Prevalence of pulmonary hypertension in aortic regurgitation and its influence on outcomes

OBJECTIVE

Aortic regurgitation (AR) can lead to pulmonary hypertension (PHT). There is a paucity of data on the prognostic importance of PHT in these patients. We therefore aimed to describe the prevalence and prognostic importance of PHT in such patients.

METHODS

In this retrospective study, we analysed the National Echocardiography Database of Australia (data from 2000 to 2019). Adults with an estimated right ventricular systolic pressure (eRVSP), left ventricular ejection fraction (LVEF) >50% and with moderate or greater AR were included (n=8392). These subjects were then categorised according to their eRVSP. The relationship between PHT severity and mortality outcomes were evaluated (median follow-up of 3.1 years, IQR 1.5-5.7 years).

RESULTS

Subjects were aged 74±14 years and 58.4% (4901) were female. Overall, 1417 (16.9%) had no PHT, and 3253 (38.8%), 2249 (26.9%), 893 (10.6%) and 580 (6.9%) patients had borderline, mild, moderate and severe PHT, respectively. Mean eRVSP was slightly higher in females than males (41±13 vs 39±12 mm Hg, p<0.0001) and increased with age in both sexes. After adjustment for age and sex, the risk of long-term mortality increased as eRVSP increased (adjusted HR (aHR) 1.20, 95% CI 1.06 to 1.36 in borderline PHT, to aHR 3.32, 95% CI 2.85 to 3.86 in severe PHT, p<0.0001). There was a mortality threshold seen from mild PHT onwards (eRVSP 41.36-44.15 mm Hg; aHR 1.41, 95%CI 1.17 to 1.68).

CONCLUSIONS

In this large cohort study, we characterise the relationship between AR and PHT in adults. In patients with ≥moderate AR, PHT is associated with a progressive risk of mortality, even at mildly elevated levels.

Prevalence of pulmonary hypertension in aortic stenosis and its influence on outcomes

OBJECTIVE

The significance of pulmonary hypertension (PHT) complicating aortic stenosis (AS) is poorly characterised. In a large cohort of adults with at least moderate AS, we aimed to describe the prevalence and prognostic importance of PHT in such patients.

METHODS

In this retrospective study, we analysed the National Echocardiography Database of Australia (data from 2000 to 2019). Adults with an estimated right ventricular systolic pressure (eRVSP), left ventricular ejection fraction (LVEF) >50% and with moderate or greater AS were included (n=14 980). These subjects were then categorised according to their eRVSP. The relationship between PHT severity and mortality outcomes were evaluated (median follow-up of 2.6 years, IQR 1.0-4.6 years).

RESULTS

Subjects were aged 77±13 years and 57.4% were female. Overall, 2049 (13.7%), 5085 (33.9%), 4380 (29.3%), 1956 (13.1%) and 1510 (10.1%) patients had no (eRVSP<30.00 mm Hg), borderline (30.00-39.99 mm Hg), mild (40.00-49.99 mm Hg), moderate (50.00-59.99 mm Hg) and severe PHT (>60.00 mm Hg), respectively. An echocardiographic phenotype was evident with worsening PHT, showing rising E:e' ratio and right and left atrial sizes(p<0.0001, for all). Adjusted analyses showed that the risk of long-term mortality progressively rose as eRVSP level increased (HR 1.14-2.94, borderline to severe PHT, p<0.0001 for all). A mortality threshold was identified in the 4th decile of eRVSP categories (35.01-38.00 mm Hg; HR 1.19, 95% CI 1.04 to 1.35), with risk progressively increasing through to the 10th decile (HR 2.86, 95% CI 2.54 to 3.21).

CONCLUSIONS

In this large cohort study, we find that PHT is common in ≥moderate AS and mortality increases as PHT becomes more severe. A threshold for higher mortality lies within the range of 'borderline-mild' PHT.

TRIAL REGISTRATION NUMBER

ACTRN12617001387314.

Prevalence of pulmonary hypertension in mitral regurgitation and its influence on outcomes

OBJECTIVE

Pulmonary hypertension (PHT) commonly coexists with significant mitral regurgitation (MR), but its prevalence and prognostic importance have not been well characterised. In a large cohort of adults with moderate or greater MR, we aimed to describe the prevalence and severity of PHT and assess its influence on outcomes.

