Exercise as therapy for neurodevelopmental and cognitive dysfunction in people with a Fontan circulation: A narrative review

People with a Fontan circulation are at risk of neurodevelopmental delay and disability, and cognitive dysfunction, that has significant implications for academic and occupational attainment, psychosocial functioning, and overall quality of life. Interventions for improving these outcomes are lacking. This review article discusses current intervention practices and explores the evidence supporting exercise as a potential intervention for improving cognitive functioning in people living with a Fontan circulation. Proposed pathophysiological mechanisms underpinning these associations are discussed in the context of Fontan physiology and avenues for future research are recommended.

Platypnea-Orthodeoxia Syndrome in the Setting of Patent Foramen Ovale Without Pulmonary Hypertension or Major Lung Disease

Background

Patent foramen ovale (PFO)‐associated platypnea‐orthodeoxia syndrome is characterized by dyspnea and hypoxemia when upright. The pathogenesis is thought to involve an increase in right atrial pressure or change in degree of right to left shunting with upright posture.

Methods and Results

We sought to characterize patients with platypnea‐orthodeoxia syndrome related to PFO without pulmonary hypertension. We retrospectively reviewed databases at 3 tertiary referral hospitals in New South Wales, Australia from 2000 to 2019. Fourteen patients with a mean age of 69±14 years had a PFO with wide tunnel separation. Mean New York Heart Association Classification was II (±0.9) and 7 inpatients had been confined to bed (from postural symptoms). Baseline oxygen saturations supine were 93%±5% and 84%±6% upright. Two patients had a minor congenital heart defect and 4 had mild parenchymal lung disease with preserved lung function. The mean aortic root diameter was 37±6 mm and distance between aortic root and posterior atrial wall was 16±2 mm. Platypnea‐orthodeoxia syndrome was preceded by surgery in 5 patients and 1 patient had mild pneumonia. Successful closure of the PFO using an Amplatzer device was performed in 11 of 14 patients. Post‐closure, all patients had New York Heart Association Classification I (improvement 1.6±0.9, P<0.003) and semi‐recumbent oxygen saturations increased by 13%±8% (P<0.001, n=10).

Conclusions

Platypnea‐orthodeoxia syndrome is a debilitating condition, curable by PFO closure. Anatomical distortion of the atrial septum related to a dilated aortic root or shortening of the distance between the aortic root and posterior atrial wall may contribute to the syndrome.

Impact of left heart disease risk factors on risk stratification and treatment response in pulmonary arterial hypertension

Background

Contemporary registries have documented a change in the epidemiology of PAH patients displaying increasing co-morbidities associated with left heart disease (LHD). These patients are often excluded from randomized clinical trials. It is unclear whether the presence of LHD comorbidities may adversely impact the accuracy of risk stratification and response to PAH therapy.

Method

Data was extracted from the Pulmonary Hypertension Society of Australia and New Zealand registry for incident patients with a diagnosis with idiopathic/heritable/toxin-induced (I/H/D)-PAH and connective tissue disease (CTD) associated PAH from 2011 - 2020. Patients without available medication and follow up data were excluded. We used the AMBITION trial exclusion criteria to define the subpopulation with LHD risk factors and haemodynamic phenotype (PAH-rLHD).

