Pathophysiology of the right ventricle and its pulmonary vascular interaction.

The right ventricle and its stress response is perhaps the most important arbiter of survival in patients with pulmonary hypertension of many causes. The physiology of the cardiopulmonary unit and definition of right heart failure proposed in the 2018 World Symposium on Pulmonary Hypertension have proven useful constructs in subsequent years. Here, we review updated knowledge of basic mechanisms that drive right ventricular function in health and disease, and which may be useful for therapeutic intervention in the future. We further contextualise new knowledge on assessment of right ventricular function with a focus on metrics readily available to clinicians and updated understanding of the roles of the right atrium and tricuspid regurgitation. Typical right ventricular phenotypes in relevant forms of pulmonary vascular disease are reviewed and recent studies of pharmacological interventions on chronic right ventricular failure are discussed. Finally, unanswered questions and future directions are proposed.

Wellbeing in Children and Adolescents with Fontan Physiology.

OBJECTIVE: To assess health-related quality of life (HRQOL) and global quality of life (QOL) in children and adolescents with Fontan physiology and identify key predictors influencing these outcomes. STUDY DESIGN: Cross-sectional analysis of 73 children and adolescents enrolled in the Australia and New Zealand Fontan Registry aged 6-17 years, at least 12 months post-Fontan operation. Assessments included the Pediatric Quality of Life Inventory (PedsQL) for HRQOL and a developmentally-tailored visual analogue scale (0-10) for global QOL, along with validated sociodemographic, clinical, psychological, relational, and parental measures. Clinical data were provided by the Australia and New Zealand Fontan Registry. RESULTS: Participants (mean age: 11.5 ± 2.6 years, 62% male) reported lower overall HRQOL (P < .001), and lower scores across all HRQOL domains (all P < .0001), compared with normative data. Median global QOL score was 7.0 (IQR 5.8-8.0), with most participants (79%) rating their global QOL ≥6. Anxiety and depressive symptoms requiring clinical assessment were reported by 21% and 26% of participants, respectively. Age, sex, and perceived seriousness of congenital heart disease explained 15% of the variation in HRQOL scores, while depressive symptoms and treatment-related anxiety explained an additional 37% (final model: 52% of variance explained). For global QOL, sociodemographic and clinical factors explained 13% of the variance in scores, while depressive symptoms explained a further 25% (final model: 38% of variance explained). Parental factors were not associated with child QOL outcomes. CONCLUSIONS: Children and adolescents with Fontan physiology experience lower HRQOL than community-based norms, despite reporting fair overall QOL. Psychological factors predominantly influenced QOL outcomes, indicating strategies to bolster psychological health could improve QOL in this population.

Long-term antibiotic prophylaxis for prevention of rheumatic fever recurrence and progression to rheumatic heart disease.