METHODS

In this retrospective study, we analysed the National Echocardiography Database of Australia (data from 2000 to 2019). Adults with an estimated right ventricular systolic pressure (eRVSP), left ventricular ejection fraction >50% and with moderate or greater MR were included (n=9683). These subjects were then categorised according to their eRVSP. The relationship between PHT severity and mortality outcomes was evaluated (median follow-up of 3.2 years, IQR 1.3-6.2 years).

RESULTS

Subjects were aged 76±12 years, and 62.6% (6038) were women. Overall, 959 (9.9%) had no PHT, and 2952 (30.5%), 3167 (32.7%), 1588 (16.4%) and 1017 (10.5%) patients had borderline, mild, moderate and severe PHT, respectively. A 'typical left heart disease' phenotype was identified with worsening PHT, showing rising E:e', right and left atrial sizes increasing progressively, from no PHT to severe PHT (p<0.0001, for all). With increasing PHT severity, 1- and 5-year actuarial mortality increased from 8.5% and 33.0% to 39.7% and 79.8%, respectively (p<0.0001). Similarly, adjusted survival analysis showed the risk of long-term mortality progressively increased with higher eRVSP levels (adjusted HR 1.20-2.86, borderline to severe PHT, p<0.0001 for all). A mortality inflection was apparent at an eRVSP level >34.00 mm Hg (HR 1.27, CI 1.00-1.36).

CONCLUSIONS

In this large study, we report on the importance of PHT in patients with MR. Mortality increases as PHT becomes more severe from an eRVSP of 34 mm Hg onwards.

Obstacles in establishing a national disease registry in Australia: lessons from the development of the CHAANZ Congenital Heart Disease Registry

ObjectivesTo provide insights into the obstacles which pose challenges to the set-up of any National Registry in Australia.MethodsAn analysis of our experience in executing a Multi-Institutional Agreement (MIA) and obtaining ethics and governance approvals, post-award of a large Medical Research Futures Fund grant in June 2020.ResultsFrom July 2020, our timeline to an executed MIA was 283 days, despite full-time staff working towards this goal. Subsequently, after lead site ethics approval, time to site governance approvals ranged from 9 to 291 days. A total of 214 emails were sent during the MIA development and signing. There were 11-71 emails sent to individual governance offices and the number of requested points of additional information ranged from 0 to 31 queries.ConclusionsThere were considerable time delays in executing the initial (pre-research) stages of a National Federal Government funded Registry project which required substantial time and resources. We report a wide variation in requirements between different states and institutions. We propose several strategies which could be implemented to facilitate a more streamlined approach to research ethics and governance. This centralised approach would allow for better use of funding and facilitate better progress in medical research.

An interactive geographic information system to inform optimal locations for healthcare services

Large health datasets can provide evidence for the equitable allocation of healthcare resources and access to care. Geographic information systems (GIS) can help to present this data in a useful way, aiding in health service delivery. An interactive GIS was developed for the adult congenital heart disease service (ACHD) in New South Wales, Australia to demonstrate its feasibility for health service planning. Datasets describing geographic boundaries, area-level demographics, hospital driving times, and the current ACHD patient population were collected, linked, and displayed in an interactive clinic planning tool. The current ACHD service locations were mapped, and tools to compare current and potential locations were provided. Three locations for new clinics in rural areas were selected to demonstrate the application. Introducing new clinics changed the number of rural patients within a 1-hour drive of their nearest clinic from 44·38% to 55.07% (79 patients) and reduced the average driving time from rural areas to the nearest clinic from 2·4 hours to 1·8 hours. The longest driving time was changed from 10·9 hours to 8·9 hours. A de-identified public version of the GIS clinic planning tool is deployed at https://cbdrh.shinyapps.io/ACHD_Dashboard/. This application demonstrates how a freely available and interactive GIS can be used to aid in health service planning. In the context of ACHD, GIS research has shown that adherence to best practice care is impacted by patients' accessibility to specialist services. This project builds on this research by providing opensource tools to build more accessible healthcare services.

Safety evaluation of the guardian device on the common carotid artery in sheep

Background

Pulse pressure intensity in middle-aged adults is a risk factor for dementia. The Guardian device (The Brain Protection Company, Sydney, Australia) has been developed to reduce pulse pressure, as a potential therapy.

