazardous/harmful alcohol use; 7% reported both. Depressive symptoms were significantly associated with less education, more difficulty understanding written medical information, non-disclosure of TB, greater TB stigma, and the SOC study arm. Hazardous/harmful alcohol use was significantly associated with male sex, as well as greater TB and external HIV stigma.

CONCLUSION

Prevalence of depressive symptoms and hazardous/harmful alcohol use were high, suggesting a need for routine screening for, and treatment of, mental health disorders in TB-HIV patients.

Pulmonary tuberculosis diagnostic practices among people living with the human immunodeficiency virus in Lesotho

SETTING

Twelve health facilities in Berea District, Lesotho, that participated in the Start TB Patients on ART and Retain on Treatment (START) Study, a mixed-methods cluster-randomized trial evaluating a combination intervention package to improve early initiation of antiretroviral therapy (ART) and anti-tuberculosis treatment success among patients with tuberculosis (TB) and human immunodeficiency virus (HIV).

OBJECTIVE

To assess TB and HIV diagnostic practices among TB-HIV patients.

DESIGN

A standardized survey assessed services at each facility at baseline. Routine clinical data were abstracted for all newly registered adult TB-HIV patients during the study period. Descriptive statistics were used to assess TB diagnostic practices, timing of the HIV diagnosis, and ART status at TB treatment initiation.

RESULTS

Between April 2013 and March 2015, 1233 TB-HIV patients were enrolled. Among 1215 patients with available data, 87.2% had pulmonary TB, of which 34.8% were bacteriologically confirmed, 40.9% tested negative and 24.3% were not tested. Among 1138 patients with available data, 53.3% had an existing HIV diagnosis, of whom 39.3% were ART-naïve.

CONCLUSIONS

The majority of pulmonary TB patients were clinically diagnosed, and many were unaware of their HIV status or were ART-naïve despite known status. The Test and Treat Strategy holds promise to prevent TB and reduce TB-related mortality among people living with HIV; however, enhanced TB diagnostic capacity and improved HIV case detection are urgently needed.

Quantification of cotinine in dried blood spots as a biomarker of exposure to tobacco smoke

OBJECTIVE

We present an ultra-sensitive, minimally-invasive method for quantifying cotinine in dried blood spot (DBS) samples as a biomarker of exposure to tobacco smoke that can be collected using a simple heel or finger prick to obtain blood samples.

METHODS

Cotinine levels were measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers to evaluate assay parameters. In addition, we applied this new method to finger-prick DBS samples that were collected from infants, children and young adults ages 1-21 to estimate exposure to tobacco smoke. Partitioning of cotinine across red blood cells and haematocrit effects were investigated.

RESULTS

Cotinine levels measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers were found to be highly correlated (R²=0.94), with 100% sensitivity and 94% specificity to differentiate reported smokers from nonsmokers. With this method, the LOQ is <0.25 ng/mL using a single 3.2 mm punch of a DBS, and haematocrit effects are negligible.

CONCLUSIONS

This sensitive, high-throughput and minimally-invasive method for quantifying cotinine in DBS samples provides a simple and cost effective means for estimating exposure to tobacco smoke in population based studies, and has particular advantages in studies involving infants and children.

Combined baseline and one-month changes in big endothelin-1 and brain natriuretic peptide plasma concentrations predict clinical outcomes in patients with left ventricular dysfunction after acute myocardial infarction: Insights from the Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) study

OBJECTIVE

Increased levels of neuro-hormonal biomarkers predict poor prognosis in patients with acute myocardial infarction (AMI) complicated by left ventricular systolic dysfunction (LVSD). The predictive value of repeated (one-month interval) brain natriuretic peptides (BNP) and big-endothelin 1 (BigET-1) measurements were investigated in patients with LVSD after AMI.

METHODS

In a sub-study of the Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS trial), BNP and BigET-1 were measured at baseline and at 1month in 476 patients.

