Sex-based differences in short- and longer-term diet-induced metabolic heart disease

Sex-based differences in the development of obesity-induced cardiometabolic dysfunction are well documented, however, the specific mechanisms are not completely understood. Obesity has been linked to dysregulation of the epitranscriptome, but the role of N6-methyladenosine (m6A) RNA methylation has not been investigated in relation to the sex differences during obesity-induced cardiac dysfunction. In the current study, male and female C57BL/6J mice were subjected to short- and long-term high-fat/high-sucrose (HFHS) diet to induce obesogenic stress. Cardiac echocardiography showed males developed systolic and diastolic dysfunction after 4 mo of diet, but females maintained normal cardiac function despite both sexes being metabolically dysfunctional. Cardiac m6A machinery gene expression was differentially regulated by duration of HFHS diet in male, but not female mice, and left ventricular ejection fraction correlated with RNA machinery gene levels in a sex- and age-dependent manner. RNA-sequencing of cardiac transcriptome revealed that females, but not males may undergo protective cardiac remodeling early in the course of obesogenic stress. Taken together, our study demonstrates for the first time that cardiac RNA methylation machinery genes are regulated early during obesogenic stress in a sex-dependent manner and may play a role in the sex differences observed in cardiometabolic dysfunction.NEW & NOTEWORTHY Sex differences in obesity-associated cardiomyopathy are well documented but incompletely understood. We show for the first time that RNA methylation machinery genes may be regulated in response to obesogenic diet in a sex- and age-dependent manner and levels may correspond to cardiac systolic function. Our cardiac RNA-seq analysis suggests female, but not male mice may be protected from cardiac dysfunction by a protective cardiac remodeling response early during obesogenic stress.

Elevated ferritin, mediated by IL-18 is associated with systemic inflammation and mortality in acute respiratory distress syndrome (ARDS)

BACKGROUND

Inflammatory subphenotypes have been identified in acute respiratory distress syndrome (ARDS). Hyperferritinaemia in sepsis is associated with hyperinflammation, worse clinical outcomes, and may predict benefit with immunomodulation. Our aim was to determine if raised ferritin identified a subphenotype in patients with ARDS.

METHODS

Baseline plasma ferritin concentrations were measured in patients with ARDS from two randomised controlled trials of simvastatin (Hydroxymethylglutaryl-CoA Reductase Inhibition with Simvastatin in Acute Lung Injury to Reduce Pulmonary Dysfunction-2 (HARP-2); discovery cohort, UK) and neuromuscular blockade (ROSE; validation cohort, USA). Results were analysed using a logistic regression model with restricted cubic splines, to determine the ferritin threshold associated with 28-day mortality.

RESULTS

Ferritin was measured in 511 patients from HARP-2 (95% of patients enrolled) and 847 patients (84% of patients enrolled) from ROSE. Ferritin was consistently associated with 28-day mortality in both studies and following a meta-analysis, a log-fold increase in ferritin was associated with an OR 1.71 (95% CI 1.01 to 2.90) for 28-day mortality. Patients with ferritin >1380 ng/mL (HARP-2 28%, ROSE 24%) had a significantly higher 28-day mortality and fewer ventilator-free days in both studies. Mediation analysis, including confounders (acute physiology and chronic health evaluation-II score and ARDS aetiology) demonstrated a statistically significant contribution of interleukin (IL)-18 as an intermediate pathway between ferritin and mortality.

CONCLUSIONS

Ferritin is a clinically useful biomarker in ARDS and is associated with worse patient outcomes. These results provide support for prospective interventional trials of immunomodulatory agents targeting IL-18 in this hyperferritinaemic subgroup of patients with ARDS.

The Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal Compared With Conventional Lung Protective Ventilation on Cardiac Function

OBJECTIVES

Lower tidal volume ventilation (targeting 3 mL/kg predicted body weight, PBW) facilitated by extracorporeal carbon dioxide removal (ECCO2R) has been investigated as a potential therapy for acute hypoxemic respiratory failure (AHRF) in the pRotective vEntilation with veno-venouS lung assisT in respiratory failure (REST) trial. We investigated the effect of this strategy on cardiac function, and in particular the right ventricle.

DESIGN

Substudy of the REST trial.

SETTING

Nine U.K. ICUs.

PATIENTS

Patients with AHRF (Pao2/Fio2 < 150 mm Hg [20 kPa]).

INTERVENTION

Transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements were collected at baseline and postrandomization in patients randomized to ECCO2R or usual care.

MEASUREMENTS

The primary outcome measures were a difference in tricuspid annular plane systolic excursion (TAPSE) on postrandomization echocardiogram and difference in NT-proBNP postrandomization.

RESULTS

There were 21 patients included in the echocardiography cohort (ECCO2R, n = 13; usual care, n = 8). Patient characteristics were similar in both groups at baseline. Median (interquartile range) tidal volumes were lower in the ECCO2R group compared with the usual care group postrandomization; 3.6 (3.1-4.2) mL/kg PBW versus 5.2 (4.9-5.7) mL/kg PBW, respectively (p = 0.01). There was no difference in the primary outcome measure of mean (sd) TAPSE in the ECCO2R and usual care groups postrandomization; 21.3 (5.4) mm versus 20.1 (3.2) mm, respectively (p = 0.60). There were 75 patients included in the NT-proBNP cohort (ECCO2R, n = 36; usual care, n = 39). Patient characteristics were similar in both groups at baseline. Median (interquartile range [IQR]) tidal volumes were lower in the ECCO2R group than the usual care group postrandomization; 3.8 (3.3-4.2) mL/kg PBW versus 6.7 (5.8-8.1) mL/kg PBW, respectively (p < 0.0001). There was no difference in median (IQR) NT-proBNP postrandomization; 1121 (241-5370) pg/mL versus 1393 (723-4332) pg/mL in the ECCO2R and usual care groups, respectively (p = 0.30).

CONCLUSIONS

In patients with AHRF, a reduction in tidal volume facilitated by ECCO2R, did not modify cardiac function.

Extracellular Matrix Protein-1 as a Mediator of Inflammation-Induced Fibrosis After Myocardial Infarction

Irreversible fibrosis is a hallmark of myocardial infarction (MI) and heart failure. Extracellular matrix protein-1 (ECM-1) is up-regulated in these hearts, localized to fibrotic, inflammatory, and perivascular areas. ECM-1 originates predominantly from fibroblasts, macrophages, and pericytes/vascular cells in uninjured human and mouse hearts, and from M1 and M2 macrophages and myofibroblasts after MI. ECM-1 stimulates fibroblast-to-myofibroblast transition, up-regulates key fibrotic and inflammatory pathways, and inhibits cardiac fibroblast migration. ECM-1 binds HuCFb cell surface receptor LRP1, and LRP1 inhibition blocks ECM-1 from stimulating fibroblast-to-myofibroblast transition, confirming a novel ECM-1-LRP1 fibrotic signaling axis. ECM-1 may represent a novel mechanism facilitating inflammation-fibrosis crosstalk.

PIM-COVID study: protocol for a multicentre, longitudinal study measuring the psychological impact of surviving an intensive care admission due to COVID-19 on patients in the UK

INTRODUCTION

Psychological distress is common in intensive care unit (ICU) survivors and is anticipated in those who were treated for severe COVID-19 infection. This trainee-led, multicentre, observational, longitudinal study aims to assess the psychological outcomes of ICU survivors treated for COVID-19 infection in the UK at 3, 6 and/or 12 months after ICU discharge and explore whether there are demographic, psychosocial and clinical risk factors for psychological distress.

METHODS AND ANALYSIS

Questionnaires will be provided to study participants 3, 6 and/or 12 months after discharge from intensive care, assessing for anxiety, depression, post-traumatic stress symptoms, health-related quality of life and physical symptoms. Demographic, psychosocial and clinical data will also be collected to explore risk factors for psychological distress using latent growth curve modelling. Study participants will be eligible to complete questionnaires at any of the three time points online, by telephone or by post.

ETHICS AND DISSEMINATION

The PIM-COVID study was approved by the Health Research Authority (East Midlands - Derby Research and Ethics Committee, reference: 20/EM/0247).

TRIAL REGISTRATION NUMBER

NCT05092529.

Fibulin-3 is necessary to prevent cardiac rupture following myocardial infarction

Despite the high prevalence of heart failure in the western world, there are few effective treatments. Fibulin-3 is a protein involved in extracellular matrix (ECM) structural integrity, however its role in the heart is unknown. We have demonstrated, using single cell RNA-seq, that fibulin-3 was highly expressed in quiescent murine cardiac fibroblasts, with expression highest prior to injury and late post-infarct (from ~ day-28 to week-8). In humans, fibulin-3 was upregulated in left ventricular tissue and plasma of heart failure patients. Fibulin-3 knockout (Efemp1-/-) and wildtype mice were subjected to experimental myocardial infarction. Fibulin-3 deletion resulted in significantly higher rate of cardiac rupture days 3-6 post-infarct, indicating a weak and poorly formed scar, with severe ventricular remodelling in surviving mice at day-28 post-infarct. Fibulin-3 knockout mice demonstrated less collagen deposition at day-3 post-infarct, with abnormal collagen fibre-alignment. RNA-seq on day-3 infarct tissue revealed upregulation of ECM degradation and inflammatory genes, but downregulation of ECM assembly/structure/organisation genes in fibulin-3 knockout mice. GSEA pathway analysis showed enrichment of inflammatory pathways and a depletion of ECM organisation pathways. Fibulin-3 originates from cardiac fibroblasts, is upregulated in human heart failure, and is necessary for correct ECM organisation/structural integrity of fibrotic tissue to prevent cardiac rupture post-infarct.