Objectives

The aim of this study was to evaluate the safety of the Guardian, a novel pulse modulation device designed to reduce the intensity of the pulse pressure that penetrates into the cerebral small vessels. The Guardian is a helix that gently wraps around the common carotid artery (CCA) to slightly change its shape, to absorb pulsatility, without lowering flow.

Methods

The Guardian was implanted bilaterally on the CCAs of 10 mature sheep for chronic implant periods of 3, 6 or 8 months. The ratio of internal device diameter to outer diameter of the CCA varied from 63% to 92% (n = 20). The implant position on the vessel was marked surgically at implant. Gross pathology and histopathology of the CCA were examined at 3- and 6-months post explant. Most devices were explanted using open surgery, however minimally invasive surgical explant techniques were examined in 2 animals to assess the potential of this approach for explant in humans if required.

Results

The Guardian was successfully implanted with no adverse events, and minimally invasive explant appeared to be viable for removal. Following implant, the device was surrounded by a thin fibrous capsule, with similar pathology at 3- and 6-months. Minimal or no movement was observed. CCA sections appeared histologically normal, with no evidence of thrombosis, stenosis, fibrosis, chronic inflammatory response, or vessel degeneration.

Conclusions

The feasibility of surgical implantation and biomaterial safety of the Guardian was confirmed over 8 months. Minimally invasive explant of the Guardian has the potential to be viable. Further work is required to demonstrate efficacy in vitro and/or in vivo before evaluation in humans.

Atrial functional mitral regurgitation: prevalence, characteristics and outcomes from the National Echo Database of Australia

AIMS

Atrial functional mitral regurgitation (AFMR) is characterised by left atrial and consequent mitral annular dilatation causing mitral regurgitation. AFMR is likely to become more common with population ageing, alongside increases in atrial fibrillation and heart failure with preserved ejection fraction; conditions causing atrial dilatation. Here, we aim to define the prevalence and characterise the patient and survival characteristics of AFMR in the National Echocardiographic Database of Australia (NEDA).

METHODS AND RESULTS

14 004 adults with moderate or severe FMR were identified from NEDA. AFMR or ventricular FMR (VFMR) was classified by LA size, LV size and LVEF. AFMR was found in 40% (n=5562) and VFMR in 60% (n=8442). Compared with VFMR, the AFMR subgroup were significantly older (mean age 78±11 years), with a higher proportion of females and of AF. Participants were followed up for a median of 65 months (IQR 36-116 months). After adjustment for age, sex, AF, and pulmonary hypertension, the prognosis for VFMR was significantly worse than for AFMR (HR 1.57, 95% CI 1.47 to 1.68 for all-cause and 1.73, 95% CI 1.60 to 1.88, p<0.001 for both). After further adjustment for LVEF, mortality rates were similar in VFMR and AFMR patients (HR 0.93, p=NS), though advancing age and pulmonary hypertension remained independently associated with prognosis.

CONCLUSIONS

AFMR is a common cause of significant functional MR that predominantly affects elderly female patients with AF. Advancing age and pulmonary hypertension independently associated with survival in FMR. Prognosis was better in AFMR compared with VFMR; however, this difference was accounted for by LV systolic impairment and not by MR severity.

Prevalence and determinants of tricuspid regurgitation after repair of tetralogy of Fallot

BACKGROUND

The prevalence and determinants of tricuspid regurgitation (TR) in patients with repaired Tetralogy of Fallot (rTOF) remain incompletely understood.

OBJECTIVES

To explore the prevalence of and factors associated with TR in patients with rTOF, specifically, the relationship of right ventricular (RV) dilatation with TR severity.

METHODS

Patients (≥17 yrs) with rTOF referred to our service (2000-2019) were identified. Those with severe pulmonary stenosis, significant shunt, or previous tricuspid valve surgery were excluded. Using standard cardiac MRI protocols, RV, right atrial (RA) and tricuspid valve (TV) parameters were measured and compared.