BACKGROUND: Rheumatic fever is a non-suppurative, inflammatory sequela of group A Streptococcus pharyngitis that can occur at two to four weeks after infection. Following an episode of rheumatic fever, there is a risk of developing rheumatic heart disease (RHD) later in life that carries significant risk of morbidity and mortality. RHD remains the largest global cause of cardiovascular disease in the young (age < 25 years). The historical literature provides inconclusive evidence that antibiotic prophylaxis is beneficial in reducing the risk of recurrence of rheumatic fever and development of RHD. Antibiotics are thought to work by reducing the carriage of group A Streptococcus and thus reducing the risk of infection. This review was commissioned by the World Health Organization (WHO) for an upcoming guideline. OBJECTIVES: 1. To assess the effects of long-term antibiotics versus no antibiotics (control) for secondary prevention of rheumatic fever recurrence and associated sequelae in people with previous rheumatic fever or RHD. 2. To assess the effects of long-term intramuscular penicillin versus long-term oral antibiotics for secondary prevention of rheumatic fever recurrence and associated sequelae in people with previous rheumatic fever or RHD. SEARCH METHODS: We systematically searched CENTRAL, MEDLINE, Embase, Conference Proceedings Citation Index-Science, clinical trial registers, ISRCTN.com and reference lists without restrictions on language or date up to 10 March 2024. SELECTION CRITERIA: We sought randomised controlled trials or quasi-randomised trials, described in any language, including participants with previous rheumatic fever and/or RHD of any age, based in community or hospital settings. Studies were included if they compared firstly antibiotic prophylaxis with no antibiotic prophylaxis, and, secondly, intramuscular penicillin prophylaxis versus oral antibiotic prophylaxis. DATA COLLECTION AND ANALYSIS: We used standardised methodological, Cochrane-endorsed procedures and performed meta-analyses with risk ratios (RR) and Peto odds ratios (Peto OR). Our primary outcomes were recurrence of rheumatic fever, progression or severity of RHD and cardiac complications. Our secondary outcomes were obstetric complications (maternal and foetal events), mortality, treatment adherence, adverse events and acceptability to participants. We performed comprehensive assessments of risk of bias and certainty of evidence, applying the GRADE methodology. MAIN RESULTS: We included 11 studies (seven RCTs and four quasi-randomised trials) including 3951 participants. The majority of the included studies were conducted in the USA, UK and Canada during the 1950s to 1960s. Most participants with previous rheumatic fever had been diagnosed using the modified Jones criteria (mJC) (four studies), were an average of 12.3 years of age and 50.6% male. We assessed the majority of the included studies to be at high risk of bias, predominantly relating to blinding and attrition bias. Comparison one: antibiotics versus no antibiotics Pooled meta-analysis of six RCTs provides moderate-certainty evidence that antibiotics overall (oral or intramuscular) probably reduce the risk of recurrence of rheumatic fever substantially (0.7% versus 1.7%, respectively) (risk ratio (RR) 0.39, 95% confidence interval (CI) 0.22 to 0.69; 1721 participants). People with early or mild RHD likely have the greatest capacity to benefit from intramuscular antibiotic prophylaxis (8.1%) compared to no antibiotics (0.7%) (RR 0.09, 95% CI 0.03 to 0.29; 1 study, 818 participants; moderate-certainty evidence). Antibiotics may not affect mortality in people with late-stage RHD (RR 1.23, 95% CI 0.78 to 1.94; 1 study, 994 participants; low-certainty evidence). Antibiotics may not affect the risk of anaphylaxis (Peto odds ratio (OR) 7.39, 95% CI 0.15 to 372; 1 study, 818 participants; low-certainty evidence) or sciatic nerve injury (Peto OR 7.39, 95% CI 0.15 to 372; 1 study, 818 participants; low-certainty evidence) compared with no antibiotics, but probably have an increased risk of hypersensitivity reactions (RR 137, 8.51 to 2210; 2 studies, 894 participants; moderate-certainty evidence) and local reactions (RR 29, 1.74 to 485; 1 study, 818 participants; moderate-certainty evidence). Comparison two: intramuscular antibiotics versus oral antibiotics Pooled analysis of two RCTs showed that prophylactic intramuscular benzathine benzylpenicillin likely reduces recurrence of rheumatic fever substantially when compared to oral antibiotics (0.1% versus 1%, respectively) (RR 0.07, 95% CI 0.02 to 0.26; 395 participants; moderate-certainty evidence). Furthermore, it is unclear whether intramuscular benzyl penicillin is superior to oral antibiotics in reducing the risk of mortality in the context of RHD (Peto OR 0.22, 95% CI 0.01 to 4.12; 1 study, 431 participants; very low-certainty evidence). There were no data available on progression of latent RHD or adverse events including anaphylaxis, sciatic nerve injury, delayed hypersensitivity/allergic reactions and local reactions to injection. AUTHORS' CONCLUSIONS: This review provides evidence that antibiotic prophylaxis likely reduces the risk of recurrence of rheumatic fever compared to no antibiotics, and that intramuscular benzathine benzylpenicillin is probably superior to oral antibiotics (approximately 10 times better). Moreover, intramuscular benzathine benzylpenicillin likely reduces the risk of progression of latent RHD. Evidence is scarce, but antibiotics compared with no antibiotics may not affect the risk of anaphylaxis or sciatic nerve injury, but probably carry an increased risk of hypersensitivity reactions and local reactions. Antibiotics may not affect all-cause mortality in late-stage RHD compared to no antibiotics. There is no evidence available to comment on the effect of intramuscular penicillin over oral antibiotics for progression of latent RHD and adverse events, and little evidence for all-cause mortality. It is important to interpret these findings in the context of major limitations, including the following: the vast majority of the included studies were conducted more than 50 years ago, many before contemporary echocardiographic studies; methodology was often at high risk of bias; outdated treatments were used; only one study was in latent RHD; and there are concerns regarding generalisability to low socioeconomic regions. This underlines the need for ongoing research to understand who benefits most from prophylaxis.