Acute hypoxaemic respiratory failure after treatment with lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal: long-term outcomes from the REST randomised trial

INTRODUCTION

Lower tidal volume ventilation, facilitated by veno-venous extracorporeal carbon dioxide removal (vv-ECCO2R), does not improve 90-day mortality in patients with acute hypoxaemic respiratory failure (AHRF). The aim of this analysis was to evaluate the effect of this therapeutic strategy on long-term outcomes.

METHODS

This was a prespecified analysis of the REST trial, a UK-wide multicentre randomised clinical trial that compared lower tidal volume ventilation, facilitated by vv-ECCO2R (intervention), with standard care in the treatment of patients with moderate-to-severe AHRF. Mortality to 2 years was assessed, while respiratory function, post-traumatic stress disorder, cognitive function and health-related quality of life were evaluated in survivors at 1 year using standardised questionnaires.

RESULTS

Of 412 patients enrolled into the REST trial, 391 (95%) had 2-year mortality outcome data available. There was no difference in the time to death between intervention and standard care (HR 1.08 (0.81, 1.44); log-rank test p=0.61). 161 patients alive at 1 year provided at least one questionnaire response. There was no difference in respiratory function, post-traumatic stress disorder, cognitive dysfunction or health-related quality of life between patients allocated to intervention or standard care.

CONCLUSION

Lower-tidal volume ventilation facilitated by vv-ECCO2R does not affect 1-year mortality in patients with moderate-to-severe AHRF. Of the patients who provided questionnaire responses, there was no treatment effect on long-term respiratory function, post-traumatic stress disorder, cognitive dysfunction or health-related quality of life.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02654327.

Association of Circulating Plasma Secreted Frizzled-Related Protein 5 (Sfrp5) Levels with Cardiac Function

Secreted frizzled-related protein 5 (SFRP5) is a novel anti-inflammatory adipokine that may play a role in cardiovascular development and disease. However, there is yet to be a comprehensive investigation into whether circulating SFRP5 can be a biomarker for cardiac function. Plasma SFRP5 levels were measured via ELISA in 262 patients admitted to a cardiology unit. Plasma SFRP5 levels were significantly lower in patients with a history of heart failure (HF), coronary artery disease (CAD), and atrial fibrillation (AF; p = 0.001). In univariate analyses, SFRP5 levels were also significantly positively correlated with left ventricular ejection fraction (LVEF) (r = 0.52, p < 0.001) and negatively correlated with E/E' (r = -0.30, p < 0.001). Patients with HF, CAD, low LVEF, low triglycerides, high CRP, and high eGFR were associated with lower SFRP5 levels independent of age, BMI, or diabetes after multivariate analysis (overall model r = 0.729, SE = 0.638). Our results show that low plasma SFRP5 levels are independently associated with the presence of HF, CAD, and, importantly, impaired LV function. These results suggest a potential role of SFRP5 as a biomarker, as well as a mediator of cardiac dysfunction independent of obesity and metabolic regulation.

Mind The Gap, Aboriginal and Torres Strait Islander Cardiovascular Health: A Narrative Review

Australia's First Nations Peoples, Aboriginal and Torres Strait Islanders, have reduced life expectancy compared to the wider community. Cardiovascular diseases, mainly driven by ischaemic heart disease, are the leading contributors to this disparity. Despite over a third of First Nations Peoples living in New South Wales, the bulk of the peer-reviewed literature is from Central Australia and Far North Queensland. Regardless of the site of publication, First Nations Peoples are significantly younger at disease onset and have higher rates of comorbidities, in turn driving adverse health events. On top of this, very few First Nations Peoples specific cardiovascular interventions or programs have been shown to improve outcomes. The traditional biomedical model of care is less efficacious and non-traditional models of communication such as clinical yarning may benefit both clinicians and patients. The key purpose of this review is to highlight the deficiencies of our knowledge of cardiovascular burden of disease for First Nations Peoples; and to serve as a catalyst for more dedicated research. We need to have relationships with communities and concentrate on community improvement and partnerships. By involving First Nations Peoples researchers in collaboration with local communities in all levels of health care design and intervention will improve outcomes.

Extracorporeal carbon dioxide removal in acute hypoxaemic respiratory failure: a systematic review, Bayesian meta-analysis and trial sequential analysis

Purpose:

To assess the safety and efficacy of extracorporeal carbon dioxide removal (ECCO2R)versusstandard care in patients with acute hypoxaemic respiratory failure (AHRF).

Methods:

MEDLINE, Embase and clinical trial registries were searched from 1994 to 31 December 2021. We included randomised controlled trials (RCTs) and observational studies. Pairs of reviewers independently extracted data and assessed the risk of bias. The primary outcome was mortality. Secondary outcomes included ventilator-free days, length of stay, safety and adverse events and physiological changes. As a primary analysis, we performed a meta-analysis of mortality until day 30 using a Bayesian random effects model. We then performed a trial sequential analysis of RCTs.

Results:

21 studies met inclusion criteria: three RCTs, enrolling 531 patients, and 18 observational studies. In a pooled analysis of RCTs, the posterior probability of increased mortality with the use of ECCO2R was 73% (relative risk 1.19, 95% credible interval 0.70–2.29). There was substantial heterogeneity in the reporting of safety and adverse events. However, the incidence of extra and intracranial haemorrhage was higher (relative risk 3.00, 95% credible interval 0.41–20.51) among those randomised to ECCO2R. Current trials have accumulated 80.8% of the diversity-adjusted required information size and the lack of effect reaches futility for a 10% absolute risk reduction in mortality.

Conclusions:

The use of ECCO2R in patients with AHRF is not associated with improvements in clinical outcomes. Furthermore, it is likely that further trials of ECCO2R aiming to achieve an absolute risk reduction in mortality of ≥10% are futile.

Remote monitoring in patients with heart failure with cardiac implantable electronic devices: a systematic review and meta-analysis

BACKGROUND

Remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) is now the standard of care, but whether the demonstrated benefits of RM translate into improvements in heart failure (HF) management is controversial. This systematic review addresses the role of RM in patients with HF with a CIED.

METHODS AND RESULTS

A systematic search of the literature for randomised clinical trials in patients with HF and a CIED assessing efficacy/effectiveness of RM was performed using MEDLINE, PubMed and Embase. Meta-analysis was performed on the effects of RM of CIEDs in patients with HF on mortality and readmissions. Effects on implantable cardiac defibrillator (ICD) therapy, healthcare costs and clinic presentations were also assessed.607 articles were identified and refined to 10 studies with a total of 6579 patients. Implementation of RM was not uniform with substantial variation in methodology across the studies. There was no reduction in mortality or hospital readmission rates, while ICD therapy findings were inconsistent. There was a reduction in patient-associated healthcare costs and reduction in healthcare presentations.

CONCLUSION

RM for patients with CIEDs and HF was not uniformly performed. As currently implemented, RM does not provide a benefit on overall mortality or the key metric of HF readmission. It does provide a reduction in healthcare costs and healthcare presentations.

PROSPERO REGISTRATION NUMBER

CRD42019129270.

Paracrine Factors Released by Stem Cells of Mesenchymal Origin and their Effects in Cardiovascular Disease: A Systematic Review of Pre-clinical Studies

Mesenchymal stem cell (MSC) therapy has gained significant traction in the context of cardiovascular repair, and have been proposed to exert their regenerative effects via the secretion of paracrine factors. In this systematic review, we examined the literature and consolidated available evidence for the “paracrine hypothesis”. Two Ovid SP databases were searched using a strategy encompassing paracrine mediated MSC therapy in the context of ischemic heart disease. This yielded 86 articles which met the selection criteria for inclusion in this study. We found that the MSCs utilized in these articles were primarily derived from bone marrow, cardiac tissue, and adipose tissue. We identified 234 individual protective factors across these studies, including VEGF, HGF, and FGF2; which are proposed to exert their effects in a paracrine manner. The data collated in this systematic review identifies secreted paracrine factors that could decrease apoptosis, and increase angiogenesis, cell proliferation, and cell viability. These included studies have also demonstrated that the administration of MSCs and indirectly, their secreted factors can reduce infarct size, and improve left ventricular ejection fraction, contractility, compliance, and vessel density. Furthering our understanding of the way these factors mediate repair could lead to the identification of therapeutic targets for cardiac regeneration.

