ECTOPIC trial: The efficacy of flEcainide Compared To metOprolol in reducing Premature ventrIcular contractions. A randomized open label cross-over study in pediatric patients.

BACKGROUND: Frequent premature ventricular contractions (PVCs) in children are usually considered benign. Symptoms and/or left ventricular dysfunction are indications for treatment with anti-arrhythmic drugs (AAD). OBJECTIVE: To evaluate the efficacy of flecainide versus metoprolol in reducing PVCs in children. METHODS: A randomized open label cross-over trial children with a PVC-burden of >15% on Holter; successively treated with metoprolol and flecainide or vice versa, with a drug free interval of at least two weeks. Holter measurements were repeated before and after the start of the AAD. RESULTS: Sixty patients were screened, 19 patients could be included. Median age was 13.9 years (IQR 5.5 years). Mean baseline PVC-burden was 21.7% (N=18, SD±14.0) before the start of flecainide and 21.2% (N=17, SD±11.5) before the start of metoprolol. In a mixed model analysis the estimated mean reduction in PVC-burden was 10.6 percentage-points (95%-CI 5.8-15.3) for flecainide and 2.4 percentage-points (95%-CI -2.7-7.5) for metoprolol, with a significant difference of 8.2 percentage-points (95%-CI of 0.86-15.46, P=0.031). Exploratory analysis revealed that 9/18 patients treated with flecainide and 1/17 patients treated with metoprolol, had a reduction to a PVC-burden below 5%. No discriminating factors between flecainide-responders and non-responders were found; the mean plasma level was not significantly different (0.34 mg/L versus 0.52 mg/L, P=0.277). CONCLUSIONS: In children with frequent PVCs flecainide led to a significant greater reduction of PVC-burden, compared to metoprolol. Flecainide was effective in only a subgroup of patients, which appears to be unrelated to the plasma level. (Dutch Trial Register number 26689).

Hybrid palliation to promote growth of left ventricle and left ventricular outflow tract.

OBJECTIVES: In patients with borderline left hearts or a severe left ventricular outflow tract obstruction, hybrid palliation can be used to stabilize the patient and postpone biventricular repair (BVR). In this study, we analysed growth of left-sided structures and outcomes of these patients. METHODS: We conducted a retrospective cohort study including patients who received hybrid palliation between January 2010 and September 2023. Echo measurements were collected at hybrid palliation, BVR and last follow-up. Growth of left ventricular structures were analysed. RESULTS: In 38 patients, hybrid palliation was used to promote growth of left ventricular structures. In total, 15 patients received a Ross-Konno/Yasui procedure, while 23 patients received conventional BVR. In patients with a conventional BVR, a significant increase was found in left ventricular volume indexed by body surface area, Z-score of aortic valve and left ventricular outflow tract between hybrid palliation and BVR. Mitral valve Z-score did not increase significantly. After BVR until follow-up, only increase of the aortic valve Z-scores and left ventricular volume indexed by body surface area was found significant. Of all included patients (n = 38), additional surgical procedures were necessary in 8 patients during the interstage period and 15 patients after BVR. Additional catheter interventions were needed in 14 patients in the interstage period and 15 after BVR. Six patients died, with no mortality in the conventional BVR group. CONCLUSIONS: Hybrid palliation as part of a staged BVR is a safe and effective initial step and promotes the growth of left ventricular structures in patients with small left-sided heart structures. Close follow-up is mandatory because extra catheter or surgical interventions are frequently needed.

Clinical Course of TGA After Arterial Switch Operation in the Current Era.

