Repeatability of ventricular arrhythmia characteristics on the exercise-stress test in RYR2-mediated catecholaminergic polymorphic ventricular tachycardia

AIMS

In catecholaminergic polymorphic ventricular tachycardia (CPVT), the exercise-stress test (EST) is the cornerstone for the diagnosis, risk stratification, and assessment of therapeutic efficacy, but its repeatability is unknown. We aimed to test the repeatability of ventricular arrhythmia characteristics on the EST in patients with CPVT.

METHODS AND RESULTS

EST-pairs (ESTs performed within 18 months between 2005 and 2021, on the same protocol, and without or on the exact same treatment) of patients with RYR2-mediated CPVT from two specialized centres were included. The primary endpoint was the repeatability of the maximum ventricular arrhythmia score [VAS: 0 for the absence of premature ventricular contractions (PVCs); 1 for isolated PVCs; 2 for bigeminal PVCs; 3 for couplets; and 4 for non-sustained ventricular tachycardia]. Secondary outcomes were the repeatability of the heart rate at the first PVC and the ΔVAS (the absolute difference in VAS between the EST-pairs). A total of 104 patients with 349 EST-pairs were included. The median duration between ESTs was 343 (interquartile range, 189-378) days. Sixty (17.2%) EST-pairs were off therapy. The repeatability of the VAS was moderate {Krippendorf α, 0.56 [95% confidence interval (CI), 0.48-0.64]}, and the repeatability of the heart rate at the first PVC was substantial [intra-class correlation coefficient, 0.78 (95% CI, 0.71-0.84)]. The use of medication was associated with a higher odds for a ΔVAS > 1 (odds ratio = 3.52; 95% CI, 2.46-4.57; P = 0.020).

CONCLUSION

The repeatability of ventricular arrhythmia characteristics was moderate to substantial. This underlines the need for multiple ESTs in CPVT patients and CPVT suspicious patients and it provides the framework for assessing the therapeutic efficacy of novel CPVT therapies.

Pediatric Graves' orbitopathy: a multicentre study

PURPOSE

Graves' orbitopathy (GO) is a rare condition in children often considered to be a less severe condition than at an older age. The aim of our study was to analyse if there are any factors that distinguish paediatric from adult GO in order to provide guidelines for assessing and managing paediatric GO.

METHODS

Study design is a multicentre retrospective observational case series; 115 paediatric patients diagnosed with GO who visited our university medical centres in the Netherlands and Iran between 2003 and 2019 were submitted for complete ophthalmological examinations, serological testing and/or orbital imaging. Main outcome measures focussed on the natural course and clinical picture as well as medical and surgical treatment in paediatric GO.

RESULTS

Clinical findings included proptosis (n = 97; 84.3%), eyelid retraction (n = 77; 67%) and diplopia (n = 13; 11.3%). Ninety-two patients (80%) presented with mild disease, 21 (18.3%) with moderate-severe disease and two (1.7%) with severe GO. Five patients (4.3%) underwent intravenous glucocorticoids and 25 patients underwent orbital decompression surgery. Strabismus surgery due to primary involvement of extraocular muscles was performed in two patients (1.7%). Overall, rehabilitative surgical treatment was planned in 31 patients (26.9%) with inactive disease. Two patients experienced reactivation of the disease.

CONCLUSION

Despite the fact that paediatric and adult GO are considered two separate entities, they might be the same disease with two different clinical phenotypes. Paediatric GO population presents with a comparable clinical picture regarding both soft tissue involvement and proptosis, which may require surgical intervention. Proptosis was present in the majority of paediatric GO patients. Orbital decompression was performed in 21.7% of patients.

An International Multi-Center Cohort Study on β-blockers for the Treatment of Symptomatic Children with Catecholaminergic Polymorphic Ventricular Tachycardia