Cognitive Functioning and Psychosocial Outcomes in Adults with Complex Congenital Heart Disease: A Cross-sectional Pilot Study.

Adults with complex congenital heart disease (CHD) are at risk for cognitive dysfunction. However, associations between cognitive dysfunction and psychosocial outcomes are poorly defined. Between June and November 2022, we prospectively recruited 39 adults with complex CHD who completed a computerized cognitive assessment (Cogstate) and validated psychosocial scales measuring psychological distress, health-related quality of life (HRQOL), and resilience. Participants had a mean age of 36.4 ± 11.2 years. Over half (62%) were women, most (79%) had complex biventricular CHD, and 21% had Fontan physiology. Prevalence of cognitive dysfunction was greatest in the domains of attention (29%), working memory (25%), and psychomotor speed (21%). Adjusting for age and sex, Pearson partial correlations between Cogstate z-scores and self-reported cognitive problems were small. Participants who lived in the most disadvantaged areas and those with a below-average annual household income had lower global cognitive z-scores (p = 0.02 and p = 0.03, respectively). Two-thirds (64%) reported elevated symptoms of depression, anxiety, and/or stress. Small correlations were observed between psychological distress and cognitive performance. Greater resilience was associated with lower psychological distress (r ≥ -0.5, p < 0.001) and higher HRQOL (r = 0.33, p = 0.02). Our findings demonstrate that adults with complex CHD have a high risk of cognitive dysfunction, though may not recognize or report their cognitive challenges. Lower socioeconomic status may be an indicator for those at risk of poorer cognitive functioning. Psychological distress is common though may not be a strong correlate of performance-based cognitive functioning. Formal cognitive evaluation in this patient population is essential. Optimizing resilience may be a protective strategy to minimize psychological distress and bolster HRQOL.

Common diagnostic errors in adults with congenital heart disease.

Owing to the great advances in the care for children with congenital heart disease by paediatric cardiac surgeons and cardiologists, there are ever increasing numbers of patients with congenital heart disease who reach adult life. At some stage during the late teenage years or soon after, these patients 'transition' from paediatric cardiac care to surveillance by cardiologists who look after adults. Many such specialists, however, are more familiar with commoner acquired heart problems such as coronary disease, heart failure, and arrhythmia in structurally normal hearts and less familiar with congenital heart disease. For this reason, international guidelines have suggested that the care of young adults with congenital heart disease take place in designated specialist adult congenital heart disease centres. It remains very important, however, for general cardiologists to have a good understanding of many aspects of adult congenital heart disease, including common pitfalls to avoid and, importantly, when to refer on, to a specialist centre. To help healthcare providers across the spectrum of cardiology practice to address common themes in adult congenital heart disease, this state-of-the-art review provides a series of case vignettes to illustrate frequent diagnostic problems that we have seen in our tertiary-level adult congenital heart disease centres, which are sometimes encountered in general cardiology settings. These include commonly 'missed' diagnoses, or errors with diagnosis or management, in these often very complex patients.

End-stage heart failure in congenitally corrected transposition of the great arteries: a multicentre study.

BACKGROUND AND AIMS: For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear. METHODS: This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death. RESULTS: From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome. CONCLUSIONS: Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.

Transcatheter occlusion of venovenous collaterals in the total cavopulmonary Fontan circulation.

BACKGROUND: Venovenous collaterals are abnormal connections between the systemic and pulmonary venous systems. They are commonly seen in the Fontan circulation and may lead to significant hypoxaemia. Transcatheter closure of venovenous collaterals is a potential but controversial treatment as the long-term benefits and outcomes are not well understood. METHODS: This retrospective cohort study utilised data from the Australian and New Zealand Fontan Registry. Patients who underwent transcatheter venovenous collateral occlusion for hypoxemia from the year 2000 onwards were included. Atriopulmonary and Kawashima-type Fontan circulations were excluded to reflect a more contemporary Fontan cohort. RESULTS: Nineteen patients (age 19.3 ± 7.8 years, 53% female) underwent transcatheter venovenous collateral occlusion. Compared to baseline, mean oxygen saturation was improved at latest follow-up (90.5% vs 87.0%; p = 0.003). Nine patients achieved a clinically significant response (defined as an increase of at least 5% to 90% or greater), and this was associated with lower baseline Fontan pressures (12.9 v 15.6 mmHg; p = 0.02). No heart failure hospitalisations, arrhythmia, transplant referrals, or mortality were observed during the median follow-up period of 4 years. Two patients experienced thromboembolic events and five patients underwent re-intervention. CONCLUSION: Transcatheter occlusion of venovenous collaterals in Fontan patients with chronic hypoxaemia resulted in a modest increase in oxygenation over a median follow-up of 4 years and longer-term prognosis did not appear to be adversely affected. Lower Fontan pressures at baseline were associated with a greater improvement in oxygenation.