Background: The number of patients with an arterial switch operation (ASO) for transposition of the great arteries (TGA) is steadily growing; limited information is available regarding the clinical course in the current era. Objectives: The purpose was to describe clinical outcome late after ASO in a national cohort, including survival, rates of (re-)interventions, and clinical events. Methods: A total of 1,061 TGA-ASO patients (median age 10.7 years [IQR: 2.0-18.2 years]) from a nationwide prospective registry with a median follow-up of 8.0 years (IQR: 5.4-8.8 years) were included. Using an analysis with age as the primary time scale, cumulative incidence of survival, (re)interventions, and clinical events were determined. Results: At the age of 35 years, late survival was 93% (95% CI: 88%-98%). The cumulative re-intervention rate at the right ventricular outflow tract and pulmonary branches was 36% (95% CI: 31%-41%). Other cumulative re-intervention rates at 35 years were on the left ventricular outflow tract (neo-aortic root and valve) 16% (95% CI: 10%-22%), aortic arch 9% (95% CI: 5%-13%), and coronary arteries 3% (95% CI: 1%-6%). Furthermore, 11% (95% CI: 6%-16%) of the patients required electrophysiological interventions. Clinical events, including heart failure, endocarditis, and myocardial infarction occurred in 8% (95% CI: 5%-11%). Independent risk factors for any (re-)intervention were TGA morphological subtype (Taussig-Bing double outlet right ventricle [HR: 4.9, 95% CI: 2.9-8.1]) and previous pulmonary artery banding (HR: 1.6, 95% CI: 1.0-2.2). Conclusions: TGA-ASO patients have an excellent survival. However, their clinical course is characterized by an ongoing need for (re-)interventions, especially on the right ventricular outflow tract and the left ventricular outflow tract indicating a strict lifelong surveillance, also in adulthood.

Long-term global longitudinal strain abnormalities in paediatric patients after multisystem inflammatory syndrome in children correlate with cardiac troponin T: a single-centre cohort study.

BACKGROUND: Multisystem inflammatory syndrome in children is an inflammatory syndrome related to severe acute respiratory syndrome coronavirus 2 with a high risk of cardiovascular complications (vasoplegia, cardiac shock). We investigated the cardiac outcomes in multisystem inflammatory syndrome in children, focusing on the identification of predictors for late cardiac function impairment. METHODS: Clinical characteristics, conventional echocardiography (left ventricle ejection fraction, fractional shortening), 4-chamber left ventricular global longitudinal strain, and cardiac MRI of multisystem inflammatory syndrome in children patients (n = 48) were collected during admission, 6 weeks, 6 months, >12-≤18 months, and >18-≤24 months post-onset. Paired over-time patterns were assessed and multivariable regression analyses were performed to identify predictors for late global longitudinal strain impairment. RESULTS: In total, 81.3% of patients had acute cardiac dysfunction (left ventricle ejection fraction <50% and/or fractional shortening <28%). The left ventricle ejection fraction and fractional shortening reached a plateau level ≤6 weeks, while the global longitudinal strain continued to decrease in the first 6 months post-onset (median -17.3%, P < 0.001 [versus acute]). At 6 months, 35.7% of the patients still had an abnormal global longitudinal strain, which persisted in 5/9 patients that underwent echocardiography >12-≤18 months post-onset and in 3/3 patients >18-≤24 months post-onset. In a multivariable analysis, soluble troponin T (>62.0 ng/L [median]) was associated with reduced global longitudinal strain at 6 months. Our cardiac MRI findings indicated acute myocardial involvement (increased T1/T2 value) in 77.8% (7/9), which recovered quickly without signs of fibrosis on convalescent cardiac MRIs. CONCLUSIONS: Late global longitudinal strain impairment is seen in some multisystem inflammatory syndrome in children patients up to one-year post-onset. Careful cardiac follow-up in patients with elevated troponin in the acute phase and patients with persistent abnormal global longitudinal strain is warranted until resolution of the global longitudinal strain since the long-term implications of such abnormalities are still unclear.

CTCA in children with severe heterozygous familial hypercholesterolaemia: Screening for subclinical atherosclerosis.

Familial hypercholesterolemia (FH) is one of the most common genetically inherited disorders in the world. Children with severe heterozygous FH (HeFH), i.e. untreated low-density lipoprotein cholesterol (LDL-C) levels above the 90th percentile for age and sex among FH mutation carriers, can have LDL-C levels that overlap levels of children with homozygous FH (HoFH), but treatment regimen and cardiovascular follow-up to prevent cardiovascular disease are less intensive in children with severe HeFH. In children with HoFH, subclinical atherosclerosis can already be present using computed tomography coronary angiography (CTCA). The question remains whether this is also the case in children with severe HeFH who have a high exposure to elevated LDL-C levels from birth onwards as well. We calculated the cumulative LDL-C exposure (CEtotal [mmol]) in four children with severe HeFH and performed computed tomography coronary angiography (CTCA). These children, aged 13, 14, 15 and 18 years, had CEtotal of 71.3, 97.8, 103.6 and 136.1 mmol, respectively. None of them showed abnormalities on cardiovascular imaging, despite high LDL-C exposure. The results of this study, do not give us an indication to recommend performing CTCA routinely in children with severe HeFH.