RESULTS

When included in the same Cox regression model, baseline BNP (p=0.0003) and BigET-1 (p=0.026) as well as the relative changes (after 1month) from baseline in BNP (p=0.049) and BigET-1 (p=0.045) were predictive of the composite of cardiovascular death or hospitalization for worsening heart failure. Adding baseline and changes in BigET-1 to baseline and changes in BNP led to a significant increase in prognostic reclassification as assessed by integrated discrimination improvement index (5.0%, p=0.01 for the primary endpoint).

CONCLUSIONS

Both increased baseline and changes after one month in BigET-1 concentrations were shown to be associated with adverse clinical outcomes, independently from BNP baseline levels and one month changes, in patients after recent AMI complicated with LVSD. This novel result may be of clinical interest since such combined biomarker assessment could improve risk stratification and open new avenues for biomarker-guided targeted therapies.

KEY MESSAGES

In the present study, we report for the first time in a population of patients with reduced LVEF after AMI and signs or symptoms of congestive HF, that increased baseline values of BNP and BigET-1 as well as a further rise of these markers over the first month after AMI, were independently predictive of future cardiovascular events. This approach may therefore be of clinical interest with the potential of improving risk stratification after AMI with reduced LVEF while further opening new avenues for biomarker-guided targeted therapies.

'There's no place like home': perceptions of home-based HIV testing in Lesotho

HIV testing has the potential to reduce HIV transmission by identifying and counseling individuals with HIV, reducing risk behaviors, linking persons with HIV to care and earlier treatment, and reducing perinatal transmission. In Lesotho, a high HIV prevalence country in which a large proportion of the population has never tested for HIV, home-based testing (HBT) may be an important strategy to increase HIV testing. We identified factors influencing acceptability of HIV prevention strategies among a convenience sample of 200 pregnant or post-partum Basotho women and 30 Basotho men. We first conducted cross-sectional surveys, followed by key informant interviews with all 30 men and focus group discussions with a sub-set of 62 women. In total, 82% of women reported positive perceptions of HBT; women and men viewed HBT as a potential way to increase testing among men and saw the home as a comfortable, supportive environment for testing and counseling couples and families together. Potential barriers to HBT uptake included concerns about confidentiality, privacy, coercion to test, conflict within the family and fear of HIV/AIDS-associated stigma. Participants emphasized community mobilization and education as important elements of HBT.

Mineralocorticoid receptor blockade-a novel approach to fight hyperkalaemia in chronic kidney disease

Hyperkalaemia continues to be a major hazard of mineralocorticoid receptor blockade in an effort to retard the progression of chronic kidney disease (CKD). In cardiac patients on mineralocorticoid receptor blockade, RLY-5016 which captures K⁺ in the colon has been effective in reducing the risk of hyperkalaemia. This compound might be useful in CKD as well.

Racial differences in biologic predictors of severe asthma: Data from the Severe Asthma Research Program

BACKGROUND

Biologic factors are known to contribute to asthma severity. It is unknown whether these factors differentially contribute to asthma severity in black compared with white subjects.

OBJECTIVE

We sought to assess the extent to which racial disparities between black and white subjects with severe asthma are attributable to physiologic, immunoinflammatory, and sociodemographic variables.

METHODS

Black and white asthmatic adults enrolled in a cross-sectional study focused on severe asthma were evaluated. Severe asthma was identified by using the American Thoracic Society definition. After initial univariable analyses, unconditional logistic regression models were used to estimate the probability of having severe asthma for black and white subjects.

RESULTS

Differences in severe asthma in black compared with white subjects were observed. In univariable analysis IgE level was not associated with severe asthma in black or white subjects, whereas in multivariable analysis IgE level was significantly associated with severe asthma for black subjects (P = .014) but not for white subjects. The odds of having severe asthma more than doubled for black subjects with 2 or more family members with asthma (P = .026), whereas the odds of severe asthma for white participants with a strong family history of asthma decreased by almost half (P = .05). Atopy was negatively associated with severe asthma in both races in univariable analysis but remained significant only in black subjects, whereas comorbidities were associated with severe asthma in white subjects.