Management of Acute Coronary Syndromes in Patients in Rural Australia: The MORACS Randomized Clinical Trial

Importance

Treatment of ST-segment elevation myocardial infarction (STEMI) in rural settings involves thrombolysis followed by transfer to a percutaneous coronary intervention-capable hospital. The first step is accurate diagnosis via electrocardiography (ECG), but one-third of all STEMI incidents go unrecognized and hence untreated.

Objective

To reduce missed diagnoses of STEMI.

Design, Setting, and Participants

This cluster randomized clinical trial included 29 hospital emergency departments (EDs) in rural Australia with no emergency medicine specialists, which were randomized to usual care vs automatically triggered diagnostic support from the tertiary referral hospital (management of rural acute coronary syndromes [MORACS] intervention). Patients presenting with symptoms compatible with acute coronary syndromes (ACS) were eligible for inclusion. The study was conducted from December 2018 to April 2020. Data were analyzed in August 2021.

Intervention

Triage of a patient with symptoms compatible with ACS triggered an automated notification to the tertiary hospital coronary care unit. The ECG and point-of-care troponin results were reviewed remotely and a phone call was made to the treating physician in the rural hospital to assist with diagnosis and initiation of treatment.

Main Outcomes and Measures

The proportion of patients with missed STEMI diagnoses.

Results

A total of 6249 patients were included in the study (mean [SD] age, 63.6 [12.2] years; 48% female). Of 7474 ED presentations with suspected ACS, STEMI accounted for 77 (2.0%) in usual care hospitals and 46 (1.3%) in MORACS hospitals. Missed diagnosis of STEMI occurred in 27 of 77 presentations (35%) in usual care hospitals and 0 of 46 (0%) in MORACS hospitals (P < .001). Of eligible patients, 48 of 75 (64%) in the usual care group and 36 of 36 (100%) in the MORACS group received primary reperfusion (P < .001). In the usual care group, 12-month mortality was 10.3% (n = 8) vs 6.5% (n = 3) in the MORACS group (relative risk, 0.64; 95% CI, 0.18-2.23). Patients with missed STEMI diagnoses had a mortality of 25.9% (n = 7) compared with 2.0% (n = 1) for those with accurately diagnosed STEMI (relative risk, 13.2; 95% CI, 1.71-102.00; P = .001). Overall, there were 6 patients who did not have STEMI as a final diagnosis; 5 had takotsubo cardiomyopathy and 1 had pericarditis. There was no difference between groups in the rate of alternative final diagnosis.

Conclusion and Relevance

The findings indicate that MORACS diagnostic support service reduced the proportion of missed STEMI and improved the rates of primary reperfusion therapy. Accurate diagnosis of STEMI was associated with lower mortality.

Trial Registration

anzctr.org.au Identifier: ACTRN12619000533190.

Patient characteristics, short-term and long-term outcomes after incident heart failure admissions in a regional Australian setting

AIMS

This study aims to (1) define the characteristics of patients with a first admission for heart failure (HF), stratified by type (reduced (HFrEF) vs preserved (HFpEF) ejection fraction) in a regional Australian setting; (2) compare the outcomes in terms of mortality and rehospitalisation and (3) assess adherence to the treatment guidelines.

METHODS

We identified all index hospitalisations with HF to John Hunter Hospital and Tamworth Rural Referral Hospital in the Hunter New England Local Health District over a 12 months. We used the recent Australian HF guidelines to classify HFrEF and HFpEF and assess adherence to guideline-directed therapy. The primary outcome of the study was to compare short-term (1 year) and long-term all-cause mortality and the composite of all-cause hospitalisation or all-cause mortality of patients with HFrEF and HFpEF.

RESULTS

There were 664 patients who had an index HF admission to John Hunter and Tamworth hospitals in 2014. The median age was 80 years, 47% were female and 22 (3%) were Aboriginal. In terms of HF type, 29% had HFrEF, 37% had HFpEF, while the remainder (34%) did not have an echocardiogram within 1 year of admission and could not be classified. The median follow-up was 3.3 years. HFrEF patients were predominantly male (64%) and in 48% the aetiology was ischaemic heart disease. The 1-year all-cause mortality was 23% in HFpEF subgroup and 29% in HFrEF subgroup (p=0.15). Five-year mortality was 61% in HFpEF and HFrEF patients. Of the HFrEF patients, only 61% were on renin-angiotensin-aldosterone blockers, 74% were on β-blockers and 39% were on aldosterone antagonist.

CONCLUSION

HF patients are elderly and about evenly split between HFrEF and HFpEF. In this regional cohort, both HF types are associated with similar 1-year and 5-year mortality following incident HF hospitalisation. Echocardiography and guideline-directed therapies were underused.

Aspirin as a Treatment for ARDS: A Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

There is no pharmacologic treatment for ARDS. Platelets play an important role in the pathophysiology of ARDS. Preclinical, observational, and clinically relevant models of ARDS indicate aspirin as a potential therapeutic option.

RESEARCH QUESTION

Is enteral aspirin (75 mg, once daily) safe and effective in improving surrogate outcomes in adult patients with ARDS?

STUDY DESIGN AND METHODS

This randomized, double-blind (patient and investigator), allocation-concealed, placebo-controlled phase 2 trial was conducted in five UK ICUs. Patients fulfilling the Berlin definition of ARDS were randomly assigned at a 1:1 ratio to receive enteral aspirin (75 mg) or placebo, for a maximum of 14 days, using a computer-generated randomization schedule, with variable block size, stratified by vasopressor requirement. The primary end point was oxygenation index (OI) on day 7. Secondary outcomes included safety parameters and other respiratory physiological markers. Analyses were by intention to treat.

RESULTS

The trial was stopped early, due to slow recruitment, after 49 of a planned 60 patients were recruited. Twenty-four patients were allocated to aspirin and 25 to placebo. There was no significant difference in day 7 OI [aspirin group: unadjusted mean, 54.4 (SD 26.8); placebo group: 42.4 (SD 25); mean difference, 12.0; 95% CI, -6.1 to 30.1; P = .19]. Aspirin did not significantly impact the secondary outcomes. There was no difference in the number of adverse events between the groups (13 in each; OR, 1.04; 95% CI, 0.56-1.94; P = .56).

INTERPRETATION

Aspirin was well tolerated but did not improve OI or other physiological outcomes; a larger trial is not feasible in its current design.

TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02326350; URL: www.

CLINICALTRIALS

gov.

Feasibility of conservative fluid administration and deresuscitation compared with usual care in critical illness: the Role of Active Deresuscitation After Resuscitation-2 (RADAR-2) randomised clinical trial

PURPOSE

Fluid overload is common in critical illness and is associated with mortality. This study investigated the feasibility of a randomised trial comparing conservative fluid administration and deresuscitation (active removal of accumulated fluid using diuretics or ultrafiltration) with usual care in critical illness.

METHODS

Open-label, parallel-group, allocation-concealed randomised clinical feasibility trial. Mechanically ventilated adult patients expected to require critical care beyond the next calendar day were enrolled between 24 and 48 h following admission to the intensive care unit (ICU). Patients were randomised to either a 2-stage fluid strategy comprising conservative fluid administration and, if fluid overload was present, active deresuscitation, or usual care. The primary endpoint was fluid balance in the 24 h up to the start of study day 3. Secondary endpoints included cumulative fluid balance, mortality, and duration of mechanical ventilation.

RESULTS

One hundred and eighty patients were randomised. After withdrawal of 1 patient, 89 patients assigned to the intervention were compared with 90 patients assigned to the usual care group. The mean plus standard deviation (SD) 24-h fluid balance up to study day 3 was lower in the intervention group (- 840 ± 1746 mL) than the usual care group (+ 130 ± 1401 mL; P < 0.01). Cumulative fluid balance was lower in the intervention group at days 3 and 5. Overall, clinical outcomes did not differ significantly between the two groups, although the point estimate for 30-day mortality favoured the usual care group [intervention arm: 19 of 90 (21.6%) versus usual care: 14 of 89 (15.6%), P = 0.32]. Baseline imbalances between groups and lack of statistical power limit interpretation of clinical outcomes.

CONCLUSIONS

A strategy of conservative fluid administration and active deresuscitation is feasible, reduces fluid balance compared with usual care, and may cause benefit or harm. In view of wide variations in contemporary clinical practice, large, adequately powered trials investigating the clinical effectiveness of conservative fluid strategies in critically ill patients are warranted.

Follistatin-like 3 (FSTL3) levels are increased in acute heart failure patients

Introduction

Follistatin-like 3 (FSTL3) is a secreted protein that has been suggested to play an important role in modulating cardiac remodeling and hypertrophy. In this study, we aim to determine whether: 1) FSTL3 is incrementally elevated in patients with HF vs those with other cardiovascular disease (CVD); and 2) increased FSTL3 is associated with 2 or more hospital admissions due to major adverse CV events (MACE) within 1 year.