The effect of electro-anatomical mapping on the success rate and fluoroscopy time in supra-ventricular tachycardia ablation in children: single centre retrospective study.

AIMS: To evaluate the effect of electro-anatomical mapping on success rate and fluoroscopy time in ablation of supraventricular tachycardia substrates in a large group of children. METHODS: Patients referred from multiple centres in the Netherlands and who received a first ablation for supraventricular tachycardia substrates in the Leiden University Medical Center between 2014 and 2020 were included in this retrospective cohort study. They were divided in procedures in patients with fluoroscopy and procedures in patients using electro-anatomical mapping. RESULTS: Outcomes of ablation of 373 electro-anatomical substrates were analysed. Acute success rate in the fluoro-group (n = 170) was 95.9% compared to 94.5% in the electro-anatomical mapping group (n = 181) (p = 0.539); recurrence rate was 6.1% in the fluoro-group and 6.4% in the electro-anatomical mapping group (p = 0.911) after a 12-months follow-up. Redo-ablations were performed in 12 cases in the fluoro-group and 10 cases in the electro-anatomical mapping group, with a success rate of 83.3% versus 80.0%, resulting in an overall success rate of 95.9% in the fluoro-group and 92.8% in the electro-anatomical mapping group (p = 0.216) after 12 months. Fluoroscopy time and dose area product decreased significantly from 16.00 ± 17.75 minutes (median ± interquartile range) to 2.00 ± 3.00 minutes (p = 0.000) and 210.5 µGym2 ± 249.3 to 32.9 µGym2 ± 78.6 (p = 0.000), respectively. In the fluoro-group, four complications occurred (2.0%) and in the electro-anatomical mapping group no complications occurred. CONCLUSION: These results demonstrate that ablations of supraventricular tachycardia substrates in children remain a highly effective and safe treatment after the introduction of electro-anatomical mapping as a standard of care, while significantly reducing fluoroscopy time and dose area product.

Transient anti-cytokine autoantibodies superimpose the hyperinflammatory response in Kawasaki disease and multisystem inflammatory syndrome in children: a comparative cohort study on correlates of disease.

BACKGROUND: Children with SARS-CoV-2 related Multisystem Inflammatory Syndrome in Children (MIS-C) often present with clinical features that resemble Kawasaki disease (KD). Disease severity in adult COVID-19 is associated to the presence of anti-cytokine autoantibodies (ACAAs) against type I interferons. Similarly, ACAAs may be implicated in KD and MIS-C. Therefore, we explored the immunological response, presence of ACAAs and disease correlates in both disorders. METHODS: Eighteen inflammatory plasma protein levels and seven ACAAs were measured in KD (n = 216) and MIS-C (n = 56) longitudinally by Luminex and/or ELISA. Levels (up to 1 year post-onset) of these proteins were related to clinical data and compared with healthy paediatric controls. FINDINGS: ACAAs were found in both patient groups. The presence of ACAAs lagged behind the inflammatory plasma proteins and peaked in the subacute phase. ACAAs were mostly directed against IFN-γ (>80%) and were partially neutralising at best. KD presented with a higher variety of ACAAs than MIS-C. Increased levels of anti-IL-17A (P = 0·02) and anti-IL-22 (P = 0·01) were inversely associated with ICU admission in MIS-C. Except for CXCL10 in MIS-C (P = 0·002), inflammatory plasma proteins were elevated in both KD and MIS-C. Endothelial angiopoietin-2 levels were associated with coronary artery aneurysms in KD (P = 0·02); and sCD25 (P = 0·009), angiopoietin-2 (P = 0·001), soluble IL-33-receptor (ST2, P = 0·01) and CXCL10 (P = 0·02) with ICU admission in MIS-C. INTERPRETATION: Markers of endothelial activation (E-selectin, angiopoietin-2), and innate and adaptive immune responses (macrophages [CD163, G-CSF], neutrophils [lipocalin-2], and T cells [IFN-γ, CXCL10, IL-6, IL-17]), are upregulated in KD and MIS-C. ACAAs were detected in both diseases and, although only partly neutralising, their transient presence and increased levels in non-ICU patients may suggest a dampening role on inflammation. FUNDING: The Kawasaki study is funded by the Dutch foundation Fonds Kind & Handicap and an anonymous donor. The sponsors had no role in the study design, analysis, or decision for publication.