CONCLUSION

Biologic factors were distinctly associated with severe asthma only in black subjects. Studies that incorporate comprehensive evaluation of biologic factors associated with asthma might lead to the development of therapies that target biologic abnormalities in black subjects.

A biohybrid artificial lung prototype with active mixing of endothelialized microporous hollow fibers

Acute respiratory distress syndrome (ARDS) affects nearly 150,000 patients per year in the US, and is associated with high mortality ( approximately 40%) and suboptimal options for patient care. Mechanical ventilation and extracorporeal membrane oxygenation are limited to short-term use due to ventilator-induced lung injury and poor biocompatibility, respectively. In this report, we describe the development of a biohybrid lung prototype, employing a rotating endothelialized microporous hollow fiber (MHF) bundle to improve blood biocompatibility while MHF mixing could contribute to gas transfer efficiency. MHFs were surface modified with radio frequency glow discharge (RFGD) and protein adsorption to promote endothelial cell (EC) attachment and growth. The MHF bundles were placed in the biohybrid lung prototype and rotated up to 1,500 revolutions per minute (rpm) using speed ramping protocols to condition ECs to remain adherent on the fibers. Oxygen transfer, thrombotic deposition, and EC p-selectin expression were evaluated as indicators of biohybrid lung functionality and biocompatibility. A fixed aliquot of blood in contact with MHF bundles rotated at either 250 or 750 rpm reached saturating pO(2) levels more quickly with increased rpm, supporting the concept that fiber rotation would positively contribute to oxygen transfer. The presence of ECs had no effect on the rate of oxygen transfer at lower fiber rpm, but did provide some resistance with increased rpm when the overall rate of mass transfer was higher due to active mixing. RFGD followed by fibronectin adsorption on MHFs facilitated near confluent EC coverage with minimal p-selectin expression under both normoxic and hyperoxic conditions. Indeed, even subconfluent EC coverage on MHFs significantly reduced thrombotic deposition adding further support that endothelialization enhances, blood biocompatibility. Overall these findings demonstrate a proof-of-concept that a rotating endothelialized MHF bundle enhances gas transfer and biocompatibility, potentially producing safer, more efficient artificial lungs.

Mass-spectrometric analysis of hydroperoxy- and hydroxy-derivatives of cardiolipin and phosphatidylserine in cells and tissues induced by pro-apoptotic and pro-inflammatory stimuli

Oxidation of two anionic phospholipids--cardiolipin (CL) in mitochondria and phosphatidylserine (PS) in extramitochondrial compartments--is important signaling event, particularly during the execution of programmed cell death and clearance of apoptotic cells. Quantitative analysis of CL and PS oxidation products is central to understanding their molecular mechanisms of action. We combined the identification of diverse phospholipid molecular species by ESI-MS with quantitative assessments of lipid hydroperoxides using a fluorescence HPLC-based protocol. We characterized CL and PS oxidation products formed in a model system (cyt c/H(2)O(2)), in apoptotic cells (neurons, pulmonary artery endothelial cells) and mouse lung under inflammatory/oxidative stress conditions (hyperoxia, inhalation of single walled carbon nanotubes). Our results demonstrate the usefulness of this approach for quantitative assessments, identification of individual molecular species and structural characterization of anionic phospholipids that are involved in oxidative modification in cells and tissues.

Aldosterone status associated with insulin resistance in patients with heart failure--data from the ALOFT study

BACKGROUND

Aldosterone has a key role in the pathophysiology of heart failure. In around 50% of such patients, aldosterone "escapes" from inhibition by drugs that interrupt the renin-angiotensin axis; such patients have a worse clinical outcome. Insulin resistance is a risk factor in heart failure and cardiovascular disease. The relation between aldosterone status and insulin sensitivity was investigated in a cohort of heart failure patients.

METHODS

302 patients with New York Heart Association (NYHA) class II-IV heart failure on conventional therapy were randomised in the ALiskiren Observation of heart Failure Treatment study (ALOFT), designed to test the safety of a directly acting renin inhibitor. Plasma aldosterone and 24-hour urinary aldosterone excretion, as well as fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were measured. Subjects with aldosterone escape and high urinary aldosterone were identified according to previously accepted definitions.