Background: Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for recurrent arrhythmic events. Beta-blockers (BBs) decrease this risk, but studies comparing individual BBs in sizeable cohorts are lacking. We aimed to assess the association between risk for arrhythmic events and type of BB in a large cohort of symptomatic children with CPVT. Methods: From two international registries of patients with CPVT, RYR2 variant-carrying symptomatic children (defined as syncope or sudden cardiac arrest prior to BB initiation and age at start of BB therapy <18 years), treated with a BB were included. Cox-regression analyses with time-dependent covariates for BB and potential confounders were used to assess the hazard ratio (HR). The primary outcome was the first occurrence of sudden cardiac death, sudden cardiac arrest, appropriate implantable cardioverter-defibrillator shock, or syncope. The secondary outcome was the first occurrence of any of the primary outcomes except syncope. Results: We included 329 patients (median age at diagnosis 12 [interquartile range, 7-15] years, 35% females). Ninety-nine (30.1%) patients experienced the primary and 74 (22.5%) experienced the secondary outcome during a median follow-up of 6.7 [interquartile range, 2.8-12.5] years. Two-hundred sixteen patients (66.0%) used a non-selective BB (predominantly nadolol [n=140] or propranolol [n=70]) and 111 (33.7%) used a β1-selective BB (predominantly atenolol [n=51], metoprolol [n=33], or bisoprolol [n=19]) as initial BB. Baseline characteristics did not differ. The HR for both the primary and secondary outcomes were higher for β1-selective compared with non-selective BBs (HR, 2.04 95% CI, 1.31-3.17; and HR, 1.99; 95% CI, 1.20-3.30, respectively). When assessed separately, the HR for the primary outcome was higher for atenolol (HR, 2.68; 95% CI, 1.44-4.99), bisoprolol (HR, 3.24; 95% CI, 1.47-7.18), and metoprolol (HR, 2.18; 95% CI, 1.08-4.40) compared with nadolol, but did not differ from propranolol. The HR of the secondary outcome was only higher in atenolol compared with nadolol (HR, 2.68; 95% CI, 1.30-5.55). Conclusions: B1-selective BBs were associated with a significantly higher risk for arrhythmic events in symptomatic children with CPVT compared with non-selective BBs, specifically nadolol. Nadolol, or propranolol if nadolol is unavailable, should be the preferred BB for treating symptomatic children with CPVT.

Genetic determinants of ferritin, haemoglobin levels and haemoglobin trajectories: results from Donor InSight

BACKGROUND AND OBJECTIVES

Blood donors might develop iron deficiency as approximately 250 mg of iron is lost with every donation. Susceptibility to iron deficiency and low haemoglobin levels differs between individuals, which might be due to genetic variation. Therefore, the aim of this study was to investigate associations between single nucleotide polymorphisms (SNPs) and haemoglobin trajectories, haemoglobin levels and ferritin levels in blood donors.

MATERIALS AND METHODS

In 2655 donors participating in the observational cohort study Donor InSight-III (2015-2017), haemoglobin and ferritin levels were measured in venous EDTA whole blood and plasma samples, respectively. Haemoglobin trajectories (stable/declining) were determined by fitting growth-mixture models on repeated pre-donation capillary haemoglobin measurements. Genotyping was done using the UK Biobank - version 2 Axiom Array. Single SNP analyses adopting an additive genetic model on imputed genetic variants were performed for haemoglobin trajectories, haemoglobin levels and ferritin levels. Conditional analyses identified independent SNPs.

RESULTS

Twelve, twenty and twenty-four independent SNPs were associated with haemoglobin trajectories, haemoglobin levels and ferritin levels respectively (P < 1 x 10^-5 ). Rs112016443 reached genome-wide significance for ferritin levels, which influences WDSUB1 expression.

CONCLUSION

Rs112016443 was genome-wide significantly associated with ferritin levels in Dutch donors. Further validation studies are needed, as well as studies towards underlying mechanisms and predicting iron deficiency using SNPs.

Genome-wide association study identifies 18 new susceptibility variants loci associated with Brugada Syndrome

 

The Brugada Syndrome (BrS) is characterized by ST-segment elevation in the right precordial leads and is associated with an increased risk of sudden cardiac death. The disorder was initially described as a monogenic primary cardiac electrical disease. However, mutations in SCN5A, encoding the cardiac sodium channel (NaV1.5), which is the major gene associated with the disorder are found in only around 20% of cases and are associated with low penetrance. Furthermore many cases did not display familial aggregation. Based on a previous GWAS conducted on 312 BrS patients and the discovery of the unexpected strong effect of 3 common variants, we proposed that the BrS may comprise a more complex inheritance model. We conducted a genome-wide association study on 2820 individuals with BrS and 10001 ancestry-matched controls to uncover additional genetic loci that modulate susceptibility to BrS, to characterize further the BrS genetic architecture and to uncover new molecular mechanisms.