[Kawasaki disease or SARS-CoV-2 related MIS-C? How to discriminate between these hyperinflammatory syndromes in children?] / Ziekte van Kawasaki of SARS-CoV-2-gerelateerde MIS-C?

Increasing waiting lists and a structural staff shortage are putting pressure on the health system. Because care production is lower than care demand, there is no longer competition. Competition is over and we are beginning to see the contours of the new health system. The new system takes health instead of care as its starting point by legally embedding health goals in addition to the duty of care. The new system is based on health regions, but does not require a regional health authority. It is based on health manifestos that include agreements about cooperation in good and bad times.

Comprehensive Evaluation of Pediatric Patients with Ebstein Anomaly Requires Both Echocardiography and Cardiac Magnetic Resonance Imaging.

With the trend towards childhood surgery in patients with Ebstein anomaly (EA), thorough imaging is crucial for patient selection. This study aimed to assess biventricular function by echocardiography and cardiac magnetic resonance (CMR) and compare EA severity classifications. Twenty-three patients (8-17 years) underwent echocardiography and CMR. Echocardiographic parameters included tricuspid annular plane systolic excursions (TAPSE), fractional area change of the functional right ventricle (fRV-FAC), fRV free wall peak systolic myocardial velocity (fRVs'), and tricuspid regurgitation (TR). End-diastolic and end-systolic volume (EDV resp. ESV), fRV- and LV ejection fraction (EF) and TR were obtained by CMR. EA severity classifications included displacement index, Celermajer index and the total-right/left-volume index. Median fRV-FAC was 38% (IQR 33-42). TAPSE and fRVs' were reduced in 39% and 75% of the patients, respectively. Echocardiographic TR was visually graded as mild, moderate, or severe in nine, six and eight patients, respectively. By CMR, median fRVEF was 49% (IQR 36-58) and TR was graded as mild, moderate, or severe in nine, twelve and two patients, respectively. In 70% of cases, fRV-EDV was higher than LV-EDV. LVEF was decreased in 17 cases (74%). There was excellent correlation between echocardiography-derived fRV-FAC and CMR-derived fRVEF (rho = 0.812, p < 0.001). While echocardiography is a versatile tool in the complex geometry of the Ebstein heart, it has limitations. CMR offers a total overview and has the advantage of reliable volume assessment of both ventricles. Comprehensive evaluation of pediatric patients with EA may therefore require a synergistic implementation of echocardiography and CMR.

Orthostatic stress response in pediatric Fontan patients and the effect of ACE inhibition.

BACKGROUND: Many cardiocirculatory mechanisms are involved in the adaptation to orthostatic stress. While these mechanisms may be impaired in Fontan patients. However, it is yet unclear how Fontan patients, who exhibit a critical fluid balance, respond to orthostatic stress. Angiotensin converting enzyme inhibitors are often prescribed to Fontan patients, but they may negatively influence orthostatic tolerance. Therefore, we evaluated the response to orthostatic stress in pediatric Fontan patients before and after treatment with enalapril. METHODS: Thirty-five Fontan patients (aged 14 years) with moderate-good systolic ventricular function without pre-existent enalapril treatment were included. Before and after a three-month enalapril treatment period, the hemodynamic response to head-up tilt test was evaluated by various parameters including cardiac index, blood pressure, cerebral blood flow, aortic stiffness and cardiac autonomous nervous activity. Thirty-four healthy subjects (aged 13 years) served as controls. RESULTS: Fontan patients had a decreased cerebral blood flow and increased aortic stiffness in the supine position compared to controls, while all other factors did not differ. Patients and controls showed a comparable response to head-up tilt test for most parameters. Twenty-seven patients completed the enalapril study with a mean dosage of 0.3±0.1mg/kg/day. Most parameters were unaffected by enalapril, only the percent decrease in cardiac index to tilt was higher after treatment, but the cardiac index during tilt was not lower (3.0L/min/m2 pre-enalapril versus 2.8L/min/m2 after treatment; P = 0.15). CONCLUSION: Pediatric Fontan patients adequately respond to orthostasis with maintenance of blood pressure and cerebral blood flow and sufficient autonomic response. Enalapril treatment did not alter the response. CLINICAL TRIAL INFORMATION: Scientific title: ACE inhibition in Fontan patients: its effect on body fluid regulation (sAFE-study). The Netherlands National Trial Register: Trail NL6415. Registered 2017-07-20. Trial information: https://www.trialregister.nl/trial/6415.