Methods and results

We measured circulating levels of FSTL3 using commercially available ELISA (R&D systems) in a total of n=696 patients. FSTL3 levels were compared between: 1) healthy-aging volunteers with no prior major CVD (n=267, age 67±6 years) and 2) patients admitted to cardiology unit for various CVD (n=429, age 66±14 years); among those (n=178, age 68±13 years) had HF. Patients with HF had 2-fold higher FSTL3 levels vs healthy age-matched controls vs those with other CVD (p&lt;0.001). Occurrences of MACE were recorded up to 1 year for patients admitted to cardiology unit. On univariate analyses, patient with 2 or more MACE within 1 year (n=91, 27%) had significant elevated FSTL3 levels (P=0.003), is associated with older age (P&lt;0.005). On multivariate analysis, high FSTL3 levels (P=0.034) is an independent predictor of 2 or more MACE admissions within 1 year after adjusting for age, clinical comorbidities and medications.

Conclusions

FSTL3 is incrementally increased in patients with HF and is associated with poorer prognosis. Elevated FSTL3 levels is associated with increased risks of cardiac hospital readmissions for patients with multiple CV morbidities.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NSW Ministry of Health EMC Fellowship (Australia)

Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal vs Standard Care Ventilation on 90-Day Mortality in Patients With Acute Hypoxemic Respiratory Failure: The REST Randomized Clinical Trial

IMPORTANCE

In patients who require mechanical ventilation for acute hypoxemic respiratory failure, further reduction in tidal volumes, compared with conventional low tidal volume ventilation, may improve outcomes.

OBJECTIVE

To determine whether lower tidal volume mechanical ventilation using extracorporeal carbon dioxide removal improves outcomes in patients with acute hypoxemic respiratory failure.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020.

INTERVENTIONS

Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with conventional low tidal volume ventilation (n = 210).

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality 90 days after randomization. Prespecified secondary outcomes included ventilator-free days at day 28 and adverse event rates.

RESULTS

Among 412 patients who were randomized (mean age, 59 years; 143 [35%] women), 405 (98%) completed the trial. The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee. The 90-day mortality rate was 41.5% in the lower tidal volume ventilation with extracorporeal carbon dioxide removal group vs 39.5% in the standard care group (risk ratio, 1.05 [95% CI, 0.83-1.33]; difference, 2.0% [95% CI, -7.6% to 11.5%]; P = .68). There were significantly fewer mean ventilator-free days in the extracorporeal carbon dioxide removal group compared with the standard care group (7.1 [95% CI, 5.9-8.3] vs 9.2 [95% CI, 7.9-10.4] days; mean difference, -2.1 [95% CI, -3.8 to -0.3]; P = .02). Serious adverse events were reported for 62 patients (31%) in the extracorporeal carbon dioxide removal group and 18 (9%) in the standard care group, including intracranial hemorrhage in 9 patients (4.5%) vs 0 (0%) and bleeding at other sites in 6 (3.0%) vs 1 (0.5%) in the extracorporeal carbon dioxide removal group vs the control group. Overall, 21 patients experienced 22 serious adverse events related to the study device.

CONCLUSIONS AND RELEVANCE

Among patients with acute hypoxemic respiratory failure, the use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality. However, due to early termination, the study may have been underpowered to detect a clinically important difference.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02654327.

Hyperoxaemia and hypoxaemia are associated with harm in patients with ARDS

BACKGROUND

Oxygen therapy is routinely administered to mechanically ventilated patients. However, there remains uncertainty about the optimal oxygen titration target in patients with the acute respiratory distress syndrome (ARDS).

METHODS

Prospectively identified adult patients meeting the Berlin definition of ARDS between 1st January 2014 and 13th December 2016 were analyzed. Oxygen exposure variables were collected at 6-hourly intervals. The primary exposure was the average time-weighted partial pressure of arterial oxygen (PaO2) calculated over a maximum of 7 days from meeting ARDS criteria. The primary outcome was ICU mortality. Univariable and multivariable logistic regression analyses were performed to assess the impact of exposure variables on clinical outcomes. Results are presented as odds ratio [95% confidence interval].

RESULTS

202 patients were included in the final analysis. Overall ICU mortality was 31%. The average time-weighted PaO2 during the first 7 days of ARDS was similar between non-survivors and survivors (11.3 kPa [10.2, 12.5] (84.8 mmHg [76.5, 93.8]) vs. 11.9 kPa [10.9, 12.6] (89.3 mmHg [81.8, 94.5]); p = 0.08). In univariable and multivariable analysis, average time-weighted PaO2 demonstrated a U-shaped relationship with ICU mortality. There was a similar relationship identified with hospital mortality.

CONCLUSIONS

In patients with ARDS, the predicted probability of both ICU and hospital mortality was lowest when the average time-weighted PaO2 was between 12.5 and 14 kPa (93.8-105.0 mmHg), suggesting this is a reasonable oxygenation target for clinicians to aim for.

Calcium/Calmodulin-Dependent Protein Kinase II Delta Inhibition and Ventricular Remodeling After Myocardial Infarction: A Randomized Clinical Trial

Importance

After anterior ST-segment elevation myocardial infarction (STEMI), left ventricular (LV) remodeling results in heart failure and death. Calcium/calmodulin-dependent protein kinase II delta (CaMKIId) is a key molecular mediator of adverse LV remodeling.

Objective

To determine whether NP202, an orally active inhibitor of CaMKIId, prevents LV remodeling in patients after anterior STEMI with early residual LV dysfunction.

Design, Setting, and Participants

A randomized, double-blind, placebo-controlled multicenter clinical trial of NP202 vs placebo in patients after primary percutaneous coronary intervention (PCI) for anterior STEMI was performed from November 19, 2015, to August 1, 2018. The study was performed at 32 sites across the US, Australia, and New Zealand. Patients presenting with anterior STEMI who underwent PCI within 12 hours of symptom onset and left ventricular ejection fraction (LVEF) less than 45% on screening echocardiogram 48 hours after primary PCI were included in the study. Baseline cardiovascular magnetic resonance (CMR) imaging was performed within 5 days of the STEMI and before administration of the study drug. Follow-up CMR was performed after 3 months. Data were analyzed from November 19, 2015, to August 1, 2018.

Interventions

Patients were randomly assigned to NP202, 1000 mg, daily for 3 months vs corresponding placebo.

Main Outcomes and Measures

The primary end point was change in LV end-systolic volume index (LVESVi) on CMR. Secondary end points were change in LV end-diastolic volume index, change in LVEF, change in infarct size, and change in diastolic function. Safety and tolerability were also assessed.

Results

A total of 147 patients (mean [SD] age, 58 [11] years; 129 men [88%]; 130 White patients [88%]) who experienced anterior STEMI treated with primary PCI were randomized to receive NP202 (73 [49.7%]) or placebo (74 [50.3%]). Baseline LVEF was similar between groups. At baseline, patients randomized to NP202 had greater LVESVi (48.2 mL/m2) than that in the placebo group (41.3 mL/m2; P = .03). However, the groups were otherwise well matched. For the primary end point of change in LVESVi from baseline to 3 months, there was no significant difference between the placebo (median [interquartile range] change, -0.60 [-9.28 to 5.99] mL/m2) and NP202 groups (-3.53 [-9.24 to 4.81] mL/m2) (P = .78). There was also no difference in the secondary efficacy end points assessed by CMR. NP202 was well tolerated and demonstrated an acceptable safety profile. Major adverse cardiac and cerebrovascular event rates were similar between groups. Two deaths occurred in each group during the follow-up period.

Conclusions and Relevance

Three months of treatment with NP202 after primary PCI for anterior STEMI with residual LV dysfunction did not improve LV remodeling. The drug was safe and well tolerated.

Trial Registration

ClinicalTrials.gov Identifier: NCT02557217.

Natural history and prognostic implications of left ventricular end-diastolic pressure in reperfused ST-segment elevation myocardial infarction: an analysis of the thrombolysis in myocardial infarction (TIMI) II randomized controlled trial

Background

The aim of the current study is to assess the natural history and prognostic value of elevated left ventricular end-diastolic pressure (LVEDP) in patients with ST-segment elevation myocardial infarction (STEMI) after reperfusion with thrombolysis; we utilize data from the Thrombolysis in Myocardial Infarction (TIMI) II study.

Methods

A total of 3339 patients were randomized to either an invasive (n = 1681) or a conservative (n = 1658) strategy in the TIMI II study following thrombolysis. To make the current cohort as relevant as possible to modern pharmaco-invasively managed cohorts, patients in the invasive arm with TIMI flow grade ≥ 2 (N = 1201) at initial catheterization are included in the analysis. Of these, 259 patients had a second catheterization prior to hospital discharge, and these were used to define the natural history of LVEDP in reperfused STEMI.

Results

The median LVEDP for the whole cohort was 18 mmHg (IQR: 12–23). Patients were divided into quartiles by LVEDP measured during the first cardiac catheterization. During a median follow up of 3 (IQR: 2.1–3.2) years, quartile 4 (highest LVEDP) had the highest incidence of mortality and heart failure admissions. In the cohort with paired catheterization data, the LVEDP dropped slightly from 18 mmHg (1QR: 12–22) to 15 mmHg (IQR: 10–20) (p = 0.01) from the first to the pre-hospital discharge catheterization.

Conclusions

LVEDP remains largely stable during hospitalisation post-STEMI. Elevated LVEDP is a predictor of death and heart failure hospitalization in STEMI patients undergoing successful thrombolysis.