We identified 21 susceptibility variants that passed the genome-wide statistical significance threshold (P&lt;5.10–8), of which 18 were novel. Eight were located at the SCN5A-SCN10A locus, illustrating the central role of NaV1.5 in the disease. Interestingly, 9 occur in the vicinity of genes known to play a crucial role in cardiac development (HEY2, TBX20, GATA4, ZFPM2, WT1, TBX5, IRX3, IRX5) and / or control cardiac ion channel expression. Of note, 2 others signals occurred in the vicinity of microtubule / cytoskeleton associated proteins (MAPRE2 and MYO18B). Through studies in zebrafish and in human iPSC-derived cardiomyocytes, we demonstrate a role of MAPRE2 on NaV1.5 function.

We identified 18 new susceptibility variants associated with BrS and uncovered a new pathophysiological molecular mechanism underlying BrS susceptibility. We provided further support for a complex genetic architecture underlying susceptibility for the disorder.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): H2020 - Marie Sklodowska Curie IF grant, Rising star grant from the Pays de la Loire regional council

DC-SIGN Polymorphisms Associate with Risk of Hepatitis C Virus Infection Among Men who Have Sex with Men but not Among Injecting Drug Users

We aimed to identify whether genetic polymorphisms within L-SIGN or DC-SIGN correlate with hepatitis C virus (HCV) susceptibility. A men who have sex with men (MSM) and an injecting drug users (IDU) cohort of HCV cases and multiple-exposed uninfected controls were genotyped for numerous L-SIGN and DC-SIGN polymorphisms. DC-SIGN single nucleotide polymorphisms (SNPs) -139, -871, and -939 correlated with HCV acquisition in the MSM cohort only. When the same SNPs were introduced into a transcription activity assay they demonstrated a reduction in expression with predicted alteration in binding of transcription factors. DC-SIGN promoter SNPs correlated with risk of HCV acquisition via sexual but not IDU exposure, likely through modulation of mRNA expression levels.

Association between thrombin-activatable fibrinolysis inhibitor (TAFI) and clinical outcome in patients with unstable angina pectoris

Decrease of fibrinolytic potential is considered to be a risk factor for arterial thrombosis. The recently described thrombinactivatable fibrinolysis inhibitor (TAFI) attenuates fibrinolysis by cleaving of the C-terminal lysine residues from fibrin, thereby inhibiting tPA mediated plasminogen activation. The role of plasma TAFI antigen (Ag) levels and gene polymorphisms in arterial thrombosis is still not elucidated. In this prospective study, the association between plasma TAFI Ag levels and the TAFI gene polymorphisms, Ala147Thr, Thr325Ile and -438A/G, with refractory unstable angina pectoris (UAP) was determined. The study population consisted of 209 patients with UAP of whom 76 were refractory and 133 non-refractory to medical treatment. In the same study population the contribution of these polymorphisms to plasma TAFI Ag levels was determined.

Plasma TAFI Ag levels were significantly higher in non-refractory patients compared to refractory patients (geometric mean 114.4 and 105.6 U/dl respectively, p=0.042). Plasma TAFI Ag levels in the lowest quartile resulted in a 2.6 fold (95% confidence interval 1.2-5.9) increased risk for refractory UAP compared to plasma TAFI Ag levels in the upper quartile. The three studied TAFI polymorphisms had an independent and additive effect on plasma TAFI Ag levels. However, no significant association between the individual TAFI polymorphisms and refractiveness was observed.

In conclusion, in this study population plasma TAFI Ag levels are significantly correlated with refractiveness in patients with UAP. Furthermore, all three polymorphisms contribute independently to plasma TAFI Ag levels, but not to refractiveness.

Part of this paper was originally presented at the joint meetings of the 16th International Congress of the International Society of Fibrinolysis and Proteolysis (ISFP) and the 17th International Fibrinogen Workshop of the International Fibrinogen Research Society (IFRS) held in Munich, Germany, September, 2002.