RESULTS

20% of subjects demonstrated aldosterone escape and 34% had high urinary aldosterone levels. At baseline, there was a positive correlation between fasting insulin and plasma (r = 0.22 p<0.01) and urinary aldosterone(r = 0.19 p<0.03). Aldosterone escape and high urinary aldosterone subjects both demonstrated higher levels of fasting insulin (p<0.008, p<0.03), HOMA-IR (p<0.06, p<0.03) and insulin-glucose ratios (p<0.006, p<0.06) when compared to low aldosterone counterparts. All associations remained significant when adjusted for potential confounders.

CONCLUSIONS

This study demonstrates a novel direct relation between aldosterone status and insulin resistance in heart failure. This observation merits further study and may identify an additional mechanism that contributes to the adverse clinical outcome associated with aldosterone escape.

Coordinated regulation of dimethylarginine dimethylaminohydrolase-1 and cationic amino acid transporter-1 by farnesoid X receptor in mouse liver and kidney and its implication in the control of blood levels of asymmetric dimethylarginine

Asymmetric dimethylarginine (ADMA) is a potent endogenous inhibitor of endothelial nitric-oxide synthase (eNOS), and increased plasma concentrations of ADMA have been regarded as a risk factor for a number of cardiovascular diseases. Circulating ADMA is largely taken up by liver and kidney via system y(+) carriers of the cationic amino acid (CAT) family and subsequently metabolized by dimethylarginine dimethylaminohydrolases (DDAHs). As such, agents targeted at enhancing ADMA metabolism may prove to be useful in the prevention and/or treatment of various types of cardiovascular disease. Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily and plays an important role in the maintenance of cholesterol and bile acid homeostasis. We report here that treatment of mice with an FXR agonist 3-(2,6-dichlorophenyl)-4-(3'-carboxy-2-chlorostilben-4-yl)oxymethyl-5-isopropylisoxazole; GW4064) led to increased expression of DDAH-1 and CAT-1 in both liver and kidney. In cultured human hepatocytes and kidney proximal tubular epithelial cells, GW4064 increased CAT-1 expression, and this was associated with a significant increase in the cellular uptake of ADMA. Promoter analyses suggest that CAT-1 is a likely target of FXR, and a functional FXR response element was found in the promoter region of CAT-1 gene. These data suggest that FXR may play an important role in regulating blood levels of ADMA via coordinated regulation of DDAH-1 and CAT-1 in liver and kidney.

Cytochrome c/cardiolipin relations in mitochondria: a kiss of death

Recently, phospholipid peroxidation products gained a reputation as key regulatory molecules and participants in oxidative signaling pathways. During apoptosis, a mitochondria-specific phospholipid, cardiolipin (CL), interacts with cytochrome c (cyt c) to form a peroxidase complex that catalyzes CL oxidation; this process plays a pivotal role in the mitochondrial stage of the execution of the cell death program. This review is focused on redox mechanisms and essential structural features of cyt c's conversion into a CL-specific peroxidase that represent an interesting and maybe still unique example of a functionally significant ligand change in hemoproteins. Furthermore, specific characteristics of CL in mitochondria--its asymmetric transmembrane distribution and mechanisms of collapse, the regulation of its synthesis, remodeling, and fatty acid composition--are given significant consideration. Finally, new concepts in drug discovery based on the design of mitochondria-targeted inhibitors of cyt c/CL peroxidase and CL peroxidation with antiapoptotic effects are presented.

Influence of smoking status on progression of endothelial dysfunction. TREND Investigators. Trial on Reversing Endothelial Dysfunction

BACKGROUND

Cigarette smoking is a major risk factor for developing coronary artery disease and is associated with increased coronary morbidity and mortality in patients with established atherosclerosis. This report describes the influence of smoking on coronary endothelial function in normotensive patients with coronary artery disease, but without left ventricular dysfunction, severe hypercholesterolemia, or insulin-dependent diabetes mellitus.