Graphic abstract

Heart failure outcomes in Aboriginal and Torres Strait Islander peoples in the Hunter New England region of New South Wales

Background Aboriginal and Torres Strait Islander suffer poor health outcomes, driven predominately by cardiovascular disease. Previous work has focused on remote communities although majority of Aboriginal and Torres Strait Islander patients live in urban New South Wales. We describe the heart failure characteristics and outcomes of the Aboriginal and Torres Strait Islander patients in Hunter New England Health, New South Wales, Australia. Methods A large retrospective, multi-centre cohort study from 2007 till 2016 in a geographically diverse Local Health District. The primary outcomes were all-cause mortality and all-cause readmission. The Aboriginal and Torres Strait Islander cohort was described by demographics, locality, and outcomes relative to the non-Indigenous patients from the same time period. Findings During the study period there were 20,480 index admissions, of which 3.1% identified as Aboriginal and/or Torres Strait Islander. Aboriginal and Torres Strait Islander people admitted were younger by an average of 15 years (81 vs 66 years, p < 0.001), were more likely to live in a non-metropolitan locality (80 vs 61%, p < 0.001). Once adjustments were made for age, there was no significant difference in all-cause mortality. Indigenous status was a strong predictor of readmission on multivariate analysis, hazard ratio of 1.31 (p < 0.001). Interpretation Aboriginal and Torres Strait Islander patients, compared to non-Indigenous patients, who are admitted with heart failure are younger, more commonly live in rural localities and suffer from a higher burden of comorbidities. Once adjustments are made for age and co-morbidities, indigenous status does not portend a worse outcome.

Impact of Delay in Surgery on Outcome in Patients Undergoing Cardiac Revascularisation Surgery

BACKGROUND

Diagnosis of critical coronary artery disease, including after acute coronary syndrome presentation (ACS), represents an important indication for early coronary artery bypass graft (CABG) surgery. The study aims to investigate the influence of time from diagnosis to CABG on outcomes and document barriers to early revascularisation.

METHODS

All patients 18 years and older with an acute presentation due to ACS or critical coronary artery disease who were considered to require urgent inpatient cardiac surgery between January 2016-February 2019 were included in the study. The primary endpoints were 30-day all-cause mortality or readmission, 1-year all-cause mortality, all-cause readmission. The secondary endpoint was the rate of complications while waiting for surgery. The time duration between diagnostic coronary angiography and surgery was considered as the time interval.

RESULTS

Of 266 eligible patients, 251 underwent surgical revascularisation with 15 (6%) not undergoing surgery due to preoperative complications (n=12) or due to perceived prohibitively high surgical risk (n=3). The majority (85%) were male (mean age 67 years), 37% of patients had diabetes and 71% had hypertension. Non-ST elevation myocardial infarction was documented in 51% of the patients. The median time between diagnosis and inpatient CABG was 7 days (IQR 5-11). Thirty-five per cent (35%) of patients experienced complications while awaiting surgery. Of the 266 patients, 140 patients (53% - cohort 1) underwent surgery within 7 days. The cohort 1 rate of complications was lower than in cohort 2 (surgery after 7 days) (24 vs 47%, p<0.001). Moreover, 1-year mortality was less in cohort 1 (2 vs 8%, p=0.029).

CONCLUSION

In patients requiring urgent inpatient CABG, delay for more than 7 days is associated with a higher rate of in-hospital complications and worse 30 day and 12-month outcomes.

Combined Mesenchymal Stromal Cell Therapy and Extracorporeal Membrane Oxygenation in Acute Respiratory Distress Syndrome. A Randomized Controlled Trial in Sheep

Rationale: Mesenchymal stromal cell (MSC) therapy is a promising intervention for acute respiratory distress syndrome (ARDS), although trials to date have not investigated its use alongside extracorporeal membrane oxygenation (ECMO). Recent preclinical studies have suggested that combining these interventions may attenuate the efficacy of ECMO.Objectives: To determine the safety and efficacy of MSC therapy in a model of ARDS and ECMO.Methods: ARDS was induced in 14 sheep, after which they were established on venovenous ECMO. Subsequently, they received either endobronchial induced pluripotent stem cell-derived human MSCs (hMSCs) (n = 7) or cell-free carrier vehicle (vehicle control; n = 7). During ECMO, a low Vt ventilation strategy was employed in addition to protocolized hemodynamic support. Animals were monitored and supported for 24 hours. Lung tissue, bronchoalveolar fluid, and plasma were analyzed, in addition to continuous respiratory and hemodynamic monitoring.Measurements and Main Results: The administration of hMSCs did not improve oxygenation (Pa_O2/Fi_O2 mean difference = -146 mm Hg; P = 0.076) or pulmonary function. However, histological evidence of lung injury (lung injury score mean difference = -0.07; P = 0.04) and BAL IL-8 were reduced. In addition, hMSC-treated animals had a significantly lower cumulative requirement for vasopressor. Despite endobronchial administration, animals treated with hMSCs had a significant elevation in transmembrane oxygenator pressure gradients. This was accompanied by more pulmonary artery thromboses and adherent hMSCs found on explanted oxygenator fibers.Conclusions: Endobronchial hMSC therapy in an ovine model of ARDS and ECMO can impair membrane oxygenator function and does not improve oxygenation. These data do not recommend the safe use of hMSCs during venovenous ECMO.

Targeting elevated left ventricular end-diastolic pressure following primary percutaneous coronary intervention for ST-segment elevation myocardial infarction – a phase one safety and feasibility study

Introduction:

Elevated left ventricular end diastolic pressure (LVEDP) is an independent predictor of mortality and heart failure in patients with ST-segment elevation myocardial infarction (STEMI). Whether lowering elevated LVEDP improves outcomes remains unknown.

Methods:

This non-randomized, single blinded study with prospective enrolment and sequential group allocation recruited patients undergoing primary percutaneous coronary intervention for STEMI with LVEDP ⩾ 20 mmHg measured immediately after primary percutaneous coronary intervention. The intervention arm (n=10) received furosemide 40 mg intravenous bolus plus escalating doses of glyceryl trinitrate (100 µg per min to a maximum of 1000 µg) during simultaneous measurement of LVEDP. The control group (n=10) received corresponding normal saline boluses with simultaneous measurement of LVEDP (10 readings over 10 min). Efficacy endpoints were final LVEDP achieved, and the dose of glyceryl trinitrate needed to reduce LVEDP by ⩾ 20%. Safety endpoint was symptomatic hypotension (systolic blood pressure &lt; 90 mmHg).

Results:

From 1 April 2017 to 23 August 2017 we enrolled 20 patients (age: 64±9 years, males: 60%, n=12, anterior STEMI: 65%, n=13). The mean LVEDP for the whole cohort (n=20) was 29±4 mmHg (intervention group: 28±3 mmHg vs. control group: 31±5 mmHg; p=0.1). The LVEDP dropped from 28±3 to 16±2 mmHg in the glyceryl trinitrate + furosemide group (p &lt;0.01) but remained unchanged in the control group. The median dose of glyceryl trinitrate required to produce ⩾ 20% reduction in LVEDP in the intervention group was 200 µg (range: 100–800). One patient experienced asymptomatic decline in systolic blood pressure to below 90 mmHg. There was no correlation between LVEDP and left ventricular ejection fraction.

Conclusion:

The administration of glyceryl trinitrate plus furosemide in patients with elevated LVEDP following primary percutaneous coronary intervention for STEMI safely reduces LVEDP.

Pulmonary Hypertension Due to Left Heart Disease

Pulmonary hypertension (PH) due to left heart disease (LHD) is the most common type of PH and is defined as mean pulmonary artery systolic pressure of >20 mm Hg and pulmonary capillary wedge pressure >15 mm Hg during right heart catheterization. LHD may lead to elevated left atrial pressure alone, which in the absence of intrinsic pulmonary vascular disease will result in PH without changes in pulmonary vascular resistance. Persistent elevation in left atrial pressure may, however, also be associated with subsequent pulmonary vascular remodeling, vasoconstriction, and an increase in pulmonary vascular resistance. Hence, there are 2 subgroups of PH due to LHD, isolated postcapillary PH and combined post- and precapillary PH, with these groups have differing clinical implications. Differentiation of pulmonary arterial hypertension and PH due to LHD is critical to guide management planning; however, this may be challenging. Older patients, patients with metabolic syndrome, and patients with imaging and clinical features consistent with left ventricular dysfunction are suggestive of LHD etiology rather than pulmonary arterial hypertension. Hemodynamic measures such as diastolic pressure gradient, transpulmonary gradient, and pulmonary vascular resistance may assist to differentiate pre- from postcapillary PH and offer prognostic insights. However, these are influenced by fluid status and heart failure treatment. Pulmonary arterial hypertension therapies have been trialed in the treatment with concerning results reflecting disease heterogeneity, variation in inclusion criteria, and mixed end point criteria. The aim of this review is to provide an updated definition, discuss possible pathophysiology, clinical aspects, and the available treatment options for PH due to LHD.