Ethyl pyruvate exerts combined anti-inflammatory and anticoagulant effects on human monocytic cells

Sepsis is characterized by a concurrent activation of inflammation and coagulation. Recently, recombinant human activated protein C was shown to decrease mortality in patients with severe sepsis presumably due to a combined anti-inflammatory and anticoagulant effect.These promising findings led to a search for other products that influence both the inflammatory and the procoagulant response to severe infection. Ethyl pyruvate (EP) was recently identified as an experimental anti-inflammatory agent during endotoxemia and sepsis. The aim of the present study was to investigate whether EP influences coagulation besides its anti-inflammatory effects. For this we investigated the effects of EP on the expression and function of tissue factor (TF), the principal initiator of coagulation activation in sepsis, in human monocytic (THP-1) cell cultures. EP dose-dependently inhibited the production of tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1α and MIP-1β by lipopolysaccharide (LPS)-stimulated THP-1 cells at mRNA and protein level, thereby confirming its anti-inflammatory properties in this in-vitro system.In addition, EP dose-dependently attenuated the increases in TF mRNA levels,TF-protein-surface expression and cell-surface-associated TF activity in LPS-stimulated THP-1 cells. These results demonstrate for the first time that EP is a compound with combined anti-inflammatory and anticoagulant effects.

Genetic variation in thrombin-activatable fibrinolysis inhibitor (TAFI) is associated with the risk of splanchnic vein thrombosis

Splanchnic vein thrombosis (SVT) has been associated with a hypercoagulable state. Thrombin-activatable fibrinolysis inhibitor (TAFI) may contribute to a hypercoagulable state, and therefore we were interested in the role of TAFI in SVT. Since the disease is frequently associated with liver insufficiency, which affects plasma levels ofTAFI, we studied the role of variation in theTAFI gene in SVT. In a multicenter case-control study on 118 patients with SVT (39 Budd-Chiari syndrome and 85 portal vein thrombosis) and 118 population-based controls, the relationship of SVT with single nucleotide polymorphisms (SNPs) and haplotypes in the TAFI gene (- 438G/A, Ala147Thr, Thr325Ile and 1583A/T) was determined. The risk for SVT was decreased (OR 0.2,95% CI 0.1–0.7) in 147Thr/Thr homozygotes and slightly,but not significantly,increased in carriers of the 325Ile allele (OR 1.6, 95%CI 0.9–2.7). Haplotype analysis confirmed that the Ala147Thr SNP has the strongest association with risk of SVT. In conclusion, genetic variation in the TAFI gene is associated with risk of SVT, suggesting a role for TAFI in the pathogenetic mechanism of SVT.

Causes of severe visual impairment and blindness in children in the Republic of Suriname

Aims

To determine the causes of severe visual impairment and blindness (SVI/BL) in children in Suriname (Dutch Guyana) and to identify preventable and treatable causes.

Methods

4643 children under 16 years of age were recruited from two locations: 33 children attending the only school for the blind were examined and 4610 medical records were analysed at an eye clinic. Data have been collected using the WHO Prevention of Blindness Programme eye examination record for children.

Results

65 children were identified with SVI/BL, 58.5% were blind and 41.5% were severely visually impaired (SVI). The major anatomical site of SVI/BL was the retina in 33.8%, lens in 15.4% and normal appearing globe in 15.4%. The major underlying aetiology of SVI/BL was undetermined in 56.9% (mainly cataract and abnormality since birth) and perinatal factors 21.5% (mainly retinopathy of prematurity (ROP)). Avoidable causes of SVI/BL accounted for 40% of cases; 7.7% were preventable and 32.3% were treatable with cataracts and ROP the most common causes (15.4% and 12.3%, respectively).

Conclusions

More than a third of the SVI/BL causes are potentially avoidable, with childhood cataract and ROP the leading causes. Corneal scarring from vitamin A deficiency does not seem to be a continuing issue in Suriname.

Natural history of spheno-orbital meningiomas

Background

To investigate the natural history and the growth rate of spheno-orbital meningiomas (SOMs).

Methods

Ninety patients with a diagnosis of SOM were included, and patient charts and imaging were evaluated. In a subset of 32 patients, volumetric studies were performed.

Results

The median follow-up for the entire group was 4 years (range, 1–15); the mean age was 47.8 (range, 26–93) years; 94% of the patients were female. The most common clinical signs and symptoms were proptosis (93%), visual deterioration (65%), retro-bulbar pain (23%) and diplopia (6%). In 35% of patients in this series, no visual deterioration occurred, and in 30% only mild proptosis was present. The median annual growth rate of the SOMs in the subset of 32 patients was 0.3 cm³/year (range, 0.03–1.8 cm³/year). We assessed a trend for more rapid tumour growth in younger patients and found the initial volume of the tumour (rho = 0.63) and of the soft tissue component (rho = 074) to be significantly related to the growth rate.