Noninvasive Plaque Imaging to Accelerate Coronary Artery Disease Drug Development.

Coronary artery disease (CAD) remains the leading cause of adult mortality globally. Targeting known modifiable risk factors has had substantial benefit, but there remains a need for new approaches. Improvements in invasive and noninvasive imaging techniques have enabled an increasing recognition of distinct quantitative phenotypes of coronary atherosclerosis that are prognostically relevant. There are marked differences in plaque phenotype, from the high-risk, lipid-rich, thin-capped atheroma to the low-risk, quiescent, eccentric, nonobstructive calcified plaque. Such distinct phenotypes reflect different pathophysiologic pathways and are associated with different risks for acute ischemic events. Noninvasive coronary imaging techniques, such as computed tomography, positron emission tomography, and coronary magnetic resonance imaging, have major potential to accelerate cardiovascular drug development, which has been affected by the high costs and protracted timelines of cardiovascular outcome trials. This may be achieved through enrichment of high-risk phenotypes with higher event rates or as primary end points of drug efficacy, at least in phase 2 trials, in a manner historically performed through intravascular coronary imaging studies. Herein, we provide a comprehensive review of the current technology available and its application in clinical trials, including implications for sample size requirements, as well as potential limitations. In its effort to accelerate drug development, the US Food and Drug Administration has approved surrogate end points for 120 conditions, but not for CAD. There are robust data showing the beneficial effects of drugs, including statins, on CAD progression and plaque stabilization in a manner that correlates with established clinical end points of mortality and major adverse cardiovascular events. This, together with a clear mechanistic rationale for using imaging as a surrogate CAD end point, makes it timely for CAD imaging end points to be considered. We discuss the importance of global consensus on these imaging end points and protocols and partnership with regulatory bodies to build a more informed, sustainable staged pathway for novel therapies.

Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure.

BACKGROUND: In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit. METHODS: REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome-a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status-was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization. RESULTS: Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; P=0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; P=0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; P=0.004). CONCLUSIONS: In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.

Immunoglobulin E Sensitization to Mammalian Oligosaccharide Galactose-α-1,3 (α-Gal) Is Associated With Noncalcified Plaque, Obstructive Coronary Artery Disease, and ST-Segment-Elevated Myocardial Infarction.

BACKGROUND: Treating known risk factors for coronary artery disease (CAD) has substantially reduced CAD morbidity and mortality. However, a significant burden of CAD remains unexplained. Immunoglobulin E sensitization to mammalian oligosaccharide galactose-α-1,3-galactose (α-Gal) was recently associated with CAD in a small observational study. We sought to confirm that α-Gal sensitization is associated with CAD burden, in particular noncalcified plaque. Additionally, we sort to assess whether that α-Gal sensitization is associated with ST-segment-elevated myocardial infarction (STEMI) Methods: We performed a cross-sectional analysis of participants enrolled in the BioHEART cohort study. We measured α-Gal specific-immunoglobulin E antibodies in serum of 1056 patients referred for CT coronary angiography for suspected CAD and 100 selected patients presenting with STEMI, enriched for patients without standard modifiable risk factors. CT coronary angiograms were assessed using coronary artery calcium scores and segmental plaque scores. RESULTS: α-Gal sensitization was associated with presence of noncalcified plaque (odds ratio, 1.62 [95% CI, 1.04-2.53], P=0.03) and obstructive CAD (odds ratio, 2.05 [95% CI, 1.29-3.25], P=0.002), independent of age, sex, and traditional risk factors. The α-Gal sensitization rate was 12.8-fold higher in patients with STEMI compared with matched healthy controls and 2.2-fold higher in the patients with STEMI compared with matched stable CAD patients (17% versus 1.3%, P=0.01 and 20% versus 9%, P=0.03, respectively). CONCLUSIONS: α-Gal sensitization is independently associated with noncalcified plaque burden and obstructive CAD and occurs at higher frequency in patients with STEMI than those with stable or no CAD. These findings may have implications for individuals exposed to ticks, as well as public health policy. Registration: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001322224.