RESULTS

68 consecutively eligible patients with rTOF were included in the study (27 ± 9 yrs., 35% female). Despite substantial RV volume overload (mean RVEDVi 153 mL/m²), the majority of the cohort (78%) had no or only mild TR. RA volumes, tenting height/area and annular diameter were normal (4.9 ± 2.0 mm, 1.1 ± 1.0 cm² and 32.4 ± 6.2 mm, respectively). There was no significant correlation of TR fraction with RVEDVi (r = 0.13; p = 0.30), RVEF (r = 0.09; p = 0.44) or tricuspid annular diameter (r = 0.07; p = 0.62). Only RAVi showed a weak but significant correlation with TR fraction (0.29; p = 0.03). In a pooled cohort analysis, including both rTOF patients and adults with a dilated RV from pre-tricuspid shunt lesions, only rTOF was independently associated with higher TR fraction (p = 0.017).

CONCLUSION

Despite substantial RV dilatation in a cohort with rTOF, there was surprisingly little TR. We found poor correlation between RVEDVi, RA volumes, tricuspid annular dilatation and the presence of significant TR. These findings question commonly held notions regarding the pathophysiology of functional TR in these patients.

A Potential Strategy for Atherosclerosis Prevention in Modernizing China - Hyperhomocysteinemia, MTHFR C677T Polymorphism and Air Pollution (PM2.5) on Atherogenesis in Chinese Adults

BACKGROUND

Atherosclerosis is one of the most important global health hazards and air pollution (AP, PM2.5) has been implicated. In addition to traditional risk factors hyperhomocysteinemia (HC) has been recognized in many parts of China related to risk of stroke.

METHODS

To evaluate the impact of HC (homocysteine >14μmol/l) and PM2.5 air pollution on atherogenesis in modernizing China, we studied 756 asymptomatic Chinese in China from 1998-2007. PM2.5 exposure, HC, folate, and methylenetetrahydrofolate reductase (MTHFR) C/T genotype were evaluated. Brachial flow-mediated dilation (FMD) and carotid intima-media thickness (IMT) were measured by ultrasound. Locations were categorized as zones 1, 2 and 3, with increasing PM2.5 exposure.

RESULTS

HC was higher (19.4±13.1 and 27.1±25.1μmol/l) in high PM2.5-polluted zones 2 and 3 than in zone 1 (9.7±4.5μmol/l, p<0.0015). The top HC tertile was characterized by lower folate and vitamin B12, but a higher proportion of the MTHFR TT genotype, Metabolic Syndrome (MS) and PM2.5 level (p=0.0018). FMD was significantly lower (7.3±2.3%) and carotid IMT thicker (0.63±0.12mm) in the top HC tertile, compared with low HC tertile (8.4±2.5%, p<0.0001; 0.57±0.1mm, p<0.0001 respectively). Similar differences in FMD and IMT were seen in zones 2 and 3, compared with zone 1 (p<0.0001). On multivariate regression, HC was related to male gender (beta=0.106, p=0.021), MTHFR-TT (beta=0.935, p<0.0001), locations (beta=0.230, p<0.0001) and folate-MTHFR interaction (beta=-0.566, p<0.0001). FMD was related to age (beta= -0.221; p<0.0001), male gender (beta= -0.194, p=0.001) PM2.5 and location (beta=-0.285 to -0.303, p<0.0001). Carotid IMT was related to PM2.5 (beta=0.173, p<0.0001), HC (0.122, p=0.006) but not to MTHFR or location, independent of age, gender, MS, and LDL-C. No significant HC-PM2.5 interaction effect on FMD and IMT was observed.

CONCLUSION

HC and PM2.5 pollution but not MTHFR genotype were both related to carotid IMT, independent of other traditional risk factors. This has potential implications in dietary and AP strategies for atherosclerosis prevention in China.

β3 adrenergic agonism: A novel pathway which improves right ventricular-pulmonary arterial hemodynamics in pulmonary arterial hypertension