Impact of fast-food outlet density on incidence of myocardial infarction in the Hunter region

BACKGROUND

There is an established association between fast-food consumption and metabolic diseases. Some studies also suggest that calorie-dense food promotes a proinflammatory response, which is itself linked with myocardial infarction (MI). Whether increased fast-food availability is a risk factor for MI remains unknown.

AIM

To investigate the role of fast-food outlet density (FFD) as a novel environmental risk factor for MI in the Hunter region, New South Wales (NSW).

METHODS

We conducted a retrospective cohort study using a database of all MI events between 1996 and 2013, extracted from the Hunter Cardiac and Stroke Outcomes unit. FFD was calculated for each local government area (LGA) of the Hunter region, allowing for a comparative analysis. Stratification by fast-food outlet data and LGA resulted in a total of 3070 cases. Weighted linear regression was used to investigate the role of FFD on incidence of MI in regional and rural Australia.

RESULTS

FFD was positively correlated with rates of MI, remaining consistent in both single and multivariate predictor models adjusting for age, obesity, hyperlipidaemia, hypertension, smoking status, diabetes and socioeconomic status (P < 0.001). An increase of one fast-food outlet corresponded with four additional cases of MI per 100 000 people per year (4.07, 95% confidence interval, 3.86-4.28).

CONCLUSIONS

FFD was positively associated with incidence of MI in both rural and metropolitan areas of NSW. This relationship remained consistent after multivariate adjustment for standard cardiovascular risk factors, highlighting the importance of an individual's food environment as a potential contributor towards their health.

Serotonin syndrome following left ventricular assist device implantation: A report and institution-specific strategy for prevention

Serotonin syndrome is a potentially lethal complication of antidepressant therapy. Cardiac surgical patients are at particularly high risk of serotonin syndrome due to the prevalence of depression in patients with advanced cardiac disease, many of whom receive multiple serotonergic agents in the perioperative period. Here, we describe a case of postoperative serotonin syndrome following methylene blue administration for perioperative vasoplegia during left ventricular assist device implantation. We additionally describe an institution-specific strategy to minimize future occurrences of serotonin syndrome in this high-risk population. <Learning objective: Antidepressant medication use is prevalent in advanced heart failure patients. With serotonergic antidepressants, perioperative drug interactions may potentiate serious adverse drug events such as serotonin syndrome. In this report, we describe a case of serotonin syndrome following treatment of perioperative vasoplegia with methylene blue and describe steps our institution has implemented to prevent future occurrences.>.

P6296The role of extracellular matrix protein 1 (ECM1) - a novel link between inflammation and cardiac fibrosis

Introduction

Cardiac fibrosis is a severe consequence of cardiovascular disease and aging, in which we currently have no effective treatments. The mechanisms underpinning the development of cardiac fibrosis remains poorly understood. Our preliminary data suggested extracellular matrix protein 1 (ECM1) is involved in cardiac fibrosis. We therefore aimed to investigate the role of ECM1 in several fibrotic cardiac diseases.

Methods

Young and ageing (3m/18m) male C57BL/6 mice, and primary mouse cardiac fibroblast (cFB) cultures, commercial human cardiac fibroblasts (Hu-cFB), human coronary artery endothelial cell (HCAEC)/smooth muscle cell (HCASMC), and human cardiac myocyte (HCM) cell lines were used. Young mice were subject to myocardial infarction (MI, 3-day/28-day, n=6/6), or pressure overload (TAC, 3-day/13-week, n=4/4). Left ventricle (LV) was collected at all time-points, and at 18m (ageing; n=3). Spleen and bone marrow was extracted from young control mice. Hu-cFB cells were treated with recombinant ECM1 (20ng/ml) for either 10, 30 or 50 min, or 48h. Immunoblotting was conducted on all samples, qPCR on LV tissue only, density gradient centrifugation and multicolour flow cytometry coupled with fluorescent ECM1 mRNA in-situ hybridisation (FISH-Flow) on bone marrow cells.

Results

ECM1 expression was upregulated in ageing LV (mRNA 2.2±0.1-fold, p=0.0002; protein 2.0-fold, p=0.0006), day-3 post-MI (mRNA, 4.9±2.0-fold, p=0.004; protein, 3.0-fold, p=0.004), a trend of ECM1 upregulation was observed at day-28 post-MI (mRNA, 13.2±12.0-fold, p=0.003; protein, 1.8-fold, p=0.2), but no change post-TAC. Both ERK1/2 and AKT phosphorylation was upregulated 10 min post-ECM1 treatment of Hu-cFBs (ERK1/2, 2.0-fold, p<0.0001; AKT, 1.9-fold, p<0.0001), and Collagen-I protein expression was upregulated 48h post-ECM1 treatment (1.9-fold, p=0.004). ECM1 protein was not expressed in cFB, Hu-cFB, HCAEC, HCASMC or HCM, however ECM1 protein was highly expressed in spleen and bone marrow; to a greater extent in granulocytes compared to monocytes (p=0.004). tSNE analysis of ECM1 mRNA FISH-Flow revealed ECM1+ are highly granular, moderate to large in size, and express (to varying levels) CD45, CD11b, CD11c, F4/80, Ly6-C, Ly-6G, and FcεrI-α. However ECM1+ cells did not express markers indicative of smaller cells (CD3 or MHC II).

Conclusions

These data demonstrate that ECM1 plays a role in ageing and post-MI fibrosis. Although ECM1 was not produced by resident cardiac cells, it was highly expressed in spleen and bone marrow; specifically, large, granular bone marrow cell sub-types such as granulocytes and/or macrophages. Our data suggest ECM1 is expressed by cardiac infiltrating leukocytes to provoke fibroblast collagen expression in a disease specific manner; potentially via the ERK1/2 and/or AKT pathway activation. Therefore, ECM1 warrants further investigation, and may be a promising target for the treatment of fibrotic cardiac diseases.

Acknowledgement/Funding

John hunter hospital charitable trust, Hunter medical research institute (HMRI) grants

Pre-hospital thrombolysis for ST-segment elevation myocardial infarction in regional Australia: long-term follow up

BACKGROUND

Delivering reperfusion therapy to patients with ST-segment elevation myocardial infarction (STEMI) in regional areas without access to tertiary cardiology care remains challenging. The systems of care in Hunter New England Health, New South Wales, Australia (area covered = 130 000 km² ) to provide reperfusion to patients with STEMI involve a 12-lead electrocardiogram in the ambulance, discussion between cardiologist and paramedic, followed by pre-hospital thrombolysis (PHT) delivered in ambulance to appropriate patients >60 min from the cardiac catheterisation laboratories. Patients who can access the cardiac catheterisation laboratories within 60 min are treated with primary percutaneous coronary intervention (PCI).

AIMS

We have previously reported excellent 12-month outcomes for patients receiving PHT and the aim of the current analysis is to look at the long term outcomes.

METHODS

We assessed long-term all-cause mortality and major adverse cardiovascular events of STEMI patients undergoing PHT in our health district from August 2008 to August 2013 and compared with the primary PCI group.

RESULTS

One hundred and fifty (mean age: 62 ± 13 years, males: 76%, n = 114) patients were administered PHT and 334 patients (mean age: 65 ± 13 years, males: 75%, n = 251) underwent primary PCI during the study period. During a median follow up of 6.2 years (interquartile range: 4.8-7.4 years) all-cause mortality was 16% and 19% in the PHT and primary PCI groups respectively (P = 0.4).

CONCLUSION

Our real-world experience shows that PHT followed by early transfer to a primary PCI-capable centre is an effective reperfusion strategy, with comparable results to primary PCI, and mortality benefits are sustained to more than 6 years.

Contemporary trends in stroke complicating cardiac catheterisation

BACKGROUND

Stroke remains an important complication of diagnostic cardiac catheterisation and percutaneous coronary intervention and is associated with high rates of in-hospital mortality.

AIMS

To evaluate the incidence of stroke over a 10-year period and assess the long-term influence of stroke following cardiac catheterisation and PCI on functional outcomes, based on modified Rankin score and mortality.

METHODS

The study was performed using a case-control design in a single tertiary referral centre. Patients were identified by correlating those patients undergoing cardiac catheterisation between October 2006 and December 2016 with patients who underwent neuroimaging within 7 days to identify possible cases of suspected stroke or transient ischaemic attack.

RESULTS

A total of 21 510 patients underwent cardiac catheterisation during the study period. Sixty (0.28%) patients experienced stroke or transient ischaemic attack. Compared to control patients, those who did experience cerebral ischaemic events were older (70.5 vs 64 years; P < 0.001), with higher rates of atrial fibrillation, hypertension and diabetes mellitus. Stroke complicating cardiac catheterisation was associated with an increased risk of readmission, with a significantly higher hazard of readmission for stroke noted. Despite minimal functional impairment based on modified Rankin score, stroke was associated with a significant risk of early and cumulative mortality. Stroke incidence remained stable over the study period despite changes in procedural practice.

CONCLUSIONS

The incidence and functional severity of stroke remains low despite evolving procedural practice with a stable incidence over time despite changes in procedural practice; however, post-procedural stroke confirms an increased mortality hazard.