Neurocognitive Dysfunction and Smaller Brain Volumes in Adolescents and Adults With a Fontan Circulation.

BACKGROUND: Neurocognitive outcomes beyond childhood in people with a Fontan circulation are not well defined. This study aimed to investigate neurocognitive functioning in adolescents and adults with a Fontan circulation and associations with structural brain injury, brain volumetry, and postnatal clinical factors. METHODS: In a binational study, participants with a Fontan circulation without a preexisting major neurological disability were prospectively recruited from the Australia and New Zealand Fontan Registry. Neurocognitive function was assessed by using Cogstate software in 107 participants with a Fontan circulation and compared with control groups with transposition of the great arteries (n=50) and a normal circulation (n=41). Brain MRI with volumetric analysis was performed in the participants with a Fontan circulation and compared with healthy control data from the ABIDE I and II (Autism Brain Imaging Data Exchange) and PING (Pediatric Imaging, Neurocognition, and Genetics) data repositories. Clinical data were retrospectively collected. RESULTS: Of the participants with a Fontan circulation who had a neurocognitive assessment, 55% were male and the mean age was 22.6 years (SD 7.8). Participants with a Fontan circulation performed worse in several areas of neurocognitive function compared with those with transposition of the great arteries and healthy controls (P<0.05). Clinical factors associated with worse neurocognitive outcomes included more inpatient days during childhood, younger age at Fontan surgery, and longer time since Fontan procedure (P<0.05). Adults with a Fontan circulation had more marked neurocognitive dysfunction than adolescents with a Fontan circulation in 2 domains (psychomotor function, P=0.01 and working memory, P=0.02). Structural brain injury was present in the entire Fontan cohort; the presence of white matter injury was associated with worse paired associate learning (P<0.001), but neither the presence nor severity of infarct, subcortical gray matter injury, and microhemorrhage was associated with neurocognitive outcomes. Compared with healthy controls, people with a Fontan circulation had smaller global brain volumes (P<0.001 in all regions) and smaller regional brain volumes in most cerebral cortical regions (P<0.05). Smaller global brain volumes were associated with worse neurocognitive functioning in several domains (P<0.05). A significant positive association was also identified between global brain volumes and resting oxygen saturations (P≤0.04). CONCLUSIONS: Neurocognitive impairment is common in adolescents and adults with a Fontan circulation and is associated with smaller gray and white matter brain volume. Understanding modifiable factors that contribute to brain injury to optimize neurocognitive function is paramount.

Endothelial thioredoxin interacting protein (TXNIP) modulates endothelium-dependent vasorelaxation in hyperglycemia.

Endothelial dysfunction, hallmarked by an imbalance between vasoconstriction and vasorelaxation, is associated with diabetes. Thioredoxin Interacting protein (TXNIP), controlled by an exquisitely glucose sensitive gene, is increasingly recognized for its role in diabetes. However, the role of TXNIP in modulating diabetes-related endothelial dysfunction remains unclear. To elucidate the role of TXNIP, we generated two novel mouse strains; endothelial-specific TXNIP knockout (EKO) and a Tet-O inducible, endothelial-specific TXNIP overexpression (EKI). Hyperglycemia was induced by streptozotocin (STZ) treatment in floxed control (fl/fl) and EKO mice. Doxycycline (DOX) was given to EKI mice to induce endothelial TXNIP overexpression. The ablation of endothelial TXNIP improved glucose tolerance in EKO mice. Acetylcholine-induced, endothelium-dependent vasorelaxation was impaired in STZ-treated fl/fl mice while this STZ impaired vasorelaxation was attenuated in EKO mice. Hyperglycemia induction of NLRP3 and reductions in Akt and eNOS phosphorylation were also mitigated in EKO mice. Overexpression of endothelial TXNIP did not impair glucose tolerance in DOX-treated EKI mice, however induction of endothelial TXNIP led to impaired vasorelaxation in EKI mice. This was associated with increased NLRP3 and reduced Akt and eNOS activation. In conclusion, deletion of endothelial TXNIP is protective against and overexpression of endothelial TXNIP induces endothelial dysfunction; thus, endothelial TXNIP plays a critical role in modulating endothelial dysfunction.