Efficacy of therapies that target the downstream nitric oxide (NO) pathway in pulmonary arterial hypertension (PAH) depends on the bioavailability of NO. Reduced NO level in PAH is secondary to "uncoupling" of endothelial nitric oxide synthase (eNOS). Stimulation of β3 adrenergic receptors (β3 ARs) may lead to the recoupling of NOS and therefore be beneficial in PAH. We aimed to examine the efficacy of β3 AR agonism as a novel pathway in experimental PAH. In hypoxia (5 weeks) and Sugen hypoxia (hypoxia for 5 weeks + SU5416 injection) models of PAH, we examined the effects of the selective β3 AR agonist CL316243. We measured echocardiographic indices and invasive right ventricular (RV)-pulmonary arterial (PA) hemodynamics and compared CL316243 with riociguat and sildenafil. We assessed treatment effects on RV-PA remodeling, oxidative stress, and eNOS glutathionylation, an oxidative modification that uncouples eNOS. Compared with normoxic mice, RV systolic pressure was increased in the control hypoxic mice (p < 0.0001) and Sugen hypoxic mice (p < 0.0001). CL316243 reduced RV systolic pressure, to a similar degree to riociguat and sildenafil, in both hypoxia (p < 0.0001) and Sugen hypoxia models (p < 0.03). CL316243 reversed pulmonary vascular remodeling, decreased RV afterload, improved RV-PA coupling efficiency and reduced RV stiffness, hypertrophy, and fibrosis. Although all treatments decreased oxidative stress, CL316243 significantly reduced eNOS glutathionylation. β3 AR stimulation improved RV hemodynamics and led to beneficial RV-PA remodeling in experimental models of PAH. β3 AR agonists may be effective therapies in PAH.

Cardio-Oncology Recommendations for Pediatric Oncology Patients: An Australian and New Zealand Delphi Consensus

Cardio-oncology is a new multidisciplinary area of expertise that seeks to pre-emptively and proactively address cardiac complications that emerge during and following cancer therapy. Modern therapies including molecular targeted therapy and immunotherapy have broadened the agents that can cause cardiac sequelae, often with complications arising within days to weeks of therapy. Several international guidelines have been developed for the acute monitoring of cardio-oncology side effects. However, none are specific to pediatrics. We have addressed this gap in the literature by undertaking a rigorous Delphi consensus approach across 11 domains of cardio-oncology care using an Australian and New Zealand expert group. The expert group consisted of pediatric and adult cardiologists and pediatric oncologists. This Delphi consensus provides an approach to perform risk and baseline assessment, screening, and follow-up, specific to the cancer therapeutic. This review is a useful tool for clinicians involved in the cardio-oncology care of pediatric oncology patients.

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.

Soldiers' Heart: A Prospective Study of Cardiac Remodeling in Soldiers Undergoing Progressive Intensity Exercise Training

PURPOSE

Most studies reporting cardiac changes with exercise have been cross sectional. The few available longitudinal studies have lacked standardization for environmental confounders. We prospectively assessed the relationship between increasing exercise intensity and cardiac remodeling in a highly standardized cohort of healthy young army soldiers.

METHODS

Sixty-three male army recruits (22 ± 3 yr) underwent a 12-wk moderate-intensity mixed strength and endurance exercise program, followed by a further 15-wk high-intensity exercise program, with highly controlled exercise, diet, and sleep patterns. Fitness (multistage fitness test), anthropometry, and 2D echocardiography were assessed.

RESULTS

Moderate-intensity exercise was associated with increased fitness and decreased body fat % (both P < 0.01). There was no significant incremental change in these parameters after high-intensity exercise. By contrast, both moderate- and high-intensity exercises were associated with dose-dependent increases in left atrial and left ventricular (LV) volumes, LV mass, and right ventricular (RV) size (all P < 0.01). At the end of high-intensity training, 51% had a dilated LV and 59% had a dilated RV compared with published normal ranges. Almost all had normal LV systolic function and strain before and after exercise training. A small number of soldiers had mildly decreased RV systolic function at baseline and after moderate-intensity exercise (3% and 6%, respectively).

CONCLUSIONS

We describe "soldiers' heart," which is characterized by balanced chamber dilatation, normal LV mass, and largely normal systolic function and myocardial strain. This prospective and highly controlled longitudinal study also found that increasing intensity exercise was associated with increasing chamber dimensions, which paralleled an increase in fitness after moderate-intensity exercise. After high-intensity exercise, however, cardiac chamber size continued to increase, but fitness did not increase further.

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.

The effect of a game-based mobile app 'MyHeartMate' to promote lifestyle change in coronary disease patients: a randomized controlled trial

Aims

Secondary prevention reduces coronary heart disease (CHD) progression. Traditional prevention programs including cardiac rehabilitation are under-accessed, which smartphone apps may overcome. To evaluate the effect of a game-based mobile app intervention (MyHeartMate) to improve cardiovascular risk factors and lifestyle behaviours.