Echocardiographic determination of pulmonary arterial capacitance

A growing body of evidence has demonstrated that pulmonary arterial capacitance (PAC) is the strongest hemodynamic predictor of clinical outcomes across a wide spectrum of cardiovascular disease, including pulmonary hypertension and heart failure. We hypothesized that a ratio of right ventricular stroke volume (RVOT VTI) to the associated peak arterial systolic pressure (PASP) could function as a reliable non-invasive surrogate for PAC. We performed a prospective study of patients undergoing simultaneous transthoracic echocardiography and right heart catheterization (RHC) for various clinical indications. Measurements of the RVOT VTI/PASP ratio from echocardiographic measurements were compared against PAC calculated from RHC measurements. Correlation coefficients and Bland-Altman analysis compared the RVOT VTI/PASP ratio with PAC. Forty-five subjects were enrolled, 38% were female and mean age was 54 years (SD 13 years). The reason for referral to RHC was most commonly post-heart transplant surveillance (40%), followed by heart failure (22%), and pulmonary hypertension (18%). Pre-capillary pulmonary hypertension was present in 18%, isolated post-capillary pulmonary hypertension was present in 13%, and combined pre-and post-capillary pulmonary hypertension was present in 29%. The RVOT VTI/PASP ratio was obtainable in the majority of patients (78%), and Pearson's correlation demonstrated moderately-strong association between PAC and the RVOT VTI/PASP ratio, r = 0.75 (P < 0.001). Bland-Altman analysis demonstrated good agreement between measurements without suggestion of systematic bias and a mean difference in standardized units of - 0.133. In a diverse population of patients and hemodynamic profiles, we validated that the ratio of RVOT VTI/PASP to be a reliably-obtained non-invasive marker associated with PAC.

The Role of Pathological Aging in Cardiac and Pulmonary Fibrosis

Aging promotes a range of degenerative pathologies characterized by progressive losses of tissue and/or cellular function. Fibrosis is the hardening, overgrowth and scarring of various tissues characterized by the accumulation of extracellular matrix components. Aging is an important predisposing factor common for fibrotic heart and respiratory disease. Age-related processes such as senescence, inflammaging, autophagy and mitochondrial dysfunction are interconnected biological processes that diminish the regenerative capacity of the aged heart and lung and have been shown to play a crucial role in cardiac fibrosis and idiopathic pulmonary fibrosis. This review focuses on these four processes of aging in relation to their role in fibrosis. It has long been established that the heart and lung are linked both functionally and anatomically when it comes to health and disease, with an ever-expanding aging population, the incidence of fibrotic disease and therefore the number of fibrosis-related deaths will continue to rise. There are currently no feasible therapies to treat the effects of chronic fibrosis therefore highlighting the importance of exploring the processes of aging and its role in inducing and exacerbating fibrosis of each organ. The focus of this review may help to highlight potential avenues of therapeutic exploration

Missed Acute Myocardial Infarction (MAMI) in a rural and regional setting

Background

Delay in treatment and/or failure to provide reperfusion in ST-segment elevation myocardial infarction (STEMI) impacts on morbidity and mortality. This occurs more often outside metropolitan areas yet the reasons for this are unclear. This study aimed to describe factors associated with missed diagnosis of acute myocardial infarction (MAMI) in a rural and regional setting.

Methods

Using a retrospective cohort design, patients who presented with STEMI and failed to receive reperfusion therapy within four hours were identified as MAMI. Univariate analyses were undertaken to identify differences in clinical characteristics between the treated STEMI group and the MAMI group. Mortality, 30-day readmission rates and length of hospital stay are reported.

Results

Of 100 patients identified as MAMI (70 male, 30 female), 24 died in hospital. Demographics and time from symptom onset were similar in the treated STEMI and MAMI groups. Of the MAMI patients who died, rural hospitals recorded the highest inpatient mortality (69.6% p = 0.008). MAMI patients compared to treated STEMI patients had higher 30 day readmission (31.6% vs 3.3%, p = 0.001) and longer length of stay (5.5 vs 4.3 days p = 0.029). Inaccurate identification of STEMI on electrocardiogram (72%) and diagnostic uncertainty (65%) were associated with MAMI. The Glasgow algorithm to identify STEMI was utilised on 57% of occasions, with 93% accuracy.

Conclusion

Mortality following MAMI is high particularly in smaller rural hospitals. MAMI results in increased length of stay and readmission rate. Electrocardiogram interpretation and diagnostic accuracy require improvement to determine if this improves patient outcomes.

Use of Cangrelor as a Bridge to Left Ventricular Assist Device Implantation in a Patient with a Recent Drug-Eluting Stent Who Developed Acute Tirofiban-Related Thrombocytopenia

Current guidelines emphasize the need for at least 6-12 months of oral dual antiplatelet therapy consisting of aspirin and a P2Y12 inhibitor following drug-eluting coronary artery stent implantation. In patients with recently implanted coronary artery stents who require urgent cardiac or noncardiac surgery, the benefits of maintaining oral dual antiplatelet therapy must be carefully weighed against the risks of excessive bleeding, and current practice is largely guided by individual surgeon preferences. When the effects of a second oral antiplatelet agent are undesirable during the perioperative period, the use of a short-acting intravenous antiplatelet agent as "bridge" therapy that can be discontinued shortly before surgery is associated with a reduced occurrence of adverse clinical events in patients with recently implanted coronary stents requiring urgent coronary artery bypass graft surgery. Cangrelor is an intravenous adenosine triphosphate analog P2Y12 receptor antagonist with a short plasma half-life that has been used off label in patients with recent coronary stents as a bridge to invasive procedures with excessive bleeding risk. To our knowledge, this is the first case report to demonstrate the safe and effective use of cangrelor as a bridge to left ventricular assist device implantation in a patient with a recently implanted drug-eluting coronary artery stent who developed acute thrombocytopenia following reexposure to tirofiban, a glycoprotein IIb/IIIa inhibitor.

Novel role of extracellular matrix protein 1 (ECM1) in cardiac aging and myocardial infarction

INTRODUCTION

The prevalence of heart failure increases in the aging population and following myocardial infarction (MI), yet the extracellular matrix (ECM) remodeling underpinning the development of aging- and MI-associated cardiac fibrosis remains poorly understood. A link between inflammation and fibrosis in the heart has long been appreciated, but has mechanistically remained undefined. We investigated the expression of a novel protein, extracellular matrix protein 1 (ECM1) in the aging and infarcted heart.

METHODS

Young adult (3-month old) and aging (18-month old) C57BL/6 mice were assessed. Young mice were subjected to left anterior descending artery-ligation to induce MI, or transverse aortic constriction (TAC) surgery to induce pressure-overload cardiomyopathy. Left ventricle (LV) tissue was collected early and late post-MI/TAC. Bone marrow cells (BMCs) were isolated from young healthy mice, and subject to flow cytometry. Human cardiac fibroblast (CFb), myocyte, and coronary artery endothelial & smooth muscle cell lines were cultured; human CFbs were treated with recombinant ECM1. Primary mouse CFbs were cultured and treated with recombinant angiotensin-II or TGF-β1. Immunoblotting, qPCR and mRNA fluorescent in-situ hybridization (mRNA-FISH) were conducted on LV tissue and cells.

RESULTS

ECM1 expression was upregulated in the aging LV, and in the infarct zone of the LV early post-MI. No significant differences in ECM1 expression were found late post-MI or at any time-point post-TAC. ECM1 was not expressed in any resident cardiac cells, but ECM1 was highly expressed in BMCs, with high ECM1 expression in granulocytes. Flow cytometry of bone marrow revealed ECM1 expression in large granular leucocytes. mRNA-FISH revealed that ECM1 was indeed expressed by inflammatory cells in the infarct zone at day-3 post-MI. ECM1 stimulation of CFbs induced ERK1/2 and AKT activation and collagen-I expression, suggesting a pro-fibrotic role.

CONCLUSIONS

ECM1 expression is increased in ageing and infarcted hearts but is not expressed by resident cardiac cells. Instead it is expressed by bone marrow-derived granulocytes. ECM1 is sufficient to induce cardiac fibroblast stimulation in vitro. Our findings suggest ECM1 is released from infiltrating inflammatory cells, which leads to cardiac fibroblast stimulation and fibrosis in aging and MI. ECM1 may be a novel intermediary between inflammation and fibrosis.

Identifying associations between diabetes and acute respiratory distress syndrome in patients with acute hypoxemic respiratory failure: an analysis of the LUNG SAFE database

BACKGROUND

Diabetes mellitus is a common co-existing disease in the critically ill. Diabetes mellitus may reduce the risk of acute respiratory distress syndrome (ARDS), but data from previous studies are conflicting. The objective of this study was to evaluate associations between pre-existing diabetes mellitus and ARDS in critically ill patients with acute hypoxemic respiratory failure (AHRF).