Persisting burden and challenges of rheumatic heart disease.

Rheumatic heart disease (RHD) is the result of episodes of acute rheumatic fever with valvular (and other cardiac) damage caused by an abnormal immune response to group A streptococcal infections, usually during childhood and adolescence. As a result of improved living conditions and the introduction of penicillin, RHD was almost eradicated in the developed world by the 1980s. However, being a disease of poverty, its burden remains disproportionately high in the developing world, despite being a fundamentally preventable disease. Rheumatic heart disease generates relatively little attention from the medical and science communities, in contrast to other common infectious problems (such as malaria, HIV, tuberculosis), despite the major cardiovascular morbidity/mortality burden imposed by RHD. This relative neglect and paucity of funding have probably contributed to limited fundamental medical advances in this field for over 50 years. Given the importance of prevention before the onset of major valvular damage, the main challenges for RHD prevention are improving social circumstances, early diagnosis, and effective delivery of antibiotic prophylaxis. Early identification through ultrasound of silent, subclinical rheumatic valve lesions could provide an opportunity for early intervention. Simple echocardiographic diagnostic criteria and appropriately trained personnel can be valuable aids in large-scale public health efforts. In addition, a better understanding of the immunogenic determinants of the disease may provide potential routes to vaccine development and other novel therapies.

Ten Years of Percutaneous Pulmonary Valve Implantation in Australia and New Zealand.

OBJECTIVE: This study sought to investigate the characteristics, morbidity (including the rate of infective endocarditis and valve replacement) and mortality of individuals undergoing percutaneous pulmonary valve implantation in Australia and New Zealand since the procedure has been performed. BACKGROUND: The outcomes of percutaneous pulmonary valve implantation in Australia and New Zealand have not been evaluated. Recent international data, including patients from New Zealand, suggests the rate of infective endocarditis is not insignificant. METHODS: A retrospective multi-site cohort study was undertaken via medical record review at the centres where percutaneous pulmonary valve implantation has been performed. All procedures performed from 2009-March 2018 were included. Individuals were identified from local institution databases. Data was collected and analysed including demographics, details at the time of intervention, haemodynamic outcome, post procedure morbidity and mortality. Multi-site ethics approval was obtained. RESULTS: One hundred and seventy-nine (179) patients attended the cardiac catheter laboratory for planned percutaneous pulmonary valve implantation. Of these patients, 172 underwent successful implantation. Tetralogy of Fallot and pulmonary atresia were the most common diagnoses. The median age at procedure was 19 years (range 3-60 yrs). There was a significant improvement in the acute haemodynamics in patients undergoing percutaneous pulmonary valve implantation for stenosis. Seven (7) patients (3.9%) experienced a major procedural/early post procedure complication (death, conversion to open procedure, cardiac arrest), including two deaths. The annualised rates of infective endocarditis and valve replacement were 4.6% and 3.8% respectively. There was one death related to infective endocarditis in follow-up. CONCLUSIONS: Percutaneous pulmonary valve replacement is a relatively safe method of rehabilitating the right ventricular outflow tract.

Right ventricular myocardial deoxygenation in patients with pulmonary artery hypertension.