Methods and results

Single-blind randomized trial of CHD patients in Sydney, 2017-2021. Intervention group were provided the MyHeartMate app for 6 months. Co-designed features included an avatar of the patient's heart and tokens earned by risk factor work (tracking, challenges, and quizzes). The control group received usual care. Primary outcome was self-reported physical activity [metabolic equivalents (METs), Global Physical Activity Questionnaire] and secondary outcomes included lipid levels, blood pressure (BP), body mass index, and smoking. Pre-specified sample size was achieved (n = 390), age 61.2 ± 11.5 years; 82.5% men and 9.2% current smokers. At 6 months, adjusted for baseline levels, the intervention group achieved more physical activity than control (median difference 329 MET mins/wk), which was not statistically significant (95% CI -37.4, 696; P = 0.064). No differences occurred between groups on secondary outcomes except for lower triglyceride levels in the intervention [mean difference -0.3 (95% CI -0.5, -0.1 mmoL/L, P = 0.004)]. Acceptability was high: 94.8% of intervention participants engaged by tracking exercise or BP and completing missions; 26.8% continued to engage for ≥30 days. Participants (n = 14) reported the app supported tracking behaviours and risk factors, reinforcing and improving self-care confidence, and decreasing anxiety.

Conclusion

A game-based app proved highly acceptable for patients with CHD but did not improve risk factors or lifestyle behaviours other than triglyceride levels.

Associations of dietary macronutrient composition with cardiometabolic health: data from the National Health and Nutrition Examination Survey (NHANES) 1999–2014

Background

Human nutrition is a leading modifiable risk factor for the prevention of cardiometabolic diseases. However, most nutritional research focuses on the role of specific nutrients rather than compositional analysis of the diet.

Purpose

We aimed to assess the association of dietary macronutrient composition with various markers of cardiometabolic health.

Methods

This study was undertaken using 24-hour food recall data from the National Health and Nutrition Examination Survey from years 1999–2014 (n=36,637). Participants included both males and females ≥20 years of age (49.8±18.3 years; 53% Female). Caloric outliers for males (&lt;800 kcal/day or &gt;4200 kcal/day) and females (&lt;600 kcal/day or &gt;3500 kcal/day) were removed from the analysis (n=1844). Cardiometabolic health markers were collected via mobile examination center and included triglycerides (n=16,444), total cholesterol (n=31,155), LDL cholesterol (n=15,798), HDL cholesterol (n=33,435), blood pressure (n=34,121), body fat percentage (n=4269), body mass index (n=35,187), glucose (n=17,208), insulin (n=16,273), oral glucose tolerance test (n=8280), and HbA1c (n=27,288). Associations of dietary macronutrients with cardiometabolic health markers were assessed using 3-dimensional general additive models (Protein; Carbohydrate; Fat) with adjustment for age, sex, misreporting, ethnicity, education level, household income, physical activity, alcohol intake, and smoking. Response surfaces on right-angled mixture triangles were generated as predictions from absolute macronutrient intake at the 50th percentile of total energy intake. Macronutrient intakes were transformed to a percentage of energy to visualize and interpret associations compositionally.

Results

There was a complex 3-way interactive non-linear association of macronutrient composition with lipid profile (Figure A-D; all p&lt;0.04), blood pressure (Figure E-F; all p&lt;0.001), body fat percentage (Figure G; p&lt;0.001), body mass index (Figure H; p&lt;0.001), and all markers of glycemic control (Figure I-L; all p&lt;0.001). Diets comprised of high protein coupled with low fat were associated with higher triglycerides but generally more favorable total cholesterol, blood pressure, and body fatness. Conversely, diets composed of high protein coupled with high fat were associated with higher HDL cholesterol but worse total cholesterol, body fatness, body mass index, and glycemic control.

Conclusions

These findings display a complex relationship between dietary macronutrient composition and cardiometabolic health. Future research is needed to evaluate how dietary source and quality may modify the observed associations.

Funding Acknowledgement

Type of funding sources: Private company.

The Australian and New Zealand Fontan Registry Quality of Life Study: Protocol for a population-based assessment of quality of life among people with a Fontan circulation, their parents, and siblings

INTRODUCTION

Advances in the care of patients with single-ventricle congenital heart disease have led to a new generation of individuals living with a Fontan circulation. For people with Fontan physiology, physical, psychological and neurodevelopmental challenges are common. The objective of this study is to describe and develop a deeper understanding of the factors that contribute to quality of life (QOL) among children, adolescents and adults living with a Fontan circulation across Australia and New Zealand, their parents and siblings.