METHODS

An ancillary analysis of a global, multi-centre prospective observational study (LUNG SAFE) was undertaken. LUNG SAFE evaluated all patients admitted to an intensive care unit (ICU) over a 4-week period, that required mechanical ventilation and met AHRF criteria. Patients who had their AHRF fully explained by cardiac failure were excluded. Important clinical characteristics were included in a stepwise selection approach (forward and backward selection combined with a significance level of 0.05) to identify a set of independent variables associated with having ARDS at any time, developing ARDS (defined as ARDS occurring after day 2 from meeting AHRF criteria) and with hospital mortality. Furthermore, propensity score analysis was undertaken to account for the differences in baseline characteristics between patients with and without diabetes mellitus, and the association between diabetes mellitus and outcomes of interest was assessed on matched samples.

RESULTS

Of the 4107 patients with AHRF included in this study, 3022 (73.6%) patients fulfilled ARDS criteria at admission or developed ARDS during their ICU stay. Diabetes mellitus was a pre-existing co-morbidity in 913 patients (22.2% of patients with AHRF). In multivariable analysis, there was no association between diabetes mellitus and having ARDS (OR 0.93 (0.78-1.11); p = 0.39), developing ARDS late (OR 0.79 (0.54-1.15); p = 0.22), or hospital mortality in patients with ARDS (1.15 (0.93-1.42); p = 0.19). In a matched sample of patients, there was no association between diabetes mellitus and outcomes of interest.

CONCLUSIONS

In a large, global observational study of patients with AHRF, no association was found between diabetes mellitus and having ARDS, developing ARDS, or outcomes from ARDS.

TRIAL REGISTRATION

NCT02010073 . Registered on 12 December 2013.

Common themes in patients requiring urgent cardiothoracic surgery after percutaneous coronary interventions: Case series and review of the literature

Urgent cardiothoracic surgical intervention for the management of complications of percutaneous coronary intervention is uncommon in the stent era. Nonetheless, given increasing procedural complexity, in part reflecting an aging population, an ongoing hazard for urgent surgery remains. We sought to review the incidence and outcome of urgent cardiothoracic surgery in patients undergoing PCI in a contemporary cohort at a tertiary referral centre. The incidence of cardiothoracic intervention for PCI related complications was low at 0.1% over a ten-year period, with iatrogenic coronary artery and aortic root dissection unable to successfully managed percutaneously recurrent precipitants for surgical involvement. Procedural features associated with the need for urgent surgery are noted and methods to overcome such complications discussed.

Outcomes following heart failure hospitalization in a regional Australian setting between 2005 and 2014

AIMS

The aim of the current study is to examine 10 year trends in mortality and readmission following heart failure (HF) hospitalization in metropolitan and regional Australian settings.

METHODS AND RESULTS

We identified all index HF hospitalizations in the Hunter New England region from 2005 to 2014, using a 10 year 'look back' period. The primary endpoint was a composite of all-cause mortality or all-cause readmission at 1 year. Secondary endpoints included all-cause mortality, all-cause readmission, and HF readmission at 30 days and 1 year. We used logistic regression to explore the predictors of the composite outcome of either all-cause death or readmission at 1 year. There were 12 114 patients admitted with a first episode of HF between 2005 and 2014, followed up until death or the end of 2015. The mean age was 78 ± 12 years and 49% (n = 5906) were male. A total of 4831 (40%) resided in regional areas and the remainder in metropolitan areas. One hundred sixty-eight patients (1.4%) were Aboriginal. Approximately 69% of patients had either died or been readmitted for any cause within 12 months of their index event. The 30 day and 1 year all-cause mortality rates were 13% and 32%, respectively, with no change in the trend over the study period. Age, socio-economic disadvantage, ischaemic heart disease, renal failure, and chronic lower respiratory disease were predictors of the primary endpoint.

CONCLUSIONS

Heart failure hospitalizations are followed by high rates of death or readmission. There was no change in this composite endpoint over the 10 year study period.

Percutaneous coronary intervention versus coronary artery bypass grafting in heart transplant recipients with coronary allograft vasculopathy: a systematic review and meta-analysis of 1,520 patients

Background

Transplant coronary artery vasculopathy (TCAV) is the major cause of late allograft failure and death in heart transplant recipients. The aim of this systematic review was to examine the outcomes of percutaneous coronary interventions (PCIs) as compared to coronary artery bypass grafting (CABG) surgery in the management of TCAV. Our secondary objective was to compare the use and outcomes of drug eluting stents (DES) as compared to bare metal stents (BMS) in this patient population.

Methods

Electronic search was performed to identify all studies in the English literature examining PCI as compared to CABG for TCAV in heart transplant recipients. All identified articles were systematically assessed for inclusion and exclusion criteria.

Results

Of the 4,989 studies identified, 29 studies were included. Among 1,520 patients who developed TCAV, 1,470 patients underwent PCI and 50 patients underwent CABG. There were no significant differences in baseline demographics and comorbidities among the PCI and CABG cohorts. Compared to the PCI cohort, patients who underwent CABG had a higher early mortality (CABG 36.4% vs. PCI 4.3%, P<0.001) and overall mortality (CABG 42.3% vs. PCI 21.4%, P=0.049). When comparing DES versus BMS cohorts, there were no significant differences in the rate of in-stent stenosis (DES 14.5% vs. BMS 24.4%, P=0.476), overall mortality (DES 17.4% vs. BMS 30.8%, P=0.302) or cardiac related mortality (DES 7.7% vs. BMS 21.8%, P=0.415).

Conclusions

CABG and PCI are both feasible modalities for revascularization in patients with TCAV where PCI is associated with lower mortality. There were no differences in outcomes among patients who underwent PCI with DES as compared to BMS. Potential bias may exist due to heterogeneity in available data. Further studies are needed to delineate evidence-based guidelines to tailor the appropriate therapy, CABG or PCI, to the appropriate patient.

The Processes and Mechanisms of Cardiac and Pulmonary Fibrosis

Fibrosis is the formation of fibrous connective tissue in response to injury. It is characterized by the accumulation of extracellular matrix components, particularly collagen, at the site of injury. Fibrosis is an adaptive response that is a vital component of wound healing and tissue repair. However, its continued activation is highly detrimental and a common final pathway of numerous disease states including cardiovascular and respiratory disease. Worldwide, fibrotic diseases cause over 800,000 deaths per year, accounting for ~45% of total deaths. With an aging population, the incidence of fibrotic disease and subsequently the number of fibrosis-related deaths will rise further. Although, fibrosis is a well-recognized cause of morbidity and mortality in a range of disease states, there are currently no viable therapies to reverse the effects of chronic fibrosis. Numerous predisposing factors contribute to the development of fibrosis. Biological aging in particular, interferes with repair of damaged tissue, accelerating the transition to pathological remodeling, rather than a process of resolution and regeneration. When fibrosis progresses in an uncontrolled manner, it results in the irreversible stiffening of the affected tissue, which can lead to organ malfunction and death. Further investigation into the mechanisms of fibrosis is necessary to elucidate novel, much needed, therapeutic targets. Fibrosis of the heart and lung make up a significant proportion of fibrosis-related deaths. It has long been established that the heart and lung are functionally and geographically linked when it comes to health and disease, and thus exploring the processes and mechanisms that contribute to fibrosis of each organ, the focus of this review, may help to highlight potential avenues of therapeutic investigation.

Accuracy of Seattle Heart Failure Model and HeartMate II Risk Score in Non-Inotrope-Dependent Advanced Heart Failure Patients: Insights From the ROADMAP Study (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients)

BACKGROUND

Timing of left ventricular assist device (LVAD) implantation in advanced heart failure patients not on inotropes is unclear. Relevant prediction models exist (SHFM [Seattle Heart Failure Model] and HMRS [HeartMate II Risk Score]), but use in this group is not established.

METHODS AND RESULTS

ROADMAP (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients) is a prospective, multicenter, nonrandomized study of 200 advanced heart failure patients not on inotropes who met indications for LVAD implantation, comparing the effectiveness of HeartMate II support versus optimal medical management. We compared SHFM-predicted versus observed survival (overall survival and LVAD-free survival) in the optimal medical management arm (n=103) and HMRS-predicted versus observed survival in all LVAD patients (n=111) using Cox modeling, receiver-operator characteristic (ROC) curves, and calibration plots. In the optimal medical management cohort, the SHFM was a significant predictor of survival (hazard ratio=2.98; P<0.001; ROC area under the curve=0.71; P<0.001) but not LVAD-free survival (hazard ratio=1.41; P=0.097; ROC area under the curve=0.56; P=0.314). SHFM showed adequate calibration for survival but overestimated LVAD-free survival. In the LVAD cohort, the HMRS had marginal discrimination at 3 (Cox P=0.23; ROC area under the curve=0.71; P=0.026) and 12 months (Cox P=0.036; ROC area under the curve=0.62; P=0.122), but calibration was poor, underestimating survival across time and risk subgroups.

CONCLUSIONS

In non-inotrope-dependent advanced heart failure patients receiving optimal medical management, the SHFM was predictive of overall survival but underestimated the risk of clinical worsening and LVAD implantation. Among LVAD patients, the HMRS had marginal discrimination and underestimated survival post-LVAD implantation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01452802.