BACKGROUND: In pulmonary arterial hypertension (PAH), progressive right ventricular (RV) dysfunction is believed to be largely secondary to RV ischaemia. A recent pilot study has demonstrated the feasibility of Oxygen-sensitive (OS) cardiovascular magnetic resonance (CMR) to detect in-vivo RV myocardial oxygenation. The aims of the present study therefore, were to assess the prevalence of RV myocardial ischaemia and relationship with RV myocardial interstitial changes in PAH patients with non-obstructive coronaries, and corelate with functional and haemodynamic parameters. METHODS: We prospectively recruited 42 patients with right heart catheter (RHC) proven PAH and 11 healthy age matched controls. The CMR examination involved standard functional imaging, OS-CMR imaging and native T1 mapping. An ΔOS-CMR signal intensity (SI) index (stress/rest signal intensity) was acquired at RV anterior, RV free-wall and RV inferior segments. T1 maps were acquired using Shortened Modified Look-Locker Inversion recovery (ShMOLLI) at the inferior RV segment. RESULTS: The inferior RV ΔOS-CMR SI index was significantly lower in PAH patients compared with healthy controls (9.5 (- 7.4-42.8) vs 12.5 (9-24.6)%, p = 0.02). The inferior RV ΔOS-CMR SI had a significant correlation to RV inferior wall thickness (r = - 0.7, p < 0.001) and RHC mean pulmonary artery pressure (mPAP) (r = - 0.4, p = 0.02). Compared to healthy controls, patients with PAH had higher native T1 in the inferior RV wall: 1303 (1107-1612) vs 1232 (1159-1288)ms, p = 0.049. In addition, there was a significant difference in the inferior RV T1 values between the idiopathic PAH and systemic sclerosis associated PAH patients: 1242 (1107-1612) vs 1386 (1219-1552)ms, p = 0.007. CONCLUSION: Blunted OS-CMR SI suggests the presence of in-vivo microvascular RV dysfunction in PAH patients. The native T1 in the inferior RV segments is significantly increased in the PAH patients, particularly among the systemic sclerosis associated PAH group.

LV non-compaction in patients with coarctation of the aorta: prevalence and effects on cardiac function.

BACKGROUND: Left ventricular non-compaction has been associated with heart failure, arrhythmia, thromboembolism and sudden death. The prevalence of non-compaction in patients with coarctation of the aorta and its clinical significance remains unknown, although obstructive left heart disease is common in patients with non-compaction. We sought to evaluate the prevalence of left ventricular non-compaction in patients with repaired aortic coarctation as well as its effect on left ventricular size and systolic function. METHODS AND RESULTS: In total, 268 patients (Mean age 26 (inter-quartile range 21-37) years, 63% male) undergoing cardiac magnetic resonance imaging for clinical follow-up were included from three tertiary centres for adult congenital heart disease. Clinical data was obtained from medical records and correlated with ventricular volumes and function. Left ventricular non-compaction was defined as a diastolic non-compacted:compacted dimension ratio >2.3 in the worst affected segment on a long-axis view. Left ventricular non-compaction was present in 8.2% of patients with repaired coarctation. Left ventricular end-diastolic volumes and stroke volumes were significantly higher in patients with non-compaction compared to those without. There were no significant differences in ventricular mass or ejection fraction in these two groups. CONCLUSIONS: Left ventricular non-compaction is relatively common in patients with repaired coarctation of the aorta and correlates with increased left ventricular end-diastolic volumes.

Decline Is Not Inevitable: Exercise Capacity Trajectory in an Australian and New Zealand Fontan Cohort.

BACKGROUND: In people with a Fontan circulation, serial cardiopulmonary exercise testing (CPET) to evaluate change in peak exercise capacity has been increasingly recognised as a useful prognostic tool; a decline is associated with adverse clinical outcomes. The aim of this study is to describe the "natural" history of exercise capacity in the Australian and New Zealand (ANZ) Fontan cohort and to identify factors associated with a decline. METHODS: The ANZ Fontan registry was retrospectively reviewed for adolescent and adult patients (≥16 years) with serial CPET results performed on a cycle ergometer ≥6 months apart. Patients were excluded if they underwent a surgical procedure or fenestration closure in-between tests or if the tests were considered as submaximal effort. Exercise capacity trajectory was defined as the change in percentage of predicted peak oxygen uptake (% pred VO2peak) points per year. RESULTS: Thirty-seven (37) patients (59.5% male, mean age 24±7 years) were eligible. Average duration between CPET was 5.3±3.9 years. At baseline, % pred VO2peak was 61.3±14.5%. Thirteen (13) (35%) had a systemic right ventricle, and 14 (38%) had an atriopulmonary type Fontan circulation. Average change in % pred VO2peak overall was +1.3±6.4 percentage points per year. Sixteen (16) had a negative exercise capacity trajectory, and the average decline in that group was -2.7±3.4 percentage points per year. There was no association between exercise capacity trajectory and clinical characteristics. Of the 18 patients with physical activity levels recorded, 12 (67%) were physically active and % pred VO2peak in that group increased by 2.7±4.0 percentage points per year compared with the physically inactive group who fell by 0.5±0.8 percentage points per year. CONCLUSIONS: In this ANZ series of Fontan patients, over half of our cohort had stable, or an increase, in peak exercise capacity. Regular participation in physical activity was common in patients with a positive exercise capacity trajectory. Clinical characteristics were not associated with exercise capacity trajectory.