METHODS AND ANALYSIS

This article presents the protocol for the Australian and New Zealand Fontan Registry (ANZFR) QOL Study, a cross-sectional, population-based study designed to examine QOL among people of all ages with a Fontan circulation, their parents and siblings. Study eligibility criteria includes (1) individuals with a Fontan circulation aged ≥6 years, at least 12 months post-Fontan procedure and enrolled in the ANZFR; (2) parents of individuals enrolled in the ANZFR; and (3) siblings aged ≥6 years of an individual enrolled in the ANZFR. A novel, online research platform is used to distribute personalised assessments tailored to participant age and developmental stage. A suite of validated psychometric self-report and parent-proxy report instruments capture potential correlates and predictors of QOL, including symptoms of psychological distress, personality attributes, coping and cognitive appraisals, family functioning, healthcare experiences and costs, access to emotional support and socioeconomic factors. Clinical characteristics are captured via self-report and parent-proxy report, as well as the ANZFR. Descriptive analyses and multilevel models will be used to examine QOL across groups and to investigate potential explanatory variables.

ETHICS AND DISSEMINATION

Approval has been obtained from all relevant Human Research Ethics Committees (HRECs), including the Sydney Children's Hospitals Network and the Royal Children's Hospital Melbourne HRECs. Study findings will be published in peer-reviewed journals and presented at national and international meetings and seminars.

Long-Term Outcomes After Atrial Switch Operation for Transposition of the Great Arteries

BACKGROUND

For patients with d-loop transposition of the great arteries (d-TGA) with a systemic right ventricle after an atrial switch operation, there is a need to identify risks for end-stage heart failure outcomes.

OBJECTIVES

The authors aimed to determine factors associated with survival in a large cohort of such individuals.

METHODS

This multicenter, retrospective cohort study included adults with d-TGA and prior atrial switch surgery seen at a congenital heart center. Clinical data from initial and most recent visits were obtained. The composite primary outcome was death, transplantation, or mechanical circulatory support (MCS).

RESULTS

From 1,168 patients (38% female, age at first visit 29 ± 7.2 years) during a median 9.2 years of follow-up, 91 (8.8% per 10 person-years) met the outcome (66 deaths, 19 transplantations, 6 MCS). Patients experiencing sudden/arrhythmic death were younger than those dying of other causes (32.6 ± 6.4 years vs 42.4 ± 6.8 years; P < 0.001). There was a long duration between sentinel clinical events and end-stage heart failure. Age, atrial arrhythmia, pacemaker, biventricular enlargement, systolic dysfunction, and tricuspid regurgitation were all associated with the primary outcome. Independent 5-year predictors of primary outcome were prior ventricular arrhythmia, heart failure admission, complex anatomy, QRS duration >120 ms, and severe right ventricle dysfunction based on echocardiography.

CONCLUSIONS

For most adults with d-TGA after atrial switch, progress to end-stage heart failure or death is slow. A simplified prediction score for 5-year adverse outcome is derived to help identify those at greatest risk.

Moderate- and High-Intensity Exercise Improves Lipoprotein Profile and Cholesterol Efflux Capacity in Healthy Young Men

Background

Exercise is associated with a reduced risk of cardiovascular disease. Increased high‐density lipoprotein cholesterol (HDL‐C) levels are thought to contribute to these benefits, but much of the research in this area has been limited by lack of well‐controlled subject selection and exercise interventions. We sought to study the effect of moderate and high‐intensity exercise on HDL function, lipid/lipoprotein profile, and other cardiometabolic parameters in a homogeneous population where exercise, daily routine, sleep patterns, and living conditions were carefully controlled.

Methods and Results

Male Army recruits (n=115, age 22±0.3 years) completed a 12‐week moderate‐intensity exercise program. A subset of 51 subsequently completed a 15‐week high‐intensity exercise program. Fitness increased and body fat decreased after moderate‐ and high‐intensity exercise (P<0.001). Moderate‐intensity exercise increased HDL‐C and apolipoprotein A‐I levels (6.6%, 11.6% respectively), and decreased low‐density lipoprotein cholesterol and apolipoprotein B levels (7.2%, 4.9% respectively) (all P<0.01). HDL‐C and apolipoprotein A‐I levels further increased by 8.2% (P<0.001) and 6.3% (P<0.05) after high‐intensity exercise. Moderate‐intensity exercise increased ABCA‐1 (ATP‐binding cassette transporter A1) mediated cholesterol efflux by 13.5% (P<0.001), which was sustained after high‐intensity exercise. In a selected subset the ability of HDLs to inhibit ICAM‐1 (intercellular adhesion molecule‐1) expression decreased after the high (P<0.001) but not the moderate‐intensity exercise program.