Preconception lifestyle intervention in women with obesity and echocardiographic indices of cardiovascular health in their children.

BACKGROUND: Improving maternal lifestyle before conception may prevent the adverse effects of maternal obesity on their children's future cardiovascular disease (CVD) risk. In the current study, we examined whether a preconception lifestyle intervention in women with obesity could alter echocardiographic indices of cardiovascular health in their children. METHODS: Six years after a randomized controlled trial comparing the effects of a 6-month preconception lifestyle intervention in women with obesity and infertility prior to fertility care to prompt fertility care, 315 of the 341 children conceived within 24 months after randomization were eligible for this study. The intervention was aimed at weight loss (≥5% or until BMI < 29 kg/m2). Children underwent echocardiographic assessment of cardiac structure and function, conducted by a single pediatric cardiologist, blinded to group allocation. Results were adjusted for multiple variables including body surface area, age, and sex in linear regression analyses. RESULTS: Sixty children (32 girls, 53%) were included, mean age 6.5 years (SD 1.09). Twenty-four children (40%) were born to mothers in the intervention group. Children of mothers from the intervention group had a lower end-diastolic interventricular septum thickness (-0.88 Z-score, 95%CI -1.18 to -0.58), a lower left ventricle mass index (-8.56 g/m2, 95%CI -13.09 to -4.03), and higher peak systolic and early diastolic annular velocity of the left ventricle (1.43 cm/s 95%CI 0.65 to 2.20 and 2.39 cm/s 95%CI 0.68 to 4.11, respectively) compared to children of mothers from the control group. CONCLUSIONS: Children of women with obesity, who underwent a preconception lifestyle intervention, had improved cardiac structure and function; a thinner interventricular septum, lower left ventricle mass, and improved systolic and diastolic tissue Doppler velocities. Despite its high attrition rates, our study provides the first experimental human evidence suggesting that preconception lifestyle interventions may present a method of reducing CVD risk in the next generation. CLINICAL TRIAL REGISTRATION: LIFEstyle study: Netherlands Trial Register: NTR1530 ( https://www.trialregister.nl/trial/1461 ). This follow-up study was approved by the medical ethics committee of the University Medical Centre Groningen (METC code: 2008/284).

Myocardial infarction due to thrombotic occlusion despite anticoagulation in Kawasaki disease - a case report.

BACKGROUND: Kawasaki disease (KD) is a pediatric vasculitis. Mainly the coronary arteries become affected due to acute inflammation and formation of coronary artery aneurysms (CAAs) can occur. The larger the CAA, the higher the risk for clinical complications and major adverse cardiac events, as the blood flow changes to vortex or turbulent flow facilitating thrombosis. Such patients may develop life threatening thrombotic coronary artery occlusion and myocardial ischemiaunless anti-platelet and anti-coagulation therapy is timely initiated. CASE PRESENTATION: We present a unique case of a 5-year-old girl with KD associated giant CAAs suffering from myocardial ischemia due to acute progressive thrombus growth despite intensive anticoagulation treatment (acetylsalicylic acid, acenocoumarol and clopidogrel) after 21 months of onset of disease. Thrombus growth continued even after percutaneous coronary intervention (PCI) with thrombolytic treatment and subsequent systemic thrombolysis, finally causing lasting myocardial damage. Acute coronary artery bypass grafting (CABG) was performed, although technically challenging at this very young age. Whereas myocardial infarction was not prevented, follow-up fortunately showed favorable recovery of heart failure. CONCLUSIONS: Anticoagulation and thrombolysis may be insufficient for treatment of acute coronary syndrome in case of impending thrombotic occlusion of giant coronary aneurysms in KD. Our case demonstrates that a thrombus can still continue to grow despite triple anticoagulation therapy and well-tailored cardiovascular follow-up, which can be most likely attributed to the state of low blood flow inside the aneurysm.

Treatment and Coronary Artery Aneurysm Formation in Kawasaki Disease: A Per-Day Risk Analysis.