Results

489 patients (I/H/D-PAH=251, CTD-PAH=238) were included in our analysis, with 103 (21.0%) fulfilling the definition of PAH-rLHD (34 had ≥3 risk factors for left heart disease (rLHD-hypertension, diabetes, obesity or ischaemic heart disease) and 76 had borderline haemodynamics (mean capillary wedge pressure 13–15 with pulmonary vascular resistance &lt;500 dynes sec/cm5) including 7 who met both criteria). Compared to classical PAH, patients with PAH-rLHD were older at diagnosis (66±13 vs 58±19, p&lt;0.001), had lower pulmonary vascular resistance (PVR: 393±266 vs 708±391, p=0.031) but worse exercise capacity (6MWD: 286±130m vs 327±136m, p=0.005). PAH-rLHD were more likely to be started on initial monotherapy, compared with “classical” PAH (73% vs 56%, p=0.002). In the monotherapy groups, endothelin receptor antagonists (ERA) were used in 73% PAH-rLHD, compared with 66% in classical PAH group. Both groups exhibited similar response to both mono- and combination therapy with commensurate improvements in WHO functional class (mean change 0.3±0.6 vs 0.3±0.8, p=0.443) and 6-minute walk distance (mean change 44±82 vs 48±101, p=0.723). There was no difference in survival between classical PAH and PAH-rLHD (log rank, p=0.29). The REVEAL 2.0 risk score effectively discriminated risk in both populations at baseline and first follow up (classical PAH: baseline C statistic 0.750, follow up 0.774 and PAH-rLHD: baseline C statistic 0.756, follow up 0.791).

Conclusion

Despite lower PVR at diagnosis, PAH-rLHD patients and “classical” PAH demonstrate similar response to first-line therapy with similar long term survival. The REVEAL 2.0 risk score can be effectively applied to the subpopulation of PAH-rLHD in real life clinical practice.

Funding Acknowledgement

Type of funding sources: None.

Atrial septal defect in adulthood: a new paradigm for congenital heart disease

Atrial septal defects (ASDs) represent the most common congenital heart defect diagnosed in adulthood. Although considered a simple defect, challenges in optimal diagnostic and treatment options still exist due to great heterogeneity in terms of anatomy and time-related complications primarily arrhythmias, thromboembolism, right heart failure and, in a subset of patients, pulmonary arterial hypertension (PAH). Atrial septal defects call for tertiary expertise where all options may be considered, namely catheter vs. surgical closure, consideration of pre-closure ablation for patients with atrial tachycardia and suitability for closure or/and targeted therapy for patients with PAH. This review serves to update the clinician on the latest evidence, the nuances of optimal diagnostics, treatment options, and long-term follow-up care for patients with an ASD.

The Australia and New Zealand Cardio-Oncology Registry: evaluation of chemotherapy-related cardiotoxicity in a national cohort of paediatric cancer patients

Cancer therapy related cardiac dysfunction (CTRCD) is an area of increasing focus, particularly during the survivorship period, for paediatric, adolescent and adult cancer survivors. With the advent of immunotherapy and targeted therapy, there is a new set of mechanisms from which paediatric and young adult patients with cancer may suffer cardiovascular injury. Furthermore, cardiovascular disease is the leading cause of morbidity and mortality in the survivorship period. The recently established Australian Cardio-Oncology Registry is the largest and only population-based cardiotoxicity database of paediatric and adolescent and young adult oncology patients in the world, and the first paediatric registry that will document cardiotoxicity caused by chemotherapy and novel targeted therapies using a prospective approach. The database is designed for comprehensive data collection and evaluation of the Australian practice in terms of diagnosis and management of CTRCD. Using the Australian Cardio-Oncology Registry critical clinical information will be collected regarding predisposing factors for the development of CTRCD, the rate of subclinical left ventricular dysfunction and transition to overt heart failure, further research into protectant molecules against cardiac dysfunction and aid in the discovery of which genetic variants predispose to CTRCD. A health economic arm of the study will assess the cost/benefit of both the registry and cardio-oncology clinical implementation. Finally, an imaging arm will establish if exercise cardiac magnetic resonance imaging and VO₂ max testing is a more sensitive predictor of cardiac reserve in paediatric and adolescent and young adult oncology patients exposed to cardiac toxic therapies.