Inspiratory Muscle Training Improves Inspiratory Muscle Strength and Functional Exercise Capacity in Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension: A Pilot Randomised Controlled Study.

BACKGROUND: Exercise intolerance is present even in the early stages of pulmonary arterial hypertension (PAH) and is associated with poorer prognosis. Respiratory muscle dysfunction is common and may contribute to exercise limitation. We sought to investigate the effects of inspiratory muscle training (IMT) to improve exercise capacity in PAH. METHODS: Adults with PAH were prospectively recruited and randomly assigned to either IMT or a control group. At baseline and after 8 weeks, assessment of respiratory muscle function, pulmonary function, neurohormonal activation, 6-minute walk distance and cardiopulmonary exercise testing variables were conducted. Inspiratory muscle strength was assessed by maximal static inspiratory pressure (PImax). The IMT group performed two cycles of 30 breaths at 30-40% of their PImax 5 days a week for 8 weeks. RESULTS: Twelve (12) PAH patients (60±14 years, 10 females) were recruited and randomised (six in the IMT group and six in the control group). After 8 weeks, the IMT group improved PImax by 31 cmH2O compared with 10 cmH2O in controls, p=0.02. Following IMT, 6-minute walk distance improved by 24.5 m in the IMT group and declined by 12 m in the controls (mean difference 36.5 m, 95% CI 3.5-69.5, p=0.03). There was no difference in peak oxygen uptake between-groups (mean difference 0.4 mL/kg/min, 95% CI -2.6 to 3.4, p=0.77). There was no difference in the mean change between-groups in neurohormonal activation or pulmonary function. CONCLUSION: In this pilot randomised controlled study, IMT improved PImax and 6-minute walk distance in PAH patients.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association.

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Pulmonary arterial hypertension with below threshold pulmonary vascular resistance.

Pulmonary vascular resistance (PVR) >3 Wood units is a criterion of the haemodynamic definition of pulmonary arterial hypertension (PAH). However, this cut-off is conservative and arbitrarily defined. Data is lacking on the natural history, response to therapy and survival of patients diagnosed with precapillary pulmonary hypertension (PH) with mild or borderline elevation of PVR.In Australia, PAH therapy could be prescribed solely on mean pulmonary arterial pressure (PAP) and pulmonary arterial wedge pressure (PAWP) criteria. Using the Australian and New Zealand Pulmonary Hypertension Registry, we aimed to study a population diagnosed with PAH between January 2004 and December 2017 with the pre-defined haemodynamic characteristics of mean PAP ≥25 mmHg, PAWP ≤15 mmHg and PVR <3 Wood units.Eighty-two patients met the pre-defined haemodynamic inclusion criteria (mean age 63±11 years; 67 females). Underlying aetiologies included idiopathic disease (n=39), connective tissue disease (CTD; n=42) and HIV infection (n=1). At diagnosis, mean PAP was 27 mmHg (interquartile range (IQR) 25-30 mmHg), PAWP 13 mmHg (IQR 11-14 mmHg) and PVR 2.2 Wood units (IQR 1.9-2.7 Wood units). Baseline 6-min walk distance (6MWD) was 352 m (IQR 280-416 m) and 77% of subjects were in New York Heart Association (NYHA) functional class 3 or 4. All patients were commenced on initial monotherapy with an endothelin receptor antagonist (ERA; n=66) or phosphodiesterase type-5 inhibitor (PDE5i; n=16). At first re-evaluation, 6MWD increased by 46 m (IQR 7-96 m) and 35% of subjects demonstrated improvement in NYHA functional class. After a median follow-up of 65 months (IQR 32-101 months), 18 out of 82 subjects (22.0%) had died, with estimated 1-year and 5-year survival rates of 98% and 84%, respectively. Death attributed to PAH occurred in six out of these 18 patients (33.3%, 7% of total cohort).Patients with precapillary PH and "borderline" PVR falling outside the current definition have adverse outcomes. Such patients appear to respond to PAH therapy; however, this requires further study in randomised trials.