OBJECTIVE: To assess whether 'treatment day' is a significant predicting factor in Kawasaki disease and imposes a risk for coronary artery aneurysms (CAAs) in a per-day analysis. CAA formation can be reduced from 25% to 10% when treated with intravenous immunoglobulin (IVIG). STUDY DESIGN: Patient data from (n = 1016) a single center were collected for an observational cohort study. After exclusions, we retrospectively analyzed 776 patients in total. A multivariate analysis was performed with treatment day as a continuous variable (n = 691). Patients were categorized as no enlargement, small CAA, medium CAA, and giant CAA. RESULTS: Late treatment per-day was a significant predicting factor for the development of larger CAAs. ORs for medium and giant CAAs per delayed day were 1.1 (95% CI 1.1-1.2) P < .05 and 1.2 (95% CI 1.1-1.2) P < .05, respectively. CONCLUSION: We showed that every day of delay in treatment of patients with Kawasaki disease inherently carries a risk of medium and giant aneurysm formation. There was no cut-off point for treatment day that could mark a safe zone.

3-Month Enalapril Treatment in Pediatric Fontan Patients With Moderate to Good Systolic Ventricular Function.

Many Fontan patients with and without systolic ventricular dysfunction are being treated with angiotensin-converting enzyme (ACE) inhibitors, despite its effectiveness remaining unclear. In the present study, we evaluated the short-term effect of enalapril on exercise capacity, vascular and ventricular function in pediatric Fontan patients with moderate-good systolic ventricular function. Fontan patients between 8 and 18 years with moderate-good systolic ventricular function and without previous ACE inhibitor treatment were included and were treated with enalapril for 3 months. During the first 2 weeks, the dosage was titrated according to systolic blood pressure (SBP). Exercise tests, ventricular function assessed by echocardiography, arterial stiffness measurements, and plasma levels of N-terminal pro-B-type natriuretic peptide assessed before and after a 3-month enalapril treatment period was compared. A total of 28 Fontan patients (median age 13.9 years, 6 to 15 years after Fontan operation) completed the study with a mean dosage of 0.3 ± 0.1 mg/kg/d. A total of 6 patients (21%) experienced a significant drop in SBP and 6 others (21%) experienced other adverse events. Enalapril treatment lowered the SBP (from 110 to 104 mmHg, p = 0.003) and levels of N-terminal pro-B-type natriuretic peptide (from 80 to 72 ng/L, p = 0.036). However, enalapril treatment did not improve exercise capacity, ventricular function, or arterial stiffness. In conclusion, short-term ACE inhibition has no beneficial effect in Fontan patients with moderate-good systolic ventricular function.

Determinants of exercise limitation in contemporary paediatric Fontan patients with an extra cardiac conduit.

BACKGROUND: Although various determinants of exercise limitation in Fontan patients have been studied, most research has been performed in patients who underwent different surgical procedures with differing haemodynamic characteristics. The aim of the current study was to evaluate non-invasively measured cardiovascular parameters and their influence on exercise performance in paediatric Fontan patients with an extracardiac conduit and moderate-good systolic ventricular function. METHODS: Fontan patients, between 8 and 18 years of age, with moderate to good systolic ventricular function and an extracardiac conduit were included. Exercise performance and cardiovascular assessment, comprising echocardiography, aortic stiffness measurement and ambulatory measurement of cardiac autonomous nervous activity were performed on the same day. Healthy subjects served as controls. RESULTS: Thirty-six Fontan patients (age 14.0 years) and thirty-five healthy subjects (age 12.8 years) were included. Compared to controls, Fontan patients had reduced diastolic ventricular function and increased arterial stiffness. No differences were found in heart rate (HR) and cardiac parasympathetic nervous activity. In Fontan patients, maximal as well as submaximal exercise capacity was impaired, with the percentage of predicted capacity ranging between 54 and 72%. Chronotropic competence, however, was good with a peak HR of 174 (94% of predicted). Lower maximal and submaximal exercise capacity was correlated with a higher HR at rest, higher pulse wave velocity of the aorta and a lower ratio of early and late diastolic flow velocity. CONCLUSION: Contemporary paediatric Fontan patients have an impaired exercise capacity with preserved chronotropic competence. Exercise performance correlates with heart rate at rest, diastolic function and aortic stiffness.

Prognostic Value of Maximal and Submaximal Exercise Performance in Fontan Patients < 15 Years of Age.