Sexual Function in Men Living With a Fontan Circulation

Introduction: It is unknown if the Fontan circulation has an impact on sexual health in men. This study assessed self-reported sexual health and fertility in men with a Fontan circulation. Aims: In this prospective, cross-sectional study, Australian men ≥18 years enrolled in the Fontan Registry of Australia and New Zealand were invited to complete the International Index of Erectile Function (IIEF), alongside questions assessing fertility. These data were compared to historical, age-matched controls. Results: Of 227 eligible men, 54 completed the survey; of those 37 were sexually active and included in the final analysis. Mean age was 28 ± 3 years, age at Fontan was 5 ± 3 years. Fontan type was extra-cardiac conduit in 15 (41%), lateral tunnel in 12 (32%), and atriopulmonary connection (APC) in 10 (27%). Ventricular function was normal in 24 (83%), and all were New York Heart Association Class I (23 patients, 79%) and II (six patients, 21%). Nine participants (24%) had erectile dysfunction (IIEF-EF score ≤25). The severity was mild (IIEF 22-24) in six (16%), mild-moderate (IIEF 17-21) in two (5%), and moderate (IIEF 11-16) in one (3%). Baseline characteristics and current medication usage were similar in those with and without erectile dysfunction. Compared with historical control values, erectile function was not significantly impaired in the Fontan population (p =0.76). Men with a Fontan circulation had decreased levels of sexual desire and overall satisfaction (p < 0.001). There was no correlation between the presence of erectile dysfunction and any assessed parameter. Eleven (30%) of the cohort reported a pregnancy with a prior partner. Conclusion: In our cohort, overall erectile function was comparable between men with a Fontan circulation and historical controls, however sexual desire and overall satisfaction were reduced. There was no correlation between study parameters and the presence of erectile dysfunction. The proportion of the cohort who had a prior pregnancy was congruent with population data.

Comparison of the effect of single vs dual antiplatelet agents on post-operative haemorrhage after renal transplantation: A systematic review and meta-analysis

OBJECTIVES

A significant proportion of renal transplant patients have cardiovascular comorbidities for which they receive treatment with antiplatelet agents. The aim of this study was to systematically review the current literature reporting perioperative outcomes for patients receiving dual antiplatelet therapy compared to single antiplatelet therapy at the time of kidney transplantation with particular reference to the risks of postoperative haemorrhage.

MATERIALS AND METHODS

Embase, Medline and Cochrane databases were utilized to identify articles reporting outcomes of renal transplant recipients on single antiplatelet therapy and dual antiplatelet therapy. These outcomes were compared using a random effects model meta-analysis where appropriate.

RESULTS

Six articles were incorporated in the analysis, including 130 receiving dual antiplatelet therapy, and 781 in the single antiplatelet therapy group. There was a significantly higher risk of post-operative haemorrhagic events in the dual antiplatelet therapy group compared to the single antiplatelet therapy group (RR 1.58, 95% CI 1.19-2.09, p = 0.001). Post-operative cardiovascular event rates were similar between both groups in individual studies, although this could not be quantitatively analysed.

CONCLUSIONS

The use of dual antiplatelet therapy was associated with a higher risk of post-operative haemorrhage compared to the use of single antiplatelet therapy without increased rates of surgical intervention. However, the use of dual antiplatelet therapy may provide protection from cardiovascular events in an inherently higher risk patient group.

Left Ventricular Non-Compaction: Review of the Current Diagnostic Challenges and Consequences in Athletes

Left ventricular non-compaction (LVNC) is a complex clinical condition with no diagnostic gold standard. At present, there is trepidation about the accuracy of the diagnosis, the correlation to clinical outcomes and the long-term medical management. This article reviews the current imaging criteria, the limitations of echocardiography and cardiac magnetic resonance and the consequences of LV hypertrabeculation in athletes.

Vascular function in adults with cyanotic congenital heart disease

BACKGROUND

Patients with cyanotic congenital heart disease (CCHD) may have a low burden of atherosclerosis. Endothelial dysfunction is an early stage of atherosclerosis and endothelial function is previously studied in smaller CCHD groups with different techniques and variable results. We aimed to examine endothelial function and carotid atherosclerosis in a larger group of CCHD patients.