Conclusions

When controlling for exercise patterns, diet, and sleep, moderate‐intensity exercise improved HDL function, lipid/lipoprotein profile, fitness, and body composition. A sequential moderate followed by high‐intensity exercise program showed sustained or incremental benefits in these parameters. Improved HDL function may be part of the mechanism by which exercise reduces cardiovascular disease risk.

Impact of Fontan Fenestration on Long-Term Outcomes: A Propensity Score-Matched Analysis

Background The long-term impact of fenestration at the time of Fontan operation remains unclear. We aimed to review the early and long-term impact of Fontan fenestration in the Australia and New Zealand cohort. Methods and Results We reviewed 1443 patients (621 fenestrated, 822 nonfenestrated) from the Australia and New Zealand Fontan registry. Data were collected on preoperative demographics, operative details, and follow-up. Propensity-score matching was performed to account for the various preoperative and operative differences and risk factors. Primary outcomes were survival and freedom from failure. Median follow-up was 10.6 years. After propensity-score matching (407 matched pairs), there was no difference in survival (87% versus 90% at 20 years; P=0.16) or freedom from failure (73% versus 80% at 20 years; P=0.10) between patients with and without fenestration, respectively. Although patients with fenestration had longer bypass and cross-clamp times (P<0.001), there was no difference in hospital length of stay or prolonged pleural effusions (P=0.80 and P=0.46, respectively). Freedom from systemic and Fontan circuit thromboembolism was higher in the nonfenestrated group (89%; 95% CI, 88%-95%) than the fenestrated group (84%; 95% CI, 77%-89%; P=0.03). There was no difference in incidence of plastic bronchitis, protein-losing enteropathy, New York Heart Association Class III/IV symptoms, or Fontan takedown. Conclusions In the propensity score-matched analysis we have demonstrated no difference in long-term survival or freedom from Fontan failure in patients with and without fenestration. There was a higher incidence of long-term thromboembolic events in patients with fenestration. Overall, it appears that fenestration in Fontan circulation does not bring long-term benefits.

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.

Novel insights into bicuspid aortic valve (BAV) aortopathy: Long non-coding RNAs TUG1 and MIAT are differentially expressed in BAV ascending aortas

BACKGROUND

Whilst a combination of genetically mediated vulnerability and haemodynamic insult is suspected to contribute to bicuspid aortic valve (BAV) aortopathy, the underlying pathophysiological mechanisms are poorly understood.

METHODS

Utilising RT-qPCR, we compared the expression of 28 potentially relevant long non-coding RNA (lncRNA) in aortic tissue from BAV patients undergoing aortic surgery for aortopathy, to healthy controls. Relative lncRNA expression was measured using ΔΔCT, with fold-change calculated as RQ=2^-ΔΔCT.

RESULTS

When comparing samples from BAV patients (n=29, males n=25; median age 58 years, Q1-Q3 51-65, maximum aortic dimension 50±5mm) with healthy controls (n=7; males n=4, p=0.12; median age 39 years, Q1-Q3 18-47, p=0.001), there were two differentially expressed lncRNA: TUG1 expression was significantly lower in BAV aortic tissue (RQ 0.59, 95% CI 0.50-0.69, p=0.02), whilst MIAT expression was significantly higher (RQ 2.87, 95% CI 1.96-4.20, p=0.01). Sensitivity analysis including only patients with normal BAV function showed similar trends of differential expression of TUG1 (RQ 0.69, 95% CI 0.50-0.90, p=0.29) and MIAT (RQ 2.55, 95% CI 1.21-5.36, p=0.29) compared to controls.

CONCLUSIONS

LncRNA TUG1 and MIAT are differentially expressed in BAV aortopathy compared to healthy controls, independent of BAV haemodynamics. Aberrant lncRNA expression may be involved in the pathogenesis of BAV aortopathy.