METHODS

Placebo-treated patients (n = 54) from a larger study assessing coronary endothelial function were classified at baseline as smokers or nonsmokers for this subgroup analysis. Patients underwent coronary angiography at baseline and again after 6-month follow-up.

RESULTS

At baseline, there was a trend for a greater decrease in target segment diameter (n = 54) in smokers compared with nonsmokers (-17.2 +/- 5.3% vs. -8.0 +/- 2.5%, acetylcholine 10(-4) mol/l). All measured coronary artery segments (n = 202) showed similar responses (-7.3 +/- 2.7% vs. -3.8 +/- 1.3%, acetylcholine 10(-4) mmol/l, for smokers vs. nonsmokers, respectively). After 6 months, smokers showed an even greater vasoconstrictor response to acetylcholine whereas nonsmokers did not (-21.7 +/- 5.3% vs. -8.3 +/- 2.5%, acetylcholine 10(-4) mmol/l). The vasodilatory response to nitroglycerin was similar in smokers and nonsmokers.

CONCLUSIONS

In current smokers, a marked decline in endothelium-dependent vasomotor response was observed over a 6-month period.

The anti-ischemic potential of angiotensin-converting enzyme inhibition: insights from the heart outcomes prevention evaluation trial

Therapy with an angiotensin-converting enzyme (ACE) inhibitor is established for reducing excessive blood pressure, reducing mortality in patients with congestive heart failure (CHF), preventing the development of CHF in patients with asymptomatic left ventricular (LV) dysfunction, and preventing death and CHF when initiated early after the onset of acute myocardial infarction (MI). Although these benefits have been attributed largely to hemodynamic mechanisms, recent preclinical and clinical evidence reveal ACE inhibition as potent in preventing ischemic events and in blocking an array of ischemic processes, including atherogenesis. A major contributor to this new evidence is the large, placebo-controlled Heart Outcomes Prevention Evaluation (HOPE) trial, which found that the ACE inhibitor ramipril ( 10 mg daily) prevented MI and other ischemic events in patients with a broad range of cardiovascular (CV) risks (including coronary artery disease, stroke, peripheral vascular disease, or diabetes plus one additional risk factor) but no LV dysfunction or history of heart failure at baseline. The data from the HOPE trial suggest a greatly expanded role for ramipril in the prevention and management of CV disease.

Eplerenone improves prognosis in postmyocardial infarction diabetic patients with heart failure: results from EPHESUS

BACKGROUND

The Epleronone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) trial demonstrated that selective aldosterone blockade with eplerenone significantly reduced total mortality by 15%, combined cardiovascular (CV) mortality/CV hospitalization by 13%, CV mortality by 17% and sudden cardiac death by 21%, vs. placebo when added to standard care in patients with left ventricular systolic dysfunction (LVSD) and signs of congestive heart failure (CHF) following acute myocardial infarction (AMI). We retrospectively evaluated the effect of eplerenone vs. placebo in a subset of 1483 diabetic patients with LVSD and signs of CHF following AMI.

METHODS

Diabetic status was determined from medical histories at screening. Analyses were based on time to first occurrence of an event. Results were based on a Cox's proportional hazards regression model stratified by region with treatment, subgroup and treatment-by-subgroup interaction as factors. The 95% confidence intervals for the risk ratios were based on the Wald's test.

RESULTS

Treatment with eplerenone in diabetic patients with CHF following AMI reduced the risk of the primary endpoint, a composite of CV mortality or CV hospitalization, by 17% (p = 0.031). The absolute risk reduction of the primary endpoint was greater in the diabetic cohort (5.1%) than in the non-diabetic cohort (3%). Hyperkalaemia occurred more often with eplerenone than with placebo (5.6 vs. 3%, p = 0.015). Among the diabetic cohorts, the prespecified endpoint of 'any CV disorder' occurred in 28% of the eplerenone group and 35% of the placebo group (p = 0.007).

CONCLUSION

Eplerenone treatment may reduce adverse CV events in diabetic patients with LVSD and signs of CHF following AMI.