METHODS

This multicentre study assessed endothelial function in adults with CCHD and controls by measuring the dilatory response of the brachial artery to post-ischemic hyperaemia (endothelium-dependent flow-mediated-vasodilatation (FMD)), and to nitroglycerin (endothelium-independent nitroglycerin-induced dilatation (NID)). Flow was measured at baseline and after ischaemia (reactive hyperaemia). Carotid-intima-media-thickness (CIMT), prevalence of carotid plaque and plaque thickness (cPT-max) were evaluated ultrasonographically. Lipoproteins, inflammatory and vascular markers, including sphingosine-1-phosphate (S1P) were measured.

RESULTS

Forty-five patients with CCHD (median age 50 years) and 45 matched controls (median age 52 years) were included. The patients presented with lower reactive hyperaemia (409 ± 114% vs. 611 ± 248%, p < 0.0001), however preserved FMD response compared to controls (106.5 ± 8.3% vs. 106.4 ± 6.1%, p = 0.95). In contrast, NID was lower in the patients (110.5 ± 6.1% vs. 115.1 ± 7.4%, p = 0.053). There was no difference in CIMT, carotid plaque or cPT-max. The patients presented with lower high-density-lipoprotein cholesterol, and higher level of inflammatory markers and S1P.

CONCLUSION

Adults with CCHD had preserved FMD in the brachial artery, but impaired NID response and lower reactive hyperaemia than controls. The preserved FMD and the comparable prevalence of carotid atherosclerosis indicate that CCHD patients have the same risk of atherosclerosis as controls.

Tricuspid regurgitation is associated with increased mortality independent of pulmonary pressures and right heart failure: a systematic review and meta-analysis

Aims

To undertake a systematic review and meta-analysis to determine the influence of tricuspid regurgitation (TR) severity on mortality.

Methods and results

We performed a systematic search for studies reporting clinical outcomes of patients with TR. The primary endpoint was all-cause mortality and secondary endpoints were cardiac mortality and hospitalization for heart failure (HF). Overall risk ratios (RR) and 95% confidence intervals (CIs) were derived for each endpoint according to the severity of TR by meta-analysing the effect estimates of eligible studies. Seventy studies totalling 32 601 patients were included in the analysis, with a mean (±SD) follow-up of 3.2 ± 2.1 years. Moderate/severe TR was associated with a two-fold increased mortality risk compared to no/mild TR (RR 1.95, 95% CI 1.75-2.17). Moderate/severe TR remained associated with higher all-cause mortality among 13 studies which adjusted for systolic pulmonary arterial pressures (RR 1.85, 95% CI 1.44-2.39), and 15 studies, which adjusted for right ventricular (RV) dysfunction (RR 1.78, 95% CI 1.49-2.13). Moderate/severe TR was also associated with increased cardiac mortality (RR 2.56, 95% CI 1.84-3.55) and HF hospitalization (RR 1.73, 95% CI 1.14-2.62). Compared to patients with no TR, patients with mild, moderate, and severe TR had a progressively increased risk of all-cause mortality (RR 1.25, 1.61, and 3.44, respectively; P < 0.001 for trend).

Conclusions

Moderate/severe TR is associated with an increased mortality risk, which appears to be independent of pulmonary pressures and RV dysfunction.

An unusual case of upper limb ischemia in a marathon runner

Acute limb ischemia in young adults warrants thorough investigation to determine the underlying cause. Here, we present a case of acute upper limb ischemia in a marathon runner secondary to paradoxical embolism. The patient had associated deep venous thrombosis of the lower limb with multiple pulmonary emboli and patent foramen ovale. This case report emphasizes the under-recognition of intense endurance exercise as a risk factor for venous thromboembolism and highlights the potentially debilitating embolic sequelae of venous thromboembolism in patients with patent foramen ovale.