Conclusion

SOMs are slow-growing tumours that cause primarily proptosis and visual deterioration. In a significant number of patients, these tumours cause minimal discomfort and symptomatology. Therefore, in the absence of risk factors, we advocate a “wait and see” policy. For patients with large SOMs or with a large soft tissue component at first visit or with fast growing SOMs (>1cm³/year), a follow-up examination every 6 months is indicated.

Surgical treatment of sphenoorbital meningiomas

AIM

To evaluate the outcome of surgery and radiotherapy in the treatment of sphenoorbital meningioma (SOM).

METHOD

A retrospective study of 66 consecutive cases treated with surgery for SOM with a minimum follow-up of 4 years. Clinical and radiological information were compared before and after the following surgical approaches: frontotemporal craniotomy, frontotemporal craniotomy combined with orbitozygomatic resection and extended lateral orbitotomy alone.

RESULTS

The median age at presentation was 46 years (range, 26-68 years) and the median follow-up after surgery was 102 months (range, 48-288 months). In total, 48 (73%) patients showed preoperative visual deterioration, with visual field defects. All patients had proptosis at presentation (mean ± SD=6.4 ± 3.0 mm). Surgery for patients with SOM arrested visual deterioration in 61% and improved vision in 30% of cases. Furthermore, a substantial reduction of proptosis was achieved in 85% of patients. The proptosis in this group was reduced by 2.6 ± 2.6 mm. There was no correlation between surgical approach and proptosis reduction (p = 0.125). The recurrence rate was 17%. Only 1 out of 15 patients who underwent radiotherapy showed signs of recurrence.

CONCLUSIONS

The surgical aims in the treatment of SOM should be the restoration of visual acuity and reduction of proptosis, rather than complete tumour removal. The surgical approach can be tailored to individual cases. The authors recommend radiotherapy in cases of subtotally removed SOM.

CAG repeat length variation in the polymerase gamma (POLG) gene: effect on semen quality

Several case-control studies have investigated the effect of CAG repeat length variation in the POLG gene on male fertility and semen quality. Some described an association between the homozygous not10 CAG-repeat genotype and male subfertility and/or reduced semen quality, whereas others did not. The aim of our study was to investigate whether the not10/not10 variant is associated with spermatogenic failure. By direct sequencing methods, we determined the CAG repeat length of POLG in a cohort of 700 consecutive included men with variable degrees of spermatogenesis to investigate its effect on semen quality. The frequency of the not10/not10 variant in our cohort was 4.7%. There were no differences in semen quality between groups with various POLG genotypes. There was a significant difference in frequency of the three CAG-repeat genotypes between ethnic subgroups. In conclusion, the not10/not10 POLG variant is not associated with clinically significant decreases in semen quality, but its frequency is dependent on ethnic background.

CAG repeat length variation in the Androgen Receptor gene is not associated with spermatogenic failure

Previous association studies that described the effect of an enlarged CAG repeat length in the Androgen Receptor (AR) gene on spermatogenesis could not prove or refute a true association because of methodological weaknesses. Here, we clearly show that there is no association between CAG repeat length variation and semen quality.

Ethyl pyruvate exerts combined anti-inflammatory and anticoagulant effects on human monocytic cells

Sepsis is characterized by a concurrent activation of inflammation and coagulation. Recently, recombinant human activated protein C was shown to decrease mortality in patients with severe sepsis presumably due to a combined anti-inflammatory and anticoagulant effect. These promising findings led to a search for other products that influence both the inflammatory and the procoagulant response to severe infection. Ethyl pyruvate (EP) was recently identified as an experimental anti-inflammatory agent during endotoxemia and sepsis. The aim of the present study was to investigate whether EP influences coagulation besides its anti-inflammatory effects. For this we investigated the effects of EP on the expression and function of tissue factor (TF), the principal initiator of coagulation activation in sepsis, in human monocytic (THP-1) cell cultures. EP dose-dependently inhibited the production of tumor necrosis factor (TNF)-alpha, macrophage inflammatory protein (MIP)-1alpha and MIP-1beta by lipopolysaccharide (LPS)-stimulated THP-1 cells at mRNA and protein level, thereby confirming its anti-inflammatory properties in this in-vitro system. In addition, EP dose-dependently attenuated the increases in TF mRNA levels, TF-protein-surface expression and cell-surface-associated TF activity in LPS-stimulated THP-1 cells. These results demonstrate for the first time that EP is a compound with combined anti-inflammatory and anticoagulant effects.