In patients after Fontan completion exercise capacity is significantly reduced. Although peak oxygen consumption (VO2peak) is a strong prognostic factor in many cardiovascular diseases, it requires the achievement of a maximal effort. Therefore, submaximal exercise parameters such as oxygen uptake efficiency slope (OUES) may be of value. In the present observational study we evaluated the exercise capacity with maximal and submaximal parameters in a group of Fontan patients with an extracardiac conduit and determined their prognostic value. Sixty Fontan patients followed up in the Leiden University Medical Center who have performed an exercise test were included in this retrospective study. Exercise tests were performed at a median age of 11 years. Fontan patients showed on average lower values for all exercise parameters compared to reference values from a healthy dataset as shown by the %predicted values: VO2peak%:mean 66%(95%CI:64 to 74) and OUES%:mean 72%(95%CI:67 to 77). Twenty percent of the patients were not able to achieve an RER>1.0. RER showed a moderate positive correlation with VO2peak but not with OUES. There was a deterioration of VO2peak% and OUES% over time. OUES was significantly lower in patients with cardiac events in the follow up period. Fontan patients have an impaired exercise performance even at young ages and it deteriorates with age. An important percentage of Fontan patients is not able to reach maximal effort so the use of submaximal parameters, like OUES, should be considered as part of the evaluation. Moreover, OUES could have a prognostic value in this group of patients.

Marked plaque regression in homozygous familial hypercholesterolemia.

BACKGROUND AND AIMS: Both plasma low-density lipoprotein (LDL) cholesterol levels and risk for premature cardiovascular disease are extremely elevated in patients with homozygous familial hypercholesterolemia (HoFH), despite the use of multiple cholesterol lowering treatments. Given its inborn nature, atherosclerotic plaques are commonly observed in young HoFH patients. Whether intensive lipid lowering strategies result in plaque regression in adolescent patients is unknown. METHODS: Two HoFH patients with null/null LDLR variants, who participated in the R1500-CL-1629 randomized clinical trial (NCT03399786) evaluating the LDL cholesterol lowering effect of evinacumab (a human antibody directed against ANGPTL3; 15 mg/kg intravenously once monthly), were included in this study. Patients underwent coronary computed tomography angiography (CCTA) before randomization and after 6 months of treatment. RESULTS: Both patient A (aged 12) and B (aged 16) were treated with a statin, ezetimibe and weekly apheresis. Evinacumab decreased mean pre-apheresis LDL cholesterol levels from 5.51 ± 0.75 and 5.07 ± 1.45 mmol/l to 2.48 ± 0.31 and 2.20 ± 0.13 mmol/l and post-apheresis LDL levels from 1.45 ± 0.26 and 1.37 ± 39 mmol/l to 0.80 ± 0.16 and 0.78 ± 0.13 mmol/l in patient A and B, respectively. Total plaque volumes were reduced by 76% and 85% after 6 months of evinacumab treatment in patient A and B, respectively. CONCLUSIONS: We describe two severely affected young HoFH patients in whom profound plaque reduction was observed with CCTA after intensive lipid lowering therapy with statins, ezetimibe, LDL apheresis, and evinacumab. This shows that atherosclerotic plaques possess the ability to regress at young age, even in HoFH patients.

Long-term outcome after the arterial switch operation: 43 years of experience.

OBJECTIVES: The objective of this study was to assess our 43-year experience with arterial switch operation (ASO) for transposition of the great arteries (TGA) by analysing cardiac outcome measures (hospital and late mortality, reoperations and catheter interventions, significant coronary artery obstruction) and to identify risk factors for reoperation and catheter interventions. METHODS: A total of 490 patients who underwent ASO for TGA from 1977 to 2020 were included in this retrospective, single-centre study. Data on reoperation and catheter intervention of hospital survivors were estimated by the Kaplan-Meier method and compared using a long-rank test. Risk factors for reoperation and/or catheter intervention were assessed by multivariate Cox regression analysis. RESULTS: Hospital mortality occurred in 43 patients (8.8%), late death in 12 patients (2.9%) and 43 patients were lost to follow-up. Median follow-up time of 413 hospital survivors was 15.6 (interquartile range 7.0-22.4) years. Reoperations were performed in 83 patients (117 reoperations). Neoaortic valve regurgitation with root dilatation was the second most common indication for reoperation (15/83 patients, 18.1%) after right ventricular outflow tract obstruction (50/83 patients, 60.2%). Risk factors for any reoperation on multivariable analysis were: TGA morphological subtype [TGA with ventricular septal defect: hazard ratio (HR) = 1.99, 95% confidence interval (CI) 1.18-3.36; P = 0.010 and Taussig-Bing: HR = 2.17, 95% CI 1.02-4.64; P = 0.045], aortic arch repair associated with ASO (HR = 3.03, 95% CI 1.62-5.69; P = 0.001) and a non-usual coronary artery anatomy (HR = 2.41, 95% CI 1.45-4.00; P = 0.001). One hundred and one catheter interventions were performed in 54 patients, usually for relief of supravalvular pulmonary stenosis (44/54 patients, 81.5%) or arch obstruction (10/54 patients, 18.5%). Main risk factor for catheter intervention on multivariable analysis was aortic arch repair associated with ASO (HR = 2.95, 95% CI 1.37-6.36; P = 0.006). Significant coronary artery stenosis was relatively uncommon (9/413 patients, 2.2%) but may be underrepresented. CONCLUSIONS: Patients after ASO typically have good long-term clinical outcomes but reoperations and interventions remain necessary in some patients. Neoaortic valve regurgitation with root dilatation is the second most common indication for reoperation after right ventricular outflow tract obstruction and an increasing need for neoaortic valve and root redo surgery in future is to be expected.