Pharmacological Treatment of Pulmonary Arterial Hypertension in Australia: Current Trends and Challenges

BACKGROUND

Combination drug therapy for pulmonary arterial hypertension (PAH) is the international standard of care for most patients, however in Australia there are barriers to drug access. This study evaluates current treatment of PAH patients in Australia and the consistency of therapy with international guidelines.

METHODS

Cross-sectional analysis of patients with Group 1 PAH enrolled in the Pulmonary Hypertension Society of Australia and New Zealand Registry (PHSANZ) at 31 December 2017. Drug treatment was classified as monotherapy or combination therapy and adequacy of treatment was determined by risk status assessment using the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0 risk calculator. Predictors of monotherapy were assessed using a generalised linear model with Poisson distribution and logarithmic link function.

RESULTS

1,046 patients met the criteria for analysis. Treatment was classified as monotherapy in 536 (51%) and combination therapy in 510 (49%) cases. Based on REVEAL 2.0, 184 (34%) patients on monotherapy failed to meet low-risk criteria and should be considered inadequately treated. Independent predictors of monotherapy included age greater than 60 years (risk ratio [RR] 1.23, 95% confidence interval [CI] 1.09-1.38; p=0.001), prevalent enrolment in the registry (RR 1.21 [95%CI 1.08-1.36]; p=0.001) and comorbid systemic hypertension (RR 1.17 [95%CI 1.03-1.32]; p=0.014), while idiopathic/heritable/drug-induced PAH subtype (RR 0.85 [95%CI 0.76-0.96]; p=0.006), functional class IV (RR 0.50 [95%CI 0.29-0.86]; p=0.012), increased right ventricular systolic pressure (RR 0.99 [95%CI 0.99-1.00]; p<0.001) and increased pulmonary vascular resistance (RR 0.96 [95%CI 0.95-0.98]; p<0.001) were less likely to be associated with monotherapy.

CONCLUSIONS

Most Australian PAH patients are treated with monotherapy and a significant proportion remain at risk of poor outcomes. This is below the standard of care recommended by international guidelines and at risk patients should be escalated to combination therapy.

Fontan-associated nephropathy: Predictors and outcomes

BACKGROUND

Nephropathy is a known complication of the Fontan circulation, but its determinants have not been identified and patient outcomes are also still unknown.

METHODS

The Australia and New Zealand Fontan Registry was used to identify those who underwent Fontan operation before and survived beyond 16-years-old with an intact Fontan circulation. Serum creatinine values were collected for each patient between 16 and 25 years and at recent follow-up. The Modification of Diet in Renal Disease (MDRD) equation was used to calculate eGFR. Patient outcomes were obtained from the Registry. Fontan failure was defined as death, transplantation, plastic bronchitis, protein losing enteropathy, Fontan takedown and NYHA class III-IV.

RESULTS

Serum creatinine measurements were available for 328 patients. Renal dysfunction was defined as eGFR <90 mL/min/1.72m². Renal dysfunction was present in 67/328 (20%) and 3/328 (1%) patients had an eGFR <60 mL/min/1.72m². The 10-year survival and 10-year freedom from death and transplantation were the same, 96% (95% CI: 0.9-1) for those with renal dysfunction, and 89% (0.83-0.95; p = 0.1) and 87% (95% CI: 0.81-0.94; p = 0.05) for patients without dysfunction. The 10-year freedom from failure were also similar, 83% (95% CI: 0.70-0.97) for those without renal dysfunction vs 80% (95% CI: 0.74-0.89; p = 0.84). There was no change in mean eGFR for the renal dysfunction group over a mean of 8 ± 5.5 years.

CONCLUSION

By the time they reach adulthood, 20% of patients with a Fontan circulation have renal dysfunction by eGFR calculation. Over the course of one decade, Fontan-associated nephropathy appears well tolerated.