Childhood onset nexilin dilated cardiomyopathy: A heterozygous and a homozygous case.

Pathogenic heterozygous NEXN variants are associated with progressive dilated cardiomyopathy (DCM) usually presenting around 50 years of age. We describe an asymptomatic boy who had transient DCM at 3 months of age, that resolved by 4 months. Presently, at 11 years of age, he has normal cardiac function with signs of mild DCM on cardiac MRI. Genetic diagnostics revealed a paternally derived, heterozygous 1949_1951del class 4 variant in NEXN. His father had mild DCM with mildly reduced systolic function. The second patient presented with fetal hydrops at 33 weeks gestation requiring emergency caesarian delivery. Postnatally she required ventilation and continuous inotropic support for left ventricle systolic dysfunction. She died after 2 weeks when therapy was withdrawn. Homozygous c.1174C > T,p.(R392*) class 4 variants in the NEXN gene were found via WES. Microscopic investigation showed endomyocardial fibroelastosis. Her parents, both heterozygous carriers, had normal cardiac function and the family history was normal. These patients show a new clinical spectrum of pediatric cardiac disease seen in heterozygous and homozygous NEXN variants, ranging from mild, transient DCM to a severe, fatal neonatal DCM. These patients support the inclusion of the NEXN gene in the investigation of pediatric patients with DCM, even in cases with transient DCM.

Dobutamine stress testing for the evaluation of atrial and diastolic ventricular function in Fontan patients.

OBJECTIVE: To assess the atrial and ventricular diastolic function response to dobutamine stress in Fontan patients, and to relate these measurements to exercise capacity and events during the follow-up. METHODS: We performed a secondary analysis of a cross-sectional multicentre study of Fontan patients with intra-atrial lateral tunnel (ILT) or extracardiac conduit (ECC) modification. Subjects underwent cardiac MRI during rest and low-dose dobutamine stress, and cardiopulmonary exercise testing. Atrial and diastolic ventricular function parameters were derived from volume-time curves.Medical records were abstracted for a composite end-point of death, listing for transplant, arrhythmia and reintervention. Spearman's r correlation tests and Cox proportional hazards models were used to assess the relation between the dobutamine response for atrial and diastolic ventricular function and outcomes, including exercise capacity. RESULTS: We included 57 patients (26 ECC; 31 ILT) aged 12.8 (IQR (10.3-15.5)) years. During dobutamine stress atrial cyclic volume change increased (3.0 (0.4-5.9) mL/m2, p<0.001), as did early (1.9 (-1.6 to 3.6) mL/m2, p=0.001) and late emptying volume (2.2 (0.2-4.4) mL/m2, p<0.001).Ventricular early filling decreased (-1.6 (-5.7 to 0.7) mL/m2,p=0.046) and ventricular late filling increased (1.0 (-0.4 to 3.4) mL/m2,p<0.001) while stroke volume remained similar.Only for patients with the ECC modification, atrial early emptying volume increase correlated with peak oxygen uptake (ρ=0.66,p=0.002). No other parameter related to exercise capacity.During a median 7.1-year follow-up, 22 patients reached the composite endpoint. No parameter predicted events during the follow-up. CONCLUSIONS: Dobutamine stress augmented atrial reservoir and pump function for Fontan patients. Atrial early emptying reserve related to exercise capacity in ECC patients. No other atrial or diastolic ventricular function parameter related